Njombe — Aloycia Mndenye has often tried to convince her husband to help her collect firewood in the forest - but her efforts always failed because he considered it a woman's job.
So, despite shouldering many responsibilities, Mndenye, a 32-year-old farmer at Lunyanywi village, in the Njombe region in Tanzania's southern highlands, spent two hours every day collecting firewood to meet her family's energy needs.
"It was very exhausting, to be honest, I had to go longer distances to get enough stock. Nights are very cold here sometimes (and) the temperature drops to freezing point," she said.
But ever since she installed a manure-fed biogas plant two years ago as part of a project supported by Sokoine University of Agriculture (SUA), there's been a gender shift in responsibility for the family's energy needs.
Mndenye's husband, who before shunned most domestic chores, now takes part in operating the biogas plant, and sometimes even cooking with the gas - leaving his wife more time to tend to her farm fields.
"This plant has simplified a lot of work. My husband and I are taking pride in the project," she said. "He's very keen to ensure that it is well maintained so that we can offset the cost of installing it."
Despite a deep pungent smell of decomposing cow manure, Mndenye's husband says he enjoys shoveling through dung from the family's dairy herd and feeding it into the digester installed just outside the family's four-bedroom house. The process, he said, involves mixing water and manure and removing impurities likely to slow down gas production.
"I only spend half an hour doing this work. It's much easier and more dignified than collecting firewood. I mix water in two buckets of manure to get enough gas" for the day, he said
The digester can create enough gas to power a cooking stove and several gas lanterns, he said, and the leftover manure slurry has become an important fertiliser for his avocado plants.
CHANGING FAMILY DYNAMICS
The use of biogas in Lunyanywi and other villages in Njombe, university researchers say, is changing family dynamics, with men stepping up to operate the digesters and in some cases use the gas, easing the load of family responsibilities - particularly firewood collection - that usually fall on women. It is also reducing the costs of buying other fossil fuel energy sources such as kerosene for lamps.
Most people living in rural Tanzania who do not have access to grid electricity depend on firewood and kerosene for lighting and cooking. According to the government, surging demand for firewood has exerted a huge pressure on the country's forests and affected water resources.
"Before setting up this project, my husband was spending over 2,500 Tanzanian shillings ($1.50) every week purchasing kerosene - but now we use our own resources to get night light," Mndenye said.
Shila Lehada, coordinator of the Tanzania Domestic Biogas Programme, a donor-funded renewable energy project, independence from traditional fuels can save a household using biogas up to 600,000 Tanzanian shillings ($375) a year, and leave women and children more time to study or earn money for the family.
Mndenye, for instance, has invested the family's savings from buying kerosene into a small shop selling a range of consumer goods. "I don't want to waste money buying clothes like most women in the village do. I put it somewhere to generate more income," she said.
EASIER TO COOK
More money, combined with easier-to-use biogas, also has also enabled her family to double the number of meals they eat a day, from two to four.
"My children enjoy a morning breakfast before they go to school. I just switch on the gas stove. It was not possible when we were still depending on firewood," she said.
Ndelilio Urio, a professor who is supporting efforts to adopt conservation agriculture in Njombe, said the residues from biogas production have proved to be a better fertiliser than dried manure because the amount of urea in the slurry increases the amount of nitrogen in the soil.
Families have been taught how to use the slurry in their home gardens to boost vegetable and fruit crops, he said. And "because of the economic benefits, men are now taking an interest in feeding the biogas plants."
Urio said that particularly in Itulike and Nyumbanitu villages, growing avocado has become a lucrative source of income.
According to the villagers, the amount of biogas each household produces is enough to meet family demands. But some families still use traditional fuels and solar power to heat and light their homes, especially in winter when the weather is freezing cold and a wood fire adds warmth.
"I want to be economical. I don't want to waste my gas boiling water for bathing. I would rather use firewood to do that, but that doesn't mean that the gas is not enough," Mndenye said.
Kizito Makoye is a journalist based in Dar es Salaam, Tanzania. He reports on climate change and governance issues.