Exciting news in the world of green energy and living! Tesla just announced their new solar roofing tiles. They are as attractive as slate and lower cost than a traditional roof when combined with projected utility bill savings.
By using standard 2Watt Polycrystalline cells, available on sites like eBay, you'll enable yourself to build a 100 Watt panel for around $125. Some people even opt for chipped, or B-Grade cells, that produce the same amount of power but are defective by the manufacturer's standards (ie chipped corners, etc). With this choice of solar cells a completed 100 Watt panel may cost less than $70.
Marin County Spring Home To-Do List - Complete List