Sure Chill trials smart controller in off-grid project
UK: An energy-saving smart controller, developed by off-grid refrigerator company Sure Chill, is being trialled in Kenya with a solar home system provider.
The Cardiff-based cooling technology company has developed an innovative refrigerator control platform that can be integrated with solar home systems. The project received £196,781 funding from UK aid through the Efficiency for Access Research and Development Fund in 2019.
Many people living in developing countries cannot afford refrigerators. In Kenya, an off-grid refrigerator and system can cost at least US$1,000. As a result, only 4% of households without access to the electrical grid in sub-Saharan Africa own a refrigerator.
Having identified this need, the Efficiency for Access Research and Development Fund supported Sure Chill in developing a prototype device that could be scaled for mass production to reduce the costs of off-grid domestic refrigeration, while improving overall system performance. The integration of the Gen2 Smart Box smart controller into Sure Chill’s off-grid domestic refrigerator led to a 32% cost reduction for the compressor control system. Sure Chill also estimates that adding a smart controller results in a US$84 cost reduction for customers.
The first version of the smart controller developed by Sure Chill, has already been integrated into 90 domestic refrigerators delivered to Kenya for a sales trial with a solar home system provider, which is working across sub-Saharan Africa. Larger production runs are planned for 2021 and will incorporate the GEN2 Smart Box controller, which is being finalised for full production.
Sure Chill’s award-winning fridge technology doesn’t need a constant power supply. It is said to be able to provide cooling for over 10 days or more without power in hot ambient conditions.
Water surrounds a Sure Chill refrigeration compartment. When it has power, the water cools and forms ice above the compartment leaving only water at four degrees cooling the contents. When the power is switched off, the water warms and rises while the ice begins to melt, keeping only 4º water cooling the contents of the compartment. So it has its own internal and entirely natural energy store that maintains a completely steady temperature.
While Sure Chill technology removes the need for a battery by storing thermal energy, the manufacturer maintains that existing compressor controllers are not optimised for cost or energy use in a direct-drive application.
The new control platform works with a range of compressors and will be adaptable for applications from small SHS with limited battery capacity to solar direct-drive (no battery). By being able to monitor both the state of the fridge and the power supply, compressor operation can be optimised to maintain cooling without compromising other loads.
Sure Chill worked closely with two solar home system distributors to integrate an authentication protocol into the GEN2 Smart Box. This enables Sure Chill’s domestic refrigerator to fit seamlessly into PAYGO systems.