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Solar Power - One Year On

by Luis de Sousa Mon Aug 8th, 2011 at 04:37:45 AM EST

front-paged by afew


Things took quite a turn since the last time I wrote about this subject. After the unsuccessful attempt to apply for the feed-in tariff in November, a new internet auction-like round of applications took place during the first days of December, 2009. Like before, at 9 a.m. it was impossible to access the registration server, clogged with the huge amounts of applicants trying to access. But this time something went different, the server was so overwhelmed that it went down. Those responsible were only able to bring it back online close to mid-day, when everyone thought it already hopeless to keep trying to apply. Every one except my vendor, who was able to register my system plus a few others of his clients.

Setup

Roof mounting started less than two months later; by March we were able to call in the certification process and finally on the 9th of April I became an happy electricity producer, right in time for the best period of the year. The system is composed by the following elements:

  • 18 x 215 W solar panel
  • 1 x electric current inverter, limiting at 3850 W
  • 1 x 2 m2 water heating panel
  • 1 x 200 litres water tank
  • 1 x electric boiler
The panels are mounted on the rooftop with an inclination of 30º and oriented to sunset (bearing: South 78º West). Not the best of settings (optimal would be to the South) but re-orienting the rooftop wasn't an option. The critical thing about this sub-optimal orientation is the push back of break-even beyond the period of maximum feed-in tariff, the first six years. The data provided by the vendor at the time was leaving me comfortable, even though it was considerably higher than that provided by the JRC Solar Calculator.

The installation included structural reinforcement to the roof; the cabling linking to the electric grid and new power meters, one for consumption, another for production; linkage of the water tank to the house water circuit and an electric water boiler that overrides the traditional natural gas boiler. Sunlight is able to heat water for all home needs from mid-March to mid-November; in the remainder of the year the electric boiler is timed to heat the water in the tank for about one hour, right before wake up time.

One year of electricity

From April of 2010 to April of 2011 I thoroughly monitored the system output, collecting weekly data whenever possible. As the Winter came to an end it became obvious the energy generated during the first year of operation would exceed 5 MWh. Here's that data:
Monthly data compared to the JRC Solar Calculator projection. Click for full version.

The first interesting thing is to compare these data to the projections by the JRC Solar Calculator:
Monthly data compared to the JRC Solar Calculator projection. Click for full version.

There are two things that immediately stand out from this graph: the wider variation of the real data and the better performance of the system in place. The latter may be due to the Calculator not including recent advancements in PV efficiency, but also to a less than perfect usage of this handy tool; I fully endorse it to assess site adequacy. The actual data for yearly production is 5140 kWh, in contrast to the 4420 kWh projected by the Calculator, a difference of more than 16%.

The wide seasonal variation, about 5 times from Winter Solstice to Summer Solstice, is very relevant for the planning of a national Energy Mix. Even in a place like Portugal Solar energy can't provide the majority of the electricity needs, especially in Winter, when light hours are at the minimum and cloudiness peaks. The good thing is that other renewable energies promoted in the country are highly complementary to Solar: Wind peaks during the stormy seasons around the Equinoxes, and rainfall peaks around the Winter Solstice, providing Hydro-power with its fuel.

Marginal price

Another important piece of information that can be calculated from this data is the marginal electricity price required by this system; it will take several steps. First of all is the computation of the total of energy produced by the system during its lifetime. The solar panel maker provides a warranty of 40 years during which time a linear decline of efficiency down to 78% of the original nameplate capacity should take place (materials worn out with time). An expression can produced to calculate expected production as a percentage of the original at the nth year of operation:

E(n) = -0.54n + 100

Production at the nth year of operation can be calculated simply using the figure for the first year of production:

P(n) = P(1) x E(n)

The total energy produced by the system during its 40 year lifetime is the integral of this production curve, which can also be calculated as a simple sum. In the case of this system it is just over 180 MWh. The upfront cost, excluding the water heating components, was in the order of 18 000 €. The marginal price is hence 0.01 €/kWh, well above traditional energy sources. This value doesn't count with maintenance or debt servicing costs, which shall be dealt with later.

Optimal System

But in the meantime prices have fell down and panel efficiency has continued to rise. Right now a system like mine, but with 245 W panels, can be bought for 13 500 €. Considering that my system isn't optimally oriented, the actual marginal price is in reality quite lower. To have an idea of what this may be, the Solar Calculator can produce optimal orientations and inclinations that help identifying an optimal site. In Portugal this would be at the Algarve, where by sheer coincidence a lot of folk from the northern states are presently spending their vacations. At 37º 14' North, 7º 56' West the Solar Calculator recommends an inclination of 32º for a bearing at South 3º East, which for a 4.4 kW system should produce 6.25 MWh in a year. But since my own experience showed that the Solar Calculator, as is, is underestimating production by some 16%, the actual value may be closer to 7.27 MWh in a year. With these figures new values for the marginal price can be computed:

Site Upfront Cost (€) First year of production (kWh) Total Energy Produced (MWh) Marginal Electricity Price (€/kWh)
Setúbal Peninsula 18700 5140 183 0.102
Algarve (JRC) 13500 6250 223 0.061
Algarve (adjusted) 13500 7268 259 0.052

These figures are compelling and not only show huge improvements in Solar power efficiency, they also point to an important approximation to other energy sources. The 5 cents per kWh is actually lower than what can be calculated from the data on Jérôme's latest offshore Wind project. So far these feed-in tariff programs for Solar micro-generation have been a success, creating an industry and most importantly reducing renewable electricity costs.

Other costs

The issue with the previous figures is that they do not take into account costs such as maintenance or debt servicing. In the 15 months my system has been in operation there has been a single maintenance issue, but with an escape valve on the water tank. It is hard to foresee what sort of maintenance issues may come up with the PV system, but of note is the warranty of the inverter being shorter than for the panels. Hence adding a parcel for a substitution of this equipment seems a sensible choice. Insurance costs are not included for these sort of micro-generation systems are usually covered by standard home insurance policies; though for industrial applications this is an issue.

Debt is the real problem because interests have soared since last year. Even renewable energy dedicated lines of credit are imposing interest over 6%/a. A 60 month loan for the upfront costs discussed above easily add over 4 500 € to the total project cost. The following table summarizes these new costs with debt on 100% of the up front investment, thus providing a top to marginal electricity prices:

Site Upfront Cost (€) Maintenance (€) Debt Servicing (€) Total Energy Production (Mwh) Marginal Electricity Price (€/kWh)
Setúbal Peninsula 18700 2000 5650 183 0.144
Algarve (JRC) 13500 2000 4700 223 0.091
Algarve (adjusted) 13500 2000 4700 259 0.078

Suddenly things got a bit bleak. Banks are charging spreads of some 5% over the Euribor interbank lending rate and with it killing many investments. Naturally this is about micro-generation systems that amount to relatively low investments, assuming financing is required for 100% of the upfront cost is a worst case scenario. Wrapping up these calculations it can be said that the marginal electricity price for a solar PV system optimally sited at the Algarve ranges somewhere between 5 and 8 cents per kWh. While not spectacular, these figures point to Solar PV entering a maturity stage now comparable to Wind power. In Portugal the consumer is presently paying close to 13 cents per kWh, with that figure projected to go over 15 cents per kWh by 2013.

