Access to reliable energy is important to human wellbeing ^[1][2][1,2]; but, according to the International Energy Agency (IEA), approximately 600 million people in sub-Saharan Africa (SSA) lack access to electricity [3]. Solar home systems (SHSs) are increasingly being used to provide energy access to energy-poor people in Africa; and, in fact, 70% of SHSs are sold in SSA [4].

There is an ongoing debate regarding the wellbeing effects of SHSs, especially in rural areas in Africa, with no access to centralised grid energy and where income generation opportunities are limited. Some studies conducted on the continent have argued that SHS adoption has enabled adopters to start generating income as well as earn additional income ^[5][6][7][8][5,6,7,8], while others have shown little or no contribution of these systems to increased income ^[9][10][9,10], due to their low energy generation capacity. Studies have noted that these technologies contribute to improvements in safety and security ^[11][12][11,12] and reductions in illness [13], but other studies have noted that due to the low capacity of these systems, there is a limited potential for SHSs to improve indoor air quality as a result of the continued use of kerosene and candles for lighting ^[14][15][14,15].

Some studies argued that SHS adoption had a positive effect on household income as it enabled these households to engage in new income-generating activities, most often charging people’s phones, or teachers giving extra lessons to students in the evening ^[5][6][5,6]. Caution is needed here, as studies suggest that very few (less than 10%) SHS adopters used the systems for income-generating purposes ^[7][8][7,8]. For the few people who used SHSs for income -generation, such as by charging mobile phones, the question which arises concerns the sustainability of these new income-generating activities. Of course, early adopters of SHSs would generate considerable income by charging the phones of people in their communities, but this income stream is expected to decrease significantly or even come to an end as more people in these rural communities adopt SHSs and start offering similar services. Thus, it is hard to argue that phone -charging as an income-generating activity can contribute towards increased household income in the medium and the long terms. Moreover, researchers have also acknowledged that some SHS adopters engage in mobile phone charging as an occasional business, and often charge nominal fees to family members and friends rather than establishing a business with the intention of earning meaningful income [14]. Arguably, charging nominal fees occasionally is unlikely to make a significant difference to the income of a household. The value of additional income lies in the fact that it enables households to meet other needs. For instance, additional income could enable households to cover healthcare costs [1]. The point emphasised here is that intermittent fees obtained from charging mobile phones in rural communities cannot be used to meet major household needs that are crucial to improvements in living standards. Additionally, the claim that new income streams produced due to SHS adoption contribute to poverty alleviation ^[16][17][56,57] is contestable. In several rural contexts on the continent, the increase in income as a result of SHS adoption would likely be captured by the rural middle class. For instance, in Kenya, teachers and other civil servants who reside in rural areas are arguably part of the rural middle class ^[18][45], and by offering extra lessons to children in the evening or opening a barber shop to earn additional income, they are consolidating their middle-income status, which is quite different from poor households that might be struggling to meet basic needs. As Jacobson (^[18][45], p. 152) put it: “the fact that the benefits accrue primarily to the rural middle- class challenges characterizations of solar PV as a tool for poverty alleviation” ^[18][45]. Arguably, SHSs cannot be a magic bullet for poverty alleviation in rural communities; they have to be part of a broader strategy for poverty alleviation. Furthermore, studies have argued that SHS adoption leads to household budgetary improvements. These studies posit that this happens, for example, as households reduce their consumption of kerosene and candles ^[15][19][15,30]. The assumption is often made that SHS adopters would recoup their investments in the systems in the long run so they are saving in terms of energy costs, since the money saved could be used to meet other household needs. However, in practice, this is not always straightforward. More precisely, studies do not often take into consideration that a significant percentage of SHSs often break down after a couple of months or years due to reasons that include low quality, poor maintenance, and lack of user education regarding how to use the systems ^[20][21][58,59]. Thus, in turn, a significant proportion of SHS adopters may not experience any household budgetary improvement due to increased expenditures as a result of SHS repairs or purchase of a new SHS when the previous becomes unusable. The situation may be dire for low-income households that have already had to make sacrifices in order to get an SHS. A study conducted in refugee camps in Rwanda noted that some SHS adopters had to reduce expenditures on food in order to make SHS payments on time [12]. An argument could therefore be made that in terms of wellbeing, people are not better off adopting SHSs if they have to reduce their food expenditure. Researchers have emphasised the relationship between kinds and quantities of foods and healthier lives ^[22][60]; and, among low-income populations, reductions in food expenditures could lead to negative health outcomes. Therefore, in turn, if people fall sick because they cannot afford nutritious food, they may struggle to make their SHS payments, which would push them either to default on their contract or to go into debt by borrowing money through informal sources. Moreover, requiring people in refugee camps to pay for access to energy by purchasing SHSs raises ethical questions, which policymakers, privately owned off-grid companies, and practitioners seem to ignore. People in refugee camps who are struggling to meet their needs also have to bear the responsibility for electricity provision. Put differently, it seems that some policymakers and practitioners appear to have largely accepted that people in refugee camps bear