A Closer Look at Renewable Energy

Article excerpt

EarthDay 2000 will be the 30th celebration of the global envirofest. The environmental community plans and hopes for a stellar media event. The central theme of EarthDay 2000 is: "Using the sun, wind, and other renewable sources to generate energy, we can end dependence on fossil fuels."

Because energy is fundamental to people, civilization, and life itself, the energy issue deservedly occupies center stage in policy debate. Although the public most often hears about alternative energy in terms of environmental concerns--global warming, say--most discussions and policy proposals to provide energy for the nations of the world focus on economic and engineering realities. Correctly so. After all, if an energy delivery system doesn't work well--or if it is too expensive--it is (or should be) irrelevant to the efficient provision of energy.

Sad to say, the economic and engineering realities of the past 20 years have rendered a verdict of "irrelevant" on the favored renewable energy sources. Twenty years after the first confident predictions that renewables would capture 50% of the nation's energy supply by the benchmark date we just passed--Y2K--the United States derives less than one percent of all energy from the favored renewables.

But, EarthDay 2000's promotions still press renewables, with their enthusiasm reflecting the technological optimism of the Digital economy: The long-term solution is to move on from fossil fuels to smarter alternatives, just as we advanced from the typewriter to the word processor.

Although the economic and engineering realities of renewable energy sources have been detailed in many venues, renewable energy's appeal continues. Not surprisingly, a survey of registered voters asked to give a ranking to federal energy funding priorities garnered 32% for renewables and 8% for fossil fuels. The appeal of renewables continues, at least in part, because of four inter-related perceptions:

--Renewable energy is abundant.

--Renewable energy is natural.

--Renewable energy is better.

--Renewable energy is free.

These notions about renewable energy do not really concern either engineering or economics. It is understandable that one might believe that, given enough time, engineers might unleash renewable energy's apparently inherent and pent-up advantages. However, the issue is not whether engineers can make renewable sources work. We already know they can and that they do. The central issue is whether there is something different--something truly special--about renewable energy sources in terms of practicality as compared with other energy resources. To understand this issue, one first needs to look not to engineering and economics, but to something more basic: the physics of energy.

Renewable energy is abundant. True, but, for all practical purposes, energy in all forms--whether renewable or fossil--is unlimited. There is no difference in the magnitude of the basic fossil and renewable resources at any scale that matters to humans.

The litany concerning the abundance of renewable energy goes something like this: By comparison global biomass growth--wood, grains, plants, etc.--is seven times greater than the world's annual consumption of fossil fuels. Energy in the waves of the ocean is at least 1,000 times greater than fossil fuel consumption. These are impressive facts, but they have no bearing on the practicality of these supposed energy sources.

Mother Earth also holds, at last count (and the count keeps growing with the passage of time and continued exploration and discovery), abundant natural fossil fuel resources. So we can just as accurately say something like this: Compared with worldwide annual fossil fuel consumption, earth has

--700 times more energy in the form of coal.

--500 times more energy in heavy oil resources.

--2,000 times more energy in natural gas locked in deep ocean methane hydrates. …