Re: All of this??
"So you can convert it back to something around 12-18 volts to power the computer that is the size of a laptop."
Well, I do exactly this.actually, and the reality is that some form of conversion is required anyway. We're off grid, but in front of me is my laptop, to the right of my desk, a small mini-ITX-based debian server which is on 24 hours a day, to my left an ADSL router and access point. My laptop comes with a AC->whatever-the-laptop-wants block, which in this case is 20V. The server, router and AP want 12v. As it's summer, my solar panels feed a 24v battery bank (I wish I;d gone for 48v, but you live and learn....) and later in the year, my small wind turbine will provide more power than the solar panels. Both the panels and the turbine put out around 50v open circuit, but the size of the battery bank makes this no big deal. The 24v battery bank gets up to 29.5v during equalisation charging, though I never let it go below 24v (50% state-of-charge with my type of batteries) but quite a range.
The battery bank feeds a small sine-wave inverter of 350w. This provides power for lights, the above-mentioned stuff, my wife's laptop, tablet charging, printer, weather station, telly,. radio, mini-hifi and so on. A bigger 1.2kW inverter provides power for the fridge, occasional vacuum cleaner, washing machine and so on - note anything with a motor, which takes a thump to get it started.
Sticking with an all-DC option would mean I need to stabilise the range of voltages coming off the battery bank as it is charged and discharged. Using power directly from the sources means even more stabilisation as the open circuit voltages fluctuate wildly. We now use mostly LED lights, which I think are minuscule voltages internally but for convenience ar simple 230v devices. The tablets want 5v. The weather station wants 6v. The telly wants 230v and so on and so on. "Mains" style voltage and AC turns out ot be a convenient standard.
I do, though, run the server, router and AP off a single 12v block. That choice very nearly halved the power draw at the battery bank for those three devices in comparison with running three transformers, so the idea of reducing the number of transformers absolutely is one that would be helpful in reducing consumption.
Not that I think Google have our situation in mind ;-)
S
Biting the hand that feeds IT
