The Energy Road Ahead     By J. Douglas Balcomb, Ph.D.

Many believe the future of humanity looks grim if we stay on our present course. I concur. Consider climate change, rising pollution, depletion of ocean fish stocks, a population grown beyond the Earth’s carrying capacity, and nonrenewable resource depletion. I’ve just turned 75 and have had the good fortune of living during times when things were mostly good. Now I worry that my children and grandchildren face an uncertain future.

Far-sighted people have proposed plans for a sustainable future. Here’s mine. I call it The Energy Road Ahead. It’s simple enough to be expressed using just one graph, with one page of explanation.

The graph shows a 50-year transition from our present fossil-based energy economy to a sustainable renewable-based economy. The units used are quads (1015 British thermal units, or Btu) of primary energy. The 2060 end-point is based on my intuition of what a good energy mix would be. The graph would seem to describe a major contraction in our standard of living, but this is definitely not the case. Why not? During the transition, end-use efficiency doubles while energy use is halved, resulting in energy productivity remaining constant. Analysis done at the Rocky Mountain Institute shows that we nearly doubled our energy efficiency from 1979 to 1999. RMI believes an additional factor of two is easily within reach, in most cases at reduced cost. Energy use is not a measure of our economic status, but rather what the energy expended is doing for us. For instance, we don’t measure a vehicle’s utility by the fuel it burns, but by the cargo- or passenger-miles it covers per gallon of fuel. Energy cost might actually decrease when measured in units of energy productivity. The result in 2060 will be a society that is sustainable and productive.

Why just look at energy? Because wanton energy use, particularly coal and oil, is at the heart of most of the problems we face. Curtail fossil energy use while switching to renewable energy use, and we then have a chance of getting a grip on the other problems. Why does the graph deal only with the United States? Because we are the biggest problem, we can only solve our own problems, and hopefully, if we set an example, the rest will follow. Throwaway will be replaced by recycling. Materialism will be replaced by a focus on education, arts, science, family, community, equality, and access to information. My children and grandchildren will prosper, facing a future in which their children and grandchildren can survive equally well on this fragile Earth, our island home.

Here is the rationale for each major component of The Energy Road Ahead graph, below.

E N E R G Y   S O U R C E S

Natural gas: Gas is our best near-term option. Gas can fuel the transition. Utilize advanced drilling techniques to access gas in shale.

Coal: Too dirty, too much CO2, which largely drives climate change. Phase out coal over 25 years.

Nuclear: Much too dangerous. Problems are 1) safety, 2) waste disposal, 3) proliferation. Phase out nuclear as existing plants are retired.

Domestic oil: Essential for quite awhile. Husband it. Eventually use oil only for lubrication and plastics.

Imported oil: Phase out imports gradually to stretch our domestic supply. Become energy independent by 2045.

Hydro: Hydro is already maxed out, but it helps to level loads. Maintain existing big dams.

Wind: Grow wind to provide 20 percent of supply. Feed this into an enhanced high-voltage smart grid.

Biomass: Phase out corn ethanol while developing cellulosic sources. Phase out chemical fertilizers. Preserve the land for food.

Geothermal: Existing fields will gradually run down. However, geothermal may be more important if hot, dry rock can be tapped.

Solar: Solar is our major energy supply for a renewable future. Use solar thermal in the southwest for utility-scale power with thermal storage to load level (67 percent of supply). Use widely distributed photovoltaics with battery backup to provide security and redundancy (33 percent of supply).

E N E R G Y   D I S T R I B U T I O N

Electricity will continue to play the dominant role. This may eventually be augmented by hydrogen for transportation, especially in airplanes.

If we prepare for an uncertain future by taking this energy road, and our fears turn out to have been overstated — for example, that climate-change projections were exaggerated — what would be the result? Well, gradually, we would be using energy much more efficiently, powering most of our economy with wind, solar, and appropriate biofuels. We would be restoring our environment, and we might all be driving hybrid vehicles. Is that a bad prospect?

Is it possible to carry out this plan? Absolutely! In fact, the plan would be self-fulfilling in that, if it were to be adopted as our national policy, then everyone could prepare, knowing what to expect. That would make it happen. No surprises. We are innovative and adaptable.

We can do it.

In order to show diverse energies together, the graph plots energies in heat units of quadrillion Btu (1015 Btu) or quads of primary energy — defined as the heat content of the material. This follows the standard set by the U.S. Energy Information Agency and works well for fossil fuels but is less suitable for sources that produce electric energy directly. To deal with this, the EIA developed appropriate conversion factors, which are used here. These factors for year 2008 are: 9884 Btu/kWh for hydro, solar, and wind; 10488 Btu/kWh for nuclear; and 21,017 Btu/kWh for geothermal. For simplicity, these factors are used throughout the 50-year graph.
Energy Type
in year
in year


Natural gas
Domestic oil
Oil, imports

Installations Required by 2060
(based on EIA’s factor of 9884 Btu/kWh to convert from primary energy to electricity)

Wind: To generate 12.6 quads (1.274x1012 kWh) would require 121,000 wind turbines, assuming 3-megawatt (MW) units operating at a capacity factor of 40%. This is only 14 times the total capacity installed in the U.S. at the end of 2008.

Solar Thermal: To generate 11.9 quads (1.204x1012 kWh) would require 1600 solar farms, assuming 200 MW each, operating at a capacity factor of 43%. These would take up about 1,600,000 acres of land, which is about 5% of the suitable land area in the seven southwestern U.S. states.

Solar PV: To generate 5.9 quads (0.597x1012 kWh) would require 63 million 3-kW systems plus 7.6 million 25-kW systems, assuming a capacity factor of 18%. This would cover most of the rooftops in the US.

These numbers are daunting, but so are the alternatives.

© J. Douglas Balcomb • All Rights Reserved
This article was first published in the April 2010 issue of Solar Today magazine.

J. Douglas Balcomb retired as a Research Fellow from the National Renewable Energy Laboratory in 2003. He is the recipient of the Ericsson Award, the Department of Energy’s highest honor for contributions to renewable energy. He earned a Ph.D. in Nuclear Engineering from M.I.T. in 1961 and has served as chairman of the American Solar Energy Society. He was instrumental in the quantification of passive solar performance, both by analysis and testing.

Other links:
American Solar Energy Society
National Renewable Energy Laboratory