Business models that pair up cheap solar technologies with cell-phone services can provide the poor with renewable energy, says Carl Pope.

Desertec, an ambitious solar power project in the Middle East and Africa, should be more transparent and participatory, argues Athar Osama.

The two regions have much to gain from coordinating research and enhancing scientific cooperation on solar energy, says Frank Lehner.

Environmental engineers Tasneem Abbasi and S. A. Abbasi warn that widespread adoption of small hydro could repeat a history of environmental damage.

Biomass fuels are often branded dirty but can be harnessed in 'greener' ways through new technologies, says Duncan Macqueen.

To make an impact, small-scale renewable energy systems must fit social expectations and cultural norms, argues Benjamin K. Sovacool.

With the right support, small-scale hydropower could be a cheap and clean fuel for development, says energy advisor Teodoro Sanchez.

South Africa must get better at acquiring green knowledge and technology transfer — or be left out of global markets, says Radhika Perrot.

African bioenergy projects must focus on new technologies and receive stronger political support, says biofuel expert Emile van Zyl.

The challenge for Latin American and Caribbean governments is to combine an approach to development with low-carbon emissions, says Omar Vidal.

Universal access to energy services is technically possible, but new approaches are needed, say Kandeh Yumkella and Morgan Bazilian.

China and South Korea have become leaders in green spending — it's time for the G20 to follow suit, says Edward Barbier.

Governments in South Asia must support solar power to make it affordable to the rural poor, says development expert Vishaka Hidellage.

Africa should follow China's lead, and foster solar innovation, production and demand, says UN-Habitat's Banji Oyelaran-Oyeyinka.

China must support technological research on solar thermal energy, say Huang Ming and Yidong Gong.

New biofuels offer a sustainable source of energy but we must consider the ethical and social implications, say Joyce Tait and Banji Oyelaran-Oyeyinka.

China is considering a low-carbon road map to reduce emissions while preserving economic growth. Technology is crucial, says Gordon Conway.

Countries must join forces and act quickly to tackle climate change, say Rosina Bierbaum and Robert Zoellick in an editorial in Science.

Climate negotiations must promote capacity building, not impose quotas, argues ZhongXiang Zhang.

Renewables like solar, wind and biomass could help India meet its growing energy needs and create millions of jobs, says Anil K. Rajvanshi.