MIT student, Matthew Orosz, spent two years with in African nation of Lesotho with the Peace Corps. While there he became determined to help the medical clinics that were operating with only diesel generators for electricity and without hot water. When he returned to MIT he set out to develop a technology that could provide a clean source of electricity and heat, the result of which is called a solar ORC system.
Phys.org reports, "The patented technology they developed uses a mirrored parabolic trough to capture sunlight, heating fluid in a pipe along the mirror’s centerline. This fluid then powers a sort of air conditioner in reverse: Instead of using electricity to pump out cold air on one side and hot air on the other, it uses the hot fluid and cold air to generate electricity. At the same time, the hot fluid can be used to provide heat and hot water — or, by adding a separate chiller stage, to produce cooling as well."
Below is a video explaining the technology.
Under the name STG International, the team is developing these trough systems to hopefully help some of the 30,000 health clinics and 60,000 schools around the world that operate without a reliable source of electricity, but have plenty of sunshine.
A pilot system is currently installed at a remote clinic in Lesotho, but it has taken years to take it from concept to a fully working and automated solution that the local communities could easily use and operate.
According to Phys.org, "While they were able to demonstrate the successful operation of their heat-powered generator — a system called an organic Rankine cycle (ORC) engine — the system required a skilled operator to adjust the temperatures, pressures and voltages as conditions changed. Since then, the STG team has developed a sophisticated computerized control system, allowing the system to run virtually hands-free. Once that system is installed, the only routine maintenance required is washing the huge mirrors every six months or so."
The team plans on installing four more of the solar ORC systems at schools and clinics in Lesotho this year. The systems will be built, operated and owned by local companies so that they also are a source of jobs and revenue for the country.