For once, the subfreezing Minnesota winter could not keep things cool enough. With the loss of its cooling tower cells in January, an electric power plant had to act fast.

Aggreko, a Houston maker of temporary power, temperature control and compressed air systems, became the supplier of 40 temporary cooling towers to Minnesota Power's Clay Boswell Energy Center power plant in Cohasset, Minn. The combined capacity of the temporary cooling towers was about 125,000 gal/min.

When the Cohasset plant lost the four cooling tower cells in one of the units responsible for producing 350 MW of electricity -- more than one-third of the facility's total output -- it knew the remaining towers could not handle the load. The towers use continuously recirculated water to remove heat generated during the electricity-production process.

The units were mobilized and installed in a matter of days, despite temperatures that dropped to -25oF (-31oC) on some days. Cooling water flowed at the unit approximately two weeks after the initial order was placed, restoring the plant to production capacity.

The Aggreko towers remained at the plant until late April, when the reconstructed cooling towers went online. For more information, visit