I’ve posted about the idea of a solar-powered Wi-Fi system before, but a couple of guys from Sun Microsystems have decided to focus on a commercial product ideal for the developing world. Their not-for-profit company, Green Wi-Fi, “has developed a low-cost, solar-powered, standardized WiFi access solution that runs out-of-the-box with no systems integration or power requirements. All that is required is a single source of broadband access,” according to the company. It says its WiFi nodes can be deployed on rooftops to form a “self-healing network” virtual 802.11b/g grid.

This isn’t a new concept. An engineer at Nortel Networks, a developer of so-called mesh network products, told me two years ago that the company was using solar to power its Wi-Fi nodes for network buildouts in Africa and other places. These things don’t require much power, so a small off-the-shell solar cell does the trick.

Red Herring has a story, based on data from London research firm New Energy Finance, that ponders whether a downturn in cleantech stock prices in the second quarter of this year represents a correction of an “overheating” sector or simply reflects the desire by some investors to enjoy a bit of profit-taking, given the stellar rise we have seen in cleantech stock. New Energy CEO Michael Liebreich says in the article that the nearly 25 per cent decline in the clean-energy stocks it tracks is partly the result of a general market decline. He pointed to the fact that the Nasdaq Stock Market fell 7 per cent during the same period, and that investors couldn’t resist a bit of profit-taking. “Finally, there were concerns that some companies, especially in the solar sector, were overvalued, as well as the crash in carbon prices in Europe,” the magazine said.