Madison Powers
February 17th, 2012
9:10 AM, Learning Skills Classroom 3
Today APES class had the opportunity to meet with the father of Proctor senior Jack Legwin, Hardy Legwin. Legwin works in the solar energy industry, starting a company with 2 other guys 6 years ago, with the mission to "make solar mainstream." What is the definition of mainstream to these men? One of his friends believed it was to get solar energy on the Monopoly board, which, on the new editions of Monopoly, it is already there. In fact, solar energy isn't even a new concept, Legwin said, but one that had roots back in 1884 ideas.
Legwin discussed how solar energy from the sun is being wasted in the United States. He said that the Southwest has great solar insulation and potential, even the Northeast has potential, but we do not harness any of that energy. Germany has very little solar insulation, yet has over half the world's solar energy collection. Every day we lose so much energy, he says. Losing this energy is not good, for we could use it for so many things, such as electricity and heating water.
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| A Solar Cell |
There are two types of solar panels that Legwin's company installs: PV (photovoltaic) panels and solar hot water panels. Th solar hot water panel has a collector plate, where the water is heated, collected by a pump, then stored in a tank, where this heat is transferred into other water. This type of panel has a glass cover, with copper coated in a special insulator, and a water and glycol mixture is what gets heated up and is pumped through the system. There is also a heat exchanger attached to the tank, through which hot and cold water run through, transferring the heat from hot to cold. Copper is used because it is a very good conductor of heat, which is important when it comes to absorbing the sun's rays. "One of these collectors creates about 50 gallons of hot water per day," Hardy said, and the average person uses 20 gallons.
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| Solar Thermal Panels |
So what is the future for these thermal panels? The panels are said to have a 30 year life span, and potentially more after that, with the only maintenance being any damage or leaks. Legwin says, "Cost per panel has not changed much, there's not much driving the price down." While the price may not change, modifications can be made to increase the efficiency and output of the panels. For example, a vacuum tube is in the works which would prevent captured heat from leaving the tube. The current issue with these is that they last half as long, and cost twice as much as thermal panels. Another idea is to make smaller panels that can be mounted easily. These panels would be curved to concentrate the sun on one tube that contains oil, a liquid that can be heated to high temperatures. These small, curved panels could concentrate 7 suns worth of rays on the single tube! Quite impressive, if you ask me, and a great source of energy.
The second type of solar panel that Legwin's company works with is photovoltaic (PV) panels. These are the panels that are used to generate electricity. These silicon panels have two types of silicon, creating a layer. The sun excites these electrons creating a current between the layer, which is then converted into electricity. The power is DC power, which then goes into an inverter and is turned into AC power, where it can be sent through a transformer and onto the grid. Currently the panels on the market are only 12-22% efficient, though lab tests have been done on panels that are 50% efficient. "The big breakthrough in PV is going to be getting the panels more efficient," Legwin says. Another issue with PV panels is they only work well if the sun is shining. There is more production as the sun goes up, but if it's cloudy out, production goes down. "It works great when the sun is shining," Legwin told us, but these panels aren't as good as the solar hot water panels, he believes. The two advancements that will make PV panels better are efficiency and battery/storage capabilities, which currently are very little.
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| PV Panels |
Both PV and thermal panels are great sources of energy, and are definitely on the rise. 10% of US electricity comes from solar, and this number is going to grow as coal and nuclear become more expensive to maintain. Both of these create harmful emissions and neither is renewable like solar is. Since 2008, the price of PV electricity has dropped by over $4, and PV is only 3x less effective than thermal, and the gap will continue to decrease as technology increases. Legwin says, "Thermal gives a bigger payback that PV." While thermal may be better, PV can be used to sell electricity back to the utilities, and also offset things like an air conditioner. If you are using less energy than you collect, you can sell it back to utility companies or store it with batteries for another time.
Legwin and his company have had many projects where they have installed both types of panels. In Camp Lejeune, 2,300 hot water collectors were installed in homes. At the Proximity Hotel in Greensboro, NC, 100 collectors were installed on the roof in 2007. His current project is a thermal farm, where 2,100 collectors will be used to create hot water for a poultry plant. Guilford College had Legwin's company help them with their energy by installing thermal panels on many buildings. This save the company 20% on their energy bill. His company owns and maintains the equipment, and sells the energy generated at a set price for a 10 year period. This saves the school money in the long run and is a very good deal for the school. While Legwin's company does more with thermal, they have also done PV projects as well. They helped a capped landfill make use of its space by placing a solar farm with PV panels on it. The panels were mounted on concrete blocks so the landfill was not disturbed. This was a 5 megawatt project, which was pretty high at the time. Now, 5 megawatts of power is the standard for PV projects, and this number will continue to grow.
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| Solar Farm |
Solar energy as a whole will also continue to grow, along with wind energy in the United States, as states are requiring that certain percentages of their energy be renewable. The states will be the driving force behind the use of renewable energy. The other driving force will be the companies, such as Hardy Legwin's, that sell and manage these products. I believe that this is key in our current energy crisis and climate change crisis. New energy sources must be used before our current ones become obsolete. There isn't a better way to capture energy than solar, for it is more than abundant; you can place a solar panel just about anywhere and gather energy. Solar is one of the solutions to our problems, and we must embrace it and use it, make it "mainstream" as Hardy says.
The transition to renewable resources in the coming years will be important. My generation and the one before it must take action, for at our current rates of energy consumption and climate change, the world is going to crash and burn. Our generations must change the way we use energy by switching to a more efficient and safe source if we wish to preserve the Earth for future generations. We currently release ridiculous amounts of carbon dioxide into the atmosphere with our use of oil and coal, but with the use of solar and other sources like wind and tides, we can reduce this amount of CO2, slow global warming, and preserve our resources. As Hardy Legwin concluded his presentation, "Nothing is as powerful as an idea whose time has come-Victor Hugo." This idea is solar energy, and its time is now.
Images:
http://www.cambridgema.gov/_resources/img/MediaCache/9909fea3ec054fe2ba99717b0db22540/129198707775724115.0.0.0.0.0.0.jpg
http://greennav.files.wordpress.com/2008/06/plates.gif
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhO4_4L9WuzlwjtpwEqiC7RxJ7EspO6G1Za9xpRV9nsPnEY2Xi-TNks956uKURXBNkjLKF2n9GfPpCwbWa0CQ3zP6LliVExugZWQiFqZWWDngwEmGVCq4u_MPeZhr8Xm0hXRR6l7YuCm7EA/s1600/solar+power+plant.JPG
http://upload.wikimedia.org/wikipedia/commons/thumb/9/90/Solar_cell.png/220px-Solar_cell.png
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