Aid agencies could save more than $500 million by choosing clean energy over fossil fuels in war zones and disaster areas, global think-tank Chatham House said in a report on Monday.
Humanitarian agencies spent about five percent of their funds – or an estimated $1.2 billion – on diesel last year, and could save $517 million each year by using cleaner energy sources such as solar power, it said.
"Humanitarians are operating in tough environments where saving lives come first," said co-author Owen Grafham from the Moving Energy Initiative (MEI), a partnership managed by London-based Chatham House.
"Energy is not given much thought – diesel is the go-to fuel because it’s what agencies are used to and it’s quick-to-deploy," he said in a statement.
Carbon-emitting fossil fuels can be used as a weapon, hijacked by militants or sold on the black market and sometimes have to be flown vast distances to reach off-grid relief camps.
That creates costs that humanitarian groups can ill afford, with wars, persecution and other violence having uprooted a record 68.5 million people last year, according to the U.N. refugee agency.
Aid agencies said curbing emissions was key to preventing climate-change related disasters.
Renewable energy is key to reducing climate-changing emissions under a global climate deal after governments in 2015 pledged to hold temperature rise to "well below" 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial times, and ideally to 1.5 degrees C.
"The burning of dirty fuels increasingly impacts poor people, particularly women and girls, who are in the midst of humanitarian crises," Sven Harmeling, head of CARE International’s climate advocacy arm, said in email.
While the technology has not advanced far enough to make a full swap viable, some solar projects are already under way in the field and aid workers expect many more to follow.
Engineer Per-Erik Eriksson, from the Doctors Without Borders (MSF) Sweden Innovation Unit, said the group was making substantial effort to use renewable energy.
"However, it is not certain that such a transformation will save us money, given the current initial costs for renewable energy infrastructure. Our operations are emergency-oriented, and therefore implicitly short term," he said.
"The investment for renewable energy solutions is always higher than for diesel generator solutions, and so the savings only come over a number of years," Eriksson said from Haiti, where he is testing solar-powered air-conditioning.
Aid groups say operations also relied on diesel generators since many local workers or volunteers already knew how to use them, whereas solar energy would be costly and require specialised knowledge.
An October report by the United Nations Intergovernmental Panel on Climate Change said renewable energy would need to supply 70-85 percent of electricity by 2050 to stay within a 1.5C limit, compared with about 25 percent now.
More than 190 countries are meeting in Poland through Dec. 14 to hammer out rules that will enable the Paris accord to be put into practice from 2020, and spur countries to strengthen their current climate action plans.
Reporting by Lin Taylor @linnytayls, Editing by Claire Cozens.