I live off-grid. It's a choice. for about what my alternative energy system cost I could be grid connected. But, being off-grid means I actually think about energy consumption a lot more. It's not a matter of waiting for a monthly bill. I can look at my battery state of charge meter (it says 97% right now) any time I want and make lifestyle decisions. For example, I can decide if it is a good time to use the electric rice cooker or cook the rice on the propane stove.

The one thing I have which is probably not typical of an off-grid house is dedicated Internet. While my system is a bit creative it roughly translates to a computer on 24/7 plus some networking hardware. That networking hardware is a bit abnormal but let's just say it adds up to about 25 watts of power. The biggie was the computer at about 80 watts.

My first attempt at reducing that draw was to replace it with a laptop, an IBM ThinkPad T23 plus and external USB disk. That got the power down to about 40 watts but I was not 100% happy with the solution. The two issues were the slow access to the disk over USB and the general tangle of cables which proved unreliable. The computer was fast enough but the other pieces made it undesirable. It also lacked the ability to write DVDs.

Plan B is now in effect. I took a traditional tower case and performed a bit of surgery. First, I removed the power supply. I then installed a mini-ATX mother board based on the VIA C7 chip set. The particular one I selected is a 1GHz processor which is cooled by a heat sink instead of a fan. I got a power supply that plugs directly into the ATX connector on the mother board and runs on 12VDC. The other peripherals in the box consist of a 1TB SATA disk and an ATA DVD reader/writer.

On the outside I downgraded form my 19 inch monitor to an old 15 inch unit I have had for years. Bottom line is under 50 watts with everything running and about 40 watts with the monitor off.

Right now the computer and the monitor are running off AC adapters but that will change. I have a new power supply on order for the computer which is capable of running on from 6 to 32 volts. That will get connected directly to my 24V battery system. For the monitor, I am going to try to be creative and modify one of the 24 to 12 volt DC-DC converters so it actually does put out 12V instead of 13.8.

Is the computer fast enough? Sure. If I was doing graphics design or whatever it might not be. But, to run a web browser, media player, NFS to access files from our laptops and such, it is more than fast enough. Makes me question the addiction so many people for a 4-core, 3GHz whatever computer in order to read their email.