TechNet-21 - Forum

This forum provides a place for members to ask questions, share experiences, coordinate activities, and discuss recent developments in immunization.
  1. Larry Schlussler
  2. Cold chain equipment
  3. Wednesday, 10 June 2020

I have been working on solar electric cooking systems which are appropriate for the developing. The system I think has the most promise is a solar direct system,no batteries. Thermal storage allows hot food to be eaten 5 hours after sunset. A  single 280 watt PV module would supply all the energy needed to cook a days worth of food for a family of 5.

A spin off  from this project are two potential products for the cold chain, A pressure cooker (sterilizer}. With a 280 watt module the pressure cookers contents could be sterilized in about one hour.

                                                   SYRINGE WASTE

A second application  would be a syringe melter and sterilizer. Needles would be encased in  the melted plastic. The volume reduction would be about  70%. For convenience syringes would be dropped directly into the melter. The melting process would take 2 to 3 hrs. The melter could be powered by a 280watt module.

                                                  ENERGY SOURCES

Power for these processes could be supplied by a 280 watt module. When the power is not needed for sterilizing or processing syringe waste it could be used for making hot water, cooking or battery charging.
If the clinic is using an SDD refrigerator for several hours a week the array could be switched to either power a sterilizer or syringe melter. This switch would be on a timer so that the SDD refrigerator is reconnected in a few hours. This switch would be made during sunny weather. Under sunny conditions the array for an SDD refrigerator is considerably over-sized..

Larry Schlussler Accepted Answer

Hi Corrie Looks like a useful product . What is the cost. Your diagram shows "available energy and fridge energy" could it also show energy which can be harvested. Larry Sun Frost

  1. more than a month ago
  2. Cold chain equipment
  3. # 1
Corrie Jones Accepted Answer

Dear Larry,

Interesting to read about your ideas for solar cooking, equipment sterilization and syringe waste processing. You wrote about potential energy sources and possibly using SDD refrigerators so I wanted to let you know about the Dulas Solar socket which can be fitted to the front of the refrigerator.

The Dulas Solar Socket allows to you to make the most of the vaccine refrigerator’s photovoltaic array by accessing energy not needed by the refrigerator. The intelligent control system continuously varies the amount of energy available to the socket, at all times prioritising vaccine storage, but still giving up to 100W of useful power. You can charge phones and electrical devices with absolutely no impact on the refrigerators vaccine storage performance.

Key Features

  • Can provide enough energy to charge laptops, phones, solar lights, radios etc
  • Prioritises the refrigerator at all times and has no impact on the performance of the product
  • Robustness designed in: over temperature, overcurrent & reverse polarity protected
  • Promotes user engagement in the refrigerator care and maintenance
  • 1 x USB 5v/1A, 1 x USB 5v/2.1A and 1 x 12V Socket

You can find more information on the website:

Or get in touch via email:

Best Wishes,


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  1. more than a month ago
  2. Cold chain equipment
  3. # 2

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