Feed-in tariffs

Of all the numbers referenced before one that may be have passed discretely so far is actually the most problematic: the 40 year system lifetime. It is like investing on oak wood, with the difference that electricity generated from solar panels is indistinguishable from that generated by other sources (actually natural gas and hydro can differentiate their product, but that's an issue for another time). Investors may chose oak wood because it is a finer product than pine, for instance, but with electricity this doesn't happen. Electricity can be seen as a perfect concurrency market where profit only exists in the presence of scarcity; on a abstractly normal market the investor would get financial break-even only at the very end of project lifetime. By other words, solar PV is a very unattractive investment from the perspective of the individual investor.

The main consequence of this is the indispensableness of feed-in tariffs. They are not a tool to increase the competitiveness of supposedly expensive renewable energies, their main function is to anticipate financial returns in time, and with it break-even. There will be no private investment on Solar energy without feed-in tariffs.

Closing, an important question can be answered with the data collected here: what feed-in tariff would be needed to anticipate financial break-even to the nth year of operation? This can be computed using the efficiency decline function, and the quotient between total energy produced at the nth year of production over cost:

B(n) = Sum1n[P(n) x E(n)] / C

Where C is the cost. For the several scenarios analysed above the resulting curves look like this:
Feed-in tariff as a function of break-even time. Click for full version.

Financial break-even before the 6th year of operation requires huge feed-in tariffs, but even at 10 years of operation all systems require 20 cents per kWh or more. As a comparison, Wind energy is today an healthy business, usually reaching break-even at the 10th year of operation with a feed-in tariff around 7.5 cents per kWh. This is the sheer weight of such a long lifetime, and possibly the biggest challenge to the success of Solar power.

Conclusions

So far I'm pretty happy to have become a solar electricity micro-producer. Financial break-even is still some 6 years away, which is not fantastic but perfectly manageable; even with a less than optimal setting, the system should after that generate a small but regular profit for decades to come. I also had the opportunity to participate in a very interesting moment for the Solar industry, where the efforts of several governments producing generous feed-in tariffs for micro-producers produced visible cost reductions and efficiency increases with economies of scale.

Optimally set systems (regarding inclination and bearing) at sunny places like southern Portugal, Spain or northern Africa are operational with marginal electricity prices between 5 and 8 cents per kWh, mostly depending on debt servicing costs. While not cheap, these figures are not expensive either and point to an important level of maturity of Solar PV technology.

But for Solar PV to make any relevant penetration on the Energy Mix, high feed-in tariffs will continue to be required, a produce of the long lifetime of this technology. Governments face a huge challenge to continue the promotion of Solar PV with this scheme, reliant on private investors and private lenders. Especially at a time where austerity and budget cuts are the main policy, it will be very hard to keep pushing feed-in tariffs that are multiples of present electricity prices.

Display:
Thanks for this interesting and informative piece, Luis.

Just a nitpick:

European Tribune - Solar Power - One Year On

The actual data for yearly production is 5140 MWh, in contrast to the 4420 MWh projected

KWh, surely?

by afew (afew(a in a circle)eurotrib_dot_com) on Thu Aug 4th, 2011 at 01:36:21 AM EST
:) Yep, thanks for tip.

You might find me At The Edge Of Time.
by Luis de Sousa (luis[dot]a[dot]de[dot]sousa[at]gmail[dot]com) on Thu Aug 4th, 2011 at 02:43:15 AM EST
[ Parent ]
Two questions.

Do you have net metering, so you can sell excess power back to the grid?

And how was the system mounted on the roof? One thing that scares me is the idea of a small contractor going onto my house and drilling holes all over the place. For one thing, they will undoubtedly leak, and secondly, 10 years from now when I need to put on new shingles, what will the process be, remove the panels to get at the shingles?

by asdf on Thu Aug 4th, 2011 at 10:30:00 PM EST
some pics of installations. Just a google hit, I have no idea how credible this site is.

This site says best to install when a house is being re-roofed! I take it then the flashing for the mount points are done before the shingles are laid, so if the flashing is well done, no worries about leaks ~ just like a well-done dormer.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Fri Aug 5th, 2011 at 12:52:39 PM EST
[ Parent ]
Hi adsf, The metering is totally separate, there's one for consumption and another for production. Meaning: the house doesn't use electricity generated by the solar system, but from the grid; the panels are connected directly to the grid. The roof is originally composed by clay tiles on a wooden structure. The installment was made with an alloy structure laying over the tiles and bolted to the masonry sidelining the tiles. The wooden structure was reinforced from the inside to support the additional weight. No tiles were drilled and the winter went by without any leaks. Hope I made it clear.

You might find me At The Edge Of Time.
by Luis de Sousa (luis[dot]a[dot]de[dot]sousa[at]gmail[dot]com) on Fri Aug 5th, 2011 at 02:42:10 PM EST
[ Parent ]
I abandoned my solar experiment for now, as the Columbia River Gorge area just doesn't have the resource. I have all of the parts, though, just in case the river runs dry or they privatize the dams (our local hydropower-derived electricity rates are $0.06).

paul spencer
by paul spencer (spencerinthegorge AT yahoo DOT com) on Fri Aug 5th, 2011 at 10:49:51 AM EST
Hi Paul. At 46º North latitude works against you. But worse than that, that region is locked between the North American cell and the Aleutian high, being a preferred path for cloudy updrafts. I imagine that between November and February PV production would be really low, much lower than peak winter in Portugal.

But this should be a great place to invest on Wind :) too bad it doesn't work very well on micro-scales.

You might find me At The Edge Of Time.
by Luis de Sousa (luis[dot]a[dot]de[dot]sousa[at]gmail[dot]com) on Fri Aug 5th, 2011 at 03:10:29 PM EST
[ Parent ]
... Seasonal variation by a factor of four... O.o
O.O

This makes solar technology as a whole utterly useless for decarbonizing the grid of anyone who lives very far from the equator. Think it through - what happens as soon as penetration goes above single digit percentages? You can adress variable output on a day-night and weekly scale by demand shifting and storage. That is straightforward engineering. But there is no social or technological solution that will let you shift electricity use by 6 motherfracking months, which makes this is an utterly useless technology for anything but greenwashing. At least the wind blows both in winter and summer.

by Thomas on Fri Aug 5th, 2011 at 02:24:37 PM EST
Thomas, I would consider your complaints if you hadn't compared Solar to Wind; the former is much stabler. Wind can vary on much larger scales from one week to another, especially in the beginning of the Winter with the succession of the polar highs.

As I wrote, on a seasonal basis Solar obviously can't have the largest share of an energy mix, but it is very well complemented by Wind and Hydro at this latitude. The solar radiation curve is almost the negative of rainfall and the strongest winds are around the Equinoxes. I don't have data on that right now, but would like to see how much Wind electricity variates from July to November.

You might find me At The Edge Of Time.
by Luis de Sousa (luis[dot]a[dot]de[dot]sousa[at]gmail[dot]com) on Fri Aug 5th, 2011 at 02:58:37 PM EST
[ Parent ]
I think there are some really homebrew home wind turbine designs that work if the household is looking to convert idle time into some return. But the returns on money rather than sweat equity are more to farmers in good wind resource areas leasing space to utility scale wind farms.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Sat Aug 6th, 2011 at 05:49:35 PM EST
[ Parent ]
I'll add something: in case you haven't considered this, there are more and more buildings that include air conditionning, event in France, where the need doesn't really arise if your building design is somewhat adapted (ie no big glass-walls offices).

