August 22, 2008
Concentrating Solar Power Growth Expected
The outlook for concentrating solar electric power is sunny.
In fact, there’s a land rush at the federal Bureau of Land Management. As of July, the BLM reported more than 125 applications to build solar power on about 1 million acres of desert, up from just a handful of proposals a few years ago.
“We think there’s a good market there,” says Travis Bradford, an expert at the Prometheus Institute, a Boston-based solar-energy market research firm. His firm sees 12,000 megawatts (12 gigawatts) of solar thermal installed by 2020 and maybe 20 times that in coming decades.
That 12 gigawatts is probably equivalent to less than 6 gigawatts of solar. In fact, if it is based on peak power at noon then is average power even 4 gigawatts? That'd amount to less than 3 new nuclear power plants. This is the problem with solar power. The big scale-up doesn't become substantial for years to come.
Concentrated solar's estimated cost is similar to that of natural gas electric. But natural gas electric is available when you want it. So solar has to be cheaper in order to compete with natural gas without subsidy. Also, natural gas electric is more expensive than coal, wind, and nuclear electric. When solar falls down far enough to compete with the latter three sources that's when it becomes very interesting.
Concentrating solar technology produces electricity for about 17 cents per kilowatt hour (kWh), Mehos estimates. But subsidies remain critical to solar thermal development in both the US and Spain, two global hotbeds of CSP development. With the federal investment tax credit, or ITC, costs drop to about 15 cents per kWh – low enough to compete with natural gas.
A key feature of solar thermal is its potential to use heat-storage technology to generate power after the sun sets. Nevada Solar One is considering adding a molten-salt or similar system to allow it to supply power for several hours after sundown.
With such storage systems, solar thermal becomes even more attractive to utilities, experts say. Arizona Public Service is contracting with Abengoa to build a 280-megawatt solar thermal plant near Phoenix that will cost more than $1 billion and have molten-salt heat storage.
Storage means additional costs. But since concentrating solar produces heat before it produces electricity that heat creates the potential for storing the heat as a way to generate electricity after the sun goes down. That gives concentrating solar an advantage over photovoltaics (PV).
While concentrating solar is currently cheaper than photovoltaics I expect that will not always be the case. The company First Solar looks set to bring solar photovoltaics costs well below current concentrating solar electric costs.
But if you want the off-peak market, you’ll have to price your cells at about US $1 per watt. That price is called grid parity, and it’s the holy grail of the photovoltaic industry. At least 80 firms around the world, from Austin to Osaka, are in the chase.
Surprisingly, at the moment no company is closer to that grail than a little start-up called First Solar, which until very recently had been known only to specialists. It’s located in Tempe, Ariz., and analysts agree that it will very likely meet typical grid-parity prices in developed countries in just two to four years. It’s got a multibillion-dollar order book, it’s selling all the cells it can make, it’s adding production capacity as fast as it can, and its stock price has rocketed from $25 to more than $250 in just 18 months.
If First Solar alone can make 1 gigawatt of PV in 2010 and PV growth rates continue near 2008's level then PV installations probably will leave concentrating solar in the dust.
Right now, First Solar depends mainly on a government-subsidized program in Germany, where it has contracts worth more than $6 billion through 2012. Other markets with the same type of subsidies (known as feed-in tariffs, which spread the cost of alternative energy among all customers) include France, Italy, Spain, South Korea, and Ontario, Canada. To fill these orders, the company is undergoing a massive expansion of its manufacturing facilities that should boost annual production capacity to just over 1 gigawatt by 2009. This capacity could supply one-sixth of that year’s estimated global solar-cell business, which is currently growing at 50 percent per year.
Maybe concentrating solar's big competitive long term advantage against PV is the ability to produce heat energy for storage. What do you think? Does concentrating solar have a big future?
I am still skeptical. Concentrating solar will use lots of stuff steel, concrete, and pipes. It needs mirrors, frames to hold the mirrors, motors to move the frames pipes to collect the hot fluid, storage contaners, etc., etc. If you build in the high desert with no water supply you will need cooling towers, big ones at that. Oh, yes, and land, lots of land.
"Devils Hole Pupfish, Saved by Court in ’76, Is at Brink in ’08" by Randal C. Archibold in the NYTimes on August 22, 2008
PV may avoid some of those costs, but storage is a daunting problem.
