Out of the Fog and Into the Sun: Demystifying Distributed Solar Photovoltaics
Written by Julia White and edited by Trent Dillon
A powerful tool to reduce greenhouse gas emissions and increase electricity access for all people is emerging. What are distributed solar photovoltaics? And why do we in GRID — as well as experts around the world — care about it?
Let’s pause and examine that first term, distributed. According to the US Environmental Protection Agency (EPA), distributed generation is any technology that generates electricity at or near where it will be used. This dispersed approach contradicts our current system, where electricity is produced at a plant and sent to consumers far away using power transmission lines and stations. Distributed generation of all kinds — renewable and fossil fueled — helps reduce the losses, costs, maintenance, logistics, and congestion of our current centralized generation system, and, importantly, increase transparency and public ownership of electricity resources.
Among these options for distributed generation, one form is uniquely inexpensive, durable, and rapidly deployable, and its powering resource, sunlight, is globally abundant and carbon-free. These factors make distributed solar photovoltaics (DSPV), systems that convert solar radiation into electricity that is consumed nearby, a game-changer when it comes to reimagining our electricity consumption. Much of GRID’s work involves co-collaborative DSPV installations. While our main focus is typically on the communities we work with, it’s worth taking a broader examination on the technology, its benefits, how it’s being used, and challenges of its expansion.
Why DSPV? — The Economic Argument
Many homeowners, companies, and governments choose DSPV to reduce reliance on fossil fuels, like diesel and coal, and thus reduce greenhouse gas emissions. But these decisions are also driven by economics. According to the International Renewable Energy Agency (IRENA), solar is cheaper than fossil fuels in many locations around the world. In the US, at the utility scale, solar PV is cheaper than both the cheapest new coal options and the operating costs for existing coal plants. Residential solar costs also fell 47–80% (depending on location and local government incentives) between 2010 and 2019. This price is expected to continue declining in the coming years, making solar even more promising for rural electrification and decreasing urban dependence on centralized grids. Much of the current proliferation of DSPV in the United States can be attributed to these economic advantages.
DSPV in the US
The US Department of Energy estimates that approximately one third of solar energy produced in the US in 2020 came from small-scale solar installations, equating to about 1% of US energy production. Overall, the US gets 2.8% of its electricity from solar and has a solar energy capacity of about 97.2 GW. Of this, 34.7 GW come from small-scale installations, according to the US Energy Information Agency. A majority of this production comes from installations in the Southwest, as well as Florida and the Northeast. Our home state, Washington, also has a sizable population of DSPV systems. GeekWire reported in December 2021 that Washington has a statewide resident-owned solar power capacity of over 200 MW. Puget Sound Energy, the largest utility supplier in the state, estimates that, since 2005, over 12,500 small-scale solar systems have been installed, and Seattle City Light says more than 5,000 customers have solar panels on their residences. While this is only about 1.3% of their customers, it’s still remarkable at this early stage of DSPV deployment.
It’s clear that there are a lot of DSPV systems in the US, but the electricity produced is still a tiny fraction of our cumulative energy consumption. There is room for growth, and when it comes to systems that empower consumers with authority and control over their electricity resources, there may be no option more promising than rooftop solar. A National Renewable Energy Laboratory analysis from 2016 found that there are over 8 billion square meters of rooftops in the US suitable for solar panel installation., and researchers from the University of Cork predict that we have enough currently viable rooftop space to satisfy the entire US energy demand.
Expanding DSPV could also greatly benefit Tribal Nations in the US. For many years, solar energy generation has been promoted as a way to increase and support Tribal Nation sovereignty. By installing DSPV systems, Tribal Nations can control their own sustainable energy supply and provide local jobs.6 Many Nations, including the Navajo Nation, Northern Cheyenne, and Spokane Tribe of Indians, have established solar energy projects powering community centers and offices. Additionally, the current federal administration is working to accelerate and spread DSPV with federal grant funding awarded to 14 projects in March 2022. These funds will be used by tribes for a variety of projects in communities from Alaska to Arizona to Minnesota.
