Small household solar power systems have been gaining traction—and investment—as means to provide affordable and sustainable energy to those living without access to electricity.
But new research led by the University of Michigan shows that simply having access to solar technology does not mean people will adopt it and realize access to meaningful energy services. In a series of three peer-reviewed articles, researchers led by Pamela Jagger published results from a two-year study that involved surveying more than 1,000 households in Malawi, an African nation with one of the world's lowest energy access rates.
The study, supported by the U.S. National Science Foundation, highlighted the barriers to sustained adoption, including relatively high costs and low power capacity. At the same time, however, the work also reveals unexpected social and economic benefits of solar technologies. Such studies offer insights for better deployment of solar technologies to alleviate energy poverty wherever people are struggling to afford and gain access to solar power, the researchers said.
"The solar revolution is happening fast in Africa," said Jagger, a professor at the U-M School for Environment and Sustainability, or SEAS . "But it could be delivering more meaningful energy services to a larger number of people, and it needs to be."
Solar needs a power-up
In one study led by Andrea Mahieu, a SEAS master's student at the time, the team found that the median power provided by household solar devices was only 6 watts. For comparison, 97% of household rooftop solar panels installed in the U.S. last year output between 400 and 460 watts, according to EnergySage, an online clean energy marketplace.
"My biggest concern is that people will say, 'Oh, people have small home solar systems. Our work here is done,'" said Jagger, who is also associate director of the U-M African Studies Center. "Solar technology uptake in Africa is happening at an exponential rate. It looks amazing, it looks like we're solving the energy access problem with rapid success. However, the capacity of most household systems is very, very low and so, in terms of energy services, what's actually being delivered is fairly modest."
In Malawi, the team found that households that had access to systems of at least 50 watts were reaping the most direct benefits and were more likely to adopt additional solar components to grow the capacity of their systems. These were also the wealthiest households surveyed for the study, which was published in the journal Energy Research & Social Science.
"The real significant energy service benefits are only coming from greater than 50 watt systems, which are very uncommon," Jagger said. "If we're really going to give people energy access in a meaningful way, then we need to figure out how to get them higher capacity systems."
Benefit analysis
In a second study, it was households with 50 watt or greater systems where the researchers saw families realizing the benefits that are most studied in the field and talked about outside of it. Those include things like cooking at home, running appliances,and working or studying later into the evening.
But in this study, published in the same journal and led by Duke University doctoral student Ryan McCord, the team saw benefits from lower power systems, too, that weren't as well-known. For example, many households chose to use their limited power to illuminate single exterior lightbulbs at night for an added sense of security.
Notably, the largest use of solar power was for charging mobile phones, which are ubiquitous in Malawian households. Phones connect people to each other, enable access to banking systems and provide vital access to information such as agricultural crop prices. More than 90% of households have a mobile phone in Malawi, but just 6% of households have access to electricity in the country's rural areas. Many Malawians pay to charge their phones at trading centers, which they may walk for hours to reach, so having solar at home provides significant time and money savings.
Another benefit was revealed in a third study published in the journal Energy Economics, led by SEAS doctoral student Congyi Dai . While working with the research team, Dai began to suspect that households with access to solar power were engaging more with mobile money. That is, they're using their phones to send and receive money through apps like Venmo, which foster greater financial inclusion and offer new ways for households to save money in regions without formal banking services.
"A lot of the research right now is focused on these very direct benefits, like are people running a small business out of their home now that they have access to electricity by adopting solar technologies?" Jagger said. "One of the overarching themes of our work is that there are a lot of benefits, but maybe we're not fully capturing some of the more subtle benefits of solar technology adoption."
Despite the accelerating rate of adoption of household solar in Malawi, Jagger described its roll-out as in its "very first stages," especially compared with where she and her team envision it can go. Their future contributions to the field of energy access and energy transitions in low-income countries, however, are on much more uncertain footing because the Trump administration has cut the NSF program that supported this work.
Jagger is confident the private sector will continue to work on the field's technical and deployment challenges because there is money to be made in solving them. But she does worry about the impact the cuts will have on the unique opportunities in training, innovation and relationship-building made possible by international collaboration. While those losses will be especially pronounced in the research community, she said it's shortsighted to expect them to end there.
"Something that very few people understand is that, by 2100, one-fourth of the people on the planet will live in sub-Saharan Africa. There are all sorts of dimensions where it makes sense to engage with Africa. That's true from an economic perspective, from a business development perspective, from a national security perspective," Jagger said.
In addition to the U-M and Duke collaborators, researchers from the University of North Carolina, Harvard University and the Lilongwe University of Agriculture and Natural Resources in Malawi contributed to the project. VITALITE Malawi, a social enterprise marketing solar technologies throughout Malawi, and Energizing Development Partnership, supported by Deutsche Gesellschaft für Internationale Zusammenarbeit GmbH, also collaborated on the project.
