Intro
Our IT habits consume about 2% of all the enrgy we use. Its usage is on a par with the airline industry. It is howeverfairly easy to move to Zero Emmisions computing for the home. I decide to do this using a solar/photovoltaic panel a
nd a car battery. Here's how it was done:
Step 1. Power usage
A normal PC with not much special gear can use only about 60 Watts or less. We will focus on this type of PCs,simple laptops and desktops. If you want to be sure how much your PC uses you can use a Wattmeter [link].
Step 2. Battery
If we want to go off grid with our PC we need to calculate the capacity of the battry we need to use:
The Batteries Ah value should be : (PC Wattage x Hours in use (daily))/Voltage (12 Volt)
For my setup this is roughly 60 x 10 divided by 12 = 58.3 Ah (12 Volt battery). More Ah than necessary is ok,
so a typical 70 Ah car battery will do fine.
To charge the battery from a photovoltaic panel you need a charger (you can get them here [link]).
Step 3. The panel
To charge the battery we will use a 12 Volt solar/photovoltaic panel. To provide a daily charge you can best use
a 60 Watt panel. You can find those on Ebay for 280 bucks. This may seem expensive, but they do last forever.
Step 4. The PC power supply
Most PCs run on 110 to 230 AC electricity, but internally the systems are low voltage DC. You can save a little on any new PC by chucking out the power supply that comes with it. Insted you can use a 12 volt dirven supply, I used the Mini-Box Pico Psu. One restriciton to the PicoPsu is that it only supports two drives or one drive and one DVD player. There is a range of adapters however that you can choose from.
the Mini-Box PicoPsu is small and plugs right into your PC board. You can order it with the backpanel plug (95 cts).
Step 5. Cabeling, Connecting the dots
I tried to keep the cables as short as possible.
If the solar panel is connected to the batery via the charger, and the battery is connected to the PC PicoPsu. This should allow you to start the PC as ususal.
Cost / Benefit analysis
Cost
Battery : 60 USD
Panel(60Watt) : 280 USD
PSU : 50 USD
Backpanel plugs : 10 USD
Charger : 20 USD
Total : 410 USD
Benefit
What Power would I have used?
10 hours x 60 Watt x 250 (days a year) = 150 Kwh per year.
This would have costed me on average: 150 * 6-10 ct= 9-15 USD
This setup would pay itself back in about 27 years if power remained
at its current price.
Conclusion
Most of the materials to go green are still very expensive. You could replace the battery by an ultracapacitor [link], and high quantitiy cost of the PSU can be 25 USD. Battery chargers are notoriously overpriced.
Solar panels will drop in price once GCIS becomes mainstream. For now it will be an expression of
responsibility and care, a small price to pay for guiltless surfing..
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