On the outskirts of Mto wa Mbu, a small village in Northern Tanzania, you hear the sunset before you see it.

It begins with the gentle ringing of bells in the distance.

The late afternoon heat softens, the sun slides behind the eastern edge of the Great Rift Valley, and the sky turns peach and yellow. The bells get louder, then more constant, before revealing their source: herds of cows and goats, returning home after a long day seeking grass and water.

Local Maasai families usher each animal into its pen for the night. As they work, the natural light and the din diminish. Then, in the quiet of late dusk, new lights appear.

A few inches wide, they glow bright and warm, perched atop homes and over stoves as people go about their evening chores.

They are solar-powered lamps, charged all day and then used all night to cook dinner, illuminate homework, or chart a safe path home.

Over the last decade, solar devices like these small lights have become essential tools for Mto wa Mbu’s daily routine. Replacing traditional fuel sources like kerosene and rubber, they represent a significant step forward for health and sustainability—growing in popularity thanks to a grassroots network of women quietly leading Tanzania’s clean energy transition.

At Solar Sister headquarters in Arusha, bright orange banners hang on the walls, declaring the organization’s commitment.

Mwanga. Tumaini. Fursa.

Light. Hope. Opportunity.

On the mantle of an unused fireplace, an array of lights, radios, and solar panels sits beneath a portrait of Samia Suluhu Hassan, Tanzania’s current, and first female, president.

From this sun-drenched second-floor office in a quiet corner of town, a deceptively simple question is asked: What if the people most impacted by problems like climate change and energy poverty were invited to solve them?

In Tanzania, women living in remote, off-grid communities bear the brunt of both concerns. They face increasingly intense droughts and floods that threaten their livelihoods. They rely on harmful fuel sources in their homes. And they often don’t have the financial resources to do anything about it.

Back in 2013, the founding team of Solar Sister Tanzania decided to change that narrative.

“In the supply chain of renewable energy, it was like women were left behind,” explains Country Director Fatma Muzo. “They were not involved at the family level or community level on renewable energy matters.”

After a decade of work, Solar Sister is steadily shifting that narrative. The organization invested heavily in women on the frontlines of climate change, helping them build thousands of solar energy microenterprises in the country’s most rural communities. Today, they include more than 4,000 women across 20 regions.

Founder and CEO Katherine Lucey describes the model as “providing the first light in the last mile.”

Solar Sister works specifically in regions, towns, and villages with low energy access levels. To a for-profit company, these aren’t commercially viable places to sell solar products. But to Katherine, that’s the whole point. “We really focus where other people don't focus.”

Often, people in these communities keep modest savings in a village community bank (known as a “VICOBA”) but don’t know how or where to invest their funds. Solar Sister’s proposition to women is this: use some of your savings to purchase a small inventory of clean energy products at wholesale prices, resell them at a higher retail price, and then keep the profit.

“It's really difficult for women across Tanzania who are unemployed to get access to loans so that they can establish their own businesses,” Fatma says, “because most of the women don't have collateral. They don't own land, so they still rely on their husbands.”

That’s what makes Solar Sister’s pitch so appealing. Rather than looking for proof of existing assets, all they require is curiosity and commitment. For many women, it’s a rare chance to take financial independence into their own hands.

Those who say yes are known as Solar Sister Entrepreneurs (SSEs). The moment they’re welcomed into the Solar Sister network, each entrepreneur is given regular training, access to a centralized supply chain, and personalized support to build their business from the ground up.

Caroline Gilbert joined Solar Sister as a Business Development Manager when the Arusha office first opened. For four years, she traveled around the country recruiting SSEs and helping them grow their businesses.

Now, as the Training Manager, Gilbert crafts business lessons that are delivered to each community. Flexibility is a key element of her strategy. A course might be designed for an hour, but she tells her team to take as long as necessary to ensure that everyone understands every concept.

“What we need is all of them to be clear about what is being taught,” Caroline says. “These women are the backbone of Solar Sister’s mission.”

In a session called “Who You Know,” SSEs learn how to develop a network and use social connections to meet new customers. In “Solution Seeking,” they practice problem-solving by using their strengths to overcome challenges.

After two years, SSEs move on to more advanced topics like business analysis, business plans, and strategic roadmaps. Gilbert’s expectation isn’t just that women succeed within the Solar Sister framework, but that they develop into well-rounded businesspeople.

“If I see them starting their business and growing from one level to another, I feel very happy,” Caroline says. “They are able to make their own decisions because they generate their own money.”

In Solar Sister parlance, SSEs are more than peers. They aren’t competitors, either.

Instead, they call themselves “sisters,” forming Sisterhood groups of up to 10 women in which they gather to share business ideas, commiserate about challenges, and encourage one another.

