Vorsana

Renewables such as wind and solar energy are not a feasible near-term solution in the short time available to deal with the impending catastrophe of global climate change. In debating legislative or other strategies for addressing the problem, it is pointless to waste time discussing the merits of renewables alone.

Wind, solar, and other renewables combined presently account for only a tiny fraction of global electricity production, and they cannot be scaled up in time.  Wind and solar, while promising, are intermittent in nature.  Because of this, they cannot comprise more than 20% of the electrical load for the grid.  Constant base load electricity is a necessity which is principally produced by burning coal and natural gas, both of which emit large volumes of carbon dioxide, among other pollutants. Therefore, the solution is not to ban coal in favor of renewables, but to find ways to reduce pollution from coal, including using renewable power to take take care of the carbon dioxide emissions.  The whole picture of emissions, in detail, can be found in the EPA's latest U.S. Greenhouse Gas Inventory Reports.

In the United States, for example, here are the figures in megawatt hours for the various forms of utility electricity production in 2006.

Renewables (wind, solar, and all others combined) are less than half a percent of coal.

Coal-fired electric power plants are the worst source of carbon dioxide emissions. Natural gas is also very large. But, as can be seen from the above table, fossil fuel combustion for electricity is indispensable. Coal is projected to remain the main source of power for the foreseeable future, especially in heavy greenhouse gas polluters like the U.S., India, and China.

Despite the merits of wind, solar, and other renewable sources of energy, it should be realized that the demand for electricity is so huge, and the capacity of renewables is so puny, that renewables are not a realistic near-term solution to the problem of global climate change.

Wind

At the end of 2006, worldwide capacity of wind-powered generators was 73.9 gigawatts, which, although it dwarfs solar, is a tiny fraction of the world power demand (~ 1%). Could wind be scaled up to replace coal in time to prevent catastrophic global climate change? That’s a vain hope.

Wind is less reliable than coal. Coal can always produce power when it is needed. Wind cannot. In North America, the times of maximum power demand coincide with times of low wind speed. Storing wind power is an unsolved problem.

Also, there are significant public policy limitations on new wind installations. The places where sufficient wind is available tend to be far from the cities where the power will be consumed. Getting environmental approval for new power lines to connect to the grid is a lengthy and difficult process. Construction of transmission lines costs about $2 million a mile. The wind farms damage migrating waterfowl and have proved to be unwelcome neighbors of rich and litigious environmentalists.

Photovoltaic Solar

Total peak power of installed photovoltaic solar installations was 6 gigawatts at the end of 2006. That is only 8% of wind, which is itself only about 1% of world power demand. So solar is not a realistic solution in the near term.

Peak power is not available at night, and only on clear sunny days. Given the emergency situation of impending global climate change, with small time left to implement any solution, and the small present deployment of photovoltaic power as well as its high expense, it appears to be pointless to debate the merits of photovoltaic solar power. That’s not to say that if we make it to the next century, solar may not become the dominant form of power production.

The world’s largest photovoltaic installation is being constructed at the Solarpark Waldpolenz project near Leipzig, Germany. It is 40 megawatts (0.04 gigawatts), and the next biggest is the 20 megawatt Solarpark Beneixama in Spain. Germany leads the world, with 2.5 gigawatts installed, followed by Japan at 1.7 gigawatts. The United States has only 0.6 gigawatts of photovoltaic power.

Concentrating Solar

Parabolic troughs, or mirror arrays, concentrate solar energy to produce heat, which in turn produces power. The worldwide amount of electricity produced by concentrating solar installations is less than half of photovoltaic solar, and installations are only economical in places where abundant sunlight and lots of vacant land are available, such as deserts.

For example, the Solar One project 25 miles SW of Las Vegas produces 64 megawatts on 350 acres at a cost of $0.15 - $0.17 per kWh. Also, there is the cost and delay of securing approval for lines to transmit the power to the grid, as discussed above under wind.

Conclusion

Our house is burning, and putting out the fire – rather than plans for remodeling – should be the focus of attention. Pollution control technologies directed at post-combustion carbon capture should be the topic for intelligent discussion of global climate change. Alternative energy sources can be considered once the crisis has passed.