Understanding wind energy

Can the farm generate 100% of its electricity with wind?

On the Berkshire Downs there is certainly enough wind, but there are many things to consider. The total that the farm can generate is limited by factors like: visual impact, overall environmental impact, distance away from byways, cost, distance to grid connections and the constraints of wind availability. All these issues need to be thought about carefully.

The simplified example in the table below shows just how difficult it might be to achieve 100% without making a high impact on the local landscape character.

Sheepdrove Organic Farm consumes around 665,000 units of electricity (kWh) per year. This amount of electricity releases approximately 260 tonnes of carbon dioxide per year. In order to offset this amount of carbon dioxide a wind turbine, or a set of several wind turbines would have to provide the same amount of electricity as Sheepdrove Organic Farm consumes.

Hypothetically speaking, to approximately match this amount of electricity demand with wind power, one of the following wind turbine options could be employed as a solution if we were to meet 100% of the farm’s electricity demand:

Hypothetical table - one of these options could match 100%

Turbine model	Number Required	Capacity (kW)	Hub Height (m)
a) Enercon E33	1	330	50
b) Fuhrländer FL 250	2	250	42
c) Wind energy solutions	4	80	31
d) Entegrity Wind EW15	7	50	25
e) Gazelle Wind Turbines	16	20	13

Each hypothetical option has its advantages or disadvantages. The overall visual impact and other potentially negative impacts may be reduced by installing a smaller number of larger units... or low height might be favoured to reduce long-distance visibility - but it would take many more small windmills to make the same electricity. Of course a combination of different sized windmills could be put in different places, to suit the surroundings.

All about Wind Energy

Follow the links below to find out about wind energy. Please bear in mind that Sheepdrove Organic Farm is seeking to address its own energy needs, looking towards small-scale wind power solution, rather than a large-scale commercial scheme.

Here is the Regen Southwest website:
http://www.regensw.co.uk/technology/wind-faq.asp

We also found a very helpful website based in Denmark: http://www.windpower.org/composite-85.htm

What the RSPB say about risks to birds.

“The available evidence suggests that appropriately positioned wind farms do not pose a significant hazard for birds. However, evidence from the US and Spain confirms that poorly sited wind farms can cause severe problems for birds, through disturbance, habitat loss/damage or collision with turbines.”

http://www.rspb.org.uk/ourwork/policy/windfarms/index.asp 

Birds and wind turbines (large scale): http://www.windpower.org/en/tour/env/birds.htm

Modern wind turbines rapidly recover all the energy spent in manufacturing, installing, maintaining, and finally scrapping them.Unusual designs include the vertical axis quietrevolution being developed locally.

What is the energy payback? http://www.windpower.org/en/tour/env/enpaybk.htm

Tower size, and what different sized blades look like when they are moving: http://www.windpower.org/en/tour/wtrb/tower.htm

Obstacles to wind: http://www.windpower.org/en/tour/wres/obst.htm

Number of blades: http://www.windpower.org/en/tour/wres/obst.htm

Here is a great website for schools: Wind with Miller

You might know of the very tall ecotricity turbine at junction 11 of the M4 motorway, said to be one of the most visible in the UK.

Of course this sort of height is not suitable in an open landscape like the Berkshire Downs. How can we fit Renewable Energy into this landscape? Read more...