[1] Hussain Alrobaei,2006, Integrated Gas Turbine Solar Power Plant/ The Energy Central Network/ energycentral.com/centers/knowledge/whitepapers.

[2] Hussain Alrobaei , 2007, Novel Integrated Gas Turbine Solar Cogeneration Power Plant/DEC, Halkidiki, Greece ,22–25 April 2007.

Before trotting out World Bank forecasts, might not be a bad idea to check their track record on predictions – looks kind of dismal to me.

I’m also skeptical about “wind” being competitive with fossil generation. Perhaps in California, but here in Kansas it’s not a contest. Coal wins by a landslide.

Regarding the scale that solar could be put into place, I would suggest you might want to check into it's record. Stearn & Wheeler (I think) reported to the DOE as early as 1997 that CSP was down to about 16 cents/kwh with much room to further drop. Funny thing is that all that data was removed before the DOE passed the report on to congress under Cheney. Now, eleven years later, we're hearing the 'breaking news' that CSP can be down to 15 cents with room to drop. If you check out the middle east or european news, you'll find that CSP is taking off in a big way. Over 4 years ago, I passed on to my senator, a white paper on a single project to supply 60% of Europe's power from North African CSP plants at a price of 5 cents over 20 years. That includes load balancing energy storage to cover other renewables' variability. Since then, I've seen two similar competing projects.

Right now, you're only seeing the profit taking on the low hanging fruit. When it does start to take off though, you can bet that with highly repetitive manufacturing and labor as it's major costs, it's prices will drop rapidly. That price and to a lesser extent, it's overall efficiency, is the only thing stopping it from being used in less sun areas like Kansas. I see the bottom end around 3 kwh/m^2/day of sun. Looking at an insolation map, that covers way up into most of Canada.

3kwh/m^2/day of sun would be fantastic. I can envision just half of my residence's rooftop here in Ontario equipped with a small-scale CSP. Just 20 to 30 m^2 would satisfy my residential energy needs easily, with lots to spare on sunny summer days. Combine this technology with some sort of decent future storage capability (in my basement), and I might even be able to divorce myself from the grid altogether all year long.

You know, if this technology were available commercially, even if it were many thousands of dollars, it would be worth pitching to new home builders as an option. When someone goes to buy a new home and spends in the order of 500 thousand on it, even adding another 10% to the mortgage to pay for a CSP system would be attractive if meant no utility bills to the home owner for the life of their mortgage.

To add to your comment, keep in mind that in the winter much of your energy needs shift a large balance from electricity to domestic heat, just like the output of CSP systems running in colder weather. Better news yet is that emergency 'backup' energy could come from natural gas which can be stored as long as you want with no 'time cost'. That means you only really need a few days' worth of storage.

Solar proponents need to keep economics in mind. I can put a $35,000 solar panel installation on the roof, but It will take decades to payback. Poor investment.

Mike

I am not an expert on solar but I assume a prohibitive amount of battery storage would be needed for a solar PV panel system to enable a residence to become independent from the grid. Concentrated Solar however sounds like it has much more potential.

Here in Ontario our provincial government tries to encourage private consumers to buy solar PV systems by paying a premium to the consumer for selling excess power back out onto the grid on sunny days rather than trying to store it. On cloudy days these consumers then simply revert back to consuming from the grid at the going utility rate.

DUH- they're all subsidized. Where do you think the grid came from, ever heard of TVA? Ever read the history of GE, or Standard Oil? Get with it dude, so you think the coal and the nukes aren't subsidized? Come on - the culprit isn't the subsidy, the culprit is the demand.

JeffK

Let me ask you a question. If you can come to the conclusion that PV is a poor business deal, then why is it the only solar being "researched" and subsidized? As you seem to have missed in the article above, CSP is usually not using expensive solar cells but rather concentrating the sun's heat to run traditional turbines. (If they are using PV now or in the next 3-5 years, I can guarantee you that some politician is involved!) The energy companies and their 'expert' analysts have got everyone convinced that CSP doesn't exist and we need to support them spending our money so they can fix PV (or wind). Doesn't that make you mad?

