Posted by nanomech on 2008/12/25
In preparing for my annual Spring course “Design of Solar Energy Conversion Systems”, I am reminded of just how many diverse technologies can be derived from our nearest large-scale fusion reactor. I will make exceptions to the obvious: horticulture and wind energy are derived from the sun too.
Here are some ideas beyond PV and concentrating PV (CPV):
- Passive/Active Solar Water Heating Systems (in your showers, dishwashers, heating your floors)
- Commercial/Distributed Space Heating Systems (using Solar Walls, Phase Change materials, Pebble-bed hot air storage).
- Solar Cooling (Yes! you can cool with the sun and heat pumps, dessicants, refrigeration cycles).
- Solar Industrial Process Heat and Solar Ponds (Do you own a mine or a refinery? Look into ways that you could dramatically reduce your energy bills!)
- Solar Thermal Power Systems (Also called Concentrating Solar Power–CSP–this is the technology with the best odds at being the next wave of electric power from the sun).
- Don’t forget solar chemistry (not just growing plants) to make hydrogen and other fuels!
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Solar is very close to breaking out. Why not invest in solar tech?
Posted in education, energy, interdisciplinary research, photovoltaics, solar, sustainability | Tagged: concentrating solar power, photovoltaics, science, solar, solar cooling, solar hot water | Leave a Comment »
Posted by nanomech on 2008/07/02
Quick question: would you interpret quantum dots as disruptive technology for light absorbing solar energy, or concentrating solar power (CSP)? One is a fairly recent topic in the photovoltaic world, and the other has been around for over one hundred years.
A quantum dot is a nanoparticle in which the excited states (high energy electrons and holes) are “confined” by the very small dimensions of the particle. This leads to increased energy in the excited states (no where to go but up in energy), and has resulted in many new technologies. One proposed technology would use quantum dots as light absorbers for a photovoltaic effect, where one could collect mulitiple electrons (increased photocurrent) or very high energy electrons (increased photovoltage). The up side is that quantum dots sound sooo cool, why not make them into PV devices? The down side is that the rates of charge carrier extraction (collecting the electrons to do work) are still way too high to get much efficiency out of them. A lot of research needs to occur before you start seeing purely quantum dot PV. The disruption appears to be far away.
On the other side, if you concentrate the sun’s power, you can use it effectively for multiple applications, and often you don’t need radical new technologies. Rather, a combination of straight forward technologies in a new way may lead to something disruptive. You can concentrate the sun’s visible light (48% of the suns power, or 656 W/m2) for photovoltaics, OR you can concentrate the sun’s infrared light (45.6% of the total power, or 623 W/m2) and use the thermal heat to do work! Either way, by concentrating you take a diffuse source and, well, concentrate it. Certainly, you would need to cool a PV collector, but what about a thermal collector powering a turbine to generate electricity? In 1878, a solar power collector was exhibited at the World’s Fair in Paris, France. Between 1907 and 1913, an American engineer (F. Shuman) developed solar powered hydraulic pumps with a concentration ratio of about 4.5:1.1
And the kicker, CSP is getting closer and closer to being the first economically viable solar technology–opening the doors to the following technologies? Is this disruption, by opening the possibilities of solar power beyond the single junction photovoltaic device?
1. D. Y. Goswami, F. Kreith, and J. F. Kreider Principles of Solar Engineering 2nd Ed. (2000) Taylor & Francis, Philadelphia, PA.
Posted in disruptive technology, next generation, solar energy | Tagged: concentrating solar power, economy, photovoltaics, science, solar | 1 Comment »
nanomech