>A solar panel takes 4 years just to
>give back the energy it took to build it

Some types of photovoltaics take less than a year to reach net energy gain, and will produce 20, perhaps 30 times their embodied energy over their lifetimes. Here are a couple of links:

http://www.apec-vc.or.jp/solar/outline/outlne09.htm
http://www.ecotopia.com/apollo2/pvpayback.htm