In India, 600 million people lack access to a clean toilet, and, lately, the government has been on a big drive to build more of them. Prime Minister Narendra Modi’s “Clean India” campaign aims to provide decent sanitation to all Indians by 2019.

SHRI, formerly called Humanure, has a solution it thinks can help. It builds a 16-toilet community block (eight for women and eight for men), with a big collection tank underneath. As the waste degrades, it pipes off the biogas to run an electric generator. Then it uses the electricity to clean groundwater, which it sells to offset the cost of cleaning the toilets.

So far, SHRI has built four blocks in Bihar state, in northern India, and co-director Joan DeGennaro says it’s just getting started. The non-profit now hopes to tap into the billions of government rupees available for toilet projects, as well as billions of dollars potentially on offer in Silicon Valley.

“We’re making a big push to fundraise in Silicon Valley from VCs and angels who normally make startup investments,” she says. “We’re appealing to them because we do have that sustainable element of generating revenue with the water.”

SHRI (which stands for Sanitation and Health Rights) was part of the 2016 crop of non-profits in the Y Combinator accelerator program. And DeGennaro says the experience helped give the group a more business-like approach (as well as a grant for $100,000). “They provide funding as well as the opportunity to gain credibility alongside traditional software startup companies. We were told we were just like any company in the batch and that, just because we’re a non-profit, that shouldn’t distract us.”

Getting sanitation to billions of underserved people is particularly challenging because it’s not just a question of building toilets. Research shows that people often need to be encouraged to use new facilities, and that cultural factors can be a deterrence. Critics say the Clean India program has been insufficiently focused on these human factors, and that the large sums of money on offer has led to corruption.

The SHRI blocks are designed for villages of 1,500 people and DeGennaro says, on average, they’re used by 800 people a day. Access is free, unlike other toilet projects where charging a fee is thought to raise the value of the service in the customer’s eyes.