Solar street lighting is a unique opportunity for sustainable recovery In response to the economic fallout from COVID-19, the European Union has formulated a major recovery plan for the continent with a key focus on adapting to the digital age and investing in cleaner and more resilient technologies for the future. In the U.S., the 2021 American Jobs Plan aims to steer $2 trillion into productivity and long-term growth, including a strong focus on building resilient and climate-friendly infrastructure. With economic and climate resilience plans taking a more concrete shape across the globe, Signify believes that solutions such as solar lighting pave the way for countries to build back better.  According to Allied Market Research the global market solar energy was $52.5 billion in 2018 and is set to grow to $223.3 billion by 2026, vastly accelerating the scale of renewables. One of the fastest growing solar street light. "Solar street lighting technology has come on leaps and bounds in recent years and is fully aligned with the goals of EU and U.S clean energy and economic stimulus initiatives. Just 15 streetlights can save enough electricity to power a home for a year," said Harry Verhaar, global head of government and public affairs at Signify. "Being a digital technology, it can be connected to sensors and be controlled remotely, enabling forward-thinking municipalities to leapfrog to solar and reap the benefits of the digital age." President Joe Biden’s administration already has proposed $621 billion of additional investment in transportation infrastructure, with $20 billion earmarked to improve road safety and $174 billion for electric vehicles. A sizeable chunk of the latter would be spent on grant and incentive programs to build a national network of 500,000 electric vehicle charging stations by 2030.  Signify advocates specifically for the wide adoption of solar and all in one solar street light which will not only help improve road safety, but also pave the way to lower emissions and eliminate the need for extra power stations to power the street lamps. This is particularly useful in more remote areas where existing infrastructure is minimal. With the strain taken off power stations, excess capacity could be diverted towards supporting charging stations for electric vehicles. Greek experience Solar is the ideal technology for serving far-flung communities with intermittent power supply or coverage. For example, in 2020, Signify installed solar streetlights on the Greek island of Leipsoi in areas lacking full electricity coverage including a playground, allowing the community to feel safer. A total of 28 autonomous Philips SunStay luminaires were used, each combining a solar panel, an LED light, a charge controller and a battery in one housing unit. The lights also contained an infrared motion sensor which detects movement and alters brightness accordingly, increasing energy efficiency and minimizing light pollution. "As we have many hours of sunshine throughout the year this is a very effective and functional solution for those areas on our island that are not connected to the power grid," said Fotis Mangos, mayor of Leipsoi. "The lights have such an aesthetic design that they seamlessly blend in with our island’s natural landscape." The electricity grid doesn’t always follow the street layout on the island and the solar installation allowed for an inexpensive, unobtrusive and environmentally friendly way to light roads and pathways without needing to dig trenches for electrical cables. "Solar lighting is a key part of our commitment to sustainability and to climate action, as we aim to help people move to cleaner technologies," said Signify’s country leader for Greece, Polydefkis Loukopoulos. "The expansion of solar lighting in new areas of Greece strengthens our vision to provide local communities with the security that results from high-quality solar lighting."  With the addition of hybrid technologies, solar lighting is a feasible solution in areas with only seasonal sunshine, allowing countries at higher latitudes to access its benefits. This technology broadens the market for solar power. A version of solar is available beyond sun-soaked countries to around 6.5 billion people in the world. According to Antonio Espada, head of public segment in Europe for Signify, solar panel street light is the best of both worlds. It uses sunlight to charge its batteries and on cloudy days seamlessly switches to electricity from the grid. It’s highly energy efficient and increases the use of renewables and balances electricity loads. The battery power can be used during peak hours so fewer power stations are required. "Solar and solar hybrid power streetlights are particularly well suited to countries and regions where power outages are common. It can help deter crime and contributes to safer, more resilient communities," added Verhaar. Ultimately, solar lighting is an accessible, efficient and future-proof solution for community development, and one which could hugely benefit global recovery on both sides of the Atlantic. Discover more on how lighting can help to meet Green Deal targets. This paper examines the gap between the design and in-situ performance of solar streetlight interventions in two humanitarian settings. Displaced settlements often lack street lighting and electricity. Given that off-grid solar streetlights produce surplus energy, we hypothesized that this energy could be made available for daily usage, to improve system performance and provide further energy access to displaced populations. We recognize, however, that solar streetlight performance and longevity have typically been poor in remote and refugee settings. Eleven solar streetlights were fitted with ground-level sockets and their performance monitored, in two displaced settlements: a refugee camp in Rwanda and an internally displaced population settlement in Nepal. Considerable performance gaps were found across all eleven systems. Inefficient lights and mismatching system components were major issues at both sites, reducing targeted designed performance ratios by 33% and 53% on average in Rwanda and Nepal, respectively. The challenges of deploying these types of systems in temporary settlements are outlined and a number of suggestions are made to guide future developments in the design and implementation of sustainable solar streetlight interventions. Today's solar street LED lights are able to provide reliable, quality lighting both in developing and developed countries, thereby reducing light poverty and the economic and environmental costs of electric outdoor lighting. Rapid technical innovation and dramatic price reduction in the LED, PV module, and battery components, which has occurred in the last 5 years, will accelerate the penetration of solar street LED lights across the world. Applications will not be limited to countries with significant insolation only but will extend to Northern regions as well. This study provides a critical overview of a technology that will play an important role en route to global sustainability. For further resources related to this article, please visit the WIREs website. In 2016, on the northern shore of Lake Victoria, Jinja City sat in darkness. The city, the second-largest in Uganda, had run up an overdue power bill of 1.3 billion Ugandan shillings ($3.5 million), so Umeme, the nation’s largest energy distributor, disconnected the city’s street lights.   Even before Umeme cut the power, most roads in this city of 870,000 near the source of the White Nile lacked illumination: Only the colonial-era center of town was equipped with solar garden light, and many of these had begun to sputter out due to age and poor maintenance. Districts that had grown as unplanned areas on the outskirts before being incorporated into the city had never been lit at all. “The area in the city that is planned is quite small,” says Kennedy Kibedi, a social media marketing specialist who works in tourism in Jinja City. “On the fringes of the city, in the suburbs, there’s a lot of informal development.” That pattern holds true for many of Africa’s largest cities. As places like Nairobi, Lagos, and Kampala have grown, they’ve absorbed informal settlements that aren’t connected to national power grids. As a result, street lighting is scarce, scattered and unreliable, and the costs for installing conventional grid-based lighting are high.  So Jinja City administrators looked to neighboring Kampala, the nation’s capital and its largest city, for an alternative solution: solar-powered street lights, powered not by the grid but by photovoltaic panels and batteries that are either attached to each light pole or housed at a mini power station to support a group of lights.  The Kampala Capital City Authority began revamping that city’s street lighting with solar-powered equipment in 2014, when just 115 kilometers of 1,200 kilometers of roads in Kampala had street lights, and only a fraction of those were operational. By 2016, when Jinja City was grappling with its power cut, the success of Kampala’s program was already apparent. Reports published that year show that the new solar spot light had reduced energy usage and costs, decreased traffic fatalities and accidents, and helped foster a more vibrant night economy in the capital city.