Some Europeans are worried about the rising cost of electricity today, and even if all the problems with it were to disappear overnight, there is no doubt that we are witnessing a price increase. As a hacker, you're in a good position to evaluate and perhaps do something about the energy-saving devices in your home. Well, [Peter] installed solar panels on the roof, but couldn't find a good way to connect them to the public grid, or at least to a straight 220V grid. Of course, a better solution would be to build a low-voltage independent DC network and install several devices in parallel.
He settled on 48V, which is high enough voltage to be efficient, easy to find devices like DC-DC, safe from legal problems, and generally compatible with solar installations. Since then, he's kept things like laptops, chargers and lights on his devices instead of plugging them into DC rails, and his home infrastructure, including a rack full of Raspberry Pi boards, is happily running 24/7. 48 V trains on weekdays. A standard AC backup power supply is available for extreme weather, and two heavy-duty LiFePO4 batteries power all connected equipment at 48V for up to two and a half days in the event of a mains failure.
The setup consumed 115 kWh of energy in the first two months, a huge contribution to the Hacker Energy Freedom Project, and the blog post has enough details for all your motivational needs. This project is a reminder that low-voltage DC grid projects are a good option at the local level; We've seen some very impressive concept projects on Hackercamps, but if you're up for it, you can build a small DC UPS. You just want to get to your feet. Maybe soon we will have a socket for such networks.
