We began as a technological venture, a company that sought sustainability in the coffee sector through roasting with solar energy. Although, for the moment, we do not use this type of energy and we prioritize reaching more families to generate a fairer and more responsible chain of consumption, our team continues to work on research and development projects of technology based on clean energy.
Technology
Solar Toaster
Over the years, we have developed several versions of machines that allow the roasting of coffee with solar energy. Our technology achieves, with only solar energy and mirrors, temperatures of more than 200°C that allow roasting. This is the most eco-friendly form of coffee roasting applied in our country so far.
This method basically depends on the sun and therefore on the climatic conditions of the roasting site. For this reason, one of the next steps was to install a system of photovoltaic panels that would provide extra energy to the roaster and at the same time allow better roasting times to be managed. This system allowed us to enable other machines and also to implement a processing center in the same community where the coffee was produced and purchased.
Currently, our technology team continues to develop, improve and test solar roaster design alternatives that will help us meet the technical requirements and production capacity needed.
Technology
Solar Dryers
Solar Dryer for Coffee Pulp
Between 2018 and 2019, members of the Compadre team together with Resto Zero, the Grupo de Apoyo al Sector Rural PUCP and the Alto Palomar Cooperative carried out the project «Dryer for Coffee Pulp and Specialty Coffees» funded by Innóvate Perú.
The development was a solar-powered dryer with an autonomous control system that allowed it to regulate the drying parameters without the need for human control.
For its operation, this dryer had a solar collector, a burner, which functioned as a backup system in case of rain or very cloudy days. In addition to a photovoltaic system that controlled its fans.
Solar Dryer
For the past years, Compadre has learned a lot more about coffee drying and how it plays a key role in quality. Most coffee farmers in Peru have small parcels, lack the training, space and tools to properly dry their coffee. Since buyers purchase coffee at a price that depends on the quality, after a year’s work, coffee farmers aren’t offered enough for them to reinvest in their farms or improve their quality of life.
From what the team learned through the design and implementation of the solar dryer for coffee pulp and other courses our members took, came the idea of our most recent coffee solar dryer.
The solar dryer has 3 solar collectors on the roof, manufactured by members of GRUPO PUCP, which heat air up to 60°C. Through flexible insulated air ducts, the air flows from the collectors to the bottom of the dryer.In order to be able to dry coffee during unfavorable climate conditions, it was decided that thermal energy would be store in a rock bank, which is located inside the drying chamber above the floor. The hot air from the collectors go through the rock bank, heating the rocks inside for later use. In case of low solar radiation or rainfall, a wood burner and an independent fan are turned on to heat the rock bank.
On days with good solar radiation, the Agrofilm walls of the dryer are opened to prevent the temperature inside the dryer to reach more than 40°C. During the night, the walls are closed and the interior is maintained at a temperature around 5°C above the ambient temperature thanks to the opening of the rock bank, which will provide heat to the interior air, reducing the re-wetting of the coffee and favoring its drying. On days when there is not enough solar radiation, only the wood burner system will be used to heat the rock bed in order to maintain the humidity percentage of the parchment coffee stable and/or to continue the drying process in case of persistent rain.