There has to be a better figure of merit than "energy". There are too many losses from the point of "capture" to the consumer. Take, for example, food:
The food energy going into a human is a small fraction of the energy that:
1) Falls on the autotrophic land.
2) Goes into the cultivation of the autotrophic species.
3) Goes into the trophic chain.
4) Goes into the cultivation of the trophic species.
5) Goes into the food processing.
6) Goes into the supply chain for the end consumer.
There are analogous losses involved in consumer electricity, consumer transportation, etc.
The best one I've come up with is ecological footprint, which is why I focused on algae as the autotrophic species under a combined use greenhouse within the Solar Updraft Tower Algae Biosphere which reduces the ecological footprint of developed nation lifestyle by about a factor of 100:
James: Thanks for the reference. I have been puzzled by the lack of interest in solar updraft towers. But one can't investigate everything and I must assume they remain stalled from difficulties not readily apparent.
Or perhaps stalled because there is no lobby for them. It is hard to lobby for what has never been proved. And what industry would benefit enough to justify the risk without public funding?
The algae production is crucial. And so far algae have been reluctant to behave as man prefers. When that is resolved the tower scheme may progress.
Or it may not; perhaps the abundant energy captured by an effective algae industry will best used in other ways.
I would not question the funding to see power generation towers designed and tested. A consortium of the solar rich nations should fund competing, independent teams. Perhaps one in the Sahara, one in the Outback, and one in India.
I have been puzzled by the lack of interest in solar updraft towers.
It's pretty simple really:
The electricity alone won't amortize the cost of construction, and all the cases where multiple uses have been proposed for the structure, the business plans have centered on electricity which is, at best, a tertiary source of value.
Now, why have the folks promoting the solar updraft tower been so dense?
That is the real question.
And so far algae have been reluctant to behave as man prefers.
The same is true of all natural phenomenon. The job of man is to engineer his systems accordingly -- hence the Solar Updraft Tower Algae Biosphere.
Mmmm... I would suggest trying to brew your own beer a few times before talking about using anything microbiological on a massive scale.
Hint: it is not easy. In fact, it would be nearly impossible the large-size structure free of biological contaminants, which would quickly turn the aglae tanks into a cesspool of every kind of nasty bacteria just loving to feast on the energy-rich concentrate of tasty biomass.
You'd probably waste more energy for draining, sterilizing and re-filling the structure every week or so and for sterilizing nutricient and water feeds, than you'll be able to generate out of it.
Mmmm... I would suggest a trip to Earthrise Farms in Imperial Valley for you...
20 acres of algae raceways maintaining FDA-standard purity of arthrospira platensis (spirulia).
Storage is an issue although some solar proposals include storage - Ausra's proposals include storage sufficient to run 24hrs a day, but can it be scaled up to do multiple days? I think the main reason we don't have any utility scale storage is because it's never been needed with fossil fuels. Now it looks like we do - or will - need it but there's a lack of incentive to do so as long as those coal plants keep on running. Thermal storage is pretty basic stuff but it won't get built on anything but prototype scale until there's a real need - probably after the grid's capacity to deal with intermittent supplies gets overwhelmed. It may well be expensive, and surely more expensive than keeping the coal fires burning (as long as external costs like climate change don't get included), but the switch to clean energy isn't optional in my opinion. I also think it's not necessarily going to be prohibitively expensive as new technologies make their way into commercial production. With First Solar, Nanosolar, CSG Solar already in production any projections of solar costs based on older manufacturing methods isn't acknowledging that they're already earmarked for obsolescence.
To Ken, or someone familar with fossil fuel electricity generation.
It seems to me that solar thermal could work well with fossil fuel generators. If solar thermal was used to heat inlet water to an intermediate temperature then wouldn't you use less fossil fuel in the steam generation stage?
And solar heated water could also be stored for use at night or when sunlight is blocked by clouds. Storing a reserve of heated water in insulated tanks wouldn't be very expensive. I think there would also be an advantage in siting and operations costs. The utility already has staff on site and no electrical grid changes would be needed.
I favor evolution rather than revolution. So I would rather steadily cut fossil fuel usage rather than wait for wonderful developments which seem always to be just around the corner.
As for contaminant organism: There are ways to reduce the size of that problem with genetic engineering. For example, genetically engineer a strain of algae that can live well in conditions which are normally very difficult for algae. Genetically engineer that same strain of algae to make a lot of oil.
