Congratulations on your decision to explore generating your own electricity through wind power. Whether you are looking to reduce your power bill and save money, achieve independence from the local power grid or limit your carbon footprint, wind is a universal and reliable energy source that will serve you well for many years to come.
Before you go any further, we must first determine if using wind power in the home is suitable for you. Here are five key criteria, in order of importance, that you MUST check first:
- Local zoning regulations
- Household energy consumption
- Supplemental power system or totally off-grid
- Location of the wind turbine
1. The Answer is Blowin’ in the Wind
This is the most important consideration you’ll make when deciding on a wind turbine for your home. Quite simply, you need wind to run your turbine.
Ideally you want to have enough wind pass through your property to power your wind turbine all year round. If your region experiences very low average wind speeds (typically below 5 m/s, 11mph or 18 kmh) or your home is in a sheltered area, you are likely to struggle to generate any meaningful power from your turbine. In this case, a wind turbine is probably not the best option for you.
Most home wind turbines typically have a cut-in speed (wind speed at which electricity is first produced) of around 3 m/s (7mph or 11 kmh), depending on the model. As the wind speed increases, so too does the energy output of the turbine until the rated wind speed is reached. Rated wind speeds for full energy production are generally between 12 and 22 m/s (27mph/43kmh and 49mph/79kmh respectively), again depending on the model.
One of the biggest contributing factors to the energy output of the turbine are the blades. Those turbines with more blades, like 9 or 11, have more surface area for the wind to act against in order to keep the rotor spinning. This means the turbine will be able to generate energy in lower wind conditions than a comparable 3-blade model.
To estimate the wind speeds in your local area, use this free, high resolution global wind atlas produced by the Technical University of Denmark and the World Bank.
2. Welcome to the Neighbourhood
Now that you have determined winds speeds in your region are sufficient to sustain long-term electricity generation, you need to find out what local zoning laws have to say with regard to wind turbines in your neighbourhood. Some communities may offer incentives to homeowners to build renewable or alternative energy systems on their properties, whilst others may not allow their installation at all.
If wind turbines are not excluded under local bylaws, check to see if related structures such as towers or detached structures over a certain height (say greater than 10m) are allowed, require a permit or are outright banned.
Local electricity authorities or utility companies may also require notification of your decision to install a wind turbine for electricity generation. This is very likely if you intend to sell any surplus electricity to the local power company for use in the grid.
3. Watts’ my Number?
To ensure you get the right wind generation system for your needs, you first have to determine how much electricity you use in your home. Please do not guess your electricity consumption, otherwise you risk installing a wind generation system that will never meet your needs. Invest some time in getting realistic energy numbers for your home.
The most obvious source of information for household electricity consumption is your monthly power bill. These days, most power bills contain a wealth of data on a household’s electricity use including the current month’s usage, monthly consumption over the past 12 months (good for assessing seasonal changes in power use), and total or average annual electricity consumption. If you don’t have your power bills handy, contact your energy provider and ask them for the last 12 months’ worth of your electricity use.
Alternatively, you can conduct a detailed energy audit of your home to determine what areas of the home, such as heating & cooling, hot water, lighting and appliances, are using all that electricity every day. This analysis will give a much more accurate picture of your household’s electricity consumption with the added bonus of helping identify potential energy-wasting devices. If you are intending to live off-grid in a new home, or are already living off-grid, then you will likely need to carry out an energy assessment of your home since you do not have the convenience of a monthly power bill.
Whichever method you use, you need to know your household’s average daily electricity consumption, measured in kilowatt-hours (kWh). Here are a few ways to calculate your daily consumption:
- Add up the kilowatt-hours used each month for the last 12 months and divide the total by 365 days in a year
- Take the total annual or average annual kilowatt-hours consumed and divide by 365
- Add up the daily kilowatt-hour demand of every electricity-based device in the house (if you calculated daily numbers as part of a detailed energy audit)
Now that you know how much electrical energy (kWh) your household uses each day, this can be compared with the estimated electricity output (kWh) of your wind turbine. If the turbine cannot produce enough electricity, then you may have to find a secondary source of power to supplement the turbine.
