Renewables accounting for more world power generation

By OGJ editors
HOUSTON, June 24 -- Renewable power generation technologies including geothermal energy and biogas-fueled generators are contributing a growing percentage of the world total bulk generating capacity.

The Norwalk, Conn.-based Business Communications Co. Inc. (BCC) said the total electricity generating capacity from renewable energy systems outside of large hydro surpassed 100 Gw in 2002.

With a world total bulk generating capacity from all sources of 3.35 Tw in place, the renewables percentage has climbed to nearly 3%—up from a minuscule percentage a decade ago, BCC said in a recent report, "Renewable Bulk Power Sources: World Markets for Biogas and Geothermal Power Plants."

Geothermal and biogas together account for more than 10% of renewables capacity. Their share of total capacity varies from region to region, depending on resource availability and the project economics.

Most renewables generating capacity is found in developed economies. Geothermal breaks this trend because Indonesia and the Philippines have large geothermal capacities.
Similarly, bulk capacity biogas is confined to countries having landfills, sewage treatment infrastructure, and industrial animal operations.

Power-on-demand systems, such as biogas-fueled energy conversion devices and small hydro, have outputs up to 10 Mw. Biomass combustion and geothermal power systems can be larger.

The report analyzes the use of anaerobic digesters at landfills, wastewater treatment plants, and concentrated animal feedlots in terms of power-generating capacity, the number of projects on a regional basis, and the annual project revenue.

The resources for geothermal energy, biomass, large wind turbines, and photovoltaics, "are perceived to be so vast that all of human energy consumption is tiny by comparison," BCC said.

"Biogas from organic waste matter has a horizon in the tens of gigawatts of capacity. But biogas is close to the point of consumption, and also a natural byproduct of the sanitary support and food industry infrastructures of modern life," BCC said.

The utility grid is not the sole determinant of a project in the case of waste biogas. Sewage treatment plants and dairy operations are capable of consuming all power onsite.

"Animal wastes, a growing environmental problem worldwide, are being turned into energy cash cows wherever large concentrations of cattle, swine, and poultry are located. It is a value proposition that municipalities and livestock operations are finding attractive," BCC said.

Regional growth rates approaching the double digits are forecast for biogas-fueled generation industry. Geothermal power projects require larger capital investments to achieve economies of scale.