Wood for Power?

The formerly great Britain has taken an unusual tactic for generating electrical power. It is planning on shutting down most of its coal and nuclear stations and replacing them with renewables. This is due to a mixture of EU mandates and Britain's own energy policy. It is now mandated that 20% of Britain's electrical power come from renewable sources.

Now, there is nothing inherently wrong with renewables in and of themselves, and in some applications they are quite useful. However, any attempt to completely remake a country's energy supply is something that should not be taken lightly. In the 21st century, a constant, predictable and sufficient supply of electricity is required. Leaving out the matter of convenience, a stable electrical supply is essential for basic public safety. It's very difficult to have clean water if the pumps don't run all the time, safe food if refrigerators cannot be run reliably, communications, medicine, and a host of other things. One of the side effects of our comfortable, safe lives is the fact that we must have a stable supply of electricity at all times.

Now, when Britain embarked on this renewable crusade, it was assumed that wind and solar power would pick up the slack. In a country as cloudy as Britain, solar is simply not sufficient, and it is now turning out that the wind farms are far more costly to install and maintain than anticipated. Offshore wind farms might be more efficient than ones on land, but the problem of how to deal with the highly corrosive saltwater has not been solved.

With solar and wind being unsuitable, and Britain unwilling to abandon its energy policy, a strange new beast has been born: converting coal power plants to burn wood chips.

You heard me. Wood Chips. Now, Britain doesn't have nearly enough wood to meet its electrical needs, and neither does continental Europe. China doesn't, India doesn't. Brazil, Indonesia, and the Congo do, but that involves cutting down huge portions of tropical rain forest, which is hardly environmentally friendly. Russia has vast forests, but there are political problems with buying wood from there. Canada also has huge forests but insufficient infrastructure to harvest and export wood on a large enough scale.

That leaves exactly one place on earth that can meet Britain's new wood demand: the southeastern United States. Often called the 'woodbasket' of the world by people in the industry, the southeast grows, harvests, and processes much of the wood used throughout North America and Europe. Contrary to popular belief, these are not regular forests that are cut. The trees are grown on plantations and harvested like any other crop. In Nassau County FL, where Starlab is located, 60% of the county is tree farms. Most of the trees are slash pine, a type that grows quickly and with little work.

Most of the tree farms in the southeast produce wood for lumber, planks, or pulp for paper. Now, an increasing number are being used to grow wood pellets to burn in Britain's power plants. Is this policy environmentally friendly or harmful? Let's do some math.

A pound of wood contains about 6,200 BTUs of energy. The value does differ slightly based on the species and moisture content. Now, a pound of anthracite coal contains about 14,000 BTUs, more than double that of wood. So, if you convert a coal power plant to burn wood, you use 2.25 times as much fuel. In a country like Britain, where either coal or wood must be imported, that extra fuel requirement is huge.

It has been said that coal is not a very clean fuel, and this is true, especially with older power plants. Newer plants capture most of the sulfur, particulates, and other pollutants. However, it is important to note that burning wood produces at least as many particulates as burning coal does. In addition, trees take in mercury, so there will be some mercury emissions as well. The act of growing, harvesting, and transporting millions of tons of wood is also hard on the environment.

To my mind, if one wishes to use combustion to produce electricity, then the sensible thing to do is to use the fuel with the highest energy density. With a more energy rich fuel, you burn less of it, which cuts down on the total amount of pollution generated. Also, if a nation has to import the fuel for its power plants, then you want to use the most energy rich fuel possible to cut down on transportation costs.

In closing, an energy policy that requires vast tracts of forest land to be cut down does not seem sensible for me. Using wood for energy was a fine technology in the 18th century, but we've moved far beyond that.


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