Some good ideas take a while to be copied. This is the case with solar building codes, which were invented in Israel 29 years ago. Within the last two to three years, this political instrument has reached all five continents and will develop solar thermal markets in a sustainable way. The world map shows the status quo in 16 countries.

India is poised to expand its role in photovoltaic manufacturing and use, and to become a global leader in this technology.

Off-grid photovoltaic systems often fail in remote villages in India due to poor monitoring and lack of maintenance. Theft is another major issue. While most of these systems are installed under central or state-run programs, a lack of maintenance staff at remote locations makes monitoring difficult. But the central Indian state of Chhattisgarh is different.

Energy efficiency and the profitable use of biomass residues are often demonstrated by pulp and paper factories, which are forerunners in this area. A new example is given by Dalkia and Metso, global players in bioenergy service and technology in France.

Whether salt crystals, spores or sulphates: aerosols have an influence on the yield and performance of solar thermal power plants that should not be underestimated.

Solar thermal systems are able to reduce energy costs. To realise such savings, government programmes in Turkey, Brazil and Mexico are promoting the integration of solar installations in social housing.

In the energy-poor country of Rwanda only 10% of households have an electricity connection. But scientists have now discovered a renewable energy source in the depths of Lake Kivu: methane gas. Rwanda aims to soon be generating so much electricity from this that it will be able to export to neighbouring countries too.

The climate around the most important renewable resource-wood-is becoming increasingly rough. On the one hand, many countries are pushing the use of wood as an energy source in order to protect the climate. On the other hand, the traditional users of wood as a raw material, the timber, pulp and paper industries, complain about prices being forced up by the current run on firewood.

Any company wishing to sell solar collectors and systems worldwide must have its products certified in order to obtain whichever certificate is required in a particular region. This is a barrier to being active on the global marketplace. The requirements are now converging, however.

Most residential water heaters in the US are electric. Now a solar hot water service in Florida helps to promote solar water heaters. What is interesting about the service is that a local power company is involved.