Fred Walters

[JR: Fortunately CP posts all have a date on them right on the bottom!]

Well, please stop. It’s misleading people into overestimating solar power’s potential — notably yourself. Your original statement was, “Solar baseload … is probably going to be lowest-cost carbon-free new generation available 24/7.”

By the way, I couldn’t find a general source for the price of electricity throughout the day, but this PG&E rate schedule,
http://www.pge.com/ myhome/ environment/ pge/ electricvehicles/ fuelrates/ index.shtml
suggests that at ~13 cents/kWh, solar power isn’t cost-effective for covering the shoulder. But six hours of storage looks about right to shift it into the 2:00–9:00 Peak period.

[JR: Solar peak is not noon. It is later. ...]

Which is why I specified “solar noon”. I’m sure we’re all familiar with the effect of daylight saving time.

Concerning the FPL nuclear cost analysis, one has to be careful not to confuse an over-night capital cost (which people often use to compare costs between different energy sources) and total costs which include all financing/interest costs, as well as escalation (i.e., inflation during the plant licensing and construction). Total costs are much higher than overnight capital costs (more than double). The price per kW quoted by FPL was a total cost, and must not be compared to overnight costs one has probably heard elsewhere for various other sources.

I believe that the FPL analysis quoted a resulting, per kW-hr, power cost, and it was much less than 10 cents, let alone 15 (I think). Also of note is the fact that their analysis (which the PUC concurred with) showed that nuclear was the cheapest option; cheaper than coal (assuming CO2 limits) and gas, as well as any renewable option.

There is a wide range of opinion/analysis concerning the relative costs of various energy sources, and thus we all spend an enormous amount of time arguing about it. The tragedy is that none of this analysis/argument is necessary. You don’t have to know which sources are most economic or promising in order to implement good energy policy. The main job of energy policy is to ensure that external costs are accounted for in the market, and more generally to prevent any given plant/source from inflicting significant public harm and/or cost. The relative economics of various sources is best sorted out by the market.

There are three main externalities out there, that are currently not captured in power prices; air pollution (which kills 25,000 Americans every single year), global warming, and the economic/geoplotical effects of our foreign oil and (soon to be) natural gas dependence. Thus, the best way to determine the relative economics of various energy options is to simply cap or tax CO2 emissions, other air pollutant emissions, and foreign energy imports, and then let the market decide how to respond.

One final consideration is subsidies. The market system described above would be fair only if the subsidies enjoyed by the major sources are at least roughly equal. The notion that nuclear power is more subsidized then other sources is a myth. It’s actually one of the least subsidized, with recent support programs merely bringing nuclear more in line with other sources. Conservation and renewables’ R&D budget is ~50% larger than nuclear’s, as shown on page 19 of:

http://www.cfo.doe.gov/ budget/ 08budget/ Content/ Highlights/ Highlights.pdf

In terms of direct operating subsidies, renewables are much more subsidized, on a per-kW-hr basis. Finally, it should be noted that the loan guarantees that are offered to nuclear under the 2005 Energy Policy Act are offered to renewables and sequestered coal as well. How’s this a relative subsidy?

Anti-nukes continually claim that renewables are less expensive then nuclear, but at the same time they’re the one’s who are always doing everything in their power to prevent a free, fair, and open competition between the two. Examples include, supporting state reactor bans, and continuing to support renewable portfolio standards which require renewables to be used regardless of price or practicality. Let’s see, you CANT build nukes, and you MUST build renewables…. Some competition!

Another recent example is the current Liberman-Warner cap-and-trade bill. Under the current plant, the govt. will get hundreds of billions of dollars from the auction of CO2 credits. Instead of leaving well enough alone and letting the market decide how best to reduce CO2 emissions (by using the money to reduce the national debt, or give every American a general tax cut, etc…) they can’t help but interevene in the market by using all this money to develop and encourage energy options they favor. Who will recieve all this largesse? My understanding is that both renewables and coal sequestration will recieve hundreds of billiong of dollars in subsidies and R&D funding, while nuclear will get virtually NOTHING!! Hmmmm… Seems like these people (e.g., Boxer) know what would happen if there was a fair competition between sequestered coal, nuclear and renewables, and it seems that they don’t like the result. They apparently think that a massive market intervention is necessary in order for coal or renewables to capture much of the non-emitting generation market.

If you look at people’s actions, as opposed to their words, it appears that most people don’t think that renewables are cheaper than nuclear. I’m looking forward to hearing your explanation Joe.

However, I think the idea of trying to store the energy for off-peak hours (i.e., to allow CSP units to be baseload plants) is stupid, at least for now. Why would you spend a large amount of money on extra equipment, and suffer some energy losses, just so you can move kW-hrs from peak-demand times, when they are needed most and fetch the highest market price, to off-peak hours where the reverse is true? Why voluntarily give up one of solar’s most attractive, and inherent, features?

If they think that adding a small amount of energy storage would allow them to tailor the power shape to best match the demand profile (and thus maximize the market price of the kW-hrs produced), that’s fine. But trying to store energy so you can generate kW-hrs at night (off peak) is just plain stupid.

Why the big push (by some) to make CSP units capable of 24/7 generation? Is this a triumphalist crusade to show that solar can do everything, and that we don’t need to pursue any other energy options? Given that solar now produces less than 0.1% of our power, I would suggest that it’s a little early for that. Gotta walk before you can run. One step at a time.

CSP’s goal for next couple decades should be to become a significant contributor, and to shave a significant fraction of the demand peak. The best way to do this is to minimize CSP’s costs, and maximize its profitability, by NOT making any attempt to store power for off-peak use. If and when CSP mostly fills this peak-shaving nitche, then (and only then) should be start talking about using CSP for off-peak generation (using storage, etc..)

If a solar plant can generate power for about hours around solar noon, and store power for another six, it can cover the peak load well, but that leaves the other twelve hours.

(Why isn’t there a preview button on this site?)

[JR: Solar peak is not noon. It is later. CSP follows the load, and that is very valuable.]

Six hours of storage only covers the peak load. To get baseload power would take several times as much storage — at a fraction the power level. The combination would make real “solar baseload” far more expensive.

The problem of course is that this is “modeling”. The recent NEI White Paper has nuclear costs at 8.4 cents/kWhr. (at least their model is based on *actual* submissions to the NRC C&OL process). There are current CPS being built around the world. The *cheapest* is about 15 cents/kWhr. Some have hot water storage. All are very expensive. No one is talking about a REAL plant being built for anything less than 10 cents/kWhr.

I’m all FOR building a molten-salt storage system for CPSs. Lets’ do it and SEE what it costs…No one has build a plus 10MWt MS storage system. Until then, it will not provide base load nor peak load but only what it can give us for 6 hours a day.

BTW…Base load is around the clock, it’s inclusive during the peak, so you have to build a CSP that can provide 24/7 power, base. Good luck with that (I mean it, it would be great to see it done).

David Walters

[JR: Actually, CSP with 6 hours storage is load following, which is better than baseload, since it displaces shoulder AND peak. In this country, it would make no sense to waste energy to store power for 4 am. But I'm calling it baseload because load following is too obscure.]

Six hours of storage only covers the peak load. To get baseload power would take several times as much storage — at a fraction the power level. The combination would make real “solar baseload” far more expensive.