What's holding up AE?
People remember the times when oil hits $40 a barrel. They forget that (so far) each oil price spike has generated more drilling, increased production and an eventual oil glut. A few years ago oil was below $10 a barrel. The effect on alternate energy development is predictable: a great deal of interest when oil prices peak and a lapse of support when gas is cheap. How often will this repeat?

My understanding is that more and more of the earth's crust has been mapped by increasingly sophisticated instruments and that new oil is being discovered at only a fraction of the rate we are using existing reserves. Sooner or later oil production will peak, while world wide demand will continue to increase as countries like China industrialize. The world is not going to run out of oil any time soon. However, rising demand and constrained supply are likely to set an increasing floor under oil prices. This will hopefully reduce the tendency of oil gluts to pull the rug out from under alternate energy development.
1 - Boom and Bust cycles on oil prices -
2 - Unrealistic Expectations -
Most people who have not looked at the engineering details greatly overestimate the amount of energy produced by a solar panel or a wind turbine. The cute little drawings accompanying newspaper articles on alternate energy often show a large town or small city apparently being powered by a half dozen modest size wind turbines or a few rows of solar panels. This is a wildly inaccurate picture. The scale is off by a factor of ten thousand.

It takes a lot of area to produce solar or wind power on an industrial scale. Just as importantly, these sources are intermittent. The energy is not available much of the time. Either the energy must be stored somehow or conventional power plants must be built to cover those dark, windless periods. (Biomass fuels such as ethonol from grain or methane produced from waste materials have an advantage here since they inherently involve chemical storage of energy.)

The simple "direct replacement" model generally won't fly. You can't put up some wind turbines and solar panels and eliminate all the conventional power plants. The characteristics are too different.
The economic, environmental and human costs of our dependance on fossil fuel (particularly oil) are increasing. There are a number of other sources of energy which may offer viable alternatives (I bought my first book on alternate energy in 1974 after the initial Arab oil embargo). Yet progress in this direction has been disappointingly slow. Why is this so? I see several key factors -
The result of the previous two points (cheap gas during oil gluts and unrealistic expectations for alternate energy sources) has been that we haven't made the commitment in the right areas to really convert a major percentage of our economy to alternate fuels. Some people simply blame it all on George Bush or the oil companies, but I think this misses the real problem. A lot of people talk big about supporting solar and wind power, the hydrogen economy, biomass, etc. However, my observation is that many more people support the idea of alternate energy than support the actual physical development of alternate energy projects, particularly ones near them.

Many people claim to support wind power, as long as its just a warm fuzzy theory. They often have a utopian vision of a few modest windmills powering a small city. In reality it takes in the order of 40,000 wind turbines with blades 50 feet in diameter to have the same average power output as one large nuke plant. When confonted with this reality, many of the same people are outraged that anyone should even suggest defiling their coastline or mountain top with such an installation.
3 - Lack of Commitment