When I started pondering the feasibility of this project last month, I started looking at the specs of various types of solar panels. Most modern, readily available panels have similar sizes, performance and, usually unnoticed, similar weight and they are reasonably heavy! In a typical roof or rack mount installation, the weight is generally less of a concern, since you want something durable that you don’t have think about. But when building a lightweight vehicle, weight becomes very critical. So I went looking at thin-film PV suppliers. There are definitely options available and the panels are thin, flexible and LIGHT (10 – 20x lighter) but only about 1/4 to 1/2 as efficient as traditional monocrystalline and polycrystalline PV panels. Since I am even more constrained for space than I am weight, I decided to keep looking as even the best thin film solutions wouldn’t get me too far down the road. Not seeing much likelihood in finding lightweight PV panels, I somewhat hopelessly Googled around. With a bit of digging, I discovered SBM Solar in Concord, North Carolina. SBM is one of the few companies manufacturing monocrystalline and polycrystalline panels with a lightweight, impact resistant plastic, versus, the traditional (heavy) glass which covers the bulk of the panels manufactured today. Their panels are 40 – 50% lighter than glass panels! This seemed like the best compromise. 27.5KG (60lbs) worth of panels mounted over my bike and trailer will yield 420W (max) output. My bike uses 600 – 800W on flat terrain at full throttle so these panels can supply roughly 1/2 of my power needs (assuming sunny conditions) and non-optimal alignment with the sun.
Yahoo! SBM Solar has generously offered to sponsor me 3 of their lightweight, 140W panels that I’ll need to charge my batteries while I’m rolling. One step closer to reality!Tweet