Our technology is a small-scale distributed co-generation platform that uses solar energy to produce thermal and electrical energy supplies. The solar thermal design uses the heat from sunlight directly to drive a heat engine and to produce hot water (or cooling via an absorption-chiller type process). By using a cogeneration scheme to recover some fraction of the "waste" heat, a higher fraction of the sun's energy is captured and turned into useful energy.
These microgenerator systems are built using widely available parts including steel, plumbing supplies, HVAC or automotive parts. Specialty components (the aluminum reflective sheeting and refrigerant working fluid) are generally available as well, though the microgenerator design can be updated to use alternative materials in areas where they are extremely costly or difficult to source. The goal is a microgenerator design that is purely mechanical and can be constructed almost anywhere, unlike silicon-based photovoltaic cells which rely upon high-tech clean rooms for manufacturability.
Initial pilot systems were designed to produce between 600W and 1kW of electricity along with ~10kW of thermal outputs (e.g. hot water). In such a configuration, a 24 square-meter array of parabolic mirrors can produce up to 600L of hot water during a sunny summer day (approximately half as much on a sunny winter day with fewer hours of sunlight). Current designs can provide between up to 3kW of electricity along with hundreds of gallons of hot water per day, optimized to provide energy for off-grid schools, clinics, or community centers where both electricity and hot water are in high demand.
The STG team has been working on the development of this technology since 2004. Several generations of prototypes have been constructed and installed in Cambridge, Massachusetts (USA); Bethel, Phamong (Lesotho), Matjotjo Village, Berea District (Lesotho), and St. Petersburg, Florida (USA).