The pledge was made yesterday (8 November) in a declaration signed by 78 countries at the Beijing International Renewable Energy Conference.
Because progress in renewable energy technology has been led by developed countries, most developing nations have been left behind, said Mohamed El-Ashry, a senior fellow with the United Nations Foundation.
“The global imbalance will increase unless the international community strengthens its commitment to the scaling up of renewable energy development and use, especially in the developing countries.”
In a message to the conference, UN secretary-general Kofi Annan urged industrialised countries to speed up the transfer of technologies and funding to developing nations.
Calling also for greater South-South cooperation, Annan said renewable energy was essential for improving the lives of poor and vulnerable people.
Zhang Guobao, vice-minister of China's National Development and Reform Commission pointed out, however, that accepting assistance from developed countries can be problematic for poorer nations.
"Sometimes, we have been forced to buy equipment from developed countries when accepting their loan, grant or technical aid," said Zhang. "The expensive equipment adds to our costs."
For example, says Zhang, electricity made in coal-fired power stations costs one-third of that using wind energy technology from industrialised nations.
China plans to build hundreds of coal-burning power stations in the coming years to support its rapid economic growth. Worldwide, its emissions of carbon dioxide, the main gas responsible for climate change, are already second only to those of the United States (see China is second biggest greenhouse gas emitter).
According to a report released on 7 November by the International Energy Agency, China will produce one-fifth of the world's emissions by 2030 (see CO2 emissions set to soar to meet rising energy demand).
To help counter this, says Zhang, China will double the contribution of renewable energy to overall supplies from seven per cent today to 15 per cent by 2020.
But he added that this would cost 1.5 trillion yuan (US$184 billion) — and some of this money would need to come from international donors and China's private sector.
Zhang added that China is considering improving the incentives it offers to businesses to invest in renewable energy.
He also said that China would help other developing countries use renewable sources of energy such as wind, solar, and biomass.
Renewable energy supplies 17 per cent of the world’s supplies, according to a report by the US-based Worldwatch Institute's Renewables 2005 - Global Status Report.
Read more about China and climate change in SciDev.Net's China & climate change spotlight.