| Step |
Instructions |
Example |
Fill in for Your Site |
| 1 |
Look at a wind map for your site and
determine the wind class number. Click
here for the best maps on the DOE web site. Maps for most US states
are available there. If a map for your state is not listed then click
here for another list of lower resolution wind maps. We
recommend a wind class of 3 or better. Sometimes a class 2 site is
also acceptable. |
assume wind class 3 |
wind class ___ |
| 2 |
Lookup the wind speed based on your wind
class number and proposed tower height. Click
here for the table. |
A wind class 3 has an
average wind speed of 11.5 to 12.5 mph at 33 feet tower height. |
average wind speed ___ to
___ mph
___ft tower height |
| 3 |
Now go to the energy output chart for the
wind turbine you are considering and read the kWH (kilowatt-hour) output
per month expected at the average wind speed from in step 2 above.
Here are some links for this type of chart: SkyStream
3.7, WhisperLink200,
AIR-X. |
Use the SkyStream 3.7 as the example.
The SkyStream chart shows almost 400kHW per month. |
generator model _________
_____kWH per month |
| 4 |
Look at one of your recent electricity
bills. Take the total charges and divide by the kWH used for the
month to estimate your cost for electricity. |
$200.00 bill for 1,000 kWH
$200.00 ÷ 1,000 kWH = $0.20 per kWH
or 20 cents per kWH. |
bill month ________
electric bill charge $_______
electric bill usage _____kWH
calculated $0.___ per kWH |
| 5 |
Calculate the value of the electricity
generated by the proposed wind turbine at your site. To do this
simply multiply the output from step 3 by the value of the electricity
from step 4. This is the estimated average monthly savings on
your electric bill. |
400kWH x $0.20 per kWH =
$80.00 |
____kWH/mo x $0.__/kWh
= $__.__ |
| 6 |
Estimate the
installed turbine cost. Click
here for a list of our wind turbine models and their costs.
Don't forget to add the tower cost at
this link. Remember that this is just the equipment
cost. Balance of system costs, foundations, wiring and
installation are additional. For an approximation add 25% for
installation. |
Assume the installed cost of
a SkyStream is $9,000.00.
|
equipment cost $_______
installed cost $_______
|
| 7 |
Determine the federal and state financial
incentives that might apply to the installation and operation of system
at your location. Click here for
a summary of these incentives. |
Assume total tax credits of
$1,000 for installation plus $0.0085 per kWh annual tax credit for
electricity generated.
$9,000 - $1,000 = $8,000 |
installed cost after credits
$_______ |
| 8 |
Finally, calculate a rough estimate of the
payback time for the wind turbine. Do this by dividing the
installed turbine cost by the savings per month. If there is a tax
credit per kWh add that to the savings using the kWh from Step 3. |
400kWh x $0.0085/kWh = $3.40/mo savings
So, $8,000 ÷ ($80.00/mo + $3.40/mo) = 96 months
or 8 years. |
Step 3: ____kWh/mo
Step 7: $__.____/kWh credit
$__.___/mo tax savings
simple payback period:
______ months
______ years |