This means that the electricity use will have a secondary (and then primary) peak in summer, which, surprise surprise is just at the time when solar is at its best.

Therefore, you might want to use some of these little grey cells of yours to find a way to power air conditionning by solar energy.

Let's hear you Thomas!

by Xavier in Paris on Mon Aug 8th, 2011 at 05:00:35 AM EST
[ Parent ]
Okay, to make things clear. Getting excited about things that are blatantly not going to do a fraction as much good as just going "I am from the ninteen fifties and the future is nuclear". Is just going to lead to another 40 years of coal and gas burning. That is not acceptable.
Whatever you want to implement, it has to at least theoretically be able to wholly displace coal and gas from electricity production.

 Solar - due to the extreme seasonal variability in any location much removed from the equator- is not going to be able to do this - at all- unless we politically annex north africa directly into the european union, willingly or not. This is not an option I am comfortable with, to put it mildly.

Nuclear means you are picking a fight with greenpeace, and the economic ideology which is preventing a rational build policy (IE: National or Union owned and operated reactors)

Wind and massive storage and super grids, involves taking on the forces of nimby, and the gas gigants.

Either of those are hard, hard fights, politically.

Relying on solar means you are trying to defeat winter That is not a hard fight, thats suicide.

by Thomas on Mon Aug 8th, 2011 at 08:43:23 AM EST
[ Parent ]
I do not see why you do not to include massive storage and supergrids in your all-nuclear solution given that a) demand varies and you do not want to use nuclear for load-balancing and b) that nuclear needs to be able to be shut down in order to operate it safely, thus creating a similar production situation as wind, but with larger steps and less predictability. Recent numbers had Vattenfall's reactors running at 55% of the time.

I also think it is a mistake to see things such that one size must fit all, or it is no good. For example, Swedens large energy outtake from forests would be impossible in Algeria, but it is still a sustainable policy for Sweden with similar potential in other forest-rich and sparsely populated countries areas like Finland and large parts of Russia and Canada.

Sweden's finest (and perhaps only) collaborative, leftist e-newspaper Synapze.se

by A swedish kind of death on Mon Aug 8th, 2011 at 09:01:32 AM EST
[ Parent ]
Solar is fine - if you are Algeria. Since this is the european tribune, I simply consider it wholly offpoint as far as any discussion of our future energy supply goes.

Yes, nuclear needs storage. Less than wind, but still, it needs quite significant storage capacity to be built. I do not have a problem with this.
In fact, I consider building this storage the logical first step to take when it comes to getting more of europes power from nuclear - the underutilization of the existing european nuclear reactor fleet due to loadbalancing concerns represents  a potential additional generating capacity equal to at least a dozen EPR reactors, and bringing this generation capacity to market would be far and away the cheapest way to reduce carbon emissions currently on the table.

Step 1: Build some of these things http://eduard-heindl.de/energy-storage/energy-storage-system.html
Step 2: enter into longterm contracts with EDF and other nuclear utilities for their surplus generation capacity. Run hvdc lines as appropriate.
Step 3: Profit, and laugh manaically as the gas peaker generator operators go out of buisness.

by Thomas on Mon Aug 8th, 2011 at 09:19:33 AM EST
[ Parent ]
So storage is ok so long as it supports the solution you've given your allegiance to and not if it supports anything else?
by Colman (colman at eurotrib.com) on Mon Aug 8th, 2011 at 09:30:13 AM EST
[ Parent ]
storage is okay as long as it is physically possible. I dont have an issue with storage to smooth out day night or short term weather fluctuations wind + piston storage is a reasonable solution for a pan-european grid.  I specifically have a problem with solar and with the suggestion that storing six months worth of electricity is going to be economic or, you know, possible.
by Thomas on Mon Aug 8th, 2011 at 09:36:58 AM EST
[ Parent ]
I'm not seriously suggesting that. I am seriously suggesting that if we find ourselves with an effectively free surplus of electricity for six months of the year that we might be able to work out something useful to do with it.
by Colman (colman at eurotrib.com) on Mon Aug 8th, 2011 at 09:51:43 AM EST
[ Parent ]
That's arguing as if there was some kind of rule that the harvesting of volatile renewable power sources has to all come from the same type of source and the same resource.

The grid doesn't care: its all electrons as far as the grid is concerned. For a mix of onshore wind power from a range of resource areas, offshore wind power from a range of resource areas, run of river hydro, concentrated thermal solar power and photovoltaic, and whatever else proves practicable ...

... the volatility of any individual source does not matter to the grid. What matters to the grid is the volatility of the portfolio, which is much lower than the volatility of any individual component.

Stored dispatchable power, such as hydro, needs substantial capacity, but not as much total energy supply as would be required to balance an all nuclear pan-european grid, given the ability to use storable schedulable power such as biocoal to supplement the effective energy supply of the dispatchable supply. And of course, used in that way, as backing power for predictable supply shortfalls, its more energy efficient than when mineral coal is used as baseload with substantial spinning reserve.

And with sufficient capacity but modest total energy in a storable, scheduled

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Tue Aug 9th, 2011 at 12:46:36 AM EST
[ Parent ]
Your last sentence here looks sorta orphaned.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Tue Aug 9th, 2011 at 01:07:27 AM EST
[ Parent ]
Yeah, it is.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Tue Aug 9th, 2011 at 01:37:27 AM EST
[ Parent ]
Its a detritus from editing, left in by careless preview ~ likely supported by the display constraints of a wide screen netbook.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Tue Aug 9th, 2011 at 01:05:25 PM EST
[ Parent ]
What is the massive installation of solar photovoltaic on German roofs about, then? A scam by Siemens? A Keynesian stimulus of same?

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Mon Aug 8th, 2011 at 09:31:49 AM EST
[ Parent ]
Yes. That is short and blunt, but basically its a massive transfer of tax payer funds to the producers of solar voltaics with no significant production of electricity whatsoever as a consequence. The money would have ended the coal industry in Germany if it had been spent on either wind or nukes instead.
by Thomas on Mon Aug 8th, 2011 at 09:40:05 AM EST
[ Parent ]
You could also call it a subsidy for the development of the technology. But okay, your point about the German fossil fuels industry is clear.

In any case, the German coal lobby is sufficiently politically powerful by itself without having to blame investment in Solar PV for its survival.

Economics is politics by other means

by Migeru (migeru at eurotrib dot com) on Mon Aug 8th, 2011 at 09:47:24 AM EST
[ Parent ]
Causation is backwards.
I strongly suspect that the reason solar got subsidized is precisely because it was - and remains - the least useful altenative powersource available to Germany, and thus it was not an actual threat to incumbents, while still serving as a show of good will to highly ecologically concious german citizens. If there had been a power source with even less potential to upset apple carts that would have gotten the euros instead. Heck, this even applies to nuclear technologies. Notice that fusion research - which is infamous for going nowhere useful - gets far more money allocated than advanced reactor designs. Because if we poured an ITER equivalent of money into molten salts and lead cooled reactors, why, we might end up with a working design so good that all our existing plants (coal, gas and nuclear) would all be so much steel to be recycled. Cannot have that.
by Thomas on Mon Aug 8th, 2011 at 10:12:42 AM EST
[ Parent ]
Now we're getting somewhere.

