CMS UK

Rural, Business and Renewable Energy Consultants

Wind Turbines: Energy security

Wind energy is not cheap but once the amortisation for the turbine and infrastructure costs are taken out, the fuel is free, and every time the cost of oil goes up, the value of wind 'fuel' increases.

Wind energy is secure - only God can cut it off. The UK is blessed with a maritime climate - we get lot's of wind, even more off shore where we don't have the inconvenience of hills, woods, cities (and citizens) getting in the way of a steady blow.

The case for wind is actually quite strong. One can't help but wonder whether the Government is afraid that highlighting the insecurity of our oil and gas supplies might cause anxiety and panic in the population - resulting in stockpiling and pensioners turning off essential heating. Perhaps the case would be better made if they stopped trying to hide the costs and started to really spell out the benefits particularly the aspects of energy security. Wind electricity also has the advantage that it does not create embarrassing amounts of heat as a bi- product of it's generation and it is ideal for supplying remote consumers.

Other countries are more committed than we are partly because they have lower fossil fuel reserves so the stakes for them are much higher. Germany and Spain are interesting examples.

SOME TECHNICAL STUFF

Wind energy starts as solar. The sun warms the land and the sea to a different extent. Warm air rises faster off the land creating a lower pressure zone, which the air from a cooler area (usually the sea) seeks to fill. This movement of balancing air is wind. Insert an obstruction in the path of this wind, such as the rotor of a wind turbine and the kinetic energy of the wind can be converted into mechanical energy at the turbine shaft. Connect the shaft to a generator and you convert the mechanical energy into electrical energy. A two bladed turbine faces away from the wind and a three bladed turbine faces into the wind.

Position

The ideal site is a smooth topped hill with a flat clear exposure away from trees and houses, which create turbulence. Other sites may be suitable and can be assessed from maps and known wind tables. Output depends on a number of factors. As rotor diameter increases output is squared eg double the diameter and the output is quadrupled. Wind speed has an even greater effect - here the cube rule applies - double the wind speed and the output increases by a factor of 8. Average wind speed across the UK is 6 metres per second at 10 metres above ground

Size

Because of the square rule, size does matter - a lot. A one metre diameter rotor might yield 100w - 1kw while a 66 metre rotor would give 1.5-2MW. The latest generation of off-shore turbines is rated at 5MW and have 125 metre rotor diameters. Noise varies depending on design, wind speed and how close you are to the rotor. They are not as noisy as the anti's make out.

Cost

Caravan/boat mounted turbines of 100w can be purchased for £300 and B&Q offer a 1kw turbine for £1500. A Grid connected 6kw turbine could be £15,000 plus installation. As a rule of thumb £3000 per kw capacity has been used but the technology is pulling down prices and there is now a growing market for 2nd hand turbines. This can be expected to grow as more powerful turbines replace the first generation machines particularly for on-shore siting where land/planning permission has already been secured.

Grant Aid

Grant aid is available for approved installations at £1000 per kW installed, capped at £5000 or 30% of the cost which ever is smaller.

Value

On self-use turbines the highest value accrues if you can use the electricity yourself at 'retail' prices. Surplus power can be sold back to the Grid but this assumes co-operation from the utility company and there are additional costs for inverters and meters.

Wind Turbines: The Future

Germany leads the field in engineering with companies like Siemens developing super turbines of 5 and 6+MW destined for off-shore use. The UK is one of the leaders in off-shore wind farming (together with Denmark and Netherlands). We have 40% of Europe's total potential wind energy resource but wind currently only meets 0.5% of our electricity requirements - room for growth!

However the technical challenges are formidable, for off-shore mega turbines. Erected in 25-40 metres of water a steel monopile would need to be 10 metres diameter and 50-60 metres below the surface. The alternative of concrete foundations requires barges capable of floating out and positioning 3000-7000 tonnes of concrete pile and tower. Barges capable of this already exist.

Drivers

What is driving the growth in wind? It's less the economics of today than the fear of tomorrow. Today the world cost of electricity is $1130 billion and the estimate for 2050 is $4300. Another important consideration must be jobs - in research, design, engineering and construction. Even if you are skeptical about the predictions of global warming, the opportunity for millions of quality jobs worldwide must make the construction of wind turbines a better option than jobs in McDonalds or going to war over rapidly diminishing stocks of fossil fuel!

''RENTAL SCHEMES"

May be suitable for landowners wishing to install turbines but worried about the capital costs and possible negative PR. CMS UK have connections with companies who are prepared to install free standing turbines of 1MW capacity. The arrangement is that through CMS UK, the turbine company makes the application in their own name and carry out the feasibility study free of charge. If permission is granted the company will install the turbine at no capital cost to the landowner. The landowner gets their own electricity at a third to half normal price and surplus electricity goes into the Grid. Under this scheme landowners can earn £10,000-15,000 from every 1MW turbine installed.

Turbines don't need to be on hill tops and the height varies between 13 and 100 metres depending on site and wind conditions. All the landowner has to provide in the first instance is a full address and postal code and an outline map of the land.

Single turbines are relatively easy to place - on a larger scale, the companies are also interested in land suitable for multiple turbines to develop wind farms.

Thomas Edison claimed "I will make electricity so cheap that only the rich can afford to burn candles." He might be embarrassed to know that the cost of his electricity now has risen to the point that windmills are back in vogue!

"Turbines don't need to be on hill tops and the height varies between 13 and 100 metres depending on site and wind conditions. All the landowner has to provide in the first instance is a full address and postal code and an outline map of the land."

"Single turbines are relatively easy to place - on a larger scale, companies are also interested in land suitable for multiple turbines to develop wind farms."