Today’s edition of madison.com featured an article about adding more wind capacity to Wisconsin’s power grid. The article is a transcript of a report run during the local news, and is at the level of detail appropriate to that forum:

Local environmentalists want to tap into Wisconsin’s wind energy potential. They say wind could power the entire city of Madison. […]

Experts say there’s not enough Wisconsin wind to go around. MG&E Energy says Wisconsin is not a very windy state. Only a small portion of the Eastern border gets wind gusts above fifteen miles per hour.

Wind farming is also more expensive than traditional power plants because of the technology used. Building a wind farm big enough to support the City of Madison would cost $500 million.

I don’t know how accurate any of these estimates are, but the implication of the story is that Wisconsin is not suited for wind development, and that costs would thus be quite high, at half a billion dollars.

I don’t know what the precise engineering constraints are, and obviously, if the wind doesn’t exist at levels which can be consistently harnassed (”not enough wind to go around”), you can’t use it. But, if it can be used, and the story certainly hints that the constraint is financial, not physical, $500 million is a steal.

Since wind capacity is unpredictable, making significant use of wind requires sophisticated management of the power grid, to redirect energy to and from other sources as needed. Current studies, and experience from Denmark (where 20% of the national demand is supplied by wind) suggest that wind can’t replace more than 20%-40% of energy demand, but there aren’t sizable scalability problems below that threshhold.

If the grid’s capacity is sufficient, there aren’t reliability problems at 4%, which is what a proposal to “power the entire city of Madison” would actually entail — converting a Madison-sized segment of Wisconsin’s power infrastructure to wind (*).

The Energy Center of Wisconsin (pro-renewable energy think tank) reports that:

Wisconsin gets 75 percent of its power from coal plants, which cause 48 million tons of greenhouse gas emissions (carbon dioxide), 206,000 tons of acid rain emissions (sulfur dioxide), and 107,000 tons of smog emissions (nitrogen oxides) each year.

Madison’s population is approximately 4% of the state’s, so we can estimate that our electricity usage is responsible for pollution on the order of 4 billion pounds of carbon dioxide, 8200 tons of sulfur dioxide, and 4300 tons of nitrogen oxide. That pollution has some non-trivial external cost that must be measured against the price tag of wind.

Furthermore, since Wisconsin imports $6 billion in coal, natural gas, and uranium each year, Madison’s share of that total can be estimated at $240 million each year.

$500 million is looking cheaper and cheaper.

It’s also an up-front cost. Depending on financing, and various engineering concerns, building out wind capacity costs between $1000 and $2000 per kilowatt-hour. The costs of producing energy on existing wind infrastructure is very low: recurring maintenance costs are about $0.0065 per kWh, and then you have the standard costs of transmission and power grid management.

In other words, the $500 million price tag represents not just the construction costs, but a large portion of the cost of providing power via wind over the system’s lifespan, which is probably on the order of 20 years or so. On this scale, the investment seems obvious, and inexpensive.

That said, I don’t really believe that we can upgrade our power grid so cheaply. I suspect that there are substantial hidden costs and unfunded liabilities involved in getting so low a number. But I could be wrong, and in any event, greening our energy usage would be worth doing at a cost far in excess of $500 million.

But large-scale investment in our public power infrastructure will require the involvement of the state government. Perhaps our governor and the state senate would like to take the lead on this issue.

(*) National electricity usage is 3.9 trillion kWh, or about 444 GW, and if we assume that Wisconsin consumes energy in proportion to the rest of the country, we’re looking at about 8100 MW of energy consumption per year.

To convert 4% of Wisconsin’s power infrastructure to wind would require building 324 MW of capacity.

Posted by Ben Brothers at 3:04 pm, 18 June 2007 and filed under Wisconsin News, Madison News. You can follow any responses to this entry through the RSS 2.0 feed.