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Mon Aug 8th, 2011 at 10:14:14 AM EST
[ Parent ]
Despite your strong suspicions, that's not why PV was funded through a FIT in Germany. PV was funded to bring in a renewable industrial base, against the will of the entrenched fossil lobby.

PV was also funded because unlike you, most energy specialists understand that a mix of all the sustainable technologies is where we're going, because sustainability itself is a value.

Further, you ignore the huge advantage in decentralization of power generation, it's inherent enhancement of the grid quality, and its assistance in breaking the hold of entrenched dinosaur industries.

The PV FIT is a starter tariff for developing industry, as Xavier pointed out. Though there is no certainty, one can expect significant cost reductions through aggressive build, as has happened in wind and such industries as computing.

In fact, the same reasoning is why onshore wind in Germany was recently given a FIT boost concurrent with PV and other technologies.

Oh, and judging from the recent public statements AND actions of some major German utilities and industrial giants, distributed renewables ARE a threat to them. Thus your argument disappears.


"Life shrinks or expands in proportion to one's courage." - Anaïs Nin

by Crazy Horse on Tue Aug 9th, 2011 at 07:52:29 AM EST
[ Parent ]
Anyone tell me the German FIT doesn't work for PV after this...



*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Aug 9th, 2011 at 09:37:46 AM EST
[ Parent ]
I actually agree that the motivation you infer was true for the thinking of some decisionmakers at one juncture in time: when the conservative parties supported the August 2004 increase of the FIT rate for photovoltaics. The Greens and SPD (who had majority in the lower house) wanted this as compensation for the end of the 100,000 Roofs Program (which gave direct subsidies to installers but ran out in 2003); while the majority of CDU/CSU-led governments in the upper house agreed to this as 'compensation' for cuts of the FIT for wind. Furthermore, the conservative about-face regarding the FIT for PV was obviously motivated by concern on the part of Big Energy friends over the unexpected fast spread of PV.

As an overall claim, your argument is of course BS; given that all renewables got a feed-in rate, and the feed-in law was explicit about the intent to create a big enough market to bring down prices (I think I posted the excerpts for you years ago already...), which was also the motivation behind the 100,000 Roofs Program.

(BTW I continue to disagree with calling the German FIT a subsidy. To me subsidy means direct payments of taxpayer money, which is not the case.)

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Aug 9th, 2011 at 09:58:14 AM EST
[ Parent ]
And PV is realistically the only renewable that passes the 'doesn't ruin property values' requirement.  Wind gets tremendous advantages with scale, whereas PV cost scales almost linearly with power.
by njh on Tue Aug 9th, 2011 at 08:17:21 PM EST
[ Parent ]
Well, renewable electric power source ~ passive solar and thermal solar are also renewable power sources that work on household scales.

Run of river hydro can also be run of drainage canal hydro, and while it is rarely of household scale except for "house in the woods with a creek" settings, it can be at the same neighborhood scale as some co-generation renewable power. With a roving combustion chamber, biocoal from locally harvested biomass could also be a neighborhood scale activity.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Wed Aug 10th, 2011 at 03:21:40 PM EST
[ Parent ]
The official plan according to the IEEE Power and Energy Society, as expressed in their internal journals, is to get people to buy electric cars, plug them in at night for "recharging," and then suck energy out of them to meet the evening demand surge. Net metering enables this, and everybody ends up happy. The one flaw is that the current distribution grid is not well suited to this. Transformers throughout the network, for example, rely on low utilization at night in order to cool down.
by asdf on Thu Aug 11th, 2011 at 04:49:23 PM EST
[ Parent ]
"Solar [alone] is not going to be able to do this" is a red herring, since none of the policies involve solar alone trying to do it.

What matters is the storage demand of the portfolio of sources on the grid, and an all nuclear pan-european power system would have massively greater energy storage requirement than a broad portfolio of a range of types of renewable energy resources from a variety of specific resource areas, connected together by a pan-european HVDC cross haul grid of grids.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Tue Aug 9th, 2011 at 11:45:21 AM EST
[ Parent ]
It's also just plain false. If the assumption is that everything stays constant except for the primary fuel source, then the "solution" is terribly skewed.

For example, one heavy user of power is computing centers. So future computing centers should indeed be located in the Sahara or Arizona. Another example is the expectation of no demand management.

There is no reason not to do this for ALL of the energy used in your house: fridge and A/C and furnace can cycle under the control of the central office, lights and computers can run from a battery for extended period, etc.

Also, as the cost of energy rises it will encourage all sorts of behavioral changes and technical improvements.

And what, exactly, is different between buying solar-cell electricity from Libya or Saudi Arabia or Iran and buying oil from them? If they fortuitously ended up where solar energy is plentiful, then by the wonders of the Miraculous and Invisible Guiding Hand of Capitalism they will reap the riches...

by asdf on Thu Aug 11th, 2011 at 04:57:00 PM EST
[ Parent ]
As far as what is the difference between buying oil from Libya and buying renewable electricity from Libya ~ the roll-out of the renewable electricity capacity will employ far more than the oil industry does, and distributing income for labor services rendered tends toward a different political-economy than redistributing mineral wealth windfalls.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Thu Aug 11th, 2011 at 05:20:41 PM EST
[ Parent ]
Maybe even a distribution change in a positive direction?
by asdf on Thu Aug 11th, 2011 at 05:23:30 PM EST
[ Parent ]
Quite ~ now once the equipment is rolled out, there would be a bit of a drop, but we're looking at a roll-out of ten to twenty years, and maybe more if a direct electric seawater to ammonia process is developed in the meantime.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Thu Aug 11th, 2011 at 05:56:46 PM EST
[ Parent ]
Plus the fact that high sunk costs makes it harder to cut your losses and bail out in the face of political crises. So it gives us a stronger vested interest in helping those countries develop sustainable political systems.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Fri Aug 12th, 2011 at 10:38:35 AM EST
[ Parent ]
And there is no "what about when it starts running out" end game.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Fri Aug 12th, 2011 at 03:12:36 PM EST
[ Parent ]
No, but there is a "now we've made the last amortisation" game, which I am not wholly certain will be less pernicious. I can see reasons why it should be, but they are not ones that I would feel entirely comfortable betting my constitution on, were it not for the fact that they will be thirty years into the future while the "running out" endgame is right about now.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Fri Aug 12th, 2011 at 03:22:41 PM EST
[ Parent ]
That's assuming quite a bit about the financial institutions in use thirty to fifty years in advance ~ and while we can reasonably plot a rising real energy user cost to things like not maintaining the equipment properly, the financial rules in place are a far more speculative question.

And we have no clue what the broader international political economy is, thirty years out.

First priority, to me, seems to be to adopt policies making it more likely to get to thirty to fifty years out.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Fri Aug 12th, 2011 at 09:20:30 PM EST
[ Parent ]
Actually, I've spent quite a bit of time working on solar power airconditioning.  It's fairly well researched, the most common solutions are based on absorption refrigeration, usually using a lithium chloride/water cycle, rarely ammonia/water.

