Those hoping that renewables will be an 'instant fix' to the developing crisis in electricity generation are in for disappointment, reveals a new report from Thinking Energy, a unit of The Thinking Companies, Inc. Only wind power is applicable for new, large-scale electricity generation at the moment. The report, 'Earth, Water, Fire & Air: Utility Strategies for Renewable Energy' assesses the suitability of renewables for electric utilities, paying attention to their economics, their impact on transmission grids, and their current state of technological development.

Despite decades of government-sponsored research, many options like geothermal energy and tidal power remain impracticable or uneconomic for utilities, and severely limited in terms of suitable locations, the study demonstrates. While photovoltaic solar power is gaining acceptance with homeowners, through subsidies and tax breaks, it is still a long way from the conversion efficiency levels needed to attract utilities.

Two popular options, hydro power and biomass combustion, have their own specific problems. While dam-building will continue in developing nations, hydro has just about reached its limits in terms of sites and public acceptability in North America and Europe. Biomass energy in the form of 'energy crops' or combustion of agricultural surpluses is a travesty of green thinking. Large-scale gathering of wastes over a wide geographical area is uneconomic, with economies of scale wiped out by logistical costs. Co-firing of biomass with coal, however, remains an attractive option.

The report suggests that wave power technology may improve sufficiently during the next decade to become attractive, but agrees that wind power is the most mature and suitable renewable technology at present. "It's not all positive news on wind energy," says author Peter R. Savage. "The best installation sites appear to be offshore, but those cost considerably more. And since wind power is intermittent, this intermittency leads to quite unattractive capacity utilization levels, rarely above 40 percent, and often below 20 percent, as well as making it undispatchable in grid terms."