An article in the July 7th edition of the Wall Street Journal (WSJ) describes how the use of wood pellets is on the rise as a fuel for electricity in the EU. They are the “new Tulip” now being traded as a commodity on the Amsterdam energy exchange. In just looking up the price for industrial wood pellets, the price is hovering in the range of 130-140 â‚¬/MT (metric ton). With an energy content near 7,500 Btu/lb, this is similar to low rank (brown or lignite) coal.
With the well-written WSJ article referenced above, I won’t discuss the issue further here, other than to marvel that the use of wood is competing for the generation of electricity and heat with fossil and other modern renewable. Granted, the wood pellet stoves are much more controlled and efficient than your great-great-great-great-great-great-great-great (i.e. great8 to great10) grandfather’s wood burning stove. But this story is still a good example of technology struggling to overcome the limits of resources and moving back to a previous fuel. Unfortunately, we know that there are limits to the quantity of wood that can be replaced sustainably, but this is also an important feedback.
Over the last 300 years industrialized society has moved away from wood because the fossil energy resources had much higher energy density and concentration in mines and fields with oil and gas. Now industrialized society is moving somewhat (albeit on a very small scale) back to biomass in the form of these wood pellets for heat and electricity (often thrown into boilers with coal), but also including biomass for biofuels. This represents the struggle of “technology” to solve problems that society wishes to solve (in this case less greenhouse gas emissions) and the lack of focus of businesses to create substitutes for the services that primary energy resources (i.e. oil, gas, nuclear materials, biomass, sun, etc.) provide and that people want.
Unfortunately we have traditionally waited for the retrospective economic effects to tell us to return to a focus upon the value that energy resources and services provide to civilization. Data from the last 40 years shows us that people and the government focus upon energy costs when they become approximately 9-10% (at least half is for oil) of the gross domestic product of the US (for example see data at the EIA and chart in this paper by Charles Hall). Full data are not out for the last two years, but it appears as though we passed this threshold in 2007 and were likely well above 10% in 2008.
But this focus upon energy services has become, will become further, and should be center to discussions of economics. What percentage of GDP should we be spending upon energy? If this percentage gets too low, consumers and industry are not focused upon energy conservation and long term impacts. If this percentage gets too high (or too high too quickly) then general economic slowdowns tend to occur, mostly driven by oil prices in the last 40 years. Another question: How much we are in control of what this “energy/GDP” is or can be? The amount of energy obtained compared to searching and obtaining primary energy resources, or energy return on energy invested (EROI), is highly influential. If we get 50 barrels of oil when using the energy equivalent of 1 barrel of oil (e.g. EROI = 50) to find and extract that oil, then we have 49 barrels of oil to power the rest of the economy. If the EROI is 20, then this is significantly different. Less energy for health care. Less energy for education. Less energy for agriculture and food production. Etc.
We must understand to associate EROI with GDP much better than we currently understand. Otherwise, we won’t be able to foresee the longer term and very important implications of our energy policy and technology decisions. EROI must be used and understood as a measure of technical innovation.