Le Anh Tuan, lecturer at Can Tho University in southern Can Tho City, spent VND130 million ($5,600) to install a 3.9 kWp rooftop solar power system in his home four years ago and is now enjoying the fruits of his investment.

Tuan was able to save up to VND1.2 million each month compared to using normal electricity, twice the amount of monthly deposit interests.

Thai Minh Bao, a representative of World Wildlife Fund (WWF) in central Thua Thien Hue Province, said his office paid VND155 million to install a 5.2 kWp rooftop solar system in 2017.

The amount of money the office was able to save each month came to around VND1 million ($43).

These two are among thousands of households and organizations in Vietnam that have installed rooftop solar in recent years. As of August 23, nearly 45,300 rooftop systems were operating nationwide with a total capacity of 1,029MW, according to power utility Vietnam Electricity (EVN).

These figures come amid a surging demand for power in one of the fastest growing economies in Southeast Asia. The government has been encouraging renewable energy as the country’s hydropower potential is almost fully exploited and oil and gas reserves are running low.

Industry insiders say rooftop solar installation prices have dropped by half in the last three years to VND14-18 million per kWp now and this has sparked increasing demand.

The government’s buying price at an incentive rate of 8.38 U.S. cents per kWh also contributed to the rising popularity of this type of power and many domestic and foreign investors have stepped into this area.

Rooftop solar panel manufacturers estimate that it will take five to seven years for users to recoup their investment.

But Nguy Thi Khanh, director of the Green Innovation and Development Centre (GreenID), estimated that the installed capacity could go up to 48,000 MW, or 48 times the current capacity.

But a lack of a national technical standard daunts potential users.

Tran Viet Nguyen, deputy head of sales at EVN, said there are currently no specific regulations on what kind of solar equipment is allowed, and this makes people hesitant.

Installation prices, though decreasing, remain a concern for buyers, and the government should provide initial financial support to encourage more people to buy, he added.