IMPLEMENTING THE SOLAR COOL CHAIN SUCCESSFULLY

Wednesday, 14th of December 2011

IMPLEMENTING THE SOLAR COOL CHAIN SUCCESSFULLY

Solar power for vaccine storage has come a long way in the last decade. In particular, the price of solar panels has come down, and battery-free solar units are now available. The European manufacturers who used to dominate the market now have Chinese competition, and the price gap between solar and conventional power sources has narrowed.

John Lloyd discusses the requirements of, and advantages of, solar cool chain for vaccine and diluent storage at

http://www.technet21.org/index.php/issue-133/implementing-the-solar-cool-chain-successfully.html

TWO COMMENTS ON JOHN LLOYD’S POSTING, FROM TECHNET21.ORG

1) Re: Implementing the solar cool chain successfully

John’s informative and interesting post draws attention to the important field problem of replacing kerosene refrigerators with the alternative technology of solar chiller (battery less solar refrigerator). During the recent review of the vaccine management in Ethiopia we were faced with the logistical nightmare of provision of kerosene to remote areas of the country.

The available information shows that battery-less solar refrigerators are used in Senegal and Vietnam, two countries with relatively hot climates. It is important to test this particular type of solar refrigerator in a country with Ethiopia’s cooler temperatures. UNICEF Ethiopia in collaboration with the Ethiopian Federal Ministry of Health and other partners is planning to purchase and test a limited number of solar chillers in different parts of the country for a period of one year. Positive results of the tests indicating that solar chillers are suitable for the cool ambient temperatures of Ethiopia could provide a potential solution for the phasing out of kerosene refrigerators. Hopefully, the economies of scale will also bring the capital cost of solar chillers to an affordable level.

Mojtaba Haghgou

2) Re: Implementing the solar cool chain successfully

Looking at the PQS sheets is is clear that direct drive refrigerators cannot freeze icepacks and they are not tested using water packs or PCM packs. If direct drive refrigerators are to be used for "freezing" phase change packs then a new test protocol will need to be developed to determine the number of packs to be loaded daily, the loading location in the refrigerator and the additional energy/solar system required to phase change the PCM packs.
Or are we missing a trick here?
"No direct drive solar refrigerators available at this time include icepack freezers, so they are only suitable where water packs or Phase Change Materials (PCM) packs are used for outreach immunization – or where there is no outreach immunization"

Guy Watson