Frequently Asked Questions
Do turbines affect TV, Radio or Telecoms reception?
Turbines do not usually create any interference.
How noisy are the turbines?
Our wind turbines are designed to operate at low speeds so are quiet. They are direct drive, so have no gearbox noise. They make a quiet 'swishing' noise that is unlikely to be heard more than 50m away.
What is the lowest and highest wind speed at which a turbine will generate electricity?
MCG wind turbines start producing electricity at wind speeds of only 2.5m/s. Maximum speed varies dependent on the size of the turbine, but have a survival speed of 40m/s.
What is the life span of a wind turbine?
You can expect your wind turbine to have a life span of about 20 to 25 years.
How much CO2 emissions will a wind system prevent?
Every 1kWh generated by a wind turbine mean 1kWh less has to be generated by conventional power stations. These power stations currently emit (on average) 0.43kg of CO2 per kWh - hence each wind turbine kWh generated prevents the emission of 0.43kg of CO2 (source: Energy Saving Trust).
What warranty is offered?
All our turbines come with a standard 5-year warranty.
Do you offer a maintenance or service plan?
MCG offer a range of competitively priced service/maintenance contracts. Please contact us for more information.
Can wind turbines be installed in urban areas?
The "surface roughness" of urban areas means wind speeds are reduced and turbulence levels increased. To work effectively a turbine needs to be in clean (turbulence free) air above surrounding obstacles. A site on a hill in an urban area may present a good location for a turbine, a site at or below the level of surrounding buildings is not recommended.
How can the annual mean wind speed for a site be estimated?
The only effective way of calculating the annual mean wind speed on any given site is via prolonged research using wind logging equipment. Shorter term logging, using temporary wind loggers, can provide some useful information, however most sites appraisals start by the use of the BWEA wind speed database. The BWEA database models wind speed for every square km of the UK. It can be accessed at: www.bwea.org. Note: The BWEA data will only provide an initial wind speed estimate for a 1km square. Topological features such as terrain, trees and buildings will very significantly affect wind strength at a given site.
Is bird strike likely?
There are rare incidents where birds do come into contact with turbines, though this is more likely for wind farms than single turbines. The RSPB has stated that "the available evidence suggests that appropriately positioned wind farms do not pose a significant hazard for birds". For more information see the RSPB web-site and the BWEA web-site.
What happens if there is no wind?
On calm days a wind system produces no electricity - all electricity required by the building comes solely from the national grid.
Can the system be used to run a dedicated load?
A grid connected system feeds into the whole building electricity network, feeding any loads that are running at the time. Feeding a single load in such circumstances is not feasible.
Do installations require batteries?
A grid connected system does not require batteries. Batteries significantly increase the cost of an installation and also reduce the overall efficiency (typically by 20-30%).
What happens during a power cut?
A grid connected system instantly switches off when a power cut occurs. This is required to meet electricity regulations and is implemented by control circuits integrated within the inverter. Disconnection during a power cut is necessary to ensure power quality and protect workers who may be repairing the fault. The system will automatically restart once the power cut ends (a three minute restart delay is required by regulations).
Can turbines be building mounted?
Turbines can be mounted on buildings, though the turbulence effects of the building can present significant impacts on turbine performance. To work effectively the turbine needs to be well above the building and any surrounding buildings. Because of the effects of turbulence, it is generally recognised that buildings are not the ideal first choice for mounting a turbine. The loads imposed by the wind on the turbine mast are considerable. Where a turbine is to be mounted on to a building, the building must be capable of withstanding these loads and any vibration effects. A structural engineer must be consulted to assess the building for suitability.
How are wind turbines rated?
Wind turbine systems are typically rated in kW (kilowatt), which is the rated instantaneous output of the wind turbine at a defined wind speed. To enable comparison between models, a wind speed of 11m/s (24.6mph) is starting to be implemented as the standard wind speed at which all turbines are to be rated.
What happens if the system generates more than the building is using?
If the wind turbine is generating more electricity than the load demand in the building, all excess is exported to the grid. Export occurs automatically and can be measured (and income collected) using an export meter.
How can the annual output for a particular wind turbine be calculated?
The annual output (kWh) of a turbine depends on the average annual wind speed "seen" by the turbine. This depends on the average wind speed for the site, the height of the tower and local site factors (e.g. is it on a hill). Accurate estimates can only be achieved by the installation of wind logging equipment fora period of at least a year. However, the cost and time constraints of such monitoring means that such analysis is usually only implemented for wind farms or large turbines. Initial estimates of site suitability and turbine output can be made using the BWEA wind speed database, with corrections for local effects and manufacturers data. MCG can provide such estimates on request.