I like Barack Obama but I have doubts about his presidency when I hear him saying that the US will “double the amount of energy that comes from renewable sources by the end of my first term." He should know that that’s not possible. But instead, during his State of the Union speech, he proclaimed that we’ll reach that goal in three years, not four.

Most anyone who has studied the energy situation must wonder about Obama's, or his advisors', energy experience. Presented with the numbers from the table (see below) he would realize that the majority of the renewable power comes from hydro and from wood, about 154 gigawatts. Readily available data show that the 6 percent for hydro and bio is pretty much all we can hope for. Trying to increase those yields we would have to ask: Where shall we find the extra rivers to dam? Lease the Amazon? And where do we find the extra land to double the wood and corn production? Annex Canada? Ukraine?

Understanding those limitations, Obama apparently relies on direct solar, wind, and geothermal energy growth. All three sources are presently producing about 19 GW. To reach the goal of generating 2 x (154 + 19) = 346 GW by 2012 (or 2011), the output of the three sources would have to increase nine-fold. That implies building many times more wind mills, solar plants, and geothermal stations in three years than have been installed in the previous decades.

The cost of these projects, projects that will provide extraordinarily expensive electricity (five to ten times more than coal or nuclear) is enormous even on the scale of the anticipated deficit spending, pardon me, stimulus package. While the cost would be prohibitive, the real question is whether the four-year, now three-year, deadline is at all realistic. Before we look into that, perhaps a comparison with past prophesies will give us a hint.

During the 1970s, Jimmy Carter committed the US to derive 20 percent of its energy from renewable sources by the year 2000. Let's check: The proportion of renewable energy production today, 9 years after the deadline and almost 40 years from inception, is essentially the same as during Carter's presidency. Worse yet, the percentage has declined recently from 7.5 to 6.7 percent over the past 10 years.

In 1978, Ralph Nader said “Everything will be solar in 30 years.” Notice that the 30-years mark just passed; the production is somewhere between 0.08 percent and 0.11 percent – depending on what is meant by “everything.”

The Union of Concerned Scientists, projected for the millennium end: “Wind farms will provide 0.68 quads of electricity” (the amount was 94 percent less than predicted), “direct solar 0.60 quads” (the amount was 87 percent less).

In 1973, Walter Morrow, Associate Director of Lincoln Laboratories at the Massachusetts Institute of Technology predicted that the US would generate 750 to 1500 GW, or 10 to 20 percent of total energy from direct solar by year 2010. The actual production is 3 GW or 0.078 percent. On the positive side, there are three more years to go.

The above were predictions. Obama has made a commitment. How is he going to fulfill his goal? Realistic hydro and bio additions are insignificant. Wind electricity is cheaper than solar, and that's probably where the emphasis will be. Ordering wind turbines will create manufacturing jobs, but unfortunately many of them will be in Denmark because that's where most of them are made. In the US, there will be jobs for a handful of construction workers erecting the mills.

That leaves us with the geothermal source, a source for both electricity and heat. It amounted for 0.35 percent of the total energy for many years. Unfortunately, some sites have exhibited decline in output after a few years of operation. Regardless, the environmental impact studies for new sites will hardly be completed in three or four years, let alone a significant number of new plants started by then.

There is a proven solution to the energy scarcity and pollution – not renewables because their potential output is negligible as said -- but nuclear plants. Nuclear often is unfairly compared to renewables. Wind and solar plants have been popularized partially due to the unrecognized difference between their name plate (which is heavily advertised) and the average power rating. While a name plate 1 GW nuclear power plant produces that level of output for most of its life (93 percent for 24/7, i.e., 930 MW continuously), a 1 MW wind mill will net a fraction of that rating, about 1/5th (200 kW) on the 24/7 basis. That means that not 930 of the 1 MW mills would replace one nuclear plant, but rather 5 x 930= 4,650 of them. Obama has committed to 428 GW, not just 1 GW.

Three or four years is too short a time to forget about a commitment. Obama should start retreating from his goal now, before funds for this extraordinary spending are cast into the concrete foundations of wind mills.

Stan Jakuba writes and lectures about energy from West Hartford, Connecticut.