Moshi Mohamedi Mgelwa is a sunflower farmer and Sisterhood leader in a village called Mawe Mairo. The fertile, freshly tilled fields surrounding her home are alive with green stalks and yellow blooms dancing in the breeze.

Moshi met Fatma at a meeting in 2014. She was attracted to the idea of bringing light to her community while increasing her income.

“At first it was difficult, but I got used to it over time,” recalls Moshi through a translator. “Standing up and doing something for myself encouraged others to do the same.”

One by one, more local women joined Moshi’s Sisterhood, forming a tight-knit group of 12 entrepreneurs—a mix of family members and neighbors who all live within walking distance.

Mwadawa Bhabani Makala is one of them. She joined the Sisterhood in 2017 while transitioning out of an assistant position in the local Office of Irrigation. She had heard rumors about Solar Sister, but when Moshi told her more about the opportunity, she was eager to join.

“She told me, instead of just sitting and not doing anything, it's better to become an entrepreneur,” says Mwadawa. “She told me to just join Solar Sister and see where it takes me.”

At the Office of Irrigation, Mwadawa was only earning a small, unpredictable commission. Today, her income as an entrepreneur has increased to the point that she’s able to invest in the construction of a new home for her family.

She credits the support of her Sisterhood as a major reason for her business success.

This particular Sisterhood is even starting to welcome a second generation of entrepreneurs.

For many years, Paskalina Ferdinandi’s main business was selling vegetables at the market. But her mother was working with Solar Sister nearby, in Gallapo, and Paskalina started to dream about starting her own solar venture.

“I got excited because I had already seen the profit that my mom was getting,” she says.

Paskalina joined Moshi’s group in 2019. Already, her three children have benefited from the new income and from access to light that allows them to study during the evening. In the future, she hopes to convince her daughter to become an entrepreneur, too.

Thanks to their work as a community and as individual entrepreneurs, the women in Moshi’s village made major improvements to their lives and the lives of their neighbors: they purchased cattle, paid for schooling, and dramatically reduced the threat of fires and illness from kerosene lamps.

Another change is more subtle but no less important: they feel like they’re finally respected for contributing to their families and communities.

Moshi says that people around town recognize her as the woman that sells solar devices. And her husband, Shabani Baraza, is proud of her. He thinks more women should start businesses like hers.

“We have managed to get our kids to school and manage our activities,” he explains. “I can go farming. She can do something else. We can both provide for the family.”

Hilaria Paschal’s home in Madukani, along the edge of Tarangire National Park, is a flurry of activity.

On a hot Thursday afternoon, a village meeting wraps up nearby, and then a spontaneous performance including drums and dancing springs up in front of Hilaria’s home. Behind them, a group of basket weavers works patiently on their newest creations.

Hilaria was one of Solar Sister Tanzania’s first recruits. She was already a lifelong entrepreneur, making and selling handmade baskets, so becoming an SSE was a natural fit. Hilaria was excited to strengthen her business skills, and she was personally motivated to increase the availability solar lamps. (She has an allergy to smoke and dust that makes it difficult to read or weave baskets by the light of kerosene lamps.)

When Hilaria began as an SSE, she jumped wholeheartedly into sales and found early success.

“At that time, it was very easy to sell, because it was a new product,” she explains.

Over the years, her job became harder, especially as competitive products entered the market. Still, Hilaria estimates that her income has increased 70% since becoming an SSE, and she’s been able to fund formal education for all of her children.

In 2017, Hilaria visited New York City to be honored as the Woman Entrepreneur of the Year by the International Network on Gender and Sustainable Energy (ENERGIA).

“The biggest change in my life is recognition,” Hilaria says. “And I have been able to employ myself and become a fully mature entrepreneur, despite difficulties during COVID.”

Many of the people gathered at Hilaria’s home are also SSEs with multiple businesses to their names. Their busy lives and myriad commitments are like the fibers in their baskets: every story shares the same structure but takes a slightly different path.

For more than 30 years, Editha Masongera worked as a tailor, designed woven handbags, and farmed a small plot of land.

She was buying solar lights from Hilaria until Hilaria convinced her to start a small business with Solar Sister. In 2017, this new role as an entrepreneur, Editha’s fourth job, sparked a virtuous cycle of growth and reinvestment in all of her ventures.

“I was able to get more capital to farm more, then buy more inventory and sell more products,” she says.

Before becoming an SSE, Editha rented her home. One year ago, she moved into a new house that she built with the proceeds from her solar business.

Even Edna Sarakikya, the Senior Business Development Associate who supports both Moshi and Hilaria’s Sisterhoods, was recently selling vegetables as her primary source of income. Like Editha, she was a Solar Sister customer, until a staff member convinced her to try selling solar products herself.

