Small scale solar ORC system for distributed power in Lesotho
The Solar ORC is an approach to off-grid generation that utilizes parabolic concentrating
solar collectors and a heat engine - an organic Rankine cycle (ORC) - constructed from massmanufactured HVAC and automotive parts. This technology can supply both electricity and
thermal products to rural institutions such as primary schools or health clinics, which face
levelized costs of electricity (LCOE) of over $0.35/kW-hour for PV panels and over
$0.50/kW-hour for diesel generators. Solar ORC technology developed by the Solar Turbine
Group at MIT can supply electricity at conservative market-entry prices of under $0.30/kWh
with hot water included (approximately 3-5 cubic meter per day at 50° C) at no extra cost.
Various components of the technology, including the solar collectors and prototype ORC
engines, were field-tested in Lesotho beginning in 2006 as part of a World Bank supported
technology transfer project. A 3 kW pre-commercial pilot of the system is currently being
installed at a health clinic in 2009, in partnership with the Lesotho government's Appropriate
Technology Services division. With electricity and hot water from a Solar ORC, the quality
of service provided to rural communities can be greatly improved for a fraction of the cost of
competing technologies.
Matthew Orosz is a Martin Fellow for Sustainability and Civil and Environmental
Engineering doctoral candidate at MIT, as well as a founder of the non-profit Solar
Turbine Group (STG). Since serving as a Peace Corps Volunteer in Lesotho from 20002002, Matthew has been committed to finding solutions to rural energy needs in
underserved markets, particularly in sub-Saharan Africa. Through work at MIT and
STG, he has pioneered the development of low-cost solar thermal technologies and
promoted engineering capacity building in renewable energy in Lesotho, in partnerships
with local government and NGO groups.