Solar Lights Fight Climate Change and Air Pollution

The mission of Unite to Light is to provide light and power to people living without electricity. We focus on helping people in rural communities in low-income countries, as these are the people who can least often afford even a low cost solar light. People in these communities typically rely on kerosene lamps as a source of lighting after the sun goes down. Kerosene is a dangerous and expensive fossil fuel that emits both carbon dioxide and black carbon (more commonly referred to as soot), when burned.

With nearly one billion (and counting) people still lacking access to electricity across the globe, we are striving to replace kerosene lamps with solar lights. When we increase access to solar lamps, we increase access to educational opportunities, healthcare, and productivity. We also decrease greenhouse gas emissions and air pollution.

Solar Sister, Vimilia, with a customer.

Since 2020, Unite to Light has been working to scale up our programs that target climate change pollutants. This work has taken two forms: a light subsidy program in Tanzania, and a project that would update the methodology for assessing the climate impacts of kerosene lamps to include black carbon (soot), as well as carbon dioxide and methane. Below we dive into the details of each project. 

​Solar Lamps Create Carbon Offsets and Economic Empowerment for Women

Over 240 million people are being left behind by current electrification efforts. These are people in “last mile” communities. They are hard to reach with grid-tied electricity and largely overlooked by traditional solar companies because typical economics don’t pencil. The majority of those being left behind are women and children. They do not have the resources to purchase even a low-cost solar light, and are disproportionately exposed to the adverse effects of kerosene use - from breathing noxious fumes, to limited daylight hours to work. 

In 2020 we partnered with the University of California (UC) and another nonprofit, Solar Sister, to offer subsidized solar lights with the goal of helping people who could not otherwise afford to switch to solar due to the upfront cost. Solar Sister customers in Tanzania got reduced-cost solar lights, and the UC got the carbon credits associated with transitioning people from kerosene to solar. ​

Carbon Offset Project Cycle

Now we are working to scale the project up. The model will be the same: the UC will invest in subsidies for solar lamps to reduce kerosene use and use those credits to offset their greenhouse gas emissions. We will partner with Solar Sister to distribute the lamps, and d.light for manufacturing. Over the next three years we hope to subsidize 300,000 lamps and offset 55,200 tonnes of carbon dioxide equivalent. This is roughly equal to getting 12,000 cars off the road for a year. 

Goals of the carbon offset project :

• replace 300,000 kerosene lamps with solar lamps;
• create economic opportunities for people living in poverty;
• reduce air pollution in homes and greenhouse gas emissions globally;
• provide the UC with robust, measurable, and impactful carbon offsets.

​Black Carbon Measurement Equals More Investment

Photo Credit: Ajay Pillarisetti

When we burn materials for light or heat (kerosene, wood, charcoal, etc), greenhouse gasses, as well as particulate matter (PM) are released into the atmosphere. By now we all know the dangers of a warming planet due to greenhouse gasses. The health implications of PM are also well known (and frightening);  it causes household air pollution which was estimated to be the cause of 3.2 million deaths in 2020. This health burden disproportionately affects women and children. 

What is less well understood, is the impact of certain types of PM on the climate. Black carbon (soot)  in particular is of significant concern. We know its release into the atmosphere has a warming effect. Black carbon is estimated to have a global warming potential (GWP) of 2,421; that is, it has a warming effect that is 2,421 times greater than that of carbon dioxide! But there are uncertainties due to the limited time in the atmosphere, location specific impacts (if the black carbon is released near snow, it can alter the albedo effect), and the other types of PM that may be co-released and have cooling effects (like organic carbon). The uncertainties around black carbon have led to it being ignored when carbon offset projects are calculating their climate impact reductions. In 2022, Unite to Light began working to establish a methodology for expanding the current offset calculations for replacing kerosene​

lamps with solar lamps to include black carbon. The timing is ripe because under Article 6 of the Paris Agreement, all regulated emitters must change how they account for GHG emissions globally. Incorporating black carbon, and other short term climate pollutants, may lead to more robust and accurate projects, while spurring investment. 

The black carbon project is made possible by the generous support of the Ghanta Family Foundation. Praveen Ghanta states:

“The Ghanta Family Foundation is delighted to support Unite to Light in advancing the replacement of kerosene lamps with solar lights. We looked for partners with the entrepreneurial spirit needed to get black carbon emissions included in carbon offset programs - and we found that." 

Photo Credit: Evan Mills

Goals of the black carbon project include:

• legitimize black carbon as a metric for carbon offset programs;
• establish a pathway for standardizing pollutants;
• develop a more acute understanding of the short and long term effects of black carbon socially and environmentally.

​As you can tell, we have a lot of work to do! We are confident that the carbon offset program and black carbon project will create tangible progress for people and planet Earth. But we can’t do it alone. Our planet is rapidly warming and people continue to live in poverty - we need your help!

Help us expand our climate change projects and light the world today!