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Investing in Solar Thermal Energy Production



May 28, 2008 – Comments (10) | RELATED TICKERS: FPL.DL , PCG , WWD

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

Quick Explanation

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 - 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

Mirror Manufacturers?

... Others?

10 Comments – Post Your Own

#1) On May 28, 2008 at 1:13 PM, madcowmonkey (< 20) wrote:

Today, we will be looking at water to help us with energy (my post).

Way to easy of an answer to the dilemma. I lived in AZ for a while and I know that there are very few homes that have basements because the ground is so hard, but I am sure the cooler lines would be pretty simple to dig. Will the steam go down or would there need to be a fan/pump that forces it to defy gravity?

Great post and thanks for all the links. 

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#2) On May 28, 2008 at 1:28 PM, madcowmonkey (< 20) wrote:

to or too?

For some reason when you put SRP I was thinking Salt River Projects, which is a utility company in AZ that deals with Nuclear, solar, coal, and whatever else. I am pretty sure they are not a publicly traded company though. 

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#3) On May 28, 2008 at 1:42 PM, binv271828 (< 20) wrote:


Thanks man. Yeah, for AZ, it really is a no-brainer. I used to live in Chandler, and it is stupid how backwards AZ about clean tech. In fact most of the HOAs (up until very recently) wouldn't even allow you to install solar panels on your roof ... in AZ!! I think things are finally starting to change there, at least I am hopeful :). And yeah, SRP (not the stock symbol but the company name) was our electricty provider.

As far as the geothermal: Yep, there is a pump to move the fluid through the geothermal coils. So for the systems as the are designed today: A pump draws water out of the reservoir, pushes it through the condenser heat exchanger and then out to the tower. The system is open and all the water is "wasted" through evaporation.

With the closed loop geothermal idea: the pump draws the water out of the coils in the earth, pushes it through the condenser, and then back down into the earth coils to cool down again. This way all the water is conserved, and doesn't have to be drawn from a reservoir.

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#4) On May 28, 2008 at 2:09 PM, madcowmonkey (< 20) wrote:


I lived off of Alma School and Warner for a little while. Now there is a Wal Mart (10+ years)  where the farm fields use to be. That city has seen some boom.



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#5) On May 28, 2008 at 2:16 PM, binv271828 (< 20) wrote:

Nice. I used to live off Gilbert and Riggs. Fairly recently. There is tons of new construction there, all new subdivisions (less than 3 ys.old). Yeah it has changed a lot!

Small world :)

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#6) On May 28, 2008 at 2:25 PM, madcowmonkey (< 20) wrote:

No doubt. I moved out to Fountain Hills after the Wal Mart came in. Hey, I found a video about a Japanese water car too. There was also one from Australia. I think I might have to make the purchase. $50, I can handle that.

Gilbert and Riggs. Riggs always seemed so far out, now it is nothing. I would still hate the commute though.

What would the coils be made of? Copper? 

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#7) On May 28, 2008 at 2:56 PM, binv271828 (< 20) wrote:

They could be made of copper, however I would be worried about them corroding in the ground. They could be coated with teflon or some plastic to protect them, but then you have to worry about it getting scratched when you installed it. Most of the geothermal systems for home use just use PVC or something similar. However for this concept, I suspect the rejected water from the condenser may be too hot for continuous operation with PVC. There are some high temperature PVC formulations, or other plastics could be used (PEEK, PET, Nylon) or made of Aluminum.

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#8) On May 29, 2008 at 8:09 AM, SpaceMonkey01 (73.93) wrote:

Binv-- great post. I was planning on blogging on the topic as I think it is an interesting play given that it is a way to play solar without the cost concerns of polysilc or teryllium. I did not know of the publicly traded names in the field, will take a look at the list!

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#9) On May 29, 2008 at 8:12 AM, SpaceMonkey01 (73.93) wrote:

doh, my bad. Read too quickly re: the companies you listed were private. I could not find a public one either.

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#10) On May 29, 2008 at 9:04 AM, binv271828 (< 20) wrote:


Thanks! Yeah, I am very optimistic that this will be the next big alternative energy breakthrough. I wish some of these companies would go public, I would really consider investing in one (the eSolar design is the most promising approach IMO). I also like the idea of a parts play, such as DRC or WGOV.

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