But, of course, DSPV systems exist outside the confines of US borders. Let’s take a brief look at DSPV integration across the globe…
DSPV Worldwide: Some Select Cases
China
In 2012 in an effort to reduce pollution in its booming cities, China began shifting its solar energy focus from large-scale solar plants to DSPV deployed on the rooftops of urban buildings throughout the country. Despite a slow start, numbers of installations have soared in the last five years as China combined this initiative with its Paris Accord commitments. In 2019, solar power made up about 4% of China’s energy production, nearly 1.5 times more than in the US, and DSPV generated over 29% of China’s solar electricity. Though the percentages of DSPV are similar between the US and China, rooftop solar capacity in the country is a whopping 108 GW, more than any other nation at this time, demonstrating that DSPV proliferation is feasible in the largest and most densely-populated nations. Over half of distributed solar generation happens in the five eastern, and primarily urban, provinces of Zhejiang, Shandong, Jiangsu, Anhui, and Henan. In addition to helping the country move towards its carbon emission goals, rooftop solar installations also benefit communities all over the country, providing job opportunities and reducing aerosol pollution levels.
India
In many other parts of the world, DSPV is being accelerated under different motivations. In 2017, the Indian government’s Saubhagya campaign began to reimagine the country’s electric grid, proposing to not only connect rural areas to centralized grids, but also to expand distributed generation. Grid connections to rural communities can be expensive and sporadic due to low demand and large distance from power stations. DSPV can be used to provide cheaper electricity when these disruptions occur, hence the dual-prong approach of the Saubhagya campaign. This relationship was observed in three rural communities followed in a study published in 2021 by Aklin and Urpelainen from the University of Pittsburgh and Johns Hopkins University respectively. The study observed that ownership and use of DSPV systems grew slightly after grid-connection, primarily for low load applications, such as providing secondary lighting and backup power during outages or in hours when electricity is not available. This case indicates that, as grid connection is pushed in many rural communities across the world, DSPV has an important role to play in providing energy stability.
Mpanta, Zambia
Slightly larger DSPV systems are also being installed in communities that may be too remote for grid connection. The specific case of Mpanta, Zambia, gives insight into this process and the considerations that must be held to replicate the development of DSPV in similar settings.
Mpanta is one of over 1200 growth centers in rural Zambia scheduled for electrification between 2008 and 2030. Here, a 60 kW solar micro-grid was installed to provide power for domestic and street lighting, commercial refrigeration, and TVs and radios. Researchers from the Stockholm Environment Institute followed the installation to assess how well it met the needs of the community and published their findings in 2019.
The DSPV system in Mpanta successfully generates electricity, providing lighting and refrigeration as well as electricity for entertainment. There were, however, major flaws in this project, and the researchers found that the system was not able to meet the full needs of the town. As a rural fishing village, subsistence practices like fishing, agriculture, and cooking are key drivers of energy consumption, and the loads required for any substantial aid to these activities were too large for the solar installation to meet. Additionally, electricity costs were much too high for many households. A large portion of the houses connected at the beginning of the project had no power within a year of installation due to high costs, particularly in the winter months when profits from fishing and agriculture declined.
The Stockholm Environment Institute team also revealed a gender disparity in electricity use and access. Men were the vast majority of shop owners and benefited the most from electricity to light their establishments for longer hours of operation and power refrigerators to provide cold products. Men were also more likely to have the leisure time and ability to visit electrified bars for TV or radio entertainment. Meanwhile, women still endured hours each day gathering firewood to fuel cooking fires and, due to social expectations to stay at home for the little leisure they have, did not interact with the new forms of leisure. The households that could afford electricity did benefit from extended lighting, but, due to this gendered discrepancy in existing access to resources and social expectations, it did not change the women’s lives as much as the men’s. As such, community members of lower socio-economic and socio-cultural status were shown to have less access to the new electricity and its benefits.
The study authors note that this installation was also impaired by project-specific flaws, which were left unspecified besides mentioning that it was the first project of its kind in Zambia. As a pilot project, there may have been a lack of experience on the ground when making direct decisions and inadequate community needs surveying. These shortcomings will improve with experience and could also be aided with the expertise and financial backing of wealthier nations or organizations. Nonetheless, the issues that surfaced in this case study must be considered in future installations to ensure sufficient and equitable energy generation and distribution.