One could even introduce a gene therapy agent periodically that would take whatever algae that are present and convert them into big oil producers.
K, actually that sounds a lot like Ausra's system - their demonstration plant was built to feed steam directly to an existing coal-fired power station, not just preheat the water. It's fully compatible with existing steam generation hardware. Details of their storage aren't clear - steam at high pressure? I seem to recall the phrase saturated vapor but couldn't find the reference.
I think thermal storage has great potential and is simple in principle even if the scale and engineering the hardware would present serious challenges. I just don't see the hurdles as that huge, just the biggest one of who will go first. I think the reality is that planning future energy supply still doesn't take conversion to clean energy seriously - just greenwash projects that represent a fraction of a percent of the investment budgets of power companies.
Whilst regulation will help, the real shift has to come from renewables getting cheap enough to be the low cost choice. Ausra and others seems to be serious about reducing the costs. They may not be at parity with coal yet, but coal prices have jumped and if ever the regulatory regime utilities operate under forces the inclusion of the externalised costs, systems like Ausra's may be the lower cost alternative.
I'm a bit puzzled by some of your commentary here. While noting that CSP's " competitive long term advantage against PV is the ability to produce heat energy for storage " and that "A key feature of solar thermal is its potential to use heat-storage technology to generate power after the sun sets", you still say, strangely, that "That 12 gigawatts is probably equivalent to less than 6 gigawatts of solar. In fact, if it is based on *peak power at noon* then is average power even 4 gigawatts? " and " But natural is available *when you want it* . So solar has to be cheaper in order to compete with natural gas without subsidy."
As you say, the advantage of CSP is exactly that it *doesn't* have a peak power or cyclical availability problem: while current systems still lose a bit of potential in the middle of the night, they still provide more than enough power through an entire daily cycle of actual use.
Similarly, it may be true that "While concentrating solar is currently cheaper than photovoltaics I expect that will not always be the case" -- but you'll still have the problem of supplying baseload power, unless we get much more efficient (in terms of cost, efficiency, AND volume) storage systems (improved batteries or hydrogen generation & storage systems).
The "natural is available when you want it" should have been "natural gas electric is available when you want it". Natural gas electric is available on demand.
Of course, electric demand at noon is much higher than electric demand at midnite. But electric power demand usually peaks late afternoon or early evening. So that's problematic for solar.
CSP has the advantage over PV that we can store the heat and use the heat later to generate electricity. So perhaps we'll see PV used for mid-day demand and CSP used for evening demand.
Solar has to be cheaper than natural gas because solar is less convenient. That's not fatal for solar for a couple of reasons. First off, we are going to run out of natural gas. Second, once PV becomes cheap solar really will be cheaper than natural gas
Like Michael, I am puzzled by this part of your post "That 12 gigawatts is probably equivalent to less than 6 gigawatts of solar. In fact, if it is based on peak power at noon then is average power even 4 gigawatts? That'd amount to less than 3 new nuclear power plants. This is the problem with solar power. The big scale-up doesn't become substantial for years to come."
Would you please elaborate ? Also I would like you to take in consideration CSP utilities such as the SunCatcher from SES Stirling Solar http://www.stirlingenergy.com that has the highest conversion to grid ratio of all solar technologies out there 31.5%, are you saying it is useless on a mass scale ?
Also if you are knowledgeable about flywheels as means of kinetic energy storage, I have researched the topic, they achieve a 95µ% efficiency, do you think they could be coupled to large scale Stirling solar farms for distribution after sunset. And if so would it be feasible to have supertankers containing say 10 400Mw flywheels for delivery to distant markets such as China ? How long do they keep their energy ?
Nabil from Morocco.
A solar installation that puts out 12 GW at noon puts out 0 GW at midnight. The average ends up being approximately about a third of the peak. So 12 GW of capacity is on average 4 GW. The exact different between max and average would depend on cloud cover and latitude. During winter the average production would be extremely low in Oslo Norway. The average would not drop in winter nearly as much in Morocco. You can find world insolation charts on the web. See, for example, this insolation chart for a large variety of US cities. Compare Seattle and Phoenix.
By contrast a 1 GW nuclear power plant produces electric power 24 hours per day and might be down for maintenance perhaps 10% of the time. So it would produce 0.9 GW on average.