Business Green: Panasonic has today announced that it has invested $30m in Tesla, the manufacturer of the Roadster electric sports car, as part of its drive to bolster its position in the fast-expanding market for battery technologies. The Japanese coporation said the investment would build on the deal the two companies signed in January, which saw Panasonic agree to supply Tesla with lithium-ion battery cells. Under the terms of the latest deal, Panasonic has bought common stock in Tesla giving the company…