Largest Solar Thermal Storage Plant to Start Up

[Fledermaus]

1 October 2008—A few weeks from now, the Andasol 1 solar thermal power plant in Andalucía, Spain, will begin charging the largest installation built expressly for storing renewable energy (other than the tried-and-true hydroelectric dam, of course). Heat from the solar thermal power station's 510 000-square-meter field of solar collectors will be stored in 28 500 tons of molten salt—enough to run the plant's 50-megawatt steam turbine for up to 7.5 hours after dark.


The lower cost of production is actually a by-product of Andasol 1's energy-storage system, according to Paul Nava, a managing director of Flagsol GmbH, the Cologne, Germany–based engineering subsidiary of Solar Millennium that designed the plant. Nava says storage is a means of maximizing the net energy production from each plant and thus maximizes the revenues paid under Spain's generous incentive program for renewable-energy generation. A feed-in tariff for solar thermal power pays 2.5 to 3 times the average power price for every MWh of energy generated for 25 years (though new rules will reduce the rate for future projects) but limits the capacity of qualifying facilities to 50 MW. Storage enables Andasol 1 to run its 50-MW turbine for more hours.

Nava estimates that Andasol 1 will generate 178 000 MWh of renewable electricity per year, whereas the same field of solar collectors and turbine would turn out just 117 000 MWh sans storage—a difference worth more than 24 million euros per year (US $36 million) at today's power prices.....

...At present, most of the anticipated U.S. solar thermal projects, which are driven by state-level renewable-energy mandates rather than a rich feed-in tariff, are focused on minimizing upfront costs, and few projects plan to integrate energy storage. But Mancini and Nava say that may change as utilities adopt time-of-day electricity pricing.

Nava says a pricing scheme already introduced by Southern California Edison should encourage what he calls a “solar booster” thermal power plant. The California utility pays 3.28 times its base rate for electricity delivered between noon and 6 p.m. on summer weekdays. A solar booster would use an undersized collector field and storage to focus generation on that sweet spot. “In the morning, you use the solar field only to charge the storage, and then from noon on, when you have that factor of three for the electricity rate, you discharge the storage and use the field in parallel to drive the steam turbine,” says Nava.

http://www.spectrum.ieee.org/oct08/6851

[Trillo]

1. Yeah. Let the free market decide.

"may change as utilities adopt time-of-day electricity pricing."

Why? Because The Free Market works so, so very well.

[kristopher]

2. That works.

Time of day pricing brings a key element of an effective market into being for electricity. Right now, much of the cost of providing electricity is a product of having to build large amounts of underused infrastructure to meet extremely rare demand peaks. On the wholesale side, electricity is priced by a formula that looks at supply/demand in different locations. This pricing calculation is ongoing and your bill reflects a sort of 'averaging in advance' of these "locational marginal prices". The idea is that if people buy electricity with an awareness of the ACTUAL cost of providing that electricity, then the demand driving those very expensive peaks will be reduced. If you see that electricity is $0.92 per kilowatt hour at 3PM when you consider running your dryer, and you know that electricity is $0.04kwh at 9PM, there is a good chance you'll alter your behavior and either hand your clothes outside or run the dryer at a time when electricity is cheaper.

Energy conservationists and the environmental community have been pushing this idea for decades.

[Trillo]

3. So it will require new circuits in refrigerators,

preferably with a PC interface for programming, so that consumers can decide if now is an affordable time for the compressor motor to cycle on.

Hey, that's good for refrigerator sales, one of the most power consuming appliances in the home! All hail Mary, praise the overlords, another new scheme to financially chain the poor!

On a more serious note, after Schwarzenegger took office, it was reported that solar photo-voltaic installations requesting rebates reportedly took a dive because under the new plan, people taking advantage of the rebate would need to change their electric grid meter to a type that would report time of day usage.

So it seems that had the opposite effect. Praise our Overlords!

[kristopher]

4. Not sure what that proves.

You don't provide enough information to be meaningful. Gov. S (allegedly) ties replacing a home's electric meter to rebates for solar - and - the number of rebates requested declined at approximately the same time.

Was the metering change to allow the consumer to track the LMP of electricity or was it to allow the consumer to sell surplus electricity back to the grid? Although I don't follow it closely, as far as I know, the installed capacity curve for home solar has shown a steady upward trend in California. I'd need to see more data before accepting your belief in a connection between metering and solar installations.

Your "humor" seems misplaced to me; more of an attempt to make a misguided argument that can slide through without a challenge. Sure, refrigerators, water pumps and other 24/7 necessities will not be affected, only those electrical purchases that are discretionary as far as time goes. However, testing has shown that even with the 24/7 appliances the consumer tends to be much more conscious of their electrical consumption an end up placing greater emphasis on the purchase of more energy efficient appliances and a greater awareness of their electricity consumption in general.

[Trillo]

5. Rebate rule chills sales of solar

By Marc Lifsher
May 08, 2007 in print edition C-1

California homeowners are rejecting new rebates for solar power equipment, saying the state has made installing the rooftop panels far more costly than expected.

As a result, Public Utilities Commission reports show a decline of 78% in rebate requests in the first three months of this year, compared with last year, and the solar installation industry says it is threatened with collapse across much of California.

At issue is a requirement the state added Jan. 1 for getting a rebate under Gov. Arnold Schwarzenegger’s Million Solar Roofs program. Applicants must first sign up for costly pricing plans offered by utilities that charge more for their electricity during hours of peak demand.
...
read more @ http://articles.latimes.com/2007/may/08/business/fi-solar8

---

I'll leave the conclusions regarding "what it proves" to readers. It's just a news item, and as such doesn't necessarily rise to any particular proof standards, other than probably trying to report facts to the general public.

[kristopher]

6. You are mixing apples and oranges

The article is lumping several issues together and is generally pointing to those issues as a cause for decline in applications for rebates on home systems. For example, from the article: "Many homeowners quickly decided that it might not be worth going solar under the new requirements. The costs would be burdensome for those who couldn’t afford or lacked the roof space to buy systems that would supply all of their electricity needs."

That shows well that the reporter is dealing less in "facts" and more in subjective quotes selected from a variety of people. The story is only tangentially talking about time of use; and then only as it relates to solar installations. We, on the other hand, are talking about time of use as a widespread means of more effectively managing the generating resources of the grid.

Those are two completely different sets circumstances, goals and decision making processes. In other words, we are left knowing absolutely nothing more than we did when you made your first baseless criticism.

[Trillo]

7. From the article above:

"utilities adopt time-of-day electricity pricing"

Utilities price something when they sell it. Duh~!

Your most recent objection, mixing "apples with oranges", seems to say "nobody buys their electricity from utilities". :(

[Fledermaus]

8. I, for one, welcome our new overloads

and I would like to remind them as a trusted engineer I could be helpful in rounding up others to work in their underground sugar caves.