The International Energy Agency (IEA) has launched a roadmap showing how solar energy could account for around one-sixth of the world's total low-temperature heating and cooling needs by 2050.
The Solar Heating and Cooling Roadmap, published just days after the IEA's first ever Medium-Term Renewable Energy Market Report was launched, outlines how best to advance the global uptake of solar heating and cooling (SHC) technologies. SHC technologies produce very low levels of greenhouse-gas emissions. While some, such as domestic hot water heaters, are already widely in use in certain countries, others are just entering the development phase.
While solar heating and cooling today makes a modest contribution to world energy demand, the roadmap envisages that if governments and industry took concerted action, solar energy could annually produce more than 16% of total final energy use for low-temperature heat and nearly 17% for cooling. This would correspond to a 25-fold increase in absolute terms of SHC technology deployment in the next four decades, the agency says.
"Given that global energy demand for heat represents almost half of the world's final energy use – more than the combined global demand for electricity and transport – solar heat can make a significant contribution in both tackling climate change and strengthening energy security," said Paolo Frankl, Head of the IEA's Renewable Energy Division.
In addition to replacing fossil fuels that are directly burned to produce heat, solar heating technologies can also replace electricity used for heating water as well as individual rooms and buildings. "This would be especially welcome in warm climate countries without gas infrastructure and lacking alternative heating fuels," says the IEA. South Africa is cited as an example of a country that would benefit, as electric water heating currently accounts for a third of average household (coal-based) power consumption there.
In addition, the report notes that solar thermal cooling technology – in which the sun's heat can be used to cool air – can reduce the burden on electric grids at times of peak cooling demand by fully or partially replacing conventional electrically powered air conditioners in buildings.
Over the next decade governments should act by creating a stable, long-term policy framework for solar heating and cooling; introducing economic incentives; and addressing barriers such as a lack of quality-control standards, according to the roadmap. They should also provide funding and support-mechanisms for research, development and demonstration "so promising technologies that are at an early stage can reach high-volume commercial production within 10 years".
