Doreen Kutilo never thought a toilet could save her so much time and money. But after a bio-latrine was built around the corner from her shack in Kibera, Africa's largest slum, she realized it could.
With the help of an NGO, residents of Kibera installed the latrine that uses human waste to produce gas to burn to heat up water that can be purchased by slum dwellers.
"At first I thought it was a very strange idea - that my own waste could be used for something - but now I'm used to it," said Kutilo, 22, stopping by the latrine to fill a basin with hot water she can then use for bathing, washing clothes or cooking.
Energy for heating is hard to come by in Kibera and most of the slum's more than 500,000 residents use charcoal, which costs about 30 cents for a small bundle.
But the bio-latrine gives the impoverished Kenyans an alternative energy source that is cheaper than charcoal, is more environmentally friendly and keeps their surroundings clean.
Kutilo said she buys less charcoal and she no longer waits as long for hot water.
"When people here use charcoal, they waste a lot of time trying to generate heat," said Peter Gachanja, who works for Ushirika wa Maisha na Maendeleo (Life and Development Cooperative), the community-based organization which operates the bio-latrine.
"If you have more time, you have more time to work and earn money," he said.
Energy harnessed from the bio-latrine, among other bio-fuel facilities, can lower reliance on firewood, charcoal and grid power, which is unreliable in many African cities and hard to come by in rural areas.
The process is relatively simple. Residents pay about six cents to use the latrine. The waste is then collected in a bio-digester, a concrete tank where it's stored for several months until it naturally produces methane gas.
The gas is then fed into a boiler that heats the water, which sells for seven cents per 10-litre basin.
More than half of Kenya's population lives on less than one dollar a day with hundreds of thousands of them crammed into informal settlements with very few toilets.
The importance of a latrine to keep Kibera clean cannot be understated. The smell of sewage wafts through the air and residents often relieve themselves on the streets because there is no toilet around or it is too expensive to use.
The area is renowned for "flying toilets" - human waste-filled plastic bags flung above the rooftops of the sprawling slum.
Several community-based organizations operate ordinary latrines in Kibera but Gachanja said they earn a paltry income because they are so expensive to maintain - the septic tank must be cleared once a week that costs about $50.
But since the human waste in a bio-latrine must be conserved for months, the clearing takes place less often and Gachanja's cooperative earns more money to invest in similar projects.
"Every other Monday they must suck their septic tanks. But here, we can wait six to seven months until the tank is full," said Gachanja, who lives in a tin-roofed shack along one of Kibera's serpentine paths.
But there are certain challenges to the bio-latrine. While maintenance is not as pricey as an ordinary toilet, it involves ensuring there is enough moisture in the bio-digester to keep producing gas and it can break down if there isn't.
What's more, while the hot water does prove useful for some people, many will choose to wash their clothes or bathe in cold water rather than spend five shillings on a basin of heated water.
Practical Action, an international non-governmental organization that helped set up the bio-latrine, said it was planning a new spin for four more it is set to build in Kibera.
"We realized that income would be higher if we had people using the gas from the latrine for cooking because the need for that service was higher," said David Kuria, a project manager with Practical Action.
Once the new bio-latrines are up and running the gas produced will be used in an attached communal kitchen where residents can cook with the methane gas instead of charcoal or kerosene.
And while experts say that rural communities who live far away from the grid could benefit from the technology, Practical Action is opting for more bio-latrines in slums because it provides not only energy but an additional toilet is always welcomed in the filthy place.
"We have so many challenges here," Kutilo said shutting the tap to the fast flowing water. "Every little bit helps."