TechNet-21 - Forum

This forum provides a place for members to ask questions, share experiences, coordinate activities, and discuss recent developments in immunization.
  1. Dr Daudi Manyanga
  2. Cold chain equipment
  3. Wednesday, 18 February 2015
The decision of a National Immunization Programme to use Solar Direct Driven (SDD) Refrigerators instead of Solar Panels to run refrigerators I think is like presenting challenges in the so called expected “better and sustainable solution” especially for the low resources countries. It is true that, SDD are compressor powered directly from the sunlight (they are really environmental friendly) and therefore does not need additional running costs for batteries which in other way these batteries are” less environmental friendly”. The other field tested facts is that, they are more efficient in maintain the temperature between +2 to + 8 degree Celsius than the absorption types where freezing can occur due to temperature excursion on the lower side especially in cold climate areas. This seem to be better solution, However the challenge remains that, they have no application for lighting and therefore the temperature cannot monitored/recorded in dark rooms and or at night. Lighting is very important, this could be provided in using solar panel instead of SDD, one will benefit with improved curative (and delivery) services at night, I understand major problem is home deliveries and maternal deaths; Improved data transmission using phone for health initiative, I believe data transmission and quality remains to be major problem; improved human resources for health by ensuring lighting for health workers houses and even security in the health facility, I believe shortage of skilled staff and equity in distribution of few available health workers is also a problem. I therefore think, solar panels installation, is more supportive for health system rather than the SDD which are primary immunization delivery centered intervention, thinking as health system strengthening intervention. More challenge is the fact that, even some of SDD have been per-qualified and within short period removed from ore-qualification, thinking of no recovery of damage. When purchasing SDD one should consider, the vaccine volume, costs, climatic condition and autonomy/safety margin for ensure no temperature excursion. However, a major issue on the spare parts which may not be a problem on using panel is extremely important. My question still remains, is SDD solution or a challenge in solution for the low resources countries? No right no wrong answers, but we need to have better decision making for the limited resources.
Larry Schlussler Accepted Answer
Hi David, We have recently developed hybrid refrigeration (http://www.technet-21.org/en/forums/a-new-solar-hybrid-refrigerator-freezer) which can provide refrigeration, ice pack freezing and energy for lights, cell phone charging, etc. Batteries can provide long life and trouble free operation. The key is to consistently shallow cycle the the batteries. A battery which can supply 600 cycles at 80% discharge can supply 6,000 cycles at 10% discharge. In our Sun Frost FRH-3 as a consequence of the high efficiency of the battery powered refrigerator compartment and the oversized solar panel even a battery as small as 40 amp hours will always be shallow cycled. After about 10 years of operation the original battery could be replaced with a locally available inexpensive battery, it would still be shallow cycled and could provide about 3 years of service. I hope another possibility does not cloud your decision making. Sincerely, Larry Schlussler, Ph.D.
  1. more than a month ago
  2. Cold chain equipment
  3. # 1
Denis Accepted Answer
Dear David, this is a very important point that you raise here with regard to energy availability at health centres, not only for refrigerators, but for other uses as well. Two points: (1) Note that a meeting will take place in WHO Geneva on 24-25 March specifically on energy for health that will address this same issue; "There is growing global interest in scaling up access to “sustainable” energy in developing countries, including for application in health care facilities. This is a major opportunity for the health sector to improve access to quality health services particularly in underserviced areas/locations where energy services may be limited or unreliable. Given this potential for health and development offered by the coming together of the sustainable energy and health agendas, WHO/PHE, through its programme on “Greening the Health Sector” is looking to scaling-up its activities and focus on sustainable energy in health care facilities"; (2) PATH and SELF are implementing a project supported by the Gates foundation that will look at how excess energy produced by photovoltaic panels used to power SDD refrigerators could be used for other purposes like lighting and mobile phone recharge. Denis
  1. more than a month ago
  2. Cold chain equipment
  3. # 2
Dan Brigden Accepted Answer
This post raises some very important points in relation to the advantages and disadvantages of SDD versus solar battery refrigerators. Seven SDD devices have recently been prequalified, not only raising the profile of SDD technology in general but also increasing the need for clear guidance on when it ought be used. I do know that a new guidance document is currently being prepared by WHO and UNICEF, tentatively entitled "Introducing solar-powered vaccine refrigerator and freezer systems", which should be published later this year. The document is intended to provide managers in national immunization programs with guidance on how to implement successful solar-powered vaccine refrigerator and freezer systems, taking into account new developments in refrigerator technology such as SDD, and is based on lessons learned during the thirty years since solar refrigerator systems were first implemented in immunization programmes. Hopefully this will be of use to decision-makers when it comes to implementing the best solar solution in low-resource countries.
  1. more than a month ago
  2. Cold chain equipment
  3. # 3


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