4. Going off the Grid
Choosing wind power doesn’t mean you have to give up the grid altogether. The flexibility of wind power generation means that you can use your wind turbine as a supplemental source of electricity, significantly reducing your power bill, but still be connected to the grid power supply for those days when winds speeds are not enough to meet all your electricity needs around the home.
Whether you choose to go completely off-grid or use wind turbines to supplement your grid power, always consider turbine kits with high rated power, measured in watts (W) or kilowatts (kW). Turbines rated less than 1kW (or 1,000W) won’t produce nearly enough energy for a reliable electricity supply and will simply waste your time and money.
A further option to consider is a hybrid system where your wind turbine is paired with photovoltaic (solar) panels. This maximises your capacity to generate electricity more consistently. Wind power works best when solar power doesn’t, such as at night, during poor weather conditions (particularly cloudy or overcast days) and throughout the winter months when sunlight levels are limited.
For off-grid systems, turbines with more than 3 blades and a 2kW (2000W) energy output are a more suitable option. You will also need to consider using batteries for energy storage.
A general rule of thumb to go by with wind turbines: Bigger is generally better.
Now here’s the trap that homeowners need to avoid when selecting a wind turbine: the power rating of the wind turbine (kW) is NOT the same as the electricity output of the turbine (kWh).
Simply put, if you took 3 different wind turbines with the same power rating of 1kW, each turbine would achieve its rated 1kW output at different wind speeds. The swept area of the turbine blades (measured in square metres), which differs from turbine to turbine depending on blade size, also has a major impact on the amount of electricity generated. Therefore, how much electricity (kWh) is produced at various average wind speeds is a much more useful means of comparing different wind turbine models. But don’t worry, we will help take all the guesswork out of this for you.
5. Location, Location, Location
Where you locate your wind turbine around your home is critical to its success. Just like an airplane, wind turbines operate at their best when exposed to strong, undisturbed (less turbulent) airflow.
As well as knowing the average wind speed at your property, understanding the direction of the prevailing winds for your region is critical to assessing the potential impact of any obstacles when choosing the best site on your property. You need to check that there are no significant obstacles in the turbine’s path that would disturb or reduce the airflow available in which to generate power.
Ideally, the turbine should be placed upwind of any buildings or trees on your property to expose it to the prevailing winds (and better airflow) as much as possible.
Wind speed increases and turbulence decreases the further away you are from the ground. This makes sense as you rise above hills, trees and buildings which act like a barrier or shelter belt to slow down the speed of wind and create pockets of turbulent air. What this means for you as a homeowner is that you are going to need a tower to operate your wind turbine effectively.
A common rule of thumb for calculating tower height is mounting the turbine at least 9 metres (30 feet) above the nearest obstacle within 150 metres (500 feet) of your home. In a suburban environment with single single-storey housing of typically 5 metres (16 feet) in height surrounding your property, you will likely need to install a 14-metre (46 foot) high tower for your wind turbine. Remember to account for the growth of trees when determining tower height.
Ultimately, good location of your wind turbine, using both position and height, will help minimise the harmful effects of turbulence. Reduced turbulence leads to higher electrical production, decreased turbine repairs and maintenance, and increased turbine lifespan. Increased lifespan leads to a better return on your investment.
Last but not Least
If you have reached the end of this checklist and discovered that your home is unable to benefit from a wind generation system, don’t despair. Whilst it might not make sense to invest in wind power right at this moment, keep checking back here on a regular basis. National governments and local authorities around the world are under increasing pressure from their communities to reduce fossil-fuel based power generation and address climate change issues. Regulations and incentives may be introduced in the near future that makes electricity generation from wind power a realistic option for you.
For those of you who can confidently tick all the boxes in the checklist – you have wind, zoning laws allow wind turbines, you know how much electricity your household consumes and whether you want to stay connected to the grid or go completely off-grid, and you have a great site for a turbine and tower – well done. You are now well on your way to enjoying the benefits of a clean, abundant and sustainable energy supply, courtesy of Mother Nature.
Check out this 11-bladed beast for powering the home in just about any wind conditions.