2020 is still not over, but can already be crowned as one of the most challenging years humanity has known in a long time. The spread of Covid-19 throughout the world, the prolonged lockdowns that followed it, the high numbers of patients and mortalities, the economic damage, all of these and more have hit almost every country around the globe, with disastrous effects that will stay with us for decades to come. The virus may not differentiate between humans and countries, but the challenges that come with it certainly do. In the United States, Europe and East Asia, the results of successful vaccine trials developed by various companies have been celebrated in recent weeks, and the people are counting the minutes until FDA approval will be announced, allowing to distribute the vaccines and begin vast immunization. This is an unprecedented scientific achievement: a year since the virus first broke, and scientists have (hopefully) already succeeded in developing an entirely new vaccine, using innovative technology. But despite the tremendous scientific achievement, for many countries, and hundreds of millions of people around the world, this is only the first part of the challenge, and some would say that it is the easier one. Once the vaccine development is officially completed and all the necessary approvals are obtained, the scientific challenge will end, and the logistical one will begin: transporting billions of vaccine doses to remote communities in developing countries, where hundreds of millions live off-grid and without access to the most basic medical services. And in case transporting billions of vaccines to remote communities was not challenging enough, there is one more factor to be considered: the temperature. To keep vaccines effective and safe to use, it is necessary to keep them refrigerated at all times, throughout the entire supply chain. The vaccine developed by Pfizer, which was the first to report results and apply for emergency approval from the FDA, requires deep freezing of -70 degrees Celsius, -94 Fahrenheit (!). Moderna, the next in line to publish the results, has developed a more durable vaccine, requiring “only” -20 C. Now, many are pinning their hopes on another type of vaccine, developed by Johnson & Johnson, which is expected to soon announce results, and is estimated to require a constant cooling of only 2 degrees Celsius. Even the most optimistic scenario poses an unprecedented challenge to governments, organizations, and companies in Africa. Carrying the vaccine all the way from the factories to the remote communities requires designated aircrafts, advanced logistics centers, refrigerated trucks, and all this just to bring the vaccine to the district medical centres. But to vaccinate the hundreds of millions living in the most remote communities, it is not enough: the medical staff will be required to transport the vaccines with the help of motorcycles, bicycles, and sometimes even animals. Then, in the village, the vaccines will have to be kept in deep refrigeration for several hours and maybe even days, in order to be able to vaccinate the entire population. And if all this sounds difficult, the challenge becomes almost impossible when one considers that in the vast majority of those remote villages, there is not even access to electricity. Solar to the rescue! Connecting hundreds of thousands of remote villages to the national electricity grid in the near future is, of course, unrealistic and impossible. Relying on temporary energy sources, such as generators, is not applicable on a wide scale. To provide the energy needed to keep the vaccines frozen in remote villages, we must use the most available and accessible resource on the ground, which will enable affordable, fast, and sustainable energy. To that end, solar power is not the perfect option; it is the only option. In recent years off-grid solar systems proved to be the most efficient, affordable, and scalable solution for connecting millions of people to electricity. In recent years, additional technologies have been added to home solar systems, providing a wide range of solutions powered solely by solar energy. One of those solutions is solar refrigerators. Solar refrigerators are nothing new: several thousand of them have already been deployed across the continent, allowing private customers, small businesses, schools and clinics to enjoy refrigeration for the first time. Now, the technology (and the entire solar sector) may be the key to solving one of the most difficult and complex challenges in history. Solar refrigerators are the most cost-effective, efficient and sustainable option for refrigerating vaccines in remote communities across sub-Saharan Africa. With relatively limited investment and focused operations, we can deploy tens of thousands of refrigerators in remote clinics in a short period of time, and allow local staff to store the vaccines refrigerated with nothing but solar power. The leading companies in the sector are now facing an opportunity for impact on a huge scale. These companies have the knowledge and infrastructure required for the rapid and extensive deployment of refrigerators and solar systems, as well as the technical teams, assistance centers, and more. Ignite, for example, started working months ago to provide solar refrigerators to remote clinics, to help as many people as possible once a vaccine is approved. The writer is an entrepreneur andinvestor, leading sustainability-driven companies in Africa.