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.

Nuclear power is no magic solution, argues Pervez Hoodbhoy — it's not safe, or cheap, and it leads to weapons programmes.

Rising costs and re-evaluated risks make nuclear power a poor choice, even for developing nations that can afford it, says José Goldemberg.

Nuclear power can benefit developing countries but requires long-term planning and an educated workforce, says Michael J. Mangala.

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

Assessments of bioenergy must consider the potential benefits for rural development and food security, say Lee R. Lynd and Jeremy Woods.

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

Sub-Saharan Africa should adopt smart grid technologies to improve energy access, argue Morgan Bazilian and colleagues.

India must reject imported technology to ensure the safety of new nuclear power stations, says A. Gopalakrishnan.

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.

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.