It began as a way for two brothers to work together: one was an amateur inventor interested in the environment; the other, a coffee roaster. From their shared passions came the idea of roasting coffee with the sun. Today, Michael and David Hartkop have turned their Solar Roast Coffee into a business.

In this video, David showed us the solar concentrators he’s designed for the business. They may be homemade and constructed with simple mirrors, but they’re powerful enough to vaporize coffee.

For more on this increasingly popular technology, we also have an article on concentrating solar power.