I'm guessing your parroted '20 year payback' line ultimately came from someone not wanting renewables to succeed. First off, let's look at that statement differently. Try this one instead: "Solar is paid off, free and clear, in 20 years with no further repetitive costs at all." Who wouldn't want a set, non-volitile payment for 20 years and zero costs (not counting repair) beyond that? Secondly, many non-PV technologies have much less payback times. But you're certainly not going to hear about the ones under a decade from KCP&L.

A common example given is of an aluminum foundry. I've heard almost everywhere that even if you could provide power to most homes and businesses by solar, you'd never get to the level where you could melt enough aluminum. There just isn't enough power. Luckily, someone forgot to tell the guys doing it without fuel costs. I'll keep looking for a link but with the new computer, my stuff's in turmoil right now. Here's a good

Thanks for the info.

Still, the majority of CO2 comes from heating and grid power generation.

I'm surprised nobody has mentioned the recent announcement that PG & E is awarding a 900MW solar tower project to BrightSource (run by the CEO of now-defunct Luz which made all the original solar thermal plants currently in the Mojave).

That's the biggest CSP installation ever announced, and I suspect it's just the beginning. I still think Ausra's frensel mirror arrangement will prove to be cheaper, but time will tell.

I also think this article is too conservative. Long term most of the pundits say we should expect large and highly optimized CSP to provide electricity as cheap as $0.07/MWh within 20 years.

Good summary and perspective. Let me add some details about those 2 large contracts by SES, inc.

In 2005, the Stirling Energy Systems Corporation signed contracts with two California electric power companies. One with Southern California Edison Electric and the other with San Diego Gas & Electric. Nearly half of the San Diego project is completed, i.e. "steel in the ground". The details are : - San Diego Gas & Electric

-300 MWe w/option to 900 MWe

- 12,000 x 25 kWe reflector dish array - 2,700 acres: under construction: 2006-2009

- $0.06/kWhr (contract price to SDG&E)

- So. California Edison Electric

-500 MWe w/option to 850 MWe

- 20,000 X 25 kWe reflector dish array - 4,500 acres: construction to start 2009 with completion by 20012

- $0.06/ kWhr (contract price to PG&E)

The cost for electric power from gas or fossil fuel powered plants will increase over the next 3-5 years while the solar power plant electric costs will stay essentially flat.

http://www.eia.doe.gov/oiaf/servicerpt/subsidy2/pdf/subsidy08.pdf

It shows that oil, coal and renewables received the lion's share. The report also notes that the 2005 Energy Policy Act and the 2007 EISA have significant additional subsidies for nuclear and renewables, so even though nuclear subsidies in 2007 were fairly small, they'll be much larger in the coming years b/c of the 2 c/kWh production tax credit provided for the first 6,000 MW of nuclear and other support such as loan guarantees and Price-Anderson risk insurance.

In terms of liquid fuels subsidies, oil companies have long received the oil depletion allowance and also received tax credits for offshore exploration in the 2005 EPAct to the tune of billions of dollars. The controversy in the last six months re Dems in Congress trying to increase subsidies for renewables arose b/c the Dems wanted to take away tax breaks provided to oil companies in 2005 in order to pay for the tax breaks for renewables (which makes a lot of sense).

A home energy supply system clearly falls into the second category, and yes, a home solar system WILL last longer than it takes to pay off including interest, so SMART people will be fighting to get them included into their mortgages. (Also applies to commercial and industrial energy-bill-replacement technology. Once they figure this out, CEO's are going to start asking some very embarassing questions to their finance people).

b. Just pay the local utility for the power you need.

The answer is currently "b".

Obvious complications are government subsidizes as well as "selling" power back to the local utility.

