A scheme backed by the Department for International Development is bringing household solar systems to remote, rural areas of Tanzania.
The scheme, which provides financing to companies that roll out the solar technology to people living in remote areas, is part of UK aid funding earmarked to help tackle climate change.
The government says it is hoping to help kick-start start a solar revolution across Africa, to help bring electricity to the two-thirds of people in sub-Saharan Africa who are currently without access to power, without relying on fossil fuels such as coal.
Overall, the UK will have spent £3.87 billion between April 2011 and March 2016 on climate aid and has pledged a further £5.8 billion from 2016 to 2021.
"I now live in a visible world", said 62-year-old Tanzanian farmer Elizabeth Mukwimba.
"Solar energy has made a great impact on my life. I see everything compared to before, when I was in darkness. It has really helped me."
The technology has allowed Mukwimba to reduce the amount she spends on expensive and polluting kerosene which has freed up money to put a new tin roof on her house.
It has also enabled her grandchildren to do their homework and read at night - improving their performance at school, she said.
The UN wants developed nations to spend $100bn (£66bn) a year derived from public and private finances on helping poor countries develop without following the same polluting track as rich nations.
The money will also be used to help them to cope with the inevitable impacts of climate change and will form a key part of any new deal on global warming agreed to at the upcoming COP21 talks in Paris.
Christian Aid's senior climate advisor Mohamed Adow said the talks would need to show rich countries delivering on their promise to provide finance to help poor countries avoid fossil fuels and develop using clean technology.
"And for those vulnerable countries already facing the impacts of climate change, they need to be helped to adapt to a changing climate, especially considering they have done nothing to cause the problem in the first place," he said.