Designing Ecological Habitats - Gaia Education

168 Designing ecological Habitats
A 10kW single-axis
tracking array, Jeff
installed at Glen
Ivy Community in
Corona, California.
cheap; but PV panels can last 50-100 years and pay for themselves many
times over (it takes three years for a solar PV panel to pay back the electricity
used to make it). Solar panels are virtually maintenance-free, lightweight
and easy to install. One kilowatt (kW) of solar PV panels will produce on
average from 60 - 130 kilowatt-hours (kWh) of power per month depending
on how sunny a climate you have.
Wind
Wind is an excellent source of power; however it is highly dependent on
local conditions and on the micro-climate of your exact area. Your neighbor
may have good wind and you may not.
With present technology, you’ll need a minimum average wind speed of
about 4.5 meters/second (10 mph) for wind to be cost-effective. You can use
slower winds to pump water or grind grain. If you have an average speed of
4.5 m/s you can expect about 40 - 60 kWh/month per rated kW of installed
capacity. A few more meters/second and the output can be as high as 150 kWh/
month per installed kW. The power goes up as the cube of the average wind
speed so professional monitoring of your site is crucial for planning purposes.
Wind can be noisy, so you might want to locate it some distance
from social gatherings and sacred places. And be prepared for regular
maintenance costs: wind systems break down and need bearings replaced
regularly. Finding a good wind generator manufacturer and installer is also
a challenge. The industry is in the current situation of not having enough