Residential wind turbines popularity is on the rise, small residential wind turbines are usually more cost effective than residential solar power systems, in many cases it pays off to combine the two. However, before you dive head on, you need to find out whether a home wind turbine does make sense for your home. This page intends to give you some background data on home wind turbines and highlight the main points to be evaluated before you take a decision
A quick feasibility study on wind power for your site
Residential wind power is an attractive proposition, however before diving into an elaborate research effort, you can spend a very short time to see whether a small size wind turbine makes sense on your actual site.
Ask yourself the following questions :
- Is my land size at least one acre (4,000 square meter)? If the answer is no, a wind turbine installed on a tall tower is not feasible.
- Can you tolerate a wind turbine tower that will stand 80 feet (24 meters) or more above ground? (A clearance with a radius greater than the tower height is needed for safety reasons and to assure smooth non-turbulent wind on the turbine blades)
- Are there good wind conditions, wind stronger than 8 MPH (3.5 m/sec) for at least 60% of the time? You can get the answer by running an internet search on the term “wind map” and by observing other people in your region who have installed a wind turbine
- Is your site connected to the utility grid (grid tied), or is it off-grid? It is most likely for a 1 acre property to be off-grid, however grid tied properties on 1 acre and more do exist
Next step: Research
Once you see that the land size is large enough, that a tall tower can be fitted and that there is enough wind you need to further research the subject. You can read resources on this site, read a book on the subject such as Paul Gipe’s book Wind Energy Basics and consult other people that you know who have installed a wind power system. Contractors, even though they have a commercial interest are good information sources, talk to more than one contractor to somehow balance the biased information. Research won’t come easy and it might take a couple of days to have a good baseline and to get sufficient background on wind power systems.
Residential Wind Turbine Sizing
How to size a wind power system for my home?
This question is being asked by many homeowners. The real trick is how to size correctly the off grid wind turbine. Obviously, it depends on the electrical power consumption of the household (or ranch). Assuming the wind turbine is the primary power generator, there need to be an auxiliary power generator such as a residential solar power generator (or diesel generator) and a substantial number of deep cycle batteries for the times with no sunshine (dark hours or cloudy days) and for times with no wind. Read my page on sizing an off grid power system
If the house is fed by the utility, sizing the wind power turbine is more straight forward, it can be designed to supply 50% to 80% of the average household consumption, the excess peak consumption will be supplied by the electric utility.
Warning - an open load is a disaster for the wind turbine
Important: wind turbines cannot sustain an open load or low load conditions. A protection mechanism is required or an alternative load must be kicked in (a very good load to kick in is a pump that will pump water up into a water tank or to kick in a water heater)
Some wind turbine basics
Wind turbines electrical power production is dependent on the turbine efficiency, on the wind speed to the power of 3, and on the turbine blade diameter to the power of 2.
There are two energy conversions occurring in a wind turbine. The kinetic energy of air mass (known as wind) is converted to mechanical rotation (The physicist Beltz proved in 1919 that the theoretical conversion efficiency limit is 59.3%). The mechanical rotation is then converted to electricity with conversion efficiency well below 100%. The overall efficiency for a well designed wind turbine taking into account the losses incurred in two conversions is 45-50% at “best wind velocity” and it roll off at higher and lower wind velocity. On the average, over the entire range of wind velocities, it might be 25-30%. Even though the efficiency is not the same for different wind velocities, the residential wind turbine will provide more power as the wind speed increases.
Wind Energy Basics, Second Edition: A Guide to Home- and Community-Scale Wind-Energy Systems
Choosing a residential wind turbine system
Only after you have deeply research the subject, call a certified contractor to see your site and ask for a price proposal and for a technical proposal based on a site survey and your needs. Run the numbers and see how much time it will take you to return the investment. Do not underestimate the cost of the mast. Get a price proposal for the wind turbine kit from a reliable store, and see whether you want to build it yourself (DIY) or give it to the contractor on a turnkey basis. Shop for quality products such as the Southwest Windpower Skystream 3.7 with 1.9 kW continuous output, 2.6 kW peak wind turbine with a built in inverter or the Bergey Excel that comes with DC output (for off grid applications) or AC output for grid-tied home and can produce 1,500 KWh/month. These are two examples; there are many more quality products on the market to choose from.
Click for more residential wind turbines information on my home energy site
- This is my main page on home wind turbines. The page highlights the technology background and history, the cost of wind turbines and some practical considerations. Click here to view the home wind energy page
- How to read a residential wind turbine specification sheet? This is very important to know if you want to compare wind turbines. Click here to view the reading wind turbine spec page
- Every wind turbine is mounted on a wind turbine tower. Click here to view the wind turbine tower page
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