Coal costs more to generate electricity

Can you replace coal-fired electric generation with solar power even though the sun isn't up 24 hours a day? Are coal mines closing because of economics, or is it just politics?

As mentioned in my first column, my father got a lifetime achievement award from the coal industry. I've been underground in coal mines. I grew up with positive dinner table talk about coal: The U.S. has hundreds of years of coal reserves. "Mine-mouth" generation was eliminating the need to ship coal before burning it. Under regulatory pressure, the industry was inventing and adopting systems that reduced sulfur, nitrogen and particulate emissions. I went to grad school in Knoxville, Tennessee, in the heart of Appalachia. In an early career assignment, I worked on metal alloys for coal power plants.

I've been in towns in which the coal mine was the only significant source of economic activity. Coal paid for my food when I was a kid. Coal still pays for the food of a lot of kids, and for their parents' houses, and for the schools and hospitals and police and fire departments in their towns. Frequently, those towns are there only because of the coal. Miners cannot easily find alternative employment. It is not easy to re-train for another job in middle age. It is not easy to move away from your friends and family for that job, when everyone else in your town is trying to do the same thing and your home does not have any value any more because nobody wants to buy it.

I don't get excited when politicians gloat about closing coal mines. I get annoyed at their lack of empathy. However, mines that produce coal for electric generation are indeed closing and will continue to close.

In the early days of electric generation using photovoltaic solar panels, it took more energy to make panels than you would get from them over their lifetimes. Over time, technologies improve. New solar panels produce more energy than it takes to make, ship and install them. The energy payback happens within a few years, and the panels are expected to last for decades.

In 1959, solar panels cost a million dollars a watt. Mass production reduces costs. By 2009, solar panels cost about $10 a watt. Today, a utility scale solar power plant costs less than a dollar a watt. Over the last 50 years, wind generation and battery costs have also fallen dramatically.

Today, in many locations, wind and/or solar generators installed at a utility scale (whether it is at a single location or on hundreds of homes) can produce energy at costs well below the costs of coal-fired generation.

When you add pumped hydro storage, or modern batteries, renewable energy can be available 24 hours a day. Faster computers, installation of renewables over large geographic areas, and changes in grid management have enabled solar and wind to be added the grid more easily. Renewable generators require less maintenance and are not subject to fuel price volatility. In places where coal might still be competitive, natural gas power plants tend to be more efficient and to have lower maintenance requirements.

Renewable power is beating coal, in more and more locations, because it offers the lowest cost, not just because of environmental regulations. Coal is being phased out because it's becoming uncompetitive.