There has always been a warm spot in the hearts of those of us following the peak oil story for Scientific American- the magazine that in 1998 published the seminal article by Colin Campbell and Jean Laherrère that launched the modern era of concern about peak oil.

In October, however, Scientific American slipped a bit when they published an essay by Leonard Maugeri, an executive vice president of the Italian oil company ENI and long-time publicist for the notion that there will be plenty of oil if only we rework existing oilfields with secondary and tertiary recovery methods. This reworking, of course is already being done, and has been for years wherever it is economically feasible. To claim that the world can be saved if only we tried harder to get more oil out of old fields has long been discarded as a panacea.

Anyway, this month Scientific American is back on track with a cover story entitled “A Plan for a Sustainable Future – How to get all energy from wind, water and solar power by 2030.” Now this is more like it.

Getting rid of, or at least making a start on getting rid of fossil fuels in the U.S. over the next 20 years is something we should all be thinking about – especially if we want to leave much of anything to the grandchildren. The authors, a professor of environmental engineering at Stanford and a research scientist at the University of California, are well qualified to do the calculations necessary to size the effort to replace the world’s fossil fuels with energy derived from wind, water and sunlight (WWS).

The article tells us that currently the world is consuming about 12.5 trillion watts of all forms of energy at peak consumption. In 20 years, the demand will be up 16.8 trillion watts given growth in population and living standards. U.S. peak demand in 2030 would be 2.8 trillion watts of all forms of energy. Interestingly enough that would decline to 1.8 trillion if the U.S. automobile fleet were converted from gasoline and diesel to far more efficient electric power. If you are worried about enough sun and wind, you shouldn’t be, as suitable wind locations will be able to provide 40-85 trillion watts, solar an additional 580 trillion watts and water power in one form or another, two trillion more.

The hardware numbers the authors arrive at to replace fossil fuel are impressive, – 3.8 million 5-megawatt wind turbines, 490,000 tidal generators, 720,000 0.74 megawatt wave converters, 1.7 billion .003 megawatt rooftop photovoltaic systems, 5,300 geothermal plants, 900 1.3-megawatt hydroelectric plants, and to top it off 49,000 concentrated solar 300-megawatt power plants and 40,000 commercial photovoltaic power plants. Total cost would be on the order of $100 trillion.

Interestingly the authors do not consider an effort of this magnitude beyond the capacity of the world’s industrial, manufacturing and construction resources. They note the massive transformation that took place during World War II when nearly every industrial nation on earth was switched over to producing war material. Producing four million wind turbines and over 20 years (200,000 per year) and the other installations required is not beyond a global civilization that has the capacity to produce 80 million automobiles each year.

Three hurdles to a transition away from fossil fuels have been identified. The first is whether there will be enough specialized materials – particularly exotic ones such as neodymium, tellurium, indium and lithium that would be necessary for the magnets of wind turbines, photovoltaic cells and high capacity vehicle batteries. While a solution to this is not immediately obvious, the authors seem to believe that alternative ways of making the necessary components plus recycling should be sufficient to produce and sustain the necessary hardware.

A major feature of the plan is the mix of solar, wind, water, and geothermal power that if harmonized in large-scale smart grids should be able to fill the demand for electrical energy around the clock despite the intermittent nature of wind, solar. With hydro (including tides, waves, and flowing rivers) and geothermal providing a base, wind and solar would provide the bulk of the load in a post-carbon world depending on the time of day and wind and sun conditions. An important requirement for such a mix would be a grid capable of moving power from areas where the sun is shining or the wind blowing adequately at any given moment to deficit areas.

Another important consideration is that costs of renewables are dropping and those of fossil fuels are growing. Wind is already competitive with the cost of coal generated electricity is some areas. The better grades of coal are depleting and will have to be replaced by lower energy coals that have to be moved long distances. In the authors’ opinion, sequestering carbon from coal and nuclear power are non-starters due to the costs and energy involved in building and operating the facilities.

The last major hurdle to this fossil-fuel-free utopia is the political will. The status quo (fossil fuels) is deeply entrenched, with massive resources to fight change. So far the need for a transition is to most largely theoretical in that there are no shortages and fossil fuels are not yet prohibitively expensive. In America, gasoline is still affordable by most, the seacoasts are not yet routinely flooding and the crops are still growing. Recent polls are showing more and more people are becoming skeptical that reducing carbon emissions from fossil fuels is really a priority in view of the current economic difficulties.

The U.S. Congress presently is debating the need to cut back on the use of fossil fuels and 10,000 will soon gather in Copenhagen to discuss emission reductions. Whether a critical mass has yet formed in the U.S. or indeed in the world to take serious action is still an open question. Fossil fuel supplies are depleting rapidly and somewhere in the next two, five, ten or 20 years, prices will rise so high that renewable energy will be the only way to hold the global civilization together.