Common Misconceptions and Reasons to Avoid Gut Instincts
It’s always windy here. What we feel at ground level may not reflect the wind energy a wind turbine can capture at 80, 100, 120, or 140 feet.
I’ll be able to eliminate my electric utility bill. Offsetting all of your electrical usage is possible in the aggregate over the course of a year, but remember that monthly service charges may apply and that there is unpredictiability in your wind resource. For average homes (~8,500 kWh/year) efficiency gains are the first step. The second step is considering your renewable budget and what incetives will offset the inital cost of the system.
I’ll be able to sell my excess power to the utility company. Avoid phrases such as “selling power” to your utility. What more accurately occurs is that your wind energy would be stored on the electrical grid and used when your electrical demand exceeds your wind turbines production.
Efficiency doesn’t have a big impact. To the contrary, efficiencies not only reduce the required size of your renewable energy budget they more importantly reduce the legacy costs of your home or business. The less glamorous efficiencies of: CFL’s, LED’s, Energy Star appliances and fuel shifting are all underappreciated positive steps towards energy independence. It’s argued that $1 in electrical efficiencies equals $3-5 in renewable energy system costs.
A rooftop turbine or a vertical axis turbine is a valid consideration. Roof top turbines and vertical axis turbines are placed in very turbulent wind conditions (see below) and at heights that do not support average wind speeds to make these technologies viable. To demonstrate this Derate your wind map wind speed to 10, 20, or 30 feet and then apply that value to a turbine manufacturers kilowatt hour power curves and annual energy production curves. You will see that the kilowatt hour producution most likely does not justify the investment. Also consider that payback numbers for rooftop turbines and vertical axis turbines can be in the hundreds of years.
Coutesy of NREL