Investing in Solar Thermal Energy Production
Solar Thermal Power generation is a very promising clean renewable energy source because of its simplicity. There are several huge benefits and a few drawbacks to this technology, but I think because of its technology readiness and very high efficiency it will be the next high impact technology when it comes to renewable alternative energy production.
In my last post Case for Alternative Energy / State of USD / Peak Oil, I discussed several different alternative energy technologies very broadly. Now I would like to focus on the one that (in my opinion) has the most near term promise to revolutionize alternative energy and to make it "mainstream": Solar Thermal
If you are reading this article chances are you are already familiar with solar thermal energy production. I will just go into a very brief overview. There are many types of solar thermal systems (it is an extremely broad category), but this post will focus on the general technology technique call Concentrated Solar Power (CSP). There are also several subtypes of CSP, and I will focus on medium temperature CSPs as this will allow the use of steam turbines, which are very efficient.
Basically the sun shines onto mirrors and those mirrors focus the heat into a fluid line. Generally this can take two forms, a mirror "field" where the fluid runs over long lengths of pipes (like Nevada's Solar One) or the tower type where the mirrors focus the heat onto one central spot (like the eSolar design) The heated fluid is moved through the system to a heat exchanger / boiler where exchanger moves the heat from the fluid to the water to make superheated steam. The steam moves the turbine to move the shaft of an electric motor.
It is beautifully simple. All of the power generation side of the system is a closed system. As long as there is sun, this system will always produce power without refueling (which is not technically true for all systems, the Nevada One uses a gas make-up heater as required, but all of the new modular designs do not). However the cooling side of the system is not closed, and does require a water supply (more on that in a minute).
The system is clean. The system is simple. The technology is very low tech or very well understood. Mirrors are very low tech and can be made economically. Self-contained control systems that allow the heliostats to track the sun can be made very economically (a few decades worth of development, devices used in many industries). Steam turbines are very well understood (these have been around for several decades). All of the pieces are there and have been for decades.
There is nothing new or revolutionary about any of these technologies. They are not dependent on a rare element like Tellurium, or the future of polysilicon production. Additionally it could be argued that zoning and land deals for placing solar thermal stations is easier that it is for wind farm. The windy areas tend to have population centers, and the people are almost always against the sight of wind farms (I personally think they are beautiful and looking at them gives me hope for the future and reassures me that their operation means less of a dependence on foreign oil, or coal or natural gas. But some people don't see it that way). There are either drawn out zoning studies or bird migration studies for wind farms. But thermal solar fields are just out in the middle of the desert. Usually in sparsely populated areas.
Speaking of deserts… That is actually a benefit. If you consider the amount of land in AZ, NM, CA, NV, UT, etc. that gets consistent, nearly year round sunshine, you realize… they are SUN FACTORIES! And when you consider Arizona: they have several major polluting coal plants with very high levels of mercury emissions, the Palo Verde nuclear plant west of Phoenix is the third worst in the nation in terms of safety and environmental violations, they should be leading the solar thermal bandwagon! It makes sense environmentally and it is very close economically.
The biggest drawback is the one that has the most impact in the desert: Water. The current state of the art for solar thermal power stations use up a lot of water. However, it is really on par with the amount of water that gets used in a coal plant for the same amount of power generated. Regardless, this is still an issue.
The jist is, once the superheated steam runs through the turbine, it is at a lower energy state. However, it still needs to be condensed before it goes into the pump to be fed back into the loop. This means a condenser heat exchanger, and the cool water in the heat exchanger is drawn up from a reservoir. This then heats up the water in the exchanger to near boiling, and has to be pumped out to a cooling tower for evaporation.
This is not an ideal situation for a station in the desert.
*** Crazy Idea Alert ***
I have not seen this idea, but I wouldn't be surprised if somebody else has had it…. Why not used the Earth as a second heat exchanger? Instead of pumping the water out of a reservoir, why not run a loop from the steam condenser heat exchanger into the Earth? It would just be a geothermal heat pump. The Earth temperature several feet down is 60 deg F. Just like with a geothermal heat pump for a house where it uses the earth a warm thermal sink in winter or a cold thermal sink in summer, why not get the cooling capacity for the water that way?
This way in the desert, it would be 100% green: No emissions, completely renewable, and does not tax the water supply? Hmmm….
If anybody has heard about this idea being combined with solar thermal for the cooling aspect, let me know. I would be very interested to see where this is heading.
Ways to invest
Okay. So all of that is well and good, but how do you invest in solar thermal?
I did a lot of research for this, and am just familiar with the subject because I think it is so promising. I have not come across a publically traded solar thermal manufacturer. Please, if anybody knows of one, please let me know. There are several private companies.
eSolar This is my favorite because of the modularity concept
BrightSource gets $115 million in new funding Google, BP, StatoilHydro invest in solar thermal firm
There are several power utilities that have small and some large scale projects ongoing with some private companies
SRP - Nevada Power, a unit of Sierra Pacific Resources
FPL Group, Inc. (FPL)
PG&E Corp (PCG)
In March, BrightSource announced power-purchase agreements with PG&E for up to 900 megawatts of electricity. It's now developing solar power plants in the Mojave Desert of Southern California, with construction of the first plant planned to start in 2009.
Supporting Tech and Water
Steam Turbine Manufacturers: DRC, SI, GE
WGOV http://www.woodward.com/engine/steam/steam.cfm - Make optimization hardware and software for steam and gas turbines. I would not be surprised if WGOV has parts in the current gen of turbines, and probably will in the next gen.
Water companies and utilities? Anomalee, had a good idea about this in his post: Growing Scarcities: The Water-Industrial Complex.. .
Geothermal Cooling (in case that is a viable option) - ORA