An alternative being tested today is bentonite/water vapour cycles powered by day/night cycles.  It looks quite promising, even for humid areas (dry areas are well served by evaporative cooling).  And it's very cheap and DIYable (bentonite is qidely available in kitty litter :)

by njh on Mon Aug 8th, 2011 at 08:33:30 PM EST
[ Parent ]
How about a solar air dryer? For example in Finland there are more days with excessive humidity levels than with excessive heat. System would make a larger solar heat collector viable by consuming extra energy in summer.
by Jute on Tue Aug 9th, 2011 at 03:44:53 AM EST
[ Parent ]
Precisely same thing here in Ohio.

Indeed, the leading solar AC units work by using heat to drive moisture out of an absorpant, then using the absorpant to deumidify outdoor air, then using evaporative cooling.

It seems just using solar heat for the dehumidifier stage, and then passing the air through a ground return loop would be effective for household AC.

For example, a solar heat collector sufficiently large for winter time solar hot water heating then having it heat generated surplus to hot water needs in the warmer months being used for the dehumidifier stage.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Tue Aug 9th, 2011 at 11:53:06 AM EST
[ Parent ]
Rereading that, "the leading" should have been "a leading".

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Tue Aug 9th, 2011 at 11:56:39 AM EST
[ Parent ]
That is exactly what I said :)  absorption cycle refrigeration is the same process whether the thing being cooled is breathing the mixture or not :)
by njh on Tue Aug 9th, 2011 at 08:13:36 PM EST
[ Parent ]
The ones I was referring to are not refrigeration cycles at all ~ heat drives water out of a dessicant in the dessicant drying phase using solar heat, then dessicant pulls humidity out of the air in the dehumidifier stage, then an evaporative cooler is used for cooling.

If the dessicant is only being used for dehumidifying, and there is some other cooling such as an earth return close loop, then the solar dehumidifier would be smaller than the dehumidifier section of the dessicant / evaporative cooling cycle.


I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Wed Aug 10th, 2011 at 03:12:45 PM EST
[ Parent ]
The ones I was referring to are not refrigeration cycles at all ~ heat drives water out of a dessicant in the dessicant drying phase using solar heat, then dessicant pulls humidity out of the air in the dehumidifier stage, then an evaporative cooler is used for cooling.

That is an absorption cycle refrigerator.  You are driving the evaporation cycle by absorption into the dessicant.

by njh on Wed Aug 10th, 2011 at 06:49:28 PM EST
[ Parent ]
It makes more sense to call them cycles when its a closed loop absorption refrigerator. When its an open loop with the air being conditioned passing through the dehumidifier, and then passed through the evaporative swamp cooler, which doesn't have to have any direct connection to the evaporative cooler at all, it makes more sense to call them stages.

Indeed, where the desiccant is a flowing liquid rather than the gel or crystals of the pizza pan variety, its possible to have the dehumidifying done by a decorative "waterfall", and piped to where the desiccant is dried between the receiving pool and the source pool.


I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Thu Aug 11th, 2011 at 09:38:07 AM EST
[ Parent ]
It shouold be well researched, one of the first thermal solar applications was a freezer at the world fair in Paris late 19th century. Have not found any signs that it went into production though.

Sweden's finest (and perhaps only) collaborative, leftist e-newspaper Synapze.se
by A swedish kind of death on Wed Aug 10th, 2011 at 04:20:51 PM EST
[ Parent ]
There's also the one Einstein and/or Szilard invented...
by asdf on Thu Aug 11th, 2011 at 04:45:26 PM EST
[ Parent ]
Powering synthetic liquid fuel production?

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Mon Aug 8th, 2011 at 05:18:36 AM EST
[ Parent ]
If you are in the chemical synthesis game, you are selling into the global market, which means that - in the event that solar kwh costs fall far enough that it makes sense to power this with solar instead of great plains wind or icelandic geothermal - the plant will all get built in the most politically stable polity on the equator. Because the return on building the plant there is inherently going to be much better than attempting to use solar influx in NE europe. So, "French Guiana Solar Synthetics". Sure. Dumping surplus from a solar grid in metropolitan France? Nope.
by Thomas on Mon Aug 8th, 2011 at 08:30:17 AM EST
[ Parent ]
The fact that chemical synthesis is more profitable elsewhere doesn't mean it cannot be used to dump a surplus.

Assuming it makes sense for Luis to have 5KWh/day of solar in the winter, it costs him nothing to just dump the surplus over the rest of the year. And then he makes money from any application whatsoever he can dream up for the surplus.

Or he could build the same solar panel on São Tomé and Príncipe, sell the power there to the most profitable application and then buy power from the grid in Portugal?

Is that what you're arguing, that every Euro of investment in Solar in Europe would be best invested on the equator.


Economics is politics by other means

by Migeru (migeru at eurotrib dot com) on Mon Aug 8th, 2011 at 09:41:17 AM EST
[ Parent ]
Or in clean generation technologies actually suited to the european climate. Renewables are all about location, location, location, and HVDC lines are much, much cheaper than trying to argue with reality.
by Thomas on Mon Aug 8th, 2011 at 09:53:15 AM EST
[ Parent ]
But we actually have a grid in Germany where the PV can be connected.

If you introduce a ten year wasteland for solar PV while you fix up HVDC lines to where you believe it makes sense, the industry will be dead (or in China, which while not quite as bad is still not in the European national interest).

Tl;dr: You work with the grid you have, not the one you would like.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Mon Aug 8th, 2011 at 10:00:25 AM EST
[ Parent ]
"You work with the grid you have, not the one you would like."

Although this is also going to drive vast improvements in the grid--the power engineers are rubbing their hands thinking about how to fix all the mistakes made over the past century...

Some interesting stuff is at
http://www.ieee.org/portal/cms_docs_tionline/tionline/tidec10.pdf

by asdf on Thu Aug 11th, 2011 at 05:15:47 PM EST
[ Parent ]
Yep, but that's not on the same time scale.

Perhaps I should have quibbed that you start with the grid you have, not the one you'd like.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Fri Aug 12th, 2011 at 10:37:43 AM EST
[ Parent ]
But then I'd suggest that food self-sufficiency concerns would tilt that toward ammonia, which can be a fertilizer feedstock, a fuel cell fuel, or a combustion fuel with the right engines or with a small amount of biodiesel to prime a diesel engine.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Wed Aug 10th, 2011 at 03:14:42 PM EST
[ Parent ]
  1. You presume that hedging against geopolitical instability is worthless.

  2. You're thinking in terms of dedicated single use monocropping. Again.

- Jake

Friends come and go. Enemies accumulate.
by JakeS (JangoSierra 'at' gmail 'dot' com) on Mon Aug 8th, 2011 at 09:50:42 AM EST
[ Parent ]
.. the technological-industrial economy is not an ecosystem. "Monocrops" are a commonplace outcome as everybody flocks to the optimal solution for a given problem, and unlike in biological systems, this does not, in fact, bites us in the ass with any frequency. Think it through. Assume we go full wind + pumped storage - how, exactly, is this going to backfire? Will the great windmill eating dragon spontaniously evolve and eat our windfarms and kites? Will the wind stop blowing? Be careful about your analogies, they can easily be both wrong and convincing.
by Thomas on Mon Aug 8th, 2011 at 10:02:25 AM EST
[ Parent ]
If we achieve full wind baseload penetration, sure we're golden.