responsibility for gaining access to renewable energy, even when this comes at the expense of reducing expenditures for things that are critical for their existence. What people are experiencing here is privately owned, off-grid energy companies “capturing consumers in a crisis” ^[23][61]. The market-based provision of energy in refugee camps or humanitarian settings may be profitable to off-grid companies, but it does not necessarily improve the wellbeing of the people in such camps. Regarding education outcome, while increased study time for children after SHS adoption is worth applauding, a deeper conversation is needed here. Specifically, what are the outcomes of longer study hours due to SHS adoption? One study found that household SHS adoption increased average years of schooling by 1.79 [13], but this study is an exception. Most studies did not examine the effects of increased study time after SHS adoption. Moreover, an assumption should not be made that children in households with SHSs will naturally benefit from longer study hours at night, as such an assumption fails to take into consideration household dynamics regarding energy allocation. For example, a study conducted in rural Kenya found that of the 80% of households with SHSs that had school-age children, just 47% used the system to study, and the author linked this to several factors, including the size and the performance of the SHS, the spatial layout of the house, and gender dynamics ^[18][45]. The point stressed here is that SHS adoption does not always lead to an increase in study time for school-age children. To reinforce this point, another study which examined 430 households with school-age children in eastern Uganda did not find a significant increase in time spent studying during high-intensity periods, such as before exams ^[19][30]. On the security front, studies noted that high quality lighting provided household members a higher degree of safety and led to a decrease in the risk of fire accidents and household break-ins; protected household members against reptiles such as snakes; and also protected their livestock against wild animals ^{[6][7][9][12][24]}[6,7,9,12,44]. However, while acknowledging the contribution of SHS adoption to improvements in the security of household members and their assets, it should be pointed out that any meaningful contribution is based on various factors, especially the size of the SHSs. A significant proportion of rural households get small SHSs, and such systems are unlikely to power an outside security light throughout the night. Additionally, some households continue to use kerosene and candles for lighting, although at a reduced rate after SHS adoption, which leaves them exposed to fire hazards. Anytime kerosene is used for lighting, it may potentially cause a fire, with obvious adverse economic and social consequences. Only households with the financial capacity to obtain a larger SHS can completely replace kerosene and candles for lighting and also have security lighting during the night. In other words, any improvement in security will likely only be enjoyed by a minority of SHS adopters. Regarding health outcomes, studies reveal that SHS adoption contributes to an improvement in indoor air quality, which is regarded as a positive aspect since poor indoor air quality is linked to several diseases ^[25][26][62,63]. However, the studies in this reviewed herein did not directly measure air quality, and the positive health benefits of SHS adoption are based on self-reported changes. One study conducted in remote areas in Cote d’Ivoire found that SHS adoption reduced the number of household members reporting illnesses over a four-week timeframe [13], while another study carried out in rural areas in Uganda found that SHS adopters were 6.5% less likely to report being burned by a lighting source ^[19][30]. However, the findings in both studies were again based on SHS-adopter self-reporting, and there was no direct measurement of key aspects related to respiratory health, for instance changes in lung function. Scholars call for caution when relying on self-reporting, as research participants sometimes tell researchers what they think they want to hear ^[27][64]. Moreover, several studies noted that some households continued to use kerosene and candles for lighting after the adoption of SHSs, as the systems could not meet their energy needs ^[7][14][15][7,14,15]. In addition, since SHSs cannot be used for cooking, households—especially those in rural areas—still use traditional energy sources such as firewood or charcoal for cooking. Arguably, therefore, any expectation of a significant improvement in indoor air quality is compromised due to the continuing use of such traditional energy sources. Several studies highlighted the important role that SHS adoption plays in facilitating the entertainment of household members, since the value of SHSs is derived from the provision of energy that is used to power household devices, such as televisions, radios, and mobile phones. These devices give users access to music, movies, etc., which contributes to emotional gratification. Feelings of excitement or pleasure, which are also related to entertainment, contribute to people’s wellbeing ^[28][29][29,65]; however, several factors shape the ability of SHSs to improve the wellbeing of household members through entertainment. Households with a small SHS may not be able to spend long periods watching television, for example, as watching a favourite TV show may come at the expense of preventing children from studying at night by turning off light bulbs. Furthermore, one cannot always assume that most rural residents have mobile phones with the capability of providing media entertainment. So, in real life, the possibility of SHS adoption to improve wellbeing through entertainment is not a given. In the social connectedness sphere, some devices also facilitate relationships between people. In one study, SHSs were associated with activities that enabled rural Kenyans to increase their connections with people ^[18][45]. Moreover, additional income generated from charging mobile phones as well as the ability to charge mobile phones at home made it possible for people in rural communities to call their relatives in urban areas ^[18][45]. In other words, SHSs facilitate social connections between people in rural and urban areas. This contribution of SHSs to facilitating communication as well as building social relationships is crucial for wellbeing.