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Blue Peter
Joined: 21 Mar 2005
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Location: Milton Keynes
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wellington womble
Joined: 08 Nov 2004
Posts: 15051
Location: East Midlands
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dougal
Joined: 15 Jan 2005
Posts: 7184
Location: South Kent
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Blue Peter
Joined: 21 Mar 2005
Posts: 2400
Location: Milton Keynes
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wellington womble
Joined: 08 Nov 2004
Posts: 15051
Location: East Midlands
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dougal
Joined: 15 Jan 2005
Posts: 7184
Location: South Kent
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dougal
Joined: 15 Jan 2005
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Location: South Kent
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Lozzie
Joined: 25 May 2005
Posts: 2595
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 Posted: Thu Jun 02, 05 10:01 am Post subject: Atricle on Wind Power on a small scale |
 
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I found this (sorry, if it is already old news. It was posted on MSN Messenger's home page a couple of days ago. There is no indication of who wrote it, I'm afraid):
Introduction
Harnessing wind as a renewable energy source involves converting the power within a moving air mass (wind) into rotating shaft power which in turn generates electricity. Modern wind turbines contain rotors fitted with aerodynamic blades, which utilise lift forces caused by the wind on the blades.
Wind energy resources
In the UK we have a large potential wind resource. Although we have 40% of Europe's total wind energy resource, it remains largely untapped, currently meeting only about 0.5% of our electricity requirements.
Power from the wind is proportional to the cube of the wind speed therefore relatively minor variations in wind speed can result in large changes in potential output.
Individual turbines vary in size and power output from a few hundred watts to 2-3 megawatts (as a guide, an electrical kettle uses approximately 2,000 watts or 2 kilowatt). Uses range from very small turbines supplying energy for battery charging systems (e.g. on boats or in homes), to turbines grouped on wind farms supplying electricity to the grid.
Small Scale Wind and your home
Wind speed increases with height so it is best to have the turbine high on a mast or tower. Generally speaking the ideal sitting is a smooth-top hill with a flat, clear exposure, free from excessive turbulence and obstructions such as large trees, houses or other buildings. However, small-scale building integrated wind turbines suitable for urban locations are currently being developed and will be available to install in homes and other buildings within the next few years, Knowledge of the local wind resource is critical to designing a wind energy system and predicting output. For domestic installations a good source of information on local wind speeds is the NOABL database which can be accessed from the British Wind Energy Association alternatively you can collect
primary information by setting up your own monitoring mast to record wind speed. An ideal way of doing this is with an anemometer which can be bought online for around �120.
Planning issues such as visual impact, noise and conservation issues also have to be considered. System installation normally requires permission from the local authority.
Stand-alone or grid-connected systems?
Small scale wind power is particularly suitable for remote off-grid
locations where conventional methods of supply are expensive or impractical.
Most small wind turbines generate direct current (DC) electricity. Off-grid systems require battery storage and an inverter to convert DC electricity to AC (alternating current - mains electricity). A controller is also required to ensure the batteries are not over or under-charged and can divert power to another useful source (e.g. space and/or water heaters) when the battery is fully charged. It is common to combine this system with a diesel generator for use during periods of low wind speeds. A combined wind and diesel system gives greater efficiency and flexibility than a diesel only
system. It allows the generator to be used at optimum load for short periods of time to charge batteries when there is little wind, rather than by constant use at varying loads.
Wind systems can also be installed where there is a grid connection. A special inverter and controller converts DC electricity to AC at a quality and standard that is acceptable to the grid. No battery storage is required. Any unused or excess electricity can be exported to the grid and sold to the local electricity supply company.
Cost and maintenance
Systems up to 1kW will cost around �3000 whereas larger systems in the region of 1.5kW to 6kW would cost between �4,000 - �18,000 installed. These costs would be inclusive of the turbine, mast, inverters, battery storage (if required) and installation, however it's important to remember that costs always vary depending on location and the size and type of system.
Turbines can have a life of up to 20 years but will require service checks every few years to ensure they continue to work efficiently. For battery storage systems, typical battery life is around 6-10 years, depending on the type, so batteries may have to be replaced at some point in the system's life.
Are there grants available?
Scotland:
Householders can access capital funding of up to �4000 from the Scottish Community and Householder Renewables Initiative (SCHRI).
For more information please see the funding and advice page or contact the SCHRI Hotline on 0800 138 8858.
Rest of the UK (England, Wales and Northern Ireland)
Householders can access grants for small scale wind from Clear Skies. For more information contact the Clear Skies Helpline on 08702 430 930 or visit their website. https://www.clear-skies.org/
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Lozzie
Joined: 25 May 2005
Posts: 2595
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dougal
Joined: 15 Jan 2005
Posts: 7184
Location: South Kent
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Rikki
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Rikki
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dougal
Joined: 15 Jan 2005
Posts: 7184
Location: South Kent
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| Posted: Thu Jun 09, 05 12:46 pm Post subject: |
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| Rikki wrote: |
| I'm currently installing a solar panel to heat my domestic hot water and have considered having a wind turbine connected to a heat sink imersion heater to heat the water in winter (when it's windy, but not sunny. Has anyone else done this. |
Its a simple-ish means of using wind energy, because it requires very little in the way of control systems and energy conversion, such as voltage stabilisation, transformers, inverters and mains synchronisation.
But its not common because usually folk *needing* wind energy are wanting to make the maximum/best possible use of it, and may well have access to plenty wood for water heating. Such folk, off grid would be charging batteries from the wind, and only when that store is full would they 'dump' wind energy into heating.
And if mains gas is available, using wind for water heating is unlikely to be very cost competitive.
| Rikki wrote: |
| I reckon the recoup period on my solar panels, home made and installed, is 10 years whereas a commercial installation would take 50 years to recoup the cost. Has anyone looked at how long it would take to recoup the �1500 of an electricity turbine? |
That's the answer no one knows yet.
And it'll be different, depending on the local wind conditions. Which could mean *very* local.
My understanding is that without specific planning permission, the whole turbine must be lower than the top of the roof. Which must mean the roof screening the turbine from some directions, and running it in turbulent air - further complicating any pre-calculation of its viability.
There is some concern that some rather optimistic assumptions must be made to have such things pay back financially before they are expected to wear out. And then there's the question of the energy in their production...
Rikki - may I suggest you register (it costs nothing), and start a new thread on your solar system? |
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woody
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Blue Peter
Joined: 21 Mar 2005
Posts: 2400
Location: Milton Keynes
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,
(and yes, Windsave's publicity does talk about "plugging in" 
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