Developing Test Methods for Off-Grid Refrigerators

Joanie Coker, Hannah Blair

The Global LEAP Awards test method for off-grid refrigerators assesses product performance and quality. This story gives insights into how the CLASP team and our partners developed the test method.

Refrigerators hold unique potential to unlock economic and social progress for the billions of people living without reliable access to electricity around the world. Refrigeration provides a wide range of benefits, from improving human health and productivity, to reducing the domestic burden on women and children who are usually responsible for food gathering and preparation. Outside of home use, refrigeration enables income-generation for small retailers and