Windpower: Foolish Energy May 11, 2009Posted by honestclimate in Discussions.
Tags: Bryan Leyland, climate change, global warming, windpower
Windpower: Foolish Energy
10 May 2009
The drive for renewable energy in the form of windpower, marine power and the like, is driven by a belief that man-made greenhouse gases will cause dangerous global warming and that large-scale adoption of these technologies will “fight climate change”. To this end, thousands of MW of heavily subsidized wind power capacity are being added worldwide each year.
In New Zealand we are told that windpower is economic compared to alternatives, that the unpredictable short term fluctuations can easily be covered by our “abundant hydropower” and it helps conserve hydropower storage. Therefore, we are told, we should happily accept destroying iconic landscapes and seriously upsetting people who live nearby.
Compared to conventional power generation, wind has a low capacity factor (the ratio between the average output and the maximum output). Capacity factors of overseas wind farms vary from 18 – 30% while 37 – 40% is typical in New Zealand.
The truth is, as I will show, that windpower is expensive compared to alternatives, hydropower schemes have no spare capacity to back up windpower in a critical dry year and wind power output is lowest in the late summer and autumn when we need it most.
Furthermore, windpower adds a new source of major fluctuations to power systems that are, anyway, inherently unstable. Constant adjustment is needed to ensure that the total generation in a power system matches the normal fluctuations in load – seldom above 50 MW – on a minute by minute basis. If the fluctuations are excessive, the lights go out. With about 1000 MW of windpower on the system we are likely to see swings of 500 MW in a few minutes. The system operator will find it very difficult – and expensive – to find generating plant that can match these swings. The cost will be passed on to the consumers.
Windpower is seasonal. I recently analysed the output of wind farms in New Zealand since 2000. I found that the output was down 9% during the critical late summer – autumn period – when the hydro lakes are at their lowest levels – and at a maximum in the springtime when it is raining and the snow is melting. So a large amount of backup from new gas turbine stations will be needed. The cost will be passed on to the consumers.
I have calculated the cost of power generated by new wind farms such as Makara in Wellington which cost $440 million for 143 MW ($3100/kW), to be about 12 c/kWh at the station gate. Geothermal power costs about 8 cents. Generation from hydropower, gas or coal costs 8 – 10 cents. When the nuclear industry begins to mass produce new, small, sealed, inherently safe, high-temperature gas reactors, or advanced versions of existing reactors, the costs are likely to be similar.
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