Secop develops effective off-grid solar cooling solution

GERMANY: Hermetic compressor manufacturer Secop is bringing to market a range of mobile cooling units powered by solar direct drive (SDD) technology and its BD Nano series compressor. 

Secop says that creating new technology which uses and stores solar energy will enable customers traveling to or in remote areas, regions, and countries with a weak grid connection to correctly store vaccines and medical samples.

Medical professionals, especially those in hot regions, without a secure power supply often have to use absorption refrigerators powered by gas and kerosene which, the company says, are maintenance intensive and inefficient, less environmentally friendly and less reliable than units powered by compressor technology. 

While battery-powered solar refrigerators have been a good solution to date, Secop maintains that the batteries needed to power them are expensive to purchase and replace long-term.

Designed to tackle these challenges head-on, the new cooling units developed by Secop, combining SDD technology and its BD Nano Series compressor, use photovoltaic energy to directly freeze the internal refrigeration material while stored energy keeps the refrigerator cold during the night or on cloudy days. This solves the issue of off-grid cooling, reducing the overall cost of vaccine refrigeration – both capital and operating costs – in remote areas. 

Working with Global Health Labs, a nonprofit corporation funded by Bill Gates and other cross-sector leaders to develop health technology solutions, to define the requirements and develop the new SDD power management module, it has also been tailored to the WHO’s PQS specifications, meeting all solar direct drive requirements.

The new solar direct drive and weak grid power management module features an AC input which enables global deployment and a DC input optimised for latest generation PV panels, providing the ability to get the maximum cooling from available PV energy. The integrated AC/DC technology eliminates the need for additional voltage stabilisers, reduces complexity, and ensures reliable and efficient operation, allowing for optimised transportation, installation, and maintenance, which positively impacts the total cost of ownership.

The new SDD power management module (PMM) features the AC/DC controller with the new generation of mobile refrigeration compressors. The design of the new PMM is said to be very robust and suitable for off-grid vaccine refrigerators, solar-powered off-grid refrigerators and freezers, and ice bank refrigerators.

Secop conducted several tests to prove the benefits of its new solution compared to existing products on the market. Replacing regular cooling solutions with the new SDD and BD Nano compressor, the system is said to have exhibited longer hold-up times, reliable operation at ambient temperatures (from 10 to 43 °C) and demonstrated extended and stabilised input voltage with surge protection.

“While there was a refrigeration option on the market which was able to keep vaccines and medicines cool in remote and hot areas, it came with a variety of challenges. By creating the new solar direct drive (SDD) power management module paired with the new BD Nano series, we have created an even better option. With energy-saving and longevity measures in place, as well as the opportunity to plug into the grid when possible, we think this is the next best evolution in cooling solutions.” said Secop CEO Jan Ehlers.

In one application an Ice Line refrigerator designed for four 90W PV panels with an external voltage stabiliser and AC power supply was optimised by Secop, replacing the cooling solution with the new SDD and BD Nano compressor. This is able to connect to a single 160-250W PV panel without the need for external components due to the integrated PMM solution. 

The system is said to have exhibited longer hold-up times and reliable operation at ambient temperatures, its extended and stabilised input voltage with surge protection, making it reliable under highly variable field conditions. 

The tests showed a 20% increase in efficiency and a 28% increase in cooling capacity, while energy consumption was reduced by 16%. In addition, compressor run-time was reduced by 18%, which had a positive impact on energy supply. The new system offered the possibility of reducing the number of panels by 75% and solar power consumption by 50%. Also, due to the complexity reduction, it was possible to reduce the PV installation time by 66%.