The unfinished area of our basement is very dark, so I've tried numerous things to provide walk lighting (so you can find the switch for the overhead lights) without burning a lot of electricity. The best thing so far is a 0.6 watt LED bulb that provides far more light than the 7 watt incandescent that it replaced.

The garage end of the house is also a dark area, so I've installed a 1.8 watt LED bulb there for outside security lighting (primarily for my wife's peace of mind, as we live in a very safe area). The LED bulb is functionally equivalent to the 40 watt incandescent it replaced (no dark corners for someone to hide in). And even with this low power, there's a dusk/dawn sensor on the light.

There are a lot of opportunities for low power solar use. Even the 1.5 watt solar panel that Harbor Freight frequently puts on sale for $10 could keep a 12 volt SLA battery charged to handle LED nightlights and some outside lighting.

We use captured rainwater for garden irrigation and I'm currently designing a small solar powered pump system to get the water to the uphill sections of the yard. A pump that draws 1.8 amps for 2 hours a week (3.6AH), combined with a 12AH battery and a solar panel that produces 120 milliamps for 6 to 8 hours a day. 120ma * 6 hours * 6 days = 4.3AH, which will fully recharge the battery - this allows for 1 day each week with zero sun (we don't usually have more than this during the growing season). The additional battery capacity (12AH) allows for more cloudy days and extends the battery's life (lower percentage discharge in normal use). In addition, the solar panel provides some charge during the non-peak hours. The total cost for the solar panel, battery, and pump is about $100US.

None of these things has a major impact on the use of resources, but lots of little things add up.

If you want specifics on the parts mentioned, send email to rain at wizardanswers dot com.

John