Thursday, May 22, 2008

Diseconomies of Scale

Last weekend I was at Moncton Market and picked up an interesting booklet at a table selling environmental cleaning products. It was produced by the Conservation Council of New Brunswick and titled 'Roadmap to a self-sufficient energy future' (pdf).

They report that New Brunswick is already experiencing the effects of climate change. The snow pack in the southern part of the province is only half the long-term average; extreme weather events have risen five fold; sea level is up 30 cm; the average annual temperature up 0.7C.

Greenhouse gas emissions in NB are up 37% from 1990-2005 and the province is the third highest per-capita emitter in Canada. The government has committed to get back to 1990 levels by 2012, and 10% below that figure by 2020. The problem is, New Brunswick Power is responsible for over half of the province's emissions, and while they do use hydro and wind power, every year they send $500 million out of the province to purchase nuclear and fossil fuels.

These are used in large and inefficient power plants. Coleson Cove, Belledune and Point Lepreau run at about 30% efficiency. They tend to be located a long way from where the power is needed, resulting in further transmission line losses. They dump large amounts of heat into the ocean.

What the Conservation Council of New Brunswick are proposing is a move to smaller combined heat and power stations which typically run in excess of 70% efficiency and can be as high as 80% or more. They would be powered by locally produced biomass, creating employment and keeping money in the province.

Since the 1980's it has been widely acknowledged that larger power plants are inefficient, expensive and time consuming to build, and down-time for repairs is hard to manage. Smaller systems however can be mass produced, more easily financed and rapidly deployed. They are faster and easier to maintain, and down-time of one generator has much less impact on the whole system. This is what is termed the Diseconomies of Scale.

NB Power Nuclear are considering building a second reactor at the Point Lepreau Nuclear Generating Station. Elizabeth May, writing in her blog about the inability of AECL to commission two medical isotope reactors at Chalk River, Ontario, asks the Government of New Brunswick:

Are you sure you want to buy a reactor from AECL that so far is only at the design stage? That's what the MAPLE reactors were. Reactors on paper. Why would anyone have confidence in AECL? Why go with a nuclear reactor when New Brunswick has so many other options?

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