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Sunday, July 6, 2014

Solar and wind? Yes, but...

I often read that countries in northern Europe, particularly Denmark and Germany, have made great progress in generating electricity from wind and solar. I don't doubt the truthfulness of these reports, and I commend the Danes and the Germans for their accomplishments.

But let's remember what retail electricity costs in Denmark and Germany:

And in the case of Germany, they haven't yet begun paying to decommission the nuclear reactors no longer in use.

At those prices, wind and solar certainly are cost-effective sources of electricity. Last month, I paid 9.9 cents per kilowatt-hour for electricity, slightly less than the U.S. national average and one-third of what the Danes and Germans pay. My consumption of electricity in June was 1279 Kw-h, down from a twelve-month peak of 2598 Kw-h in January. As you might imagine, I live in an all-electric neighborhood and therefore my electricity consumption in winter is higher than in summer, despite air conditioning. German summers are not so hot, on average, and not many Germans use air conditioning at home; few Germans rely on electricity for winter heat.

What would life be like if I paid the same price for electricity as Germans? My June invoice would have been $410 and my January invoice, $830. Could I afford it? To be honest, the answer is yes; I could also afford to retrofit my house with some kind of alternative heat source in the winter. But a large number of my fellow North Carolinians could not afford either a tripling of their electricity expenses or the capital investment needed to reduce their consumption of energy. What do we tell them — to lower their thermostats to 55°F in winter and never to use their air conditioning? Most homes built in the South since 1970 were designed to rely on air conditioning. Nor do we want a return to the days when people burned coal in their homes.

One can argue correctly that a unit price of 9.9 cents for electricity is misleadingly low because most of my electricity comes from coal (CO₂ emission, heavy metal emission, SO₂ emission that causes acid rain, heavy metal ash, personal injuries to miners, environmental impact of mining). The reality, however, is that American society has been structured on an assumption of inexpensive, plentiful electricity — the Reddy Kilowatt scenario — in which some costs are hidden from the consumer, or at least deferred. Undoing this policy in the name of saving the planet will impose hardship on those who can least afford it, unless we are prepared to include a provision that protects them.

I agree that wind and solar are important to our future. But let me point out that here in central North Carolina, the wind doesn't blow hard over long periods of time and the sun is often obscured by cloud. Further, bear in mind that electricity is both perishable and expensive to transport. In other words: electricity cannot (in general) be stored in large amounts, and a typical 345 kilovolt transmission line dissipates about 4% of its current as heat every 100 miles. For that reason, the former Carolina Power & Light operated five generating plants close to the Triangle (Harris, Moncure, Goldsboro, Roxboro, and Mayo). You cannot power North Carolina from the Texas wind fields or the Arizona desert.

The last time I worked out the math of a solar farm large enough to produce 100% of the electricity consumed by Wake County on a 365-by-24 basis, with the assumption of an affordable storage system on a massive scale (which doesn't exist), about one-fifth of the land in the county would have to be covered by solar panels. Assuming that we are willing to pay German prices, we could put solar farms down east and put wind farms in our sounds and off our beaches, but we would lose a substantial fraction of the electricity in transit — and accept the risk that a future hurricane would do more damage than Arthur did this week.

This issue is exceedingly complex, and that's why change is slow.