About $944 billion of investment is needed by 2020 for Asian countries to meet their national energy efficiency and greenhouse gas emission reduction goals, a study indicates.

China represents 92 percent of that energy efficiency investment potential, or $865 billion, followed by India at 7 percent and Southeast Asia at the remaining 1 percent.

The study, "Accelerating Energy Efficiency in Asia," released by the Asian Development Bank to coincide with the 8th Asia Clean Energy Forum in Manila this week, noted the region's share of primary global energy consumption is on course to increase from 34 percent in 2010 to almost 56 percent in 2035.

By that time, most of the countries in the region will produce less than half of the energy they need, triggering greater reliance on fuel imports.

Using energy more efficiently, ADB says, reduces the need to build power plants and lowers imported fuel bills, potentially freeing up government funds that could be spent on providing electricity to the estimated 628 million people in the region who don't have electricity.

"There is [a] huge potential for saving energy by making buildings, vehicles, machinery and water pumps more energy efficient to the benefit of consumers and the environment, and the time is right for ADB to do more in this area," said Bindu Lohani, ADB's vice president for knowledge management, at the opening of the forum Tuesday.

"We want to promote demand-side energy efficiency through public and private sector partnership, with ADB taking a lead role in providing customized policy advisory services, technical assistance, and innovative financing support in developing member countries," Lohani said.

ADB said it invested more than $970 million in energy efficiency projects last year.

Noting implementing energy efficiency measures is more cost effective than increasing power generation, the ADB report said investments in energy efficiency equivalent to 1- to 4 percent of energy sector spending could meet as much as 25 percent of the projected increase in primary energy consumption in developing Asia by 2030.

"Robust deployment of energy efficiency can relieve pressure on existing energy infrastructure while reducing emissions and other pollutants that harm air quality and contribute to climate change," the report said.

But carrying out energy efficiency measures can be hampered by a lack of governmental leadership and the absence of a centralized authority or agency to encourage or manage such initiatives, the report said.