Never-the-less, "b" will remain the answer for the vast majority of home owners well into the future.

If the solar installation is only $1000, then it's a good investment.

As far as subsidizes are concerned, nobody should receive them beyond the research and start-up stage.

I suppose, however, avoiding taxes is a subsidy of sorts.

Had not really considered the oil & gas folks and do not have a good handle on that industry. Does the government send them money or are we talking about avoiding taxes?

Mike My mistake.

Re small scale solar, you're actually correct in many cases: solar for homeowners generally doesn't make economic sense, in the traditional sense of that phrase. In other words, as Len pointed out, under the traditional analysis, solar PV is not a "good investment" b/c you can make more on your money elsewhere. And this is true even in states like CA and NJ where there are good rebates available (a rebate is actually a sum sent to the homeowner). In states where there is not very good sun or not rebates, it gets even worse.

However, I agree with Len's second type of financial analysis as a legitimate perspective - particularly when we consider that a homeowner can lock in the cost of electricity with solar PV in order to protect against higher utility rates. For example, one our local utilities, So Cal Edison, has announced its intent to double rates over the next five years.

Also, if a homeowner has a very large utility bill in a state where tiered rates are in force, solar PV can make sense b/c it can remove the highest tier or two, which in CA can be as high as 30 c/kWh.

Moreover, solar for businesses does in fact make economic sense from a traditional perspective in states like California and NJ. Businesses have more tax advantages, particularly the lack of a cap on the 30% federal investment tax credit (which is capped at $2k for homeowners) and accelerated depreciation.

But the focus of my article is on large scale solar so none of this analysis is apropos of my article's topic.

Grid shift is when you use electricity from the grid at night and supply it back during the day. Currently, there isn't much incentive around the country for the homeowner but that's destined to change. It'll change because the peak prices will rise in comparison to baseload when natural gas prices rise and with the advent of more nuclear. This change will make the homeowner's sold product more valuable than his purchased product. Perhaps Tam can correct me if I'm wrong, but TOU (time of use) rates in CA are around 9 cents at night and reach 56 cents during the afternoon. The net result is that you only have to make half or less of the power you use in total to have a net zero cost monthly bill. Your mileage may vary.

Adding to that scenerio, the loan for the system will be locked against not only volitility but inflation as well while the utility bills will rise due to inflation and 'crisis mode' volitility. For example, taking out a loan for $35K for 20 years at 8% costs $293 per month. If you offset an average $213/month in bills (depending on what part of the country you're in) at 3% inflation, your balance would be as follows. At 10 years, you'd be $5,394 upside down. At 20 years, you'd be dead even (yeah, that's why I picked that example). At 21 years, you'd be $4726 up and at 30 years, you'd be $54,288 to the good. This isn't even counting on any subsidies.

You seem to be stuck with PV solar as your model of residential renewables. While they are getting better now and have lots more room to continue that, you need to open up a little and review some others. There are many others both now and upcoming that have much better economics.

Is a large scale concentrated solar energy plant a good investment -- today?

Is it a good deal for the consumer -- today?

As your article notes, it is not yet clear what the actual cost to the consumer will be.

Would be an interesting analysis to compare concentrated solar, natural gas, coal and nuclear all on the same basis, say: 15 year note at 8%, Owners Equity at 35%, indirect cost of say 25%, no subsidies for anyone. Natural gas at $10/mmBTU, coal at $1.80/mmBTU, nuclear at $1/mmBTU. Direct capital costs: coal $1700/kW, gas $600/kW, nuclear $3300/kW. We can even add an integrated gasification combined cycle plant if you like.

Figure we want a 12% return on Owner's equity and let's see what the price of power needs to be for our investor (cost to consumer).

If somebody can provide the direct construction cost of a concentrated solar unit and average capacity factor, I can pop out the results in an hour or so.

Mike

PS Len , too complicated for you?

