... to state the obvious. Spain is doing the strategic thing, with a higher tariff for CSP than for PV.

The parts of the US which are especially suited for CSP (both thermal and PV) happen to have a peak period which is largely driven by air conditioning, if I have understood directly. This means that PV can actually get the best tariffs, and that the storage possibilities of thermal CSP are negated.

This is a severe handicap for thermal CSP, because the southwest USA is where it's at currently for utility-scale solar.

PV CSP is starting to take off in a big way there, for that reason.
SDG&E, Soitec Add 2 Local Solar Sites | Xconomy

San Diego Gas & Electric has added two more 25-year contracts with French-based Soitec, which will supply a total of 125 megawatts from solar energy sites using Soitec's Concentrix CPV (Concentrating Photo-Voltaic solar panel modules.

In a statement today, the two companies say Soitec Solar Development will manufacture the modules in a new factory to be built in San Diego. The two local agreements follow three previous contracts for 30 megawatts of CPV-generated solar power.

(Note that the Concentrix system doesn't require water cooling.)

Will there be only one cost-competitive technology, at the end of the day?

Tracking the CPV Global Market: Ready to Fulfill Its Potential? | Renewable Energy World Magazine Article

As with all forms of renewable energy the first question anybody usually asks is 'What does it cost?'. With an emerging sector like CPV there is currently no simple answer. The big hope for CPV is that by using smaller amounts of photovoltaic material at high efficiencies it will be able to drive down costs and compete with fossil fuels - a hope shared by thin-film PV and concentrating solar thermal.

At present, CPV still has some way to go, although it does have some factors in its favor. Certainly, in terms of installation costs per kW, CPV is far from the cheapest. According to GTM, the pre-profit cost for a high-concentrating multi-junction system is roughly $3.35/W installed, compared to $2.04/W for thin-film CdTe and $2.52/W for polysilicon.

What really matters, though, is the cost per kWh produced, and here things are a little better for CPV - it can operate at capacity factors of up to 26 percent, compared with 20 percent for CdTe. Once that is taken into account, CPV is considered to be broadly competitive with non-concentrating PV.

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