Wind power is one of the fastest-growing sectors of energy production on the planet. Even though the burning of fossil fuels still dominates the energy landscape – not only because of the way machinery and technology has been developed to utilize it, but also because of a lack of political will to change things when so many major political parties receive large donations from coal, oil and gas companies – ‘greener’ sources of energy such as wind are becoming a more frequent part of the conversation about how we will provide the energy we need on a planet that has reached peak oil and continues to add to its population.
There are several reasons why wind is a valuable source of energy production. Besides not polluting the atmosphere as the combustion of fossil fuels does, wind power is green because it is sustainable. As long as the wind blows (and winds will blow as long as the sun shines, because winds are caused by the heating of the atmosphere by the sun, in combination with the irregularities in the Earth’s surface and rotation of the planet) it can be harnessed to produce energy. And, another benefit, wind is free. Wind power does require some investment in the first instance, via the purchase of turbines and related generators and batteries, but after that the cost of producing energy is minimal. And compared to other sources of energy production, wind power uses very little space.
While wind farms run by government agencies and private organizations are dotted around the county, and some farmers have taken to installing turbines on their land to bring their energy bills down, permaculture gardeners can also harness this great green source of power to provide energy on their site. As mentioned, the permaculturist will need to make the initial investment in the technology, but once installed the energy created is very cheap to produce – and may even provide you with a source of income.
You will first need to assess whether your site will benefit from a wind turbine. Assess the amount and direction of the wind that your site gets. As a general rule you want your site to experience average wind speeds of at least ten miles per hour. This will be affected by the surrounding topography of the land, as well as the placement of items like buildings and trees, which can interrupt and divert airflow. Most rural locations are likely to have sufficient wind to merit a wind turbine, but in urban areas there may be too many obstacles for it to be efficient.
Urban areas are more likely to have planning and ordnance restrictions on the use of wind turbines. Such restrictions can make the turbine inefficient, and it may be advisable to explore other renewable energy options such as solar power in such locations. Consult your local municipal authority to check on any permission required for installation. Even in rural locations there may be restrictions on the minimum size of a plot for siting a turbine or on the minimum distance the device must be from the property boundary. It is also a good idea to talk to your neighbors to allay any fears they may have about the installation.
There are two types of wind turbine for domestic use: off-grid and grid-connected. Off-grid systems produce power that is fed directly into the property’s electrical system – either via a transformer or into batteries that can then be appended to an electrical device – while grid-connected systems are attached to the municipal electricity supply. This can have two benefits. Firstly, if the wind conditions do not produce enough power for the needs of the property, the municipal system can ’top up’ the supply, and secondly, if the turbine produces more energy than the permaculturist needs, it can be sold into the municipal system, generating income for the homeowner and reducing the need for energy produced by burning fossil fuels. Check with your local supplier about their arrangements for feed-in schemes.
Domestic wind turbines range is size from around two kilowatts to approximately ten kilowatts. The actual size the permaculture gardener will need will depend on factors including the average wind speed in their locations, the height that the turbine will be placed at, and the energy needs of the property. For instance, if you are looking to use wind power to fuel your home and certain garden devices, such as air pumps for aquaculture systems or pumps to move harvested rainwater around the site, you may need a larger turbine than someone just looking to power part of their home consumption.
The higher the wind turbine the more electricity it will produce. An ideal location would by on an exposed hillside that is free from obstructions that can cause turbulence, such as buildings, trees and very undulating topography. In urban areas, effectiveness is restricted by surrounding buildings and as mentioned, the likelihood of height restrictions.
There are two primary means of securing a pole-mounted wind turbine: with line tethers or with the base set in concrete. The latter is advisable for taller structures or those that experience strong winds, as it gives more stability, and unless you can pour concrete yourself, you may need to hire someone to perform this task. Tethering involves using guidelines to secure the pole holding the turbine, and is suitable for lower wind speed areas and shorter structures. In urban locations, it is more common to install the turbine on the structure of the house, by bracketing to an outside wall so the turbine is higher than the roofline.
It is recommended that a qualified technician checks the wind turbine once a year to ensure that it is still securely installed and that the energy supply is being correctly harnessed and utilized, particularly if using a grid-connected system that could be earning you money from feed-in tariffs. Check with your home insurer whether your policy covers wind turbines in case of damage or required repairs.