If we are halfway there a serious raw materials shortage comes around to bite us on the ass, we had damn well better have something else in the pipeline as well, or we will be looking at a twenty to forty year ramp-up period.

And no, nuclear isn't a mature alternative, until you've built a reactor that will shut down on passives alone.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Mon Aug 8th, 2011 at 10:06:54 AM EST
[ Parent ]
If we are halfway there when a serious raw materials...

Proofreading is not my friend today.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Mon Aug 8th, 2011 at 01:46:20 PM EST
[ Parent ]
Resource shortages. of. eh. what ? Steel and composites? Cement? Magnets? Granite bedrock? O.o o.O

Wind energy does not rely on anything likely to ever go in short supply. Neither does pumped storage.

Solar voltaics is the tech that might suddenly get a lot less viable because the world experiences a shortage of exotica. Honestly, I really dont get why there is such an obsession with solar. It costs ten times what other renewables does, it kills land, the production of the panels involves the large scale use of numerous poisons, and in general it is far and away the least promising of the pure renewables we have. And then multiply all of those issues by a factor of 10 because europe is just flat out not a good spot for the collection of solar flux. Why, exactly are we spending money developing a technology that is not very promising at all (solar cells are as old a tech as reactors. And have been rather noticably less of a success!) and in the unlikely case of success will promptly hand a large competetive edge to. Eh. Saudi Arabia?

by Thomas on Mon Aug 8th, 2011 at 02:17:09 PM EST
[ Parent ]
Magnets. Gearboxes. Control electronics. To name just three areas where supply bottlenecks are not wholly inconceivable. Modern, economically viable wind turbines are marvels of technically sophisticated heavy industry. That means long supply chains. Long supply chains means lots of places for Daemon Murphy to sneak in a fuckup.

It may even turn out that you are right about wind's inability to achieve full baseload penetration. I can't see why you would be, but I am not entirely comfortable with betting my subcontinent's electricity supply on my personal prescience. The fact that I cannot point out where and when the problem will arise does not mean that it is worthless to hedge against it. In fact, if I knew precisely where and when a show-stopping problem would crop up, we could take steps to avert it.

Redundancy is no less a virtue in your technological portfolio than it is in the design of individual machines.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Mon Aug 8th, 2011 at 02:27:13 PM EST
[ Parent ]
"wind's inability to achieve full baseload penetration" is a phurphee, a red herring, a meaningless distraction.

The designation of specific power sources to be specific baseload and scheduled follow load supplies is a consequence of the use of fueled power sources, and then supported by the institutions that have developed to implement and manage them.

There is nothing intrinsic in electricity demand about baseload. There is the predictable components demand, on various time scales, and unpredictable demand.

In a portfolio of harvested volatile renewable power sources, you have a predictable component to the total supply, and an unpredictable component. The greater the diversity of types of sources and specific resource regions connected together, the greater the predictability and so the greater the predictable component of supply and the less the unpredictable component of supply.

Therefore for a fully renewable grid, you need some combination of buffering stores, and storable schedulable renewable power, and storable dispatchable renewable power, sufficient to bridge any mismatch between the current harvested supply and current harvested demand.

Given the potential renewable European subcontinental sources of dammed hydro and biocoal, and the range of distinct harvestable volatile renewable power sources, the notion that there has to be storage sufficient to turn each distinct renewable into the functional equivalent of one type or another of fueled power source is nonsense.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Thu Aug 11th, 2011 at 09:51:28 AM EST
[ Parent ]
So we create some new seasonal industries to harvest the bounty when it's there.
by Colman (colman at eurotrib.com) on Mon Aug 8th, 2011 at 05:22:06 AM EST
[ Parent ]
.. industries that absorb 3 times the average power consumption of northern europe? What did you have in mind? Launching spaceships out of the solar system with launch lasers capable of dicing small moons?
by Thomas on Mon Aug 8th, 2011 at 08:46:29 AM EST
[ Parent ]
Sounds good to me.
by Colman (colman at eurotrib.com) on Mon Aug 8th, 2011 at 08:50:33 AM EST
[ Parent ]
Or we could inflate big balloons and use them to drive wind farms in winter!
by Colman (colman at eurotrib.com) on Mon Aug 8th, 2011 at 09:31:12 AM EST
[ Parent ]
Maybe you know that big data centers use more power in summer than winter. The problem is always to get rid of excess heat. So while your house may need heating in winter, overall the grid demand may skew towards higher in summer...
by asdf on Mon Aug 8th, 2011 at 08:23:13 AM EST
[ Parent ]
Did someone suggest an all-solar solution? Did I miss a memo?
by Colman (colman at eurotrib.com) on Mon Aug 8th, 2011 at 09:27:43 AM EST
[ Parent ]
Thomas is thinking in terms of the full decarbonization of electricity generation and in that context residential solar instalations may seem like a distraction.

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Mon Aug 8th, 2011 at 09:43:16 AM EST
[ Parent ]
It reads more like full nuclearization is his real concern.
by Colman (colman at eurotrib.com) on Mon Aug 8th, 2011 at 09:46:50 AM EST
[ Parent ]
Or full wind. Or a mix. Whichever is the fastest. I just like tech that actually has a record of working. And doesnt try to fight geography.
by Thomas on Mon Aug 8th, 2011 at 09:56:15 AM EST
[ Parent ]
Except that 40 years ago Wind didn't have a record of working and 60 years ago Nuclear didn't either.

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Mon Aug 8th, 2011 at 10:05:00 AM EST
[ Parent ]
As for fighting geography...

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Mon Aug 8th, 2011 at 11:50:37 AM EST
[ Parent ]
My problem with your arguments is that there are completely black or white ones.

In the case of solar, the problems limiting the yield of the PV cells to 15% is not due to geography, but to physics: there are too many electron hole recombinations in the current (crystalline Silicon) cell design that happen before getting those to the collecting grid.

There are at the same time a lot of research being done, a great art of which is industrial research. You can NOT get industrial actors to do some research if you do not guarantee a minimum (financial) yield in the next few years. That is exactly what the solar power fixed prices are for.

If you don't understand the mechanics of industrial production, I can't do much for you really, apart suggesting that you try to work in a developping business-line in your company. I've been there, and it's a daily fight with upper management to get going. I can only tell you that if you don't have perspectives, you'll get nowhere.

Regarding your comment on taxpayer's money: I understand that you live in France. In this country, it is not taxpayer's money that pays for solar/wind, but consumer's money. This means that it is much more equally reparted than your average tax: just compare how much you pay per month to social insurance of all sorts (half your salary) and how much you pay for solar/wind fixed prices: it's far from being half of your electricity bill. Private actors pay also (companies, businesses...) which lowers the burden.

On the contrary, ITER (nuke)  is almost fully paid by the taxpayer: the money is substracted to the scientific (and defense) research budget.