These calculations are very hypothetical to start with because there are many assumed variables for interest rate, amortization period, subsidies, etc. Your assumptions for these numbers today can and will change in future, and at any point in time they differ between jurisdictions around North America.

What matters is whether a given source will be in the same ballpark cost relative to the others, and in the case of a privately owned residential power system how much if any it reduces one's energy dependence on utility companies.

"The reference technology to which these assumptions apply is a new 100 MW solar trough system with an oil working fluid transferring heat to a secondary water cooling system that operates a steam turbine. The reference design is assumed to have 6 hours of thermal storage and no natural gas backup, and be located in the Mojave desert."

"The base overnight capital cost for new CSP plants is $3389/kW, prior to applying zonal cost multipliers and financing costs during construction costs (see Table B). This value is based on Black & Veatch 2006 cost assumptions, adjusted for inflation and recent increases in the cost of materials. (See “Financing and Incentives” report.) Reference case variable O&M costs for CSP are $0/MWh and fixed O&M costs are $53.45/kW-year. The reference case capacity factor is 40%, which follows the Black & Veatch 2006 design specifications."

Much other useful data.

I also think it's fair in this discussion to propose that decision yea or nay on support for the technology should be based on at minimum, the articles projected year 2020 costs, when they expect the capital cost figures to have dropped by 20% in current dollars, and IMHO we can anticipate the costs of competing N Gas to have risen substantially. In order to get there now, i'd suggest it's worth a 20% capital subsidy immediately reducing as install volume increases, not charged to cost calculations.

Black & Veatch has made the following conclusions about the deployment of CSP from this analysis: • California has high quality solar resources sufficient to support far more CSP than either the 2,100 MW or 4,000 MW scenarios analyzed. • Depending on the CSP plant interconnection point and the load profile of the local electricity provider, CSP with 6 hours of storage could perform peaking and/or intermediate generation roles for a utility. • Investment in CSP power plants delivers greater return to California in both economic activity and employment than corresponding investment in natural gas equipment: - Each dollar spent on CSP contributes approximately $1.40 to California’s Gross State Product; each dollar spent on natural gas plants contributes about $0.90 - $1.00 to Gross State Product. - The 4,000 MW deployment scenario was estimated to create about 3,000 permanent jobs from the ongoing operation of the plants.

• Operations period expenditures on operations and maintenance for CSP create more permanent jobs than alternative natural gas fueled generation. For each 100 MW of generating capacity, CSP was estimated to generate 94 permanent jobs compared to 56 jobs and 13 jobs for combined cycle and simple cycle plants, respectively.

• Energy delivered from early CSP plants (startup in 2007) costs more than that delivered from natural gas combined cycle plants5 ($157 per MWh vs. $104 per MWh, based on a 30 percent ITC for CSP). With technology advancements, improvements to CSP construction efficiency, and with higher gas prices consistent with 2015 MPR projections, CSP becomes competitive with combined cycle power generation ($115 per MWh vs. $119 per MWh, even with the permanent 10 percent ITC). Most of the economic and employment advantages are still retained.

• CSP plants are a fixed-cost generation resource and offer a physical hedge against the fluctuating cost of electricity produced with natural gas.

• Each CSP plant provides emissions reductions compared to its natural gas counterpart; the 4,000 MW scenario in this study offsets at least 300 tons per year of NOx emissions, 180 tons of CO emissions per year, and 7,600,000 tons per year of CO2.

Also, none of these these projections consider the price beyond the loan term period which is the favorite trick of the nuclear advocates.

I'll use B&V's $3900/kW direct construction cost and 40% capacity factor and see what we get.

I'm not so sure touting creating more jobs is such a great benefit for solar. My general thinking is that the idea is to minimize the cost to the consumer, not create another WPA operation (Great Depression program created by Roosevelt for you younger guys).

