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Solar Power for Cooling Systems and Data Collection
Spray operators spraying a wall with a supervisor watching them. Photo credit: Arnaud Rakotonirina, VectorLink Madagascar Monitoring and Evaluation Manager
Malaria continues to be a serious health threat in much of Sub-Saharan Africa. With the impacts of climate change becoming more extreme, countries are increasingly concerned with how climate change will affect vectors like malaria-transmitting mosquitoes. Transitioning to solar power enables malaria services to remain resilient against shocks like climate change. And as a renewable energy source, solar helps the U.S. Agency for International Development (USAID) achieve its Climate Strategy 2022-2030, which supports actions that prevent, limit, or sequester six billion metric tons of carbon dioxide.
A key malaria control intervention is indoor residual spraying (IRS). The U.S. President’s Malaria Initiative (PMI) VectorLink Project operates in 24 countries and implements IRS in 13. In each country, the Abt-led project establishes operational sites as bases for teams that go door-to-door to spray houses with insecticide. Historically, the electric grid and generators provided electricity for powering cooling systems for insecticide storerooms and charging electronic devices for mobile data collection. However, more reliable and more affordable solar power can provide the required electricity.
Adapting to High Temperatures in Madagascar
In Madagascar, solar panels were a necessary adaptation to high temperatures. The maximum recommended storeroom temperature for IRS insecticides is 35°C (approximately 95°F). Higher temperatures could lead to insecticide degradation or damage the integrity of insecticide containers. In Betioky District, temperatures can reach 42°C (approximately 107°F) even in the shade.
“One of the major concerns in Madagascar is the impact of climate change like high temperatures and violent storms,” said Environmental Compliance Officer Tahina Masihelison of PMI VectorLink Madagascar. “These interfere with the storage conditions of the insecticides because either the storerooms are not electrified, or the power is cut for several days after the passage of storms.”
Environmental Compliance Officer Tahina Masihelison showcasing the solar powered system at Tongobory operations site in Madagascar. Photo Credit: Tahina Masilhelison
PMI VectorLink Madagascar tested the use of a solar-powered cooling and ventilation system in the Tongobory operations site. The ventilation system comprises a solar panel that can produce 500 watts of electricity; a battery; an AC/DC inverter; a humidifier; and a fan. The battery stores the energy collected by the solar panel and powers the fan and humidifier when the sun is not shining. The ventilation system keeps the storeroom cool and distributes the air evenly, eliminating hot spots.
The advantages of solar power over generators are significant. While generators are widely available and easy to install, their fuel pollutes, they require recurring fuel costs, and they’re bulky and noisy. Solar panels, in contrast, are quiet and light. In Madagascar, a 500-watt installation with a humidifier costs around $430, which is less expensive than the $738 to run a generator up to eight hours a day for 30 days.
After PMI VectorLink Madagascar installed the solar powered system, the storeroom temperature decreased by 12°C on average. Therefore, if the outside temperature was 40 - 44°C (approximately 104 to 111°F), the temperature inside the storeroom was cooled to between 28 and 32°C (approximately 82 to 90°F). Solar-powered systems thus can cool storerooms to below the recommended maximum storage temperature and do so at a lower economic and environmental cost than generators.
Reliable Power for Data Collection
Beyond their use for coolong storerooms, solar panels can be effective for charging devices for mobile data collection. In 2020, PMI VectorLink Tanzania piloted the use of solar panels for charging the devices and in 2021, Abt scaled up the use of solar-panels as we transitioned to full mobile-data collection. The mobile devices increase efficiency by enabling same-day processing of data. Key information collected included structures we visited and key populations we protected. We also tracked spray coverage. The data will inform IRS campaign monitoring.
Mobile data collection requires a reliable source of electricity to keep devices charged. In the past, the project rented generators and purchased fuel, power stabilizers, and extension cables. Abt also used electricity at sites where it was available. However, maintenance issues and frequent power cuts often rendered electricity unreliable.
Solar Panels powering the charging banks for mobile devices used in data collection. Photo Credit: Allan Were, Vector Control Director
Transitioning to solar power provided the team with a more dependable power source, especially in hard-to-reach areas. It also cut costs. Since the project owns the solar panels and charging banks, it can use them for a prolonged period. And the portability of the solar chargers enables a smooth reallocation of the panels across IRS operational sites. While electricity costs less in the short-term for areas on the grid, approximately $4,152 per campaign, the grid doesn’t reach many rural settings, which have relied instead on generators to provide the necessary electricity. However, solar power is more cost effective than generators—approximately $12,266 initially compared with $33,959 per campaign. Currently, the Tanzania team has 532 solar panels and enough phone chargers for the 1,325 active devices.
“The rollout of solar charging systems enhanced the quick availability of data that helped timely decision-making and adjusted field supervision priorities among operations sites. Spray operators were able to operate with charged phones every day, establishing a stable synchronization process at the end of the spray day,” stated Abt’s Ditrick Novat, PMI VectorLink Tanzania’s monitoring and evaluation officer.
Solar-powered systems provide a renewable, reliable, and cost-effective way to meet electricity needs. In Madagascar, the solar installation supports electrification of the central store beyond a spray campaign, and trained storekeepers are responsible for maintenance until the next spraing season begins. In Tanzania, the panels are available to the National Malaria Control Program if requested. Scaling up these systems can help significantly with a spray campaign’s electricity needs, enabling malaria services to remain resilient.