The sunlight streams in through the drawn curtains in Freetown, Sierra Leone, as Sheku Bockarie talks about how Solar Direct Drive (SDD) refrigerators work.
“We’ve got six panels on the roof,” he says, gesturing towards the ceiling of the city’s Military Hospital.
As health supervisor for Freetown’s Western Area Rural District, Mr Bockarie oversees the mobile team that goes out to deliver Covid-19 vaccinations. That afternoon, they’re driving out to a college to make sure students are protected against the virus.
“The fridge ensures that the vaccines maintain their potency,” he says, turning the camera towards a dark blue chest fridge.
Cold-chain technology goes hand in hand with the Covid-19 vaccination roll-out. As the jabs contain biological products that are sensitive to heat, they need to be stored in cool temperatures from the outset.
In countries that don’t have a national grid to power conventional refrigerators, solar energy can often be the only viable alternative.
“SDD refrigerators have been specifically designed for developing country settings,” says a spokesperson for the global vaccine alliance, Gavi. Their latest figures show that over 45,000 SDD units have been installed in 42 countries.
Joyce Anusumana is the lead for the Essential Program for Immunisation (EPI) cold chain and logistics team in Sierra Leone. She says solar technology is essential for vaccinating people living in remote areas.
“They’re a very good innovation for saving lives,” she says. “They are powerful and marvellous and have helped a lot with immunisation.”
Though the technology requires a steep initial investment, its upkeep isn’t as expensive as might be imagined given the usual costs associated with renewable energy. Figures from 2019 show that the total cost of ownership for SDD refrigerators compares favourably to gas or electric-powered refrigerators.
“They’re very easy to use and very easy to maintain,” says Baboucarr Boye, an immunisation specialist for Unicef in Sierra Leone.
District technicians have been trained to provide routine maintenance for the solar fridges, but Mr Boye says both health facility staff and technicians have reported that the fridges need minimal repair and maintenance after installation.
Given their cost efficiency, easy maintenance and vital role in vaccination rollout, the Ministry of Health is working alongside Unicef and Gavi to ensure that every health facility in Sierra Leone has access to an SDD fridge.
By December 2021, Mr Boye says they’re on track to equip over 90 per cent of the country’s 1,367 health facilities with SDD refrigerators.
Over in Kenya, most of the country’s vaccination stations are connected to the power grid.
Yet this does not mean that SDD fridges are not valuable assets. As Kenya progresses its Covid-19 vaccine roll-out strategy, it will begin to offer jabs in the 2,000-strong ‘lower level’ facilities which have access to solar-powered fridges.
Dr Lucy Mecca, the team lead of Vaccine Supply and Quantity in Kenya’s National Vaccine and Immunisation program, says: “It is envisioned that subsequent vaccine deployments will distribute vaccines amongst the lower level facilities, some of which have SDD fridges. This means that access to the jabs won’t be limited to places connected to mains power.”
To accelerate Covid-19 vaccine delivery across Africa , Gavi is in the process of securing a further 4,500 SDD refrigerators and freezers.