She started small, investing in an inventory of 10 small lights, which she quickly sold for a profit of 40,000 Tanzanian Shillings (about $17). Over the next six months, she became more ambitious, buying and selling a larger inventory as her income increased.

The Solar Sister team noticed Edna’s talent and invited her to become a full-time staff member. Now she spends her days encouraging and supporting other women who are just getting started as entrepreneurs.

“I like helping the community at large, helping mothers get income to help raise their kids,” Edna says.

Until Solar Sister arrived, she explains, most families in the area had no access to electricity or solar devices. These days, every entrepreneur has a light in their house, and in the last year alone, her community of SSEs has helped more than 2,000 families access clean energy.

Members of the Sisterhood in Mto wa Mbu point to distinct differences in their lives before and after starting businesses.

“​​At first it was a challenge to be allowed to be an entrepreneur,” says Suzana Simon, one of two founding members. “But now, it's normal for a woman to be an entrepreneur.”

Over five years, she says she's gained more confidence, started to build a foundation for a new home, and sent her kids to school.

Nadamu, her neighbor and fellow Solar Sister, agrees. Two years ago, she says her primary identity was as a housewife. Today, she relishes her new identity as a businessperson.

“Through Solar Sister, I believed in myself,” she says. “I got to meet people and get customers for other businesses apart from Solar Sister.”

Namayani, another entrepreneur, appreciates the monthly lessons that equip her to build a strong financial strategy over time.

“The main thing I’ve learned is how to differentiate capital and profit,” she says. “This is profit, and this is what I can start to invest in other things, reinvest in the business.”

The benefits of clean energy here are just as stark.

Selengei Nguchicha is the Business Development Associate in Mto wa Mbu. She explains that families used to burn rubber from tires and shoes to get a steady light source. Most of them live in poorly ventilated homes made of dried mud and branches, which leave them susceptible to fires and illness.

Thanks to the local Sisterhood, most families own rechargeable lights and clean cookstoves that minimize smoke inhalation. Some women, including Namayani, have even completed new concrete homes for their families.

In other words, “they have safe and clean light,” Selengei says. “No more burning houses, no more coughing.”

Of course, no entrepreneurial venture is easy. As much as Solar Sister invests in training and support, the women in Mto wa Mbu—and across the country—must navigate complex obstacles outside their control.

Transportation is one such challenge. An SSE might secure a client in a remote location but have no easy way to reach them. Unless that entrepreneur owns a motorcycle, she must rent one—or, in many cases, simply walk.

Climate change has also had a dramatic impact on the Maasai community. As pastoralists, they rely on rain to provide food and water for cattle. But lately, Mto wa Mbu has been weathering a six-month drought.

That means the whole community is struggling to get by, and demand is lower than usual for products like lights, cookstoves, or solar panels.

Nadamu summarizes the effects bluntly: “When there is no cow, it means no income.”

Still, the women are optimistic about finding new ways to maintain their businesses and spread solar energy more widely. They’re getting creative about traveling to far-flung markets and reaching new customers outside their typical networks.

Selengei is taking it upon herself to ensure that the Sisterhood thrives while they wait for the rain to fall. “I have to go to other places, where I have never gone, to find other customers and clients.”

Solar Sister was never intended to be an entrepreneurial organization. It was created to find a solution to energy access in off-grid communities.

“Our understanding of the impact has changed a lot,” Katherine says. “The first question we asked ourselves is, ‘Well, who's our customer?’ And the customer was the woman in the household.”

In other words, Solar Sister focused on women entrepreneurs because they were most impacted by energy poverty, and they were the most effective distribution channel for solar devices. But as their team began collaborating with each woman, they realized a lot more was happening than a straightforward transition to clean energy.

“This is so much harder than I thought, but the impact is so much greater,” Katherine admits.

Fatma feels similarly. She sees SSEs as ambassadors for clean energy in their communities. They were once shy, but now they stand up in public meetings to share their opinions. They were once expected to stay at home, but now they’re going out into their communities and confidently running businesses.

Both Fatma and Katherine sense that change is on the horizon. Small solar products were the perfect product for the last ten years, but energy needs across Tanzania are evolving—and the competitive landscape is quite different than it was in 2013.

Lately, SSEs and their customers have expressed interest in newer, larger products. The Solar Sister team is hard at work finding ways to make that happen. The most promising opportunities include solar energy systems that can be put to productive use, like solar water pumps for a farm, or refrigeration for a small shop.

This winter, Solar Sister launched a pilot program with local VICOBAs to help entrepreneurs secure financing for larger electrical systems and access more expensive inventory.

Solar Sister’s plan for the next phase of growth remains as ambitious and simple as it’s always been: promote clean energy, invest in women, and watch the magic happen.

“We hope to see women as the face of the renewable energy sector,” Fatma says. “Right now, they're still left behind, but we hope, in the future, they'll be at the forefront.”