The bad news about off shore wind cost

An estimated figure of 10 trillion dollars to be spent on AGW mitigation by 2030 is being talked about at the Copenhagen Climate change conference. Nicholas Stern, the Chief Economist of the World Bank, who has researched the cost of mitigation told The Sunday Telegraph,

we should be prudent with public finances, but if we were to ask future generations: would you rather have a desecrated earth or more debt, then the answer would be they would like to have more debt. You can get out of debt, but you can't get out of the other. It's one of the few cases where there's actually an argument for more borrowing. There's a logical justification to it.

I agree with Lord Stern's assessment, completely, but I wish to note, that the investment of 10 trillion dollars will not be the total cost of fighting AGW, and that if we are going to spend that much money, we should spend it on effective mitigation tools. In addition we should in our mitigation efforts also focus on improving the quality of life for the poorest 3/4ths of the world's population. This will require us to make wise investments.

Yet I do not see a passion for wise mitigation investments coming out of the Copenhagen conference, in fact very much the opposite seems to be the case. For example the New York Times carried a story about New Your city Mayor Bloomberg's flyover visit to the Danish Horn Rev 2 wind project. The Mayor is reported to have been very impressed, and called for the building of a similar facility off Long Island. Perhaps the Mayor was not well informed about the cost of electricity from the Horn Rev 2 facility. The facility costs 1 billion dollars and and has a rated capacity of 200 MWs of electricity. But its average output is only about a third of that, 34% to be exact. So one billion dollars gets you an average of 68.5 MWe of electrical output. Put another way, each watt of average electrical output from the Horn Rev 2 facility carries a capital costs $14.60.

Costs for thew German off shore Alpha Ventures wind farm suggests that German off shore wind is going to be extremely expensive as well. A year ago Der Spiegel reported that

German offshore Alpha Ventus is to cost €180 million ($282 million) to build -- nearly three times as much as a similar installation on land. . . . Maintenance . . . running makes up some 20 to 30 percent of total costs,

Alpha Ventures has a rated capacity of 60 MW, Now over a year later the total cost of the Alpha Ventures project is up too $357 million, or $5.95 per watt. The Germans appear to be guarding Alpha Ventures capacity factor as if the survival of Germany and of the German people were dependent on maintaining its secrecy. However we can infer from German statements about future German wind capacity factors that North Sea capacity factors, are on the south side of .40. Assuming a capacity factor of .40 we get an astonishing $15 per watt of real world average electrical output. The German Government has approved the building of as many as 2500 off shore windmills between now and 2030. But the German commitment to offshore wind may be wavering.

The United Kingdom expects to spend 100 billion pounds (around 160 billion dollars) by 2020 on 25 GWs of offshore wind schemes by 2020, according to the British Crown Estate's. That is $6.40 per name plate watt, but once we compute for capacity factor, it gets much more expensive, but even at $6.40 per watt, we are moving into the nuclear cost range. British offshore capacity factors estimates run from .20 to .40, but even if we take the top end of the range we get $16 investment dollars for every watt of output. But the cost of offshore wind doubled between 2003 and 2008, and we have no assurance that offshore wind cost will

not continue their rapid assent in the future, especially since there is a big push in Europe to build offshore wind facilities.

We also should note that the see environment is hard on machinery. We should note that the German Alpha Ventus project, maintenance is expected to run as high as 30% of the total cost of the project. In addition, the expected lifespan of offshore wind turbines runs to 25 years, but this is just a guess, and perhaps a very optimistic guess at that. The life expectancy of onshore windmills is around 16 years, based on actual experience, although manufacturers say they expect a 25 year life span. It is probably the case that offshore windmills will not survive as long as onshore windmills, 25 years may well be optimistic and is perhaps very optimistic. At any rate after a period of time generously estimated to be 25 years, windmills will have to be replaced, although presumably some of the investment, for example offshore electrical cables and the structural towers can be recycled. Perhaps the replacement would cost 50% or the original cost. The expenses would add very considerably to the long term cost of offshore wind.

David Milborrow discusses the British use the concept of "capacity credit" as

“The reduction, due to the introduction of wind energy conversion systems, in the capacity of conventional plant needed to provide reliable supplies of electricity.”

The formula for calculating this suggests that if the British built 40 GWs of mainly off shore wind, they could retire 7 GW of fossil fuel generating capacity. Of course, if we replace those fossil fuel power plants with conventional reactors, we could do it with a one on one swap. Lets us assume that the reactors cost $8 billion, the cost of the 7 reactors would be $56 billion perhaps a fifth of the cost of the wind facilities. In addition the reactors will last for at least 60 years, verses a maximum of 25 years for the windmills, and the cost of maintaining the reactors would be far less as well. Question for the British politicians, "Which is the better deal for the British Electrical customers.

In addition David Milborrow notes

the effect of reducing the load factor on the remaining thermal plant, . . pushes up their generation costs.

At the beginning of this essay, I pointed to the importance of wise investment in AGW mitigation measures. I have in the course of this investigation uncovered evidence, based primarily on the European and particularly the European experience, that in terms of capacity factor and in terms of capacity credit, the cost of offshore wind is far higher than the cost of nuclear power. This is of course a case study and case studies in the United States though perhaps yielding somewhat different finding, are unlikely to yield different conclusions. My findings are entirely consistent with my over all contention that the cost of nuclear power is significantly lower than the cost of renewable generated electricity.