Keeping vaccines safe and effective in countries with limited and unreliable power supplies calls for the need for uninterrupted refrigeration.
After all, weak links in the cold chain system can easily cause millions of dollars’ worth of Covid-19 vaccines, something that countries avoid, especially now with the limited production of approved shots during pandemic.
This is where the Solar Direct Drive comes into play. Basically, the Solar Direct Drive utilizes energy from the sun to power a compressor, which cools or freezes a liquid that then cools the Covid-19 vaccines.
The technology was the result of the United Nations Environment Programme Division of Technology Industry and Economics (UNEP-DTIE) collaboration with Greenpeace, UNICEF, and industry in 2001, where they worked on developing a better refrigeration system for locations with unreliable and limited power supply.
That is when Vestefrost, an industry partner, came up with a 19.5-liter prototype unit that used the Solar Direct Drive Technology. Instead of batteries, the prototype stores the energy of the sun in ice. During the day, the equipment powers the compressor through the photovoltaic solar panels. When the sun comes down, the ice compartment keeps the vaccine vials at specific temperatures to keep them effective.
Ultimately, in 2010, the World Health Organization has already prequalified this environmentally-friendly, inexpensive, and battery-free refrigeration system. This allowed the prototype to be tested in a laboratory setting to determine which climatic condition it is suitable for use. Results revealed that the first generation Solar Direct Drive technology was prequalified for locations up to 27°C.
Since then, research and development accelerated for the cold chain industry, where several other suppliers began receiving prequalification for their version of the prototype utilizing the Solar Direct Drive technology.
So far, a second generation has been created that can be used in regions of up to 32 °C, and currently, work is ongoing on a third generation for countries with temperatures up to 43 °C.