Pundits everywhere are screaming we need to spend more money on alternative energy solutions, with little regard to what’s viable.
“Most of the proposed solutions to global warming that get serious attention employ technologies that continue to warm the planet at an alarming rate. Politicians also talk about the Hydrogen economy as if it’s a solution! It takes enormous energy to create hydrogen fuel.”
Wind, solar, geothermal, hydro, nuclear, and tidal are the only potentially saving solutions – but they’re too expensive, too difficult, or too restrictive. Or are they? Depends on how they’re done. My biggest bets are on wind and solar thermal (not the more popular solar-PV). Solar thermal, done right, seems to be the most immediately scalable, the cheapest, and the least restrictive.
The Parabolic Trough – the future of electricity.
I used to work in the solar-PV (PV = photovoltaic – the kind that go on your roof) industry – and let me tell you … what a boondoggle. All the research money goes to PV solar cells (which I used to make), instead of going to solar-thermal. The problem is – PV costs so much to make and takes so much time and space to purify the needed silicon, and the energy required to do so comes at such a high price as to make a mass adoption of the technology absolutely impossible for the next 100 years. That isn’t to say it will always be that way … in fact there’s good reason to believe that PV will be the solution in 10-20 years because costs are going down fast. But we need solutions NOW, not in 10 to 20 years.
Electricity generated from Solar-Thermal power fits that profile, it’s cheap easy and can supply the worlds needs at a ridiculously faster and more economical rate than PV with no technological bottlenecks. It’s simple too:
1) Cheap way: A parabolic trough concentrates sunlight onto a black pipe with circulating oil. More expensive: Parabolic Dish to focus on a single point for sterling engine use or to generate H2 for the hydrogen economy. There are other focusing mechanisms too like fresnel (pronounced: freh-nail’ ) lenses, fresnel mirrors, but regardless of what mechanism used, it’s very cheap.
2) Thermal fluid expansion converts the thermal energy into physical energy to spin an electric generator. You can incidentally also skip the electric portion and directly spin a rotor to pump water, grind wheat, etc, instead of spinning an electric generator.
The largest solar-PV plant in the world generates only 12MW but by comparison the largest solar-thermal plant in the world generates 354MW (SEGS in Mojave Desert – uses cheap parabolic trough design) and it was built 20 years ago! That 20 times more!
And how many people even know about solar-thermal electricity? Squat (relatively speaking of course). There is at least 10 to 100 times more money spent on relatively worthless PV solar than what is spent on Thermal solar which is 10 to 100 times more promising for power plants.The current cost of electricity with solar-thermal is comparable to grid – about $0.10/KWh, but it is expected within the next 15-20 years that cost will drop to 1/2 if not 1/3 of regularly produced electricity ($0.035 /KWh)! How many plants are being built with this technology? Practically zippo (relatively speaking). See http://www.parc.xerox.com/research/publications/files/5706.pdf
So what do the cost numbers tell us? Scalability. Technologies can only be scaled up if they are very profitable. Solar Thermal is far more profitable than any other alternative energy candidate and will be for dozens of years . It doesn’t require exotic or highly refined or technologically advanced materials, and maintenance per MW is comparable to any coal powered plant. It seems a slam dunk, but instead solar-PV gets all the money despite that it’s only advantage is portability and distributed integration (solar thermal is largely a power-plant technology only).
“Solar Thermal Electricity is 10X more viable to fix our environment than Solar PV, but it gets less than 1/10th the grant and development money that solar PV gets. It’s an upside down pyramid.”
Now don’t get me wrong about solar PV. It isn’t a completely worthless technology, and eventually it will probably replace Solar-Thermal in terms of cost, maintenance, and expandability but none of the best experts see that happening any time soon and we can’t wait that long, but PV development is critical, which is why I still strongly support PV subsidies (not to mention that it’s needed to compensate for fossil fuel subsidies).
Europe is already sold on parabolic trough technology (see the CSP plants above, concentrated solar power = trough technology), expecting it to play largest role in their future. The US on the other-hand is far more ideal for the technology (see world map above) and despite amazing success from the 20 yr old Mohave Desert plant solar trough implementation has approached a relative standstill since then. Solar troughs plants however have the potential to supply our continents electricity all from Nevada, and ultimately cost less than what we’re paying right now per kWh.