Wind Turbines - Other renewable options
It may be that your requirements and location mean that to just to install a VAWT is not the best solution and that other technology may give better options instead of, or perhaps in conjunction with, a VAWT.
For more information about any and/or all of the renewable options below, please visit the Alvesta Ltd main site http://www.alvestaltd.com
During our initial discussions with you we will assess your needs and discuss how our solar collectors, bio-digesters, hydro-generation, air and ground source heat pumps and/or under floor heating might help to achieve your objectives. A brief overview of the other technologies follows:
Bio Gas Generators:
This is a dual tank Alvesta bio-gas generator (biodigester) which produces methane under pressure from a range of organic material including sewage, kitchen waste, garden waste, paper, cardboard, animal slurry and grass cuttings. The system produces methane with grey water and dry compost as by-products. It can replace a septic tank or sewage treatment plant.
The methane produced can be used to fuel cooking appliances, burnt to produce heat or even converted to electricity via a gas turbine. The water can be taken directly for irrigation through a hydroponic system and the compost is ready to use and clear of all pathogens.
Solar Collectors:
Solar collectors take the power of the Sun and convert it either to electricity or use the warmth to heat water for use in central heating systems and/or the domestic hot water supply.
To convert the power to electricity requires photovoltaic panels but these currently take many years to pay back the cost of installation, if ever and although Alvesta supply photovoltaic panels we do not recommend them in many situations.
Evacuated tube solar collectors are much more cost effective and feed hot water to a thermal store from where it can be fed to an under floor heating system without further temperature boost or can be boosted to the higher temperature needed for a conventional central heating system. It can also be connected to the domestic hot water system, it will not normally require boost and in most cases will be mixed down with cold water to a safe temperature at the tap.
A 30 tube evacuated tube solar collector like the one above will generate around 1,250 kWh per annum in a UK installation. It does not require direct sunlight and will generate adequate amounts of heat from early April to late October as well as on sunnier days during the winter, even on an overcast winter day water temperatures as high as 60oC can be generated.
Heat Pumps:These are of two basic types, air source and ground source. Air source heat pumps work like a refrigerator in reverse and take heat from the air, use it to heat water and store it in a thermal store in the same way as solar collectors, indeed they can feed the same thermal store. From the thermal store the water can be used to feed central heating or the domestic hot water supply although for radiator systems the water might require a further boost.
The air source heat pumps that we supply have a Coefficient of Performance of almost 4:1 which means that they use one unit of electrical power to produce four units of heating and if used in conjunction with a VAWT the power will of course be provided from a renewable source.
Alvesta supply air source heat pumps with outputs of 9kW or 12kW, the unit can be sited in a loft space, garage or even outside the building. Installation is fairly simple and takes just a few hours.
A Mitsubishi “Mr. Slim” 9kW air source heat pump
Ground source heat pumps carry out a similar process but extract heat from the ground and then carry it to the property in a sealed loop where it will either directly heat the property through an under floor heating system or can feed the domestic hot water system. Ground source heat pumps need to have the heat exchange system buried in the ground, either in a vertical borehole or a horizontal trench. This expensive groundwork increases the cost of a ground source heat pump with the typical installation costing £7,000 - £12,000 compared to the £3,500 of an air source heat pump.
Under Floor Heating:
This is a really good option for a new build property as the patented Alvesta “Warmdec” under floor heating system can be installed for a similar cost to a conventional radiator system but uses water at 50 – 60oC instead of 70 – 80oC which provides an immediate 25% saving in fuel costs. Either solar collectors and/or heat pumps can provide water at this temperature without any further boost. One important feature of Warmdec is that for upper floors it is modular and provides the floor and insulation, it can be used with joists or I-beams, is fitted at the “first fix” stage, does not require a plumber at that stage and avoids the need for safety bagging whilst working on the floor.
Once pressure tested any floor surface can be laid over the Warmdec as long as it has an insulation rating of no more than 2 tog, and this includes a concrete screed.
Although best used in new builds, improvements or conversions Warmdec can be retrospectively fitted to existing property provided that there is scope to either re-lay the floor or to raise the floor by 35mm without affecting the door frames or skirting boards.