Friday, July 20, 2007
When Christie Milesi moved from Italy to the United States, she was immediately smitten with our lawns. She loved the way the green grass of our urban lawns stayed defiantly lush, long past the browning hillsides of native Montana prairie. While finishing her PhD, she enrolled in a business class, where students were expected to come up with viable business ideas. Her idea was to create a service that monitored rain and let people know when and how much to water their lawns. That was when she made an important discovery- the total amount of lawn in the United States was unknown.
So she submitted a research proposal to NASA Earth System Science Fellowship Program to produce a national estimate of lawn area and the impact of those lawns on ecological factors like the carbon and water cycles.
What she found was astounding. When most people think of fertilizer and irrigation, do they think of agriculture or our landscapes? It turns out that there is more lawn than corn grown in the US, a crop that creates no food, yet uses untold amounts of water, fertilizer and other resources.
Check out the story at the NASA Earth Observatory website. Then zoom around a little- this is a great source for cool info.
Thursday, July 19, 2007
I'm working on a LEED certified Science Center at a community college, and one of this buildings' features is geothermal energy to supply the huge amount of energy required to power the laboratory ventilation systems. I didn't know much about geothermal when I started the project, and today I found an article that may help to explain some of the mysteries of this renewable energy source.
There are two main types of systems for geothermal energy.
The first is geothermal exchange, a low cost solution that can reduce the heating and cooling costs of a building by 70%. This is basically a large coil that winds its way below the surface of the soil and then makes its way into the foundation of a house, and uses the constant thermal mass of the earth to either heat a home in winter or cool it in the summer.
The second is enhanced geothermal systems (EGS), and involves drilling to utilize the heat of the earth's core, several kilometers down with temperatures of over 465 degrees fahrenheit. This extreme temperature drives steam to turbines to produce energy.
According to the article, "In 2003, this type of geothermal power supplied just 0.416 percent of the world's energy, reports the International Energy Agency (IEA), indicating tremendous potential for expansion... Last year, an MIT study evaluated the potential for EGS in the United States, concluding it could supply a substantial portion of the country's future electricity, probably at competitive prices and with minimal environmental impact. With an investment of $1 billion over the next fifteen years, geothermal could provide at least 10 percent of U.S. electricity by 2050, says the expert panel behind the report."
The initial costs of geothermal systems can be expensive, but these systems are not subject to fluctuating fuel costs. The potential for geothermal to replace many of our current power supply systems is huge.
For years a friend of mine has been telling me about the little town of Klamath Falls and its use of geothermal to heat city buildings and even keep the streets and sidewalks free of snow in the winter. I finally googled the place, and found a cool site with schematics on the systems.
Check out Klamath Falls, yo.
For the original geothermal article at ENN