Breakthroughs in Green Energy Tech 2009 – Part 2, Solar (again)
Filed Under: Green Technology on December 21, 2009
In the first installment of this series, I talked about breakthroughs in small-scale solar. The kind of solar panels and 
photovoltaics you install at your home, office, or small building. Today, I want to talk about large-scale or utility-scale solar power generation.
These breakthroughs are large, physically. Most utility-scale solar photovoltaics take one of three basic schema:
- Straight solar photovoltaics – huge fields of solar panels collecting sunlight and generating electricity.
- Solar collection focused on a central point which super-heats a liquid to create steam for turning a turbine and generating power.
- Solar conversion for converting solar energy into another energy type, usually hydrogen or another energy-dense element.
The second type is the most common for megawatt scale power generation, though most of the earliest solar power plants were using the first method. The third method is the most experimental with research going into all kinds of bio-generation and other methods for producing hydrogen, methane, and other gases or elements for energy storage and conversion to electricity.
As I pointed out in the first installment, the biggest down-side to solar power is that it’s only available when there’s sunlight. If anything interferes with that (night time, exploding volcanoes, Al Gore’s head) light hitting those solar panels, then the power won’t be generated. In addition, the rate of power generated will depend in large part on the geo-location of the panels, the time of year, and so forth. Solar power is, to put it bluntly, fickle.
So this explains why the third avenue of solar power generation is such a hot topic now. In order to really replace petroleum sources (including coal), solar has to be reliable and available 24/7/365.
Spain’s huge Solar Tower, for instance, generates 20 megawatts of power.. but only for about six hours a day. The rest of the time, it’s under-capacity or not producing at all. The tower, for the record, is one of the second type of generators, producing steam to turn a turbine inside the tower.
Don’t worry, though, some of the brightest minds in engineering and electronics are working on that problem. MIT, for instance, is looking into terawatt-scale photovoltaics. Why mess around with the small stuff? Right?
Solar has come a long way and is continuing to advance. While it’s not likely to be the only big hitter of our power needs as we turn away from methods that burn and pollute, it’s going to be the right cross or the haymaker in the overall repertoire we use to box with power generation in the near future.
In our next installment of this series, we’ll look at two of my favorite subjects: wind and hydrogen. Stay tuned!
