It all started with my dad deciding that he was paying too much to our Internet Service Provider (ISP) to host our two web sites. I offered to replace the services the ISP provided for half the price. My dad agreed and I built my first server.

About that time we were getting into solar energy. Our solar panel was generating more energy than we used at the time so we had a surplus that was just getting wasted. This was mostly because we didn't really have many devices using the power since we weren’t using a large inverter that could power any household appliance and maybe spin our meter backwards.

A month or two after the server was built, PG&E told us that they were going to replace our power lines and we would be without power for eight hours. We really didn't want to turn off the server for that long, so we bought a small inverter. We hooked it up to the battery pack and solar panel and presto; we were running our server off the sun! We continued running the server this way for a couple months. The major downside of powering the server this way was that we didn't have enough power to run the server constantly. That meant that my dad had to manually switch from normal power to solar power every morning and back again every night. We decided a laptop would be much better because it took in 12 to 15 Volts naturally and it’s power consumption was much lower. About a month ago, we switched over to a laptop server, and it’s been running smoothly ever since.

Our whole system is powered by a Solarex MSX 120 solar panel, which is about 1 square meter. A solar panel works by photons (light) hitting the panel and knocking electrons (electricity) free. We originally used a smaller solar panel but it didn’t put out enough power for the laptop so we upgraded to the panel we have now. The panel feeds our main power bus, which changes quite a bit because we keep upgrading our system.

Our two Deka Power master GC15s (golf cart batteries which are 6 Volts each) and a generic 1.5-Volt cell, hooked up in series, are connected to the power bus. The voltage comes out to about 15 Volts. The reason we use the extra 1.5-Volt cell is that if we didn’t, when the voltage got low enough from things like the sun going down, the laptop would decide it didn’t have enough power and would switch to internal battery power.

We monitor our battery pack with a Xantrex Link 10 battery monitor. The Link 10 was originally called the E-Meter, but there is a Scientology device with the name E-Meter so Xantrex changed the name. The Link 10 tells us how much power is left in our batteries, the bus voltage, and the amount of power flowing in or out of the pack. We usually don’t go below about 70% charged except on dark and cloudy days.

I think our system is somewhat unique because we don’t use a large inverter and a grid intertie like everybody else so we have to find creative ways to use our power. The main load on our system other than the laptop is our semi-router which also stays on 24 X 7. We power several other things around the house including my electronic keyboard, our doorbell, and several LED-based night-light systems.

The laptop server itself is a Toshiba Tecra 730 CDT. We bought it used from a parent at Peninsula School. It has functioned almost perfectly since we got it and does just fine with the fluctuating bus voltage. We run Linux on it for two reasons. One, I’m already familiar with creating and running Linux servers. Two, it’s free. Our Internet access is standard PacBell DSL that operates between 384 Kbps and 1.5 Mbps. We put a gateway router between our laptop and the DSL so that all our computers can use the same DSL connection.

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