Rome, Nov. 8 (BUS): By merging two of Italy’s wonders – coffee and sunlight – two engineers in Rome have devised an eco-friendly way to roast coffee beans without electricity or gas.
The Associated Press (AP) reports that Antonio Dorby and Daniel Tommy spent nearly six years building and perfecting their solar-powered coffee roaster.
The result is a system that takes a plot the size of half a tennis court and sunny weather to roast up to 50 kilograms (110 pounds) of coffee per hour.
The entire plant is powered by energy from the sun. The sun’s rays are concentrated by a set of mirrors in the coffee roaster and even the few electric parts are powered by a small solar panel. Computer-controlled sensors allow the mirrors to track the sun’s rays throughout the day and focus its light onto a rotating steel basket containing fresh coffee beans. The basket reaches a maximum temperature of about 240-250°C (450-480°F), depending on the brightness of the sun, and the beans can be roasted in 20 minutes.
This process is not only environmentally friendly and economically convenient. According to Durbe and Tummei, it also better preserves the aroma of coffee, giving it a richer flavour. Unlike traditional hot air ovens, which typically run on gas, concentrated sunlight roasts the coffee without heating the air around it – by penetrating the beans in a more uniform manner and without burning the outside surface.
Naturally, the regime depends on good weather. On cloudy days or after sunset, coffee lovers need to relocate.
However, in sunny southern Italy, a factory with 40 mirrors can roast up to 30,000 kilograms (66,000 pounds) of coffee per year, saving about 60,000 kilowatt-hours of electricity, according to the inventors.
Purosole, or pure sun, coffee can be purchased online, but the inventors’ main goal is to sell solar coffee roasting plants to environmentally sensitive small businesses. Currently, they are running their plant in a friend’s garden.
The system can also be used for other uses. At the end of a long work day, Durbe and Tummei put a grill in front of the mirrors to prepare some delicious roast in the sunshine.
RAE