And you still haven't answered to my question: how do you best manage to produce electricity specifically needed in summer, especially with your fixed output full nuke prod system ?

by Xavier in Paris on Tue Aug 9th, 2011 at 05:49:56 AM EST
[ Parent ]
the problems limiting the yield of the PV cells to 15% is not due to geography, but to physics

If you mean light-to-electricity conversion efficiency, it is now above 15% for the best panels, not to mention cells. I'm not sure which earlier discussion of yield you refer to, but the percentage associated with it is the capacity factor. The efficiency has little relevance, because the light energy that 'goes to waste' doesn't come from a fuel you have to pay for and doesn't overheat engine parts; it is relevant only via the available surface area, which is also influenced by latitude. The capacity factor is average actual power divided by maximum power, and actual power is limited by the diurnal and seasonal cycles in irradiation angle, as well as cloudy weather. Over the full year, it should be a bit above 20% for the very best locations, the rule-of-the-thumb average for mid-latitude and less sunny Germany is 11%, and it should be even lower for Sweden. Luís's own installation had a capacity factor of 15.2% in its first year, which is rather good considering the non-ideal positioning (facing the sunset rather than the midday Sun).

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Aug 9th, 2011 at 06:39:24 AM EST
[ Parent ]
I was refering to Thomas numbers in the thread above (see my first comment and his answers).

I know that experimental PV has better light to electricity yields, thanks. Even if other problems arise (on the industrialization process side). But Thomas doesn't, so I just wanted to make a note.

by Xavier in Paris on Tue Aug 9th, 2011 at 07:29:38 AM EST
[ Parent ]
I scanned the thread but couldn't find the 15% figure (or any other numbers except for "40 years") in his comments, hence one part of my confusion. The way I read him, Thomas's concern is about supply in winter when (1) supply is scaled for maximum summer demand (2) photovoltaics is considered as a monocrop supply (why, is still not clear to me), and the one mention of geographic variation I can find in the discussion with you was in this context; hence the rest of my confusion.

I don't mean experimental PV, that's much higher, but commercial models. I recall readig of module efficiencies near 18% and cell efficiencies near 20%, now I find the current best is apparently the SunPower E20, with module efficiency of 20.1% and cell efficiency of 22.5%.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Aug 9th, 2011 at 09:29:35 AM EST
[ Parent ]
Maybe I've been too fast on that one strawman. Thanks for remarking it. Let it be known then that Thomas hasn't mentionned the light-to-electricity ratio yet.

I'm not following you with the "irrelevance point" though: the light to electricity ratio is what is limiting the global yield of PV, compared to thermic-solar which is economically sound, even in winter. It is driving the production, given a geography location. Just imagine a 40% efficient cell instead of the current 15% ones! What would then be the return on investment of Luis if we could produce these at the same price as crystalline silicon?

It is also able to compensate partially the geographical location, as some physical designs are more efficient in cloud covered skies than others (eg amorphous vs crystalline silicium).
All the other technics are already mature (electronics driving of the installation, redresser, grid). The great progress still to be made lies in the cell design.

I recall from some experiments three years ago in a parisian lab that you can strongly increase the yield if you give a nanostructuration of the surface exposed to the sun. The problem being to get that structure cheap (and compatible with ITO collecting grid).
You also can increase the collecting of electrons by using nano-rods of silicium on your surface. There is also some research to be done on the use of bi-material cells, with two different band gap materials in the cell to increase photon collecting.

There are a lot of leads to better cells, but companies need money to investigate these. That is my message really.

by Xavier in Paris on Tue Aug 9th, 2011 at 08:02:51 AM EST
[ Parent ]
thermic-solar which is economically sound, even in winter

Is it? I thought there are only pilot installations around.

It is driving the production

If you have a limited available area, that is. Which, OK, is true for a single home owner whose roof has enough room for a capacity that would produce electricity of the same magnitude or less than his consumption. I was thinking from the viewpoint of global supply (for which there is more than enough surface area available) rather than a single small producer.

Just imagine a 40% efficient cell instead of the current 15% ones! What would then be the return on investment

How can you think of economics without unit costs? If a square metre of the 40% efficient cell costs three times as much as a square metre of the 15% efficient cell, then I rather buy three panels of the 15% efficient cell. Or just one if surface area is limited and the profit margin is narrow.

The problem being to get that structure cheap

Yeah. This is a two-level problem: on one hand, you have to bring down the cost of building and running the production machinery; on the other hand, you have to run up production levels so that economies of scale can emerge. If I am not mistaken, most of the radical (50%) cost cuts in the last five years were due to the increased automation and production volume of cell and module production, while in the same timeframe, efficiency improvements for the most produced cell designs were miniscule in comparison (5% range).

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Aug 9th, 2011 at 08:45:51 AM EST
[ Parent ]
I thought there are only pilot installations around.

Well upon checking, I seem to be far behind the news! Wikipedia lists 15 operating facilities in Spain with 800 MW of combined capacity, most of it going on-line in 2010 or this year; and several in construction. AFAIK the FIT rate is still around 0.27 €/kWh, so I wonder if costs could be brought down significantly.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Aug 9th, 2011 at 10:27:22 AM EST
[ Parent ]
solar thermic is already in line, both in its industrial form and its individual homeowner form (like Luis's 2m²)

As approximately 25% to one third of total energy consumed in France is used to heating the house and water, thermic solar is a great technology to tackle energy supply problems. (I'm not talking electrical energy here).

I'll add that a great part (20%?, don't remember) of electricty produced in France is used for heating. So you can assimilate on kwh of solar heat to one kwh of electricity (displaced) up to this limit.

Regarding unit production costs, my sentence says that exactly... ;-)

by Xavier in Paris on Tue Aug 9th, 2011 at 11:20:10 AM EST
[ Parent ]
... I only see it addressed when its imagining if the higher physical energy efficiency was available at the same cost.

Imagine if 5% energy efficiency was available at 1/10 the cost of 20%. Except for space constrained set-ups, the 5% energy efficiency wins hands down.

Indeed, given that unit cost comparison, it'd pay to rent unused space in the neighborhood and still use the 5% efficient technology.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Tue Aug 9th, 2011 at 12:04:32 PM EST
[ Parent ]
please read my comment in relation to Thomas's, to whom I was answering.

Yes, I perfectly know that one axis of research on PV cells is in the direction you mentionned: low yield/low cost PV. I can add that some of the technology used there are also explorer in the fuel cell world.

This alone will not help the industry, because if you only produce low yield PV cells, then you get behind thermic solar in terms of system overall optimum.

Nowadays, in France, there is some electricity (20-25%) that is produced by nukes and hydro that is only used to heat houses and offices. For this particular use, thermic solar has 80% yield. Logically, if electrical energy is expensive enough,which should be the case eg if we develop electrical cars, then you will have a preference for thermic solar before you start on low (or high) yield electrical PV.

If you want to develop an electricity production in a scarce energy world, you need high yield between the primary source (wind, light, heat) and the electrons that goes out. Otherwise, other (thermic) sources will be preferable up to something around 60Twh/year in France (=electricity used for heating in France in 1997). Only if you produce more than that will it be interesting to use a low yield electricity source.

by Xavier in Paris on Tue Aug 9th, 2011 at 01:08:34 PM EST
[ Parent ]
This alone will not help the industry, because if you only produce low yield PV cells, then you get behind thermic solar in terms of system overall optimum.

System overall optimum what. Lowest cost per delivered kWh is lowest cost per delivered kWh ... whether that's dirty cheap low efficiency or more expensive higher efficiency is just however that pans out. As far as the policy, the same feed-in tariff supports both without discrimination.

As far as being "ahead of" or "behind" thermic solar seems a non-issue, since the losses in converting from heat to electricity or electricity to heat tilt the field toward a mix in any event.

Indeed, the 5% efficiency at substantially lower cost could be a synergistic system ~ a sandwich of a high efficiency row underneath cheap strip concentrator lenses between vacuum heat collectors ~ with backing cooling for the high efficiency row the first stage of the heat collector ~ and while the PV part of the sandwich would add an increment to cost, its installation would be close to free with installation of the thermic collector.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Tue Aug 9th, 2011 at 02:48:55 PM EST
[ Parent ]
Optimum:
you have energy needs (motors, heat, cold...). There are different physical ways to satisfy these needs.

Some of these physical ways are stupid, from a physical point of view, because they do not extract the maximum energy amount possible from the environnement.
Such is the electrical heating (use of electricity to produce heat), which maximizes the losses between primary energy source and energy used.

The optimum is to use each available source of primary energy at its best: heat for heating, cold (as in local geothermy or canadian well) for cooling, electricity for motors and non heat uses, and gasoil as a highly concentrated energy medium.

Is that clearer?

by Xavier in Paris on Wed Aug 10th, 2011 at 09:16:45 AM EST
[ Parent ]
That's an energy use optimum, but not necessarily an economic optimum. For an economic optimum, yield is your return on investment, not primary energy input.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Wed Aug 10th, 2011 at 10:23:03 AM EST
[ Parent ]
Energy maximum harvest per square foot is not even necessarily an energy use optimum, depending on the EROI of the various technologies in question.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Wed Aug 10th, 2011 at 03:17:00 PM EST
[ Parent ]
What DoDo said ~ extracting maximum energy from the environment is almost never an optimum, and its certainly not optimum if 5% costs 1/10 per square foot what 20% cost, since the first gives 2.5 times as much generating capacity per dollar.


I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.
by BruceMcF (agila61 at netscape dot net) on Wed Aug 10th, 2011 at 02:25:36 PM EST
[ Parent ]
Ah, so you meant solar heating, not solar thermal power plants. I have one, too, and it's great as it gives all the hot water needed from around April to September. But what did you mean by being 'economically sound even in winter'?

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Tue Aug 9th, 2011 at 03:26:55 PM EST
[ Parent ]
Because I live in a temperate place, so it's still somewhat usable even in winter, with a small additionnal input from other heat sources.
by Xavier in Paris on Wed Aug 10th, 2011 at 09:18:33 AM EST
[ Parent ]
So it's the geography that matters after all :-)

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Wed Aug 10th, 2011 at 10:16:38 AM EST
[ Parent ]
you could always add some more tubes i suppose.

Anyway, I'm off, this thread is too long for me. ;-)

by Xavier in Paris on Wed Aug 10th, 2011 at 04:44:07 PM EST
[ Parent ]
Just one I've found:
why try to convince of the interest of alternative electricity sources, when you have this published in mainstream media:

http://www.lemonde.fr/idees/article/2011/08/10/l-aigle-dore-victime-de-l-or-vert_1558153_3232.html
<blocquote>D'un côté, des turbines pesant 200 t, mesurant plus de 100 m de hauteur, avec des pales longues de 40 m qui tournent à la vitesse de 300 km/h.

De l'autre, des aigles majestueux de 2 m d'envergure, pesant environ 5 kg, habitués à se poser au sommet des pylônes électriques pour repérer leurs proies puis foncer sur elles et à migrer à travers des écosystèmes autrefois accueillants mais où vrombissent désormais de bruyantes turbines.</blocquote>

trans:
<blocquote>One one hand, wind turbines weighing 200 tons, higher than 100m with with blades 40 m long running at a speed of 300 km / h.

On the other, 2meter wingspan majestic eagles , weighing about 5 kg, used to stand on top of electricity pylons to locate their prey and pounce on them and to migrate through the once welcoming ecosystem now replaced by noisy turbines.</blocquote>

It's almost as well argumented as some comments on forum discussions...

by Xavier in Paris on Wed Aug 10th, 2011 at 05:09:29 PM EST
[ Parent ]
(blockquote)

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Thu Aug 11th, 2011 at 03:26:53 AM EST
[ Parent ]
Thomas wrote: "This makes solar technology as a whole utterly useless for decarbonizing the grid of anyone who lives very far from the equator."

Let me guess - you oppose PV far from the equator because it's too summer-skewed. And you'd oppose wave power for the UK because it's too winter-skewed. Ooh, wait a minute, that gives me an idea ...

Anyway, broadly speaking, I agree that it would get extremely hard for UK PV penetration to exceed single-figures, by mean annual power. 10% would be 20GW of PV electricity, i.e. an installed capacity of circa 200GW! (based on DUKES 2011 figures that UK Final Energy Demand is circa 200GW, and typical UK PV capacity factor is 10%)

So maybe there's some strawman-fighting going on here. For the UK I think 1-5% penetration of PV is pretty sound - that's an installed base of 2-10GW, so we've got some installing to do yet. And yes, the closer to the equator you go, the higher the viable percentage.

by LondonAnalytics (Andrew Smith) on Tue Aug 9th, 2011 at 06:34:18 AM EST
[ Parent ]
Why final energy demand? Are you assuming a full electrization of energy supply, without future increases or decreases due to efficiency changes?

If , conservatively (assuming no storage, demand management or exports), we scale PV buildup in the UK to summer peak demand (around 40 MW), then at a 10% capacity factor, we get 35 TWh annual generation, or 9% of 2010 total consumption (384 TWh).

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Aug 9th, 2011 at 07:00:30 AM EST
[ Parent ]
And the UK would get a natural complement to onshore and offshore wind (which are natural complements to each other, due to different dirunal patterns of average power delivery).

And if the home installations were hybrid PV/thermic, the UK would also get a reduction in summer load.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Tue Aug 9th, 2011 at 02:52:31 PM EST
[ Parent ]
Yes, I am assuming a couple of things:

  1. electrification of all heating and most transport (as the most likely route to decarbonise each);

  2. unknown efficiency savings combined with unknown growth in demand for energy services, which I've just let cancel out to zero, for the sake of providing illustrative numbers that are likely to be within +/- 50% of the right number
by LondonAnalytics (Andrew Smith) on Wed Aug 10th, 2011 at 03:35:57 AM EST
[ Parent ]
Another assumption here is that people can't move. Why do so many people live in Western Europe? Does it have anything to do with the cheap coal power that allowed the development of the industrial revolution and that has powered it ever since?

Depending on the rate of change in the climate and the economic environment, dislocation and re-distribution of population on a grand scale is not out of the question...

by asdf on Thu Aug 11th, 2011 at 05:22:09 PM EST
[ Parent ]
About the output diagram (second posting below the fold): isn't the caption wrong? As for the curve, is it smoothed, or (my guess) spline-fitted?

The marginal price is hence 0.01 €/kWh

0.1 €/kWh?

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Tue Aug 9th, 2011 at 06:14:04 AM EST
Luis, thanks for posting this diary. One data point in the ramp-up to distributed, sustainable energy.

"Life shrinks or expands in proportion to one's courage." - Anaïs Nin
by Crazy Horse on Tue Aug 9th, 2011 at 07:54:52 AM EST


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