Create the Future: Entries to NASA's Design Contest
by Collin Dunn, Corvallis, OR, USA on 10.30.07
Electricity-producing roads, a zero-energy home and a smart rainwater collector (the last two are pictured above) are just a few of the cool sustainable designs entered in NASA's Create the Future Design Contest. The contest, which tasks entrants to "Demonstrate your design and engineering skills. Share your best ideas for new products. Compete and win great prizes. Become famous.", rewards the best ideas for new products, and celebrates breakthrough thinking about problems of all kinds, large and small.
The entrant period ended a few weeks back, but there's lots of good stuff to see and do before they select a winner in January 2008, including the competition for the Top Ten Most Visited Entries, which continues through December 31, 2007. There's an entire category for sustainable technology, and some pretty interesting, green entries in the "transportation" category as well. If they can put a man on the moon, they can find the next big sustainable breakthrough; see all the entries here. ::NASA's Create the Future Design Contest via ::Cool Hunting
The rainwater collector is a good idea, but the other two ideas are critically flawed.
Have you ever tried to ride your bicycle through sand? It's pretty hard to move forward because the sand lets your tire sink and you're constantly forced to go uphill. The same concept applies to piezoelectric cloth embedded in roadways. This concept sounds good on paper until you take the law of Conservation of Energy into account. The cloth has to bend (piezo = movement or stress) to produce electricity. This electricity is generated by stealing energy from a car's forward momentum. Perhaps this technology would provide some benefits in the last fifty feet or so leading up to a stop sign, although hybrids with regenerative braking would be more efficient.
As for the Energy Free house... Wouldn't you agree that every time energy is converted from one state to another (electrical to kinetic, or chemical to thermal for instance) that a certain percentage of that energy is lost? This house uses solar-generated electricity to pump water (electric to kinetic) during the day into a tank in the attic, and at night the water is transferred through gravity to a basement tank where it runs a turbine and "generates a couple kilowatts of power" (kinetic to electric).
How does this water system offer "daytime heating and cooling possibilities" unless the tanks are actively heated or cooled?
Here's my recommendation - Use your grid-tied PV panels to run an energy efficient heat pump. This mature technology has little to no service costs, and it's a much simpler and more efficient system than elaborate water tanks and turbines with moving parts.
I agree with the first commenter. However, for the energy-producing roads, there may be locations where the material can be used strategically (like approaches to turns or stops).
The energy-free house is a bit unrealistic for a couple of reasons. First, 20 m^3 of water is something like 44,000 pounds (20k kg). A house weighs something like 80-160,000 pounds (without the foundation). That's a lot of water weight - the structure would be drastically affected. Secondly, the amount of energy in that much water 30 feet (~3 stories) above the lower tank is only capable of providing 0.5 kWh of energy, without any turbine inefficiency taken into account. That isn't much energy - the same as a 100W light bulb on for 5 hours. It's a very expensive energy storage solution for really an insignificant amount of energy. Batteries may be a better solution, or as the other commenter suggested a good heat pump.
The prospects for using the mass of the water for passive/active heating/cooling are there, but may interfere with the action as a method of storing gravitational potential energy...
There are systems that do this on a larger scale. I know of at least one in Colorado that pumps water up to a reservoir during the night and then runs it through turbines to offset peak load during the day. Same idea. Works well, but on a larger scale.
Nonetheless, I'm glad there are a lot of people out there thinking things and pushing the limits. It may spawn some good ideas that will help.
Here's my recommendation - Use your grid-tied PV panels to run an energy efficient heat pump.
or charge some batteries if you want to store energy.