TechNet-21 - Forum

This forum provides a place for members to ask questions, share experiences, coordinate activities, and discuss recent developments in immunization.

Discussions tagged Solar

UNICEF/WHO guidance on Decommissioning and safe disposal of CCE now available in ARABIC and RUSSIAN

Dear TechNet-21 community,

Further to the publication of the English and French versions of the Decommissioning and safe disposal of cold chain equipment guidance earlier this year (available here, we are glad to share with you that the Arabic and Russian versions of the document are now available in the TechNet-21 Resource Library.

To access these documents, please click on the following li...

Les inscriptions pour la formation en chaîne de froid solaire sont ouvertes

Nous avons le plaisir de vous informer que le Centre LOGIVAC organise la Formation en Chaîne de Froid Solaire, du 12 au 17 février 2018. Les dossiers d’inscription seront reçus jusqu’au 30 janvier 2018.

Délivrée entièrement en présentiel à destination des agents de maintenance et logisticiens du PEV, la formation en chaîne du froid solaire répond aux enjeux de conservation optimale des vaccins par les équipements fonctionnant à l’énergie solai...

When to consider solar, based on hours of mains/generator electricity available each day

I’ve been reading with great interest the most recent issue of Vaccine, which is dedicated to “Building Next-Generation Immunization Supply Chains”.

I particularly enjoyed the following article but was surprised to read that the authors identified a discrepancy between WHO PQS and Gavi Cold Chain Equipment Optimization Platform guidance relating...

New reports on harvesting unused energy from SDD installations

To ensure that solar direct drive (SDD) appliances can keep vaccines at acceptable temperatures continuously, the installed photovoltaic array often produces excess power that is not used by the primary cooling load and this excess power generally goes unutilized.

If this power is to be used, the primary SDD appliance load must be prioritized above any other load. WHO and other organizations have been working to define how this can be done safely and reliably. In support of WHO/PQS, P...

New case studies on SDD vaccine refrigeration projects

WHO and UNICEF have just published a new evidence brief on solar direct-drive (SDD) vaccine refrigerators and freezers. It includes case studies from Tanzania, Colombia and Kenya, as well as an overview of SDD technology and how to make sure that SDD technology is the right choice. Here's the link:

This is the document summary:


Experience about solarchill in Colombia


I like to share with you in this space a video about the instalation, basic maintenance and operation of one of the solar equipments with PQS that are installed in my country (Colombia), nowadays we have 300 equipments in operation.

Best regards


Universal, hybrid refrigerator for vaccines?

Among the TECHNET postings on cold-chain equipment there are embedded remarks pointing towards the need to make vaccine refrigeration simpler and less expensive to procure, more responsive to energy changes and easier to use and maintain. For example, to choose a refrigerator now current WHO, UNICEF and GAVI guides require that you make equipment choices according to energy availability and quality conditions. But in practice, energy availability and quality are changing, they do not remain s...

Performance evaluation of solar adsorption cooling systems for vaccine preservation in Sub-Saharan Africa

In case this new article published in Applied Energy is of interest

An intermittent solar adsorption refrigerator can supply cold needed in third world countries, especially for vaccine and medicine preservation. This paper investigated theoretically the potential of solar adsorption refrigerators in Sub-Saharan Afric...

Error in suggested sizing method for SDD systems

I was recently looking at the “System Sizing tool 3/3” in a 2DI3 “Technical evaluation and Methodology” a unicef publication. The publication originated from a 2DI3 SDD industry meeting.

The sizing method prescribed is based on the premise that “the daily potential solar energy supply is calculated as the number of sunshine hours 1000 W/m2 multiplied with the corrected power output.” The compressor of an SDD refrigerator requires about 70 watts to run and start. When the output of the...

Reorganizing Nigeria’s vaccine supply chain reduces need for additional storage facilities, but more storage is required

Interesting paper on system design in Nigeria from Health Affairs.


One of the major problems facing Nigeria’s vaccine supply chain is the lack of adequate vaccine storage facilities. Despite the introduction of solar-powered refrigerators and the use of new tools to monitor supply levels, this problem persists. Using data on vaccine supply for 2011–14 from Nigeria’s National Primary Health Care Development Agency, we created a simulation model to explore the effects o...

Next Generation Supply Chains – A Dialogue with EPI and Child Health Managers

Reposted from JSI's The Pump

Jeff Sanderson,Senior Technical Advisor

African immunization supply chains need to be transformed. Between 2010 and 2020, new vaccine introductions will quadruple the volume of vaccines per immunized child. The number of vaccine doses that health workers will administer is increasing six-fold. Evidence from

Solar vaccine fridges and freezers - new guidance available

WHO and UNICEF have just released a new joint publication on solar fridges and freezers that is intended to provide managers in national immunization programmes with guidance on how to implement successful solar-powered vaccine refrigerator and freezer systems. It takes into account new developments in refrigerator technology like solar direct-drive (SDD) refrigerators and water-pack freezers, as well as containers with passive cooling, and is based on lessons learned during the 30 years sinc...

Reviews of the SunDanzer BFRV 55 solar direct-drive refrigerator

Choices, choices, choices – they are both the bane and blessing of our times. As immunization managers, we now have a wide array of PQS-prequalified cold chain equipment to choose from, but how do we make the right choices and get the best value for our bucks? The TechNet Product Reviews area helps you do just that, with users in the field, who are constantly ‘testing’ the product, giving you feedback about the equipment they are using be it refrigerators, thermometers or vaccine carriers. Take,...

A New Solar Hybrid Refrigerator/Freezer

Sun Frost developed a hybrid refrigerator/ice pack freezer, the FRH-3. The Sun Frost FRH-3 has a SDD freezer and a battery powered refrigerator. The SDD freezer is the same size as our F-1 ( and incorporates the same t...

Solar power in health: What’s your story?

Success has many fathers, failure is an orphan. Yet, we can learn so much more from failure than successes. The amazing safety of modern flight is a result of this systems-based analysis of failures. In contrast, medical safety continues poorly with a culture of 'blame' focusing on individuals rather than systems diagnosis – and cure! As reported in the April 2012 issue of GIN, the CCLT is aiming to support efforts to accelerate solarization of the cold chain, with benefits for the planet as ...

Implementing the solar cool chain successfully

With many thanks to John Lloyd for this post. Countries that currently use absorption refrigeration (gas, electric or kerosene-powered) are facing increasing pressure to switch to solar photovoltaic-powered refrigeration for vaccine as manufacture of absorption equipment shrinks. We have a substantial evidence from the field on the success of solar refrigeration systems that point to a few critical success factors: ? Systems designed rigorously to match climatic and irradiation, site-...

Solar Cold Chain Training

Compressor Replacement Without a Vacuum Pump

Compressor Replacement Without a Vacuum Pump

Replacement of a compressor requires the use of a vacuum pump. Solar
powered vaccine refrigerators are generally located away from the
utility grid. Most vacuum pumps are powered by AC grid power making
compressor replacement difficult. We have developed a method of
removing the air from a system without the use of a vacuum pump. The
method requires the installation of an access valve on the high and ...

Target service life for vaccine refrigerators

What service life do you think vaccine refrigerators should be able to provide? For example, some products may suggest a 10 year life while others suggest longer, with typical repairs. PQS requires a 2 year warranty for a vaccine fridge.
Solar powered vaccine fridge systems require solar electric modules (minimum 20 year warranty is typical and 20 year is required by PQS). Most also have batteries (5 year warranty per PQS).

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