n 2014, India signed the Paris Agreement, pledging to generate 40 percent of its power from non-fossil fuel sources by 2030. By 2018, the nation had already exceeded its original five-year benchmark: 35 percent of the country’s electricity now comes from renewable sources. To understand the root of India’s successes, it’s worth taking a close look at Visakhapatnam, a city on the country’s central eastern coast that is a leader in alternative energy development.

Visakhapatnam, also known as Vizag, has long struggled with severe income inequality and spotty delivery of electricity, resulting in many “electricity deserts” within the city. But in the past 15 years, Vizag has experimented with new advances in energy generation technology that have brought upward mobility and reliable, sustainable power into reach for the average citizen says Chaganti Sundara Rao, a social and environmental activist.

According to Rao, who has spent the past 16 years working as the president of Praja Spandana, a nonprofit organization dedicated to improving the quality of life in Visakhapatnam, the newfound abundance of electricity is built on two novel technologies: modified Stirling engines that can burn cow dung fuel and “floatovoltaics”—floating solar panels (FPVs).

Originally designed in the 1800s, Stirling engines are a type of external combustion engine. A modern version of the device, developed by NASA in the 1980s, connects to a biogas chamber that can use almost any biological substance as fuel. A model manufactured by Netherlands-based Microgen Engine Corporation, for instance, produces 1,000 watts of electricity per hour on roughly two to three kilograms of dry cow dung.

Asok Dasgupta, an engineer and community liaison for Microgen, became passionate about finding ways to help people meet their urgent daily needs while studying physics at the University of Calcutta. “There’s so much poverty in India,” he says. “For many people, these engines are a way out.”

According to Dasgupta, many Vizag residents had limited access to electricity because the existing power grid was inadequate and would often break down, or they were never connected to the infrastructure in the first place. These electricity deserts hamper communities, he says. No power means, among other things, no studying after sunset, no refrigerating surplus crops or food, and no recharging phones.

Bureaucratic hang-ups within the federal government mean that over the past decade India’s electricity infrastructure has expanded only slowly. Despite skepticism from government officials, entire neighborhoods in Vizag have been bypassing the federal government’s red tape by pooling resources to purchase Stirling engines directly.

As Dasgupta points out, as more neighborhoods have invested in Stirling engines, the percentage of India’s energy stemming from renewable sources has shot up. While some of that number comes from a transition from fossil fuels to renewable sources, more of it comes from people who are now able to use electricity for the first time, he says.

Cow-dung fueled Stirling engines are already a success for one group in Vizag: the Visakha Society for Protection and Care of Animals. Its cow sanctuary houses calves rescued from illegal slaughter, and finding a way to operate without causing harm to living places is part of the organization’s mission. Biogas engines, fueled by cow waste, helped solve the group’s problem.

The second new technology powering Visakhapatnam is floatovoltaics, a recent development in solar energy technology first patented in 2008. In November 2018, the Greater Visakhapatnam Municipal Corporation (GVMC), which oversees the governance of the city, commissioned a solar power plant designed to float on the city’s Meghadrigedda reservoir from India-based ReNew Power Limited.

According to ReNew, the reservoir allows the water and solar panels to form a mutually beneficial system. The water limits evaporation in the photovoltaic cells, and cools the solar panels, boosting their efficiency. Compared to an equivalent solar panel on land, a FVP converts 22 percent more of the energy it absorbs into electricity before triggering a mechanism that prevents overheating.

As technology advances, a GVMC representative says the Meghadrigedda reservoir project could generate more than 4.2 million kilowatt-hours of energy, enough to power approximately 2.7 million homes. The GVMC estimates the project will reduce 3,080 tonnes of carbon dioxide emissions every year—the ecological equivalent of planting more than 1.3 million mature trees.

Rao acknowledges that there is currently little data on the long-term ecological effects of floatovoltaics. Also, solar energy prices can be volatile, making investing in the technology tricky.

That said, biogas-based Stirling engines and floatovoltaics are already working in other places. Japan and China have begun installing floatovoltaic farms, and in North America biogas engines have brought some large-scale California dairy farms within the state’s methane regulation mandates.

India is close to meeting its 2030 renewable energy goal, and it’s only 2019. Looking at Visakhapatnam’s success and the technologies’ improvements, municipal government officials, activists like Rao, and engineers like Dasgupta see reason for optimism.