Also, may not be reasonable to rely on "future" improvements in solar without also accounting for "future" improvements to the fossil technologies (gas turbine firing temperatures move ever upwards as do the corresponding efficiencies).

http://www.energy.ca.gov/2007publications/CEC-200-2007-011/CEC-200-2007-011-SF.PDF

Three quibbles 1) the assumption of a 27% capacity factor for PT Solar Thermal seems low and also ignores the potential of relatively cheap thermal storage to greatly extend capacity. 2) the forward projections of natural gas prices for the next 20 years appear over-enthusiastically optimistic to say the least, approximately equal to overall economic inflation. I thought we should have learned at least that much from the 1990's. 3) No inclusion of effects of changes in relative currency values, especially important to LNG import assumptions.

Man. Did the “investors” ever give that group (LUTZ) a hard time. Nuts. Demanding cash escrow during construction phase, risk premiums for tax shelter returns in case the government didn’t renew tax breaks each year, Absolute killer schedules, etc. etc. That’s not investing, it’s (clearly something else).

The Army Corps of Engineers' '05 report estimated that we can expect $1500/kw and a levelized cost of under 8 cents soon. That's using the new hybrid plants that we are seeing go in and getting planned today.

"Concentrating solar power technologies currently offer the lowest-cost solar electricity for large-scale power generation (10 MW-electric and above). Current technologies cost $2,000-$3,000 per kilowatt, which competes with nuclear and environmentally compliant coal plants. This results in a cost of solar power of 9¢-12¢ per kilowatt-hour (kWh). New innovative hybrid systems that combine large concentrating solar power plants with conventional natural gas combined cycle or coal plants can reduce costs to $1,500 per kilowatt and drive the cost of solar power to below 8¢ per kWh."

I found the Sandia report on LUZ informative, though probably for different reasons than you and Len did. I have had occasion to go by the station at Kramer Junction several times a year since before the first station was built. The site appears to have added stations fairly regularly since then, even after the date of the Sandia report 17 years ago. Has a similar report been issued for operation of the stations for the interim and to date? Of course, the other thing that struck me in the lessons learned section of the report was the recognition of "returns to scale" by the author and presumably his organization. Remarkable.

The URL you gave for your paper doesn't work. It needs a reference to the paper itself. This one should work:

http://www.energycentral.com/centers/knowledge/whitepapers/report.cfm?rid=102295

It requires a login to Energy Central, but that shouldn't be a problem for any readers of Energy Pulse.

As to the concept itself, perhaps I'm missing something, but the only significant difference I can see between your proposal and a conventional CCGT in parallel with a solar thermal plant is that instead of separate steam turbines for the bottom cycle of the CCGT and for the solar thermal plant, there is a single ST that serves both. That may be advantageous in terms of system capital cost, but I don't see any advantage in terms of time spreading of the solar output.

Currently nobody is doing this though. It's all theoretical at this point, but the numbers work if the long-term thermal storage technology is put into place. Whether that means storing hot salt, or using giant steam storage chambers underground - it's a great idea that everyone is talking about but nobody is currently doing. It's almost as if they're afraid to find out that it wouldn't work. In my mind it seems a phenomenal engineering feat to keep that much thermal energy isolated for 12 hours or more. I'd love to see it work.

I once read about a thermal storage analysis for making hydrogen via high temperature electrolysis (more efficient). The problem with solar is that the lower plant usage raised costs, even with thermal storage. So they recommended nuclear power.

Has anyone actually done the numbers on something like this? Even roughly? According to Sandia, a tank 30 feet tall and 80 feet in diameter could store enough heat in salt to power a 100 MW turbine for 4 hours. I guess that works out to roughly 2.6 kW-hr (electric) per cubic foot of salt stored. I guess that's not too bad.

If we drop the efficiency to only 1 kw-hr per cubic foot, that still would be OK. This makes me think that smaller sized units might be more reasonable, given the fact that so few people actually live in the desert....