In the fourth installment of Science Channel’s Ecopolis, host Dan Kammen reviewed four projects dealing with buildings. The major environmental issue facing structures, both commercial and residential, is the exorbitant amount of energy these units consume. According to Kammen, buildings consume two-thirds of all energy. The main culprits are heating, cooling and lighting. Kammen looked at Duncan Earl’s funneling solar radiation/light into interior rooms using fiber optic cables (seen here in a short YouTube clip), green roofs which use the evaporating and insulating nature of plants to cool buildings, Aerogel insulation, and solar photovoltaic panels built into the sides of structures. Kammen decided that the possibilities of photovoltaic systems producing energy represented the best option for Ecopolis. In Freiburg, Germany numerous structures contain photovoltaic cells to produce electricity, thereby acting as a test site for the feasibility of solar energy. Within Freiburg one home stands out beyond all others. Known as Heliotrope, this structure has a 1000 square foot solar panel system on the roof that rotates with the sun, producing five times more energy than the home consumes.

One major problem facing wide spread adoption of the technology is the prohibitive price of silicon. Jeffery Grossman, a researcher at UC Berkeley, uses nanotechnology to produce cheaper solar cells using a form of carbon known as Fullerene. Grossman is working to increase the efficiency of his nano-solar cells two or three fold, from the current 6%. He believes that these cells could work in clothing, windows and paint to produce electricity. The calculations by the Center for Alternative Technology indicate a 28% drop in carbon dioxide emissions with this technology.

The production of renewable energy using solar photovoltaic cells (pv) must be accompanied by a decrease in overall consumption. Bringing down the cost and increasing the efficiency of these systems is essential in order to gain traction in the commercial market. Federal and state subsidies can play a major role in achieving these goals in the current economic environment. Manufacturing and installation of pv systems represent two areas of job creation, which is key to an economic turn around.

- Eric Wilson