Solar Systems

March 2nd, 2016

I have been determined to find a way to harvest enough solar energy to run our home off the grid since we moved out to this home in 2006. We have a big beautiful home but our intention when we moved was to simplify. I was thinking we would move to the country and live in a cottage by the lake. I was imagining a downsize but we fell in love with a beautiful home, bigger than our previous home but cheaper due to its location. I figured we could still live a simpler life by having chickens, growing veggies in the garden and using solar and geothermal energy to run our home.

We purchased a geothermal system, we do grow herbs and veggies during the summer and, we hope to have chickens this Spring. However, the solar system still eludes me. We met with a gentleman a few years ago about having solar panels in the field in front of the barn. They took enormous space, it was a long term investment and we were responsible for monitoring the amount of energy generated by our panels through a computer system. We were still paying off our geothermal system so we decided to hold off.

A month ago, my husband was talking about replacing our roof. I visited a local business to discuss the possibility of installing a solar system on our roof. We have a lot of space on our roof and we are a south-facing property. It seemed like a good fit. The estimate came back and, apparently, the best location would be the barn rough. Again, the up-front investment was huge and the return on investment, negligible. I felt very discouraged.

Earlier this week, I saw a Facebook post about Tesla's Powerwall, a battery that hangs like a painting on the wall of your home. I did some research. Could this be a solution? Turns out, you still need solar panels on your roof or on your property to harvest the solar energy, then the battery allows you to use this stored energy during peak hours in the evening. The batteries are meant to last about ten years and their storage capacity is impressive. However, their output is insufficient. You can get about 2KW per Powerball.

I tuned into some Ted Talks about solar energy. The amount of competition among universities to invent the next generation of solar systems reminded me of the race to the moon.

Dave Follett in Solar Energy At The Gigawatt Scale explains that the main issue with solar energy is that the sun is diffuse. We need large solar panels to harvest enough energy which makes this venture very expensive. Dave's solution is to concentrate the sun using mirrors. He demonstrated his model at the University of Arizona which looks like a ferris wheel composed of a steel frame and eight mirrors which magnifies the sun onto photovoltaic cells. He states that you can get the same power from 3 sq inches as you normally get from a 4 by 4 foot area because the solar energy is magnified 1000 times.

Next, I watched a speech by a professor at MIT, Donald Sadoway, The Missing Link to Renewable Energy. He believes the battery is the key to solving the issue of capitalizing on solar energy. He and his team of students invented a liquid metal battery. He was looking for a battery composed of elements that are abundant. His battery uses a low density liquid metal on top (magnesium), a high density liquid metal at the bottom (anemone) and molten salts in the centre. He presented cells stacked into modules then piled into a 40 ft container which creates 2MW hours. Donald says this could support 200 households. Very interesting.

Bill Gross believes the key to achieving more from your solar system is to harvest more solar energy. In, A Solar Energy System That Tracks The Sun, he explains the process he used to come up with his design, a 12 petal unit that tracks the sun for 6.5 hours per day. His system has a modern Stirling engine in the centre. There are sensors on the petals that search for the sun, the petals move to be in the best position to receive solar energy, once they are hot enough, the engine starts, converting the sun energy to electricity.

Finally, I watched Rusty Towell who was inspired by his trip to India where he witnessed the need to simplify how we generate electricity in order to make it accessible. His answer was Thorium. He claims Thorium is present in earth all over the world and we only need a small amount. He uses a Liquid Fluoride Thorium Reactor (LFTR) to produce electricity. The key is to changing the nuclear structure of an atom instead of changing the electron energy levels. By focusing on the nucleus, you produce one million times more energy.

All of these systems are promising. As each inventor is inspired by another, I am hoping that one final version can be invented that is affordable and effective.

Anne Walsh
www.artnsoul.org