There’s a lot to see at the Fraunhofer Center for Sustainable Energy Systems in a rehabbed old building in Boston. Fraunhofer is a big German research and development non-profit organization, with a couple of branches in the USA. They have been working with solar power for years, and last year held the record for making the world’s most efficient solar cell. Now they are looking to reinvent the way solar panels are installed.Christian Hoepfner, the director of the center, explains that much of the cost of installing photovoltaics is in the frame they are mounted on, and in the connections, the wiring of it all together. This needs about 26 hours of a qualified electrician and a lot of work by the roofer, and presently totals about $ 4.90 per watt installed.
Food and shelter are crucial for living, but nobody can survive for very long without water. That’s why, since the beginning of history, civilizations have lived near abundant sources of H20.But it’s not enough just to have plenty of it. The same water that gives life can also make people sick or even kill them, if it contains dangerous substances or disease-causing microbes. And since people use water for activities such as irrigating crops, washing and waste disposal, sources of water close to a human population can easily become contaminated
.As a result, humans have been trying to purify water for thousands of years. As far back as 1500 B.C., Egyptians used the chemical alum to filter suspended sediment out of their drinking water. But it wasn’t until the late 1800s and early 1900s that scientists figured out that microbes caused illnesses and that water could be treated with chlorine or ozone to eliminate them