To make the hydrogen useful, doesn't it need to be condensed/pressurized? You could probably use a windmill to turn a compressor pump, to avoid using the grid power, and cheaper than solar. What sort of yield do you expect? And what are your plans for the hydrogen you produce? This sounds really cool, something living producing fuel, just a little skeptical about whether it could produce a useful quantity. I can see there could be a lot of stuff going on to keep the algae healthy, happy, and productive. The water would need to be changed and monitored often, nutrients add, waste products removed. Bacteria might be a tough battle to fight. Climate control, you'll want to keep the temperature in sort of a tight range. Algae is way more active at a specific temperature range, tends to die out when it gets a little to hot or cold, and with GW about to kick in any time now, it might be a concern. But this is the ultimate green energy source, so I hope it works out.