ROSES FROM MINNESOTA

Roses.

Roses, snapdragons, tomatoes, lettuce, green peppers andpine seedlings.

Our December report on growing peanuts and cotton in the German Agrotherm Project had an unusually large response. True, that is so far the only case of rejecting heat from power plants directly into the earth for growing outdoor crops; but there is plenty of use for power plant heat in America, too.

Northern States Power Company's new Sherburne County Power Plant (Sherco), about 50 miles northwest of Minneapolis-St.Paul, is running a demonstration project using some of its walls water to heat 14 greenhouses with a total area of 23,000 square feet (about half an acre). The warm water at 85 degreesF heats the greenhouses via pipes buried in the soil underneath and via heat exchangers in an air duct. It flows at 700 gals/min, leaving the greenhouses for the cooling towers at 75degreesF (from where it returns to the condensers at 55 degreesF). The greenhouses are made of strong, corrugated fiberglass, with a layer of polyethylene inside to provide an insulating air space. When the Minnesota winter envelops the greenhouses at 25 below zero at night, the inside maintains a temperature of about 60 degrees that's 10 degrees more than New Jersey's Governor Bryne allows, under penalty of arrest and prosecution, for businesses operating more than 40 hours a week. (An old story: Where the free market wasn't allowed to work, police and jailers will eventually step in.)

After a successful small pilot project run by NSP and the University of Minnesota in 1974, the demonstration project is now running to check whether the method is economically feasible. The results look promising, and private commercial growers could begin operating their own facilities at the Sherco plant site, with NSP leasing them the land and selling them the heat of the cooling water, this year or next.

Yes, private commercial growers: They have a way of extracting the maximum benefit from "waste" heat. They don't get their money from tas-exempt sham-foundations and don't use it for progressive, societally relevant research projects (maybe "The sexual mores of the poor in thermally polluted greenhouses").

3-77/2

The first crop, planted in January 1976, included 50,000 long stemmed red and yellow roses, 25,000 tomatoes (vine ripened not picked green for shipping to the north-central region), and more than 5,000 sweet green peppers.

Now in the world: 3,000 jackpine and red pine seedlings, to be seeded in small containers in the greenhouses. Evergreens are expected to grow to field planting size 4 to 5 times faster than in outdoor nurseries.

[More: Write Northern States Power Co., Research Dept., 4th floor, 414 Nicollet Mall, Minneapolis, MN 55401.]