The World Bank approved a $3.75 billion loan Thursday to help South Africa build a coal-fired power plant over opposition from the United States and environmental groups. The bank said the loan is aimed at helping South Africa achieve a reliable power supply, to export electricity to neighboring countries and to avoid the power shortages in South Africa that led to blackouts in 2008. The bank said the 4,800 megawatt coal-powered plant would be run by the state-owned Eskom electricity utility and use for the first time on the African continent the same proven, “supercritical technology,” that major industrialized nations employ in similar plants. The United States, the bank's largest shareholder, abstained from the executive board's discussion, expressing worries about the climate impact of the power plant project and saying it would produce significant greenhouse gas emissions. Environmental groups and others opposed the loan, saying the bank should not finance fossil fuel plants. A statement from the US Treasury Department said the loan was incompatible with the bank's “commitment to be a leader in climate change mitigation and adaptation.” The Americans said they did not expect similar projects for middle income countries such as South Africa without plans in place to ensure the planned projects would cause no net increase in carbon emissions. The board's other members, including India, China and Saudi Arabia, who represent other countries, went ahead with approving the project by consensus, which means without a vote. But a top World Bank official defended the loan. “Without an increased energy supply, South Africans will face hardship for the poor and limited economic growth,” said Obiageli K. Ezekwesili, the bank's vice president for Africa.