Electricity cannot be stored in commercial quantities, but generation has to match demand. We have an ‘Island’ grid, with only a small link to France, and whereas ‘Traditional’ power stations are able to rapidly increase/decrease output in line with demand, wind can not..
Electricity generated by wind:
Demand + no wind = No Power
No demand + wind = No power.
Demand + wind = useable power
BUT :
Wind speed > 45 mph. = 20% reduced power
Wind speed > 56 mph = turn off turbine!
European experience over nearly 20 years – wind generated power is variable, unpredictable and uncontrollable.
Annual production – “routinely disappointing”.
White D, Renewable Energy Foundation, 2004
E ON Netz Gmbh
Transports 44% of Germany's wind electricity capacity
Installed capacity 5900 MW
Average electricity generation 969MW
Load factor of 16%.
Over ½ the year, power generation less than yearly average.
Load factor (capacity)
Germany averages 15-17 %
Denmark averaging 20% over 20 year period.
UK 24% in 2004.
To guarantee reliable electricity supply,`traditional' power stations must be immediately available to cover 80% of theoretical wind generating capacity.
•When electricity demand is high -
“wind power plants could only make a minor contribution towards covering consumption”.
•“….wind power plants cannot replace the usual power station capacities…., but can basically only save on fuel.”
•Wind Report, 2004
•Co2 emissions
Wind power electricity free of CO2 emissions at point of generation.
•BUT
–national emissions benefit more complicated.
Wind Power in the UK
–has to be assessed on the impact that the accommodation of wind power into the grid will have on the whole supply chain;
•needs significant ‘traditional’ power stations operating at low power output, ready for rapid response;
•and fossil-fired capacity operating in parallel.
•when operating below optimum efficiency leads to increased CO2 / KWh.
• White D, Renewable Energy Foundation, 2004
•The more wind capacity that is introduced, the more of the lower efficiency capacity will be required to operate on part load.
•This leads to increased emission of CO2.
•This CO2 emission from back-up generation is significant and must be taken into account when assessing potential emission reduction.
•The Peak demand is 70GW.
•To guarantee meeting demand, 84GW of conventional capacity currently required.
•To meet the target of 10% electricity from wind, 13GW of wind capacity needed plus 81GW of conventional capacity.
•This assumes load factor of 35%, which is unlikely.It does not take into account costs of ‘ramping’ up and down of ‘traditional’ power stations to meet variations in wind power. Neither does it look at CO2 emissions.
•Environmental Change Institute, 2005
Wind Power in Ireland
•As level of wind capacity increases, CO2 emissions actually increase as a direct result of having to cope with variation in wind power output.
•ESB National Grid, 2004
Summary
•7000 x 2MW turbines would be needed to generate 10% of UK electricity needs.
•96.4% of our ‘traditional’ power stations would have to keep operating to guarantee supply.
•Any reduction in CO2 emissions likely to be marginal, as CO2 production will rise from part-loaded power stations.
North Northumberland
•We should support energy saving measures.
•We should support reducing CO2 emissions.
•We should support renewable energy sources.
BUT
Is wind the right renewable for this area??•
*******
For light reading on the Science !
An electricity supply for the Uk (Council for Science and Technology)
Wind Power and the UK wind resource (Environmental Change Institute, University of Oxford)
Wind Report 2004 (E.On Netz Gmbh.)
Reduction in Carbon Dioxide emissions : estimating the potential contribution from wind power. (D White Renewable Energy Foundation)
Wind Power in The UK : has the Sustainable Development Commission got it right? (Keay M. Oxford Institute for Energy Studies)
The dash for wind: West Denmark's experience and the UK's energy aspirations.
(Sharman H Incoteco (Denmark)) Aps