Challenges to Expanding DSPV
The Mpanta installation is a reminder that, despite the benefits, there are still challenges to expanding DSPV and ensuring that community needs are met. Economic barriers are one major hurdle. Large upfront costs greatly hinder electrification efforts in low-income areas, particularly in many areas of Africa where DSPV is cheaper than grid extension, but still extremely expensive. Domestically, in the United States, Tribal Nations in need of electrical infrastructure experience other cost impediments. Current federal investment tax credits for installing solar energy generation are limited to taxable entities, which the Tribal Nations are not, leaving them excluded from economic incentives. Additionally, if Tribes install DSPV on agricultural lands, the lands must be rezoned and could be reclassified, resulting in fees that further increase the financial infeasibility of projects. These cost barriers underscore the general trend that DSPV is typically only available to the socio-economically and socio-culturally advantaged members of a nation or community, in large part due to structural racism.
Though cost and systematic oppression are some of the greatest challenges to DSPV adoption, they aren’t the only barriers. For example, the task of integrating a large number of individual generators within existing utility grids — without putting unsafe strain on infrastructure — is a technical challenge that must be met carefully through research and data-driven control algorithms. However, it’s safe to say that the predominant barriers to the type of DSPV adoption we envision at GRID are severe and structural disparities in the distribution of wealth and power in our society.
Overcoming the Challenges
Despite the magnitude of overcoming large-scale and long-lasting inequalities to promote fair DSPV deployments, there are some options at our disposal. Reducing cost barriers for individuals and communities is one way to enable broader DSPV implementation. Net metering, a process that allows consumers to sell extra electricity produced by their set-up back to the grid, is recommended by the Solar Energy Industries Association.. Rebates and incentives can also expand the percentage of people who can afford to switch to distributed solar. On a national level, governments could levy carbon taxes, encouraging companies to switch to distributed solar for facilities. The tax revenue could be used for progressive rebates, grants, and other forms of funding.
For rural communities, governments and organizations can promote hybrid solutions to distributed generation such as a DSPV system paired with a battery and diesel generator. Hybrid systems can reduce cost as the solar system can be smaller while also reducing how frequently a diesel generator must run, how much gas it consumes, and how much pollutants it produces. This hybrid approach could also be used with wind and geothermal energy resources. There are also opportunities for communities and smaller governments to work with international investors and organizations. China in particular has programs to aid in electrification of rural areas worldwide that communities in southeast Asia, as well as throughout Africa, have taken advantage of to expand DSPV. Better community surveying and participation can also aid in determining acceptable costs as well as ensuring that electricity serves the needs of and is available to all in the community.
Addressing economic barriers is an important step in increasing the number and capacity of DSPV systems quickly. However, where the strategies above are implemented, they do not always work. Many times, this is because, in the process of installing systems, the fundamental benefit and spirit of distributed systems is lost. DSPV is by definition a tool for energy autonomy, allowing those who use it to be independent of large energy companies economically and functionally. But to install the systems that lead to this freedom, communities must navigate a veritable maze of red tape and biased regulations to obtain capital and legal permission. Unfortunately, the companies, organizations, and governments that control the economic measures noted above are frequently structured within racist and classist systems. Due to this, the communities that would most benefit from DSPV often are excluded from receiving the aid they need or, if they receive it, blocked from the decision making process and have their needs ignored. The power and authority in DSPV projects must be put in the hands of the underserved communities that need them most. Support should still be offered, but autonomy is crucial if DSPV systems are to be widespread and sufficient for the communities that rely on them.
As DSPV and solar energy continue to proliferate, we need to look beyond innovation as strictly technological. As technology innovations indeed reduce cost and improve efficiency, we must also identify innovations that, like DSPV itself, have the potential to put power into the hands of the disempowered. From this perspective, it is clear that DSPV, if done right, can promote a positive feedback cycle — a technology both dependent on and capable of producing a more equitable distribution of resources and power.
