Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
An old source gives US transmission losses in 1995 at 7.2%.

Online commentators will often give a far larger number from misunderstanding an energy efficiency of electricity generation figure that is dominated by efficiency of power plants.

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 Jun 23rd, 2011 at 07:39:38 PM EST
[ Parent ]
That's interesting since I've always heard the far larger numbers. Especially with regard to building a new American energy grid. One of the biggest arguments for it is that so much energy is lost with the old grid.
by Upstate NY on Fri Jun 24th, 2011 at 01:24:42 PM EST
[ Parent ]
Two sources:

(1) total confusion of losses in generation with losses in distribution ~ if you carelessly read "energy source" when the aggregate energy flows through the system are described as being on the "after the generator" side, you easily get 60%~70% losses, the majority of which are really are losses between the energy content of thermal fuels and energy output at the generator.

(2) confusing maximum long-haul AC losses with average grid losses, because the long haul AC interconnects do not carry a majority of the power consumed, but rather only excess of local production over local consumption or deficit of local consumption over local production.

There are two type of "new energy grid" required:

wholesale-grid: inter-regional connections allowing cross-haul of volatile renewable, scheduled renewable and dispatched renewable sources (eg, wind, biocoal, and dammed hydro). This is grid to grid, high voltage DC, which is an excellent efficient long haul point to point technology. In the US we've been relying on natural gas pipeline infrastructure and locally sited natural gas power plants to avoid expanding our long-haul network as energy consumption expands, but we cannot sustain that strategy indefinitely ~ sooner or later we have to catch up with the long-haul power infrastructure deficit, if we are going to take advantage of economy of geographic scope to reduce total volatility of volatile renewables;

retail-grid: "smart" grid to final consumer to permit greater system efficiency by permitting power consuming devices to intelligently shift demand, eg, an energy efficient DVR that charges an internal battery pack when power is cheap and shuts down the power connection when power is expensive or, for consuming device that draws less power than a DVR/set-top box in the average American home, a refrigerator/freezer that schedules topping up the ice-cube tray for periods of inexpensive power.

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 Jun 25th, 2011 at 02:56:58 PM EST
[ Parent ]
What proportion of retail electricity consumption is really "re-scheduable" and how can this be increased.  Electrical cars recharging at night and storage heaters seem to me to be almost the only non-trivial applications. Fridges don't use much extra power to freeze a few ice-cubes and the extra cost of the smart appliance - unless such features are mandated for all new appliances - would strongly disincentivise significant take-up.

Presumably some industrial processes can be rescheduled for off-peak times but what we probably really need is the mass production of ammonia based electricity storage devices to act a bit like a water header tank in the attic - a small local store of power for most domestic devices.

Index of Frank's Diaries

by Frank Schnittger (mail Frankschnittger at hot male dotty communists) on Sat Jun 25th, 2011 at 06:03:58 PM EST
[ Parent ]
You mean, like air conditioners that freeze water into ice overnight and then use that as the heat pump sink during the day to shift AC demand from peak to off-peak.

Of course, you pluck the lowest hanging fruit first ~ first you convert from stand up to drawer freezer/fridge. Once you have that, though, time-shifting operation ~ taking it to a lower temperature at off-peak than on-peak periods, doing ice cube making off peak, etc ~ that's the obvious next step.

As far as cost, its already controlled by an electronic controller, powered from the mains power ~ taking the signal off the mains power and feeding it as data into the control board might add a few Euro to the cost, but its mostly programming.

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 Jun 25th, 2011 at 07:35:55 PM EST
[ Parent ]
This leads into a gripe of mine about recycling and energy efficiency. Right now it is mostly placed upon the consumer - at least on this side of the pond. There is a real limit to what can be done at that level. At a certain point it starts to cost real money and a fair amount of time for ever decreasing gains. Far more can be accomplished for a much lower cost by looking at the manufacturing sector and demanding that they start producing appliances/packaging that work with recycling and energy efficiency.

aspiring to genteel poverty

by edwin (eeeeeeee222222rrrrreeeeeaaaaadddddd@@@@yyyyaaaaaaa) on Sun Jun 26th, 2011 at 12:02:53 PM EST
[ Parent ]
Mining consumer product energy inefficiency is always an up-front strategy that has to be combined with a long term strategy to build up sustainable power generation and reconfiguration of the big consuming technologies ~ since with each efficiency gain, the mining the remaining inefficiency tends to be harder with less result.

The shift from upright to drawer refrigerator/freezers is a fundamental energy efficiency issue: upright refrigerators are just fundamentally less efficient than drawer refrigerators, because the drawer retains cool air when the upright looses it.

However, the smart grid applications cited are not about energy efficiency directly as much as they are about making use of volatile power as it becomes available ~ of shifting consumption to match harvest.

In the US, the scope for consumer side energy efficiency gains is still tremendous, and in New York State they are getting a serious start on it with establishing finance paid through the utility bill based on financial savings from lower operating costs. Given our thoroughly corrupt political system, having that financial support in place is part of the political pre-requisite for gaining producer side regulation, since the greater the prospect of a market side win as a result of complying, the more likely the regulation is to get put into place.

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 Sun Jun 26th, 2011 at 01:11:47 PM EST
[ Parent ]
Central air conditioning and refrigerators combined account for 28% of US household electricity consumption.

AC is obviously a main driver of peak demands, and why the US summer peaks are higher than the winter peaks. Refrigeration is not as peaky, but is primarily focused on the hours of the day that the door is being opened and closed ~ and as a heat source inside the house, increases the load on AC.

Energy efficiency might cut 8 percentage points out of that. If half of the balance can be shifted from on-demand to on-supply-available, shifting 10% of average demand into, say, 8 off-peak hours could easily represent a doubling of off-peak demand.

In both of those cases, there are substantial efficiency untapped gains available right now if there was Connie Mae style financing available with payments made as part of utility bills, and the first step is to reduce the size of the peak by reducing wasted energy during the peak. But for the refrigeration case especially, its the energy efficiency that requires an overhaul in what people expect to see when they buy a refrigerator ~ given a switch from intrinsically inefficient uprights to intrinsically efficient drawer refrigerators, the switch to the smart grid shifting of refrigerating load to periods when power is being offered cheap is so inexpensive to add that you'd not notice it.

Of course, you have to have the smart grid available to pick all the low hanging fruit that may be there to pick once the smart grid is in place.

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 Sun Jun 26th, 2011 at 01:37:46 PM EST
[ Parent ]
a pet peeve of mine. And it isn't just on-line commentators. I've corrected technical documentation that claimed 66% losses in transmission...
by jam on Fri Jun 24th, 2011 at 03:21:50 PM EST
[ Parent ]


Occasional Series