SOLAR POWER THE REAL THING

The two basic disadvantages of this type of rich man's toy large collecting areas and cumbersome storage facilities to bridge the sunless periods cannot be eliminated by any amount of research money.

Yet there is a type of solar power, dutifully ignored by the fashionable sunworshippers, which can harness solar power by the hundreds of megawatts for 24 hours a day, and on midget-sized areas.

That method is Ocean-Thermal Energy Conversion (OTEC).

The laws of physics cannot be beaten, of course, and one still has to use a square meter of area to expose it to one kilowatt of solar power. The point is that the earth's oceans, disdaining congressional appropriations, are already collecting that energy on millions of square miles. Their upper layers are warm, their depths remain cold, and the temperature difference between the two can be used to run turbines on relatively small platforms or ships. And though this difference amounts to only about 20 degreesC in tropical waters, it is there day and night the oceans with their enormous water volume also act as an energy storage facility. Man needs only move in and tap it.

The 72 degrees F at the surface of tropical seas is hot enough to boil a liquid with a low boiling point - ammonia is now almost sure to be chosen and after whooshing through a turbine, its vapor is condensed by cooling it with water pumped up from the cold ocean depths. Except for using ammonia vapor rather than steam, the rest of an OTEC plant works much like a conventional power plant. Because most of the produced energy is used for pumping up the cold water, the efficiency is pitiful a few per cent but who is worried about efficiency when there are no fuel costs?

None of which is news to our early subscribers; we reported on it in Dec. 1973, and described the Lockheed and TRW designs in Jan. 1976.

But a number of things have happened since then. Government funding has drastically increased: From $3 million in fiscal 1975 to $19 million in fiscal 1977. (But how much more money would be available from independent investors if it had not been siphoned off from taxpayers and allocated for solar eyewash by politicians and bureaucrats?)

ERDA's plans now call for a 1 MW pilot plant in 1979, 5 MW in 1981, 100 MW in 1984, and 400 MW or more in the late 80's.

Now we're talking solar power! 400 megawatts is music that does not come out of toys or inaugural tribunes. There is, in fact, no clear upper limit to what solar sea power can produce. The US has direct access to warm seas in the Gulf Stream off Florida and Georgia, off the Virgin islands, and off Hawaii. In a $425,000, 16-month feasibility study, Prof. W.E. Heronemus of the U. of Massachusetts concluded that the ultimate power potential of an area 550 miles long by 15 miles wide, from Charleston, S.C., to the Florida Keys,, is of the order of 2 trillion kWh/year, about twice the present US electric power consumption! The study envisions 4,500 floating solar sea plants with cold-water inlet pipes 1500 feet long and 87 feet in diameter.

Now Prof. Heronemus has long suffered from chronic optimism. But suppose he is overestimating the potential by 300No; then there would still be more than enough to replace all gas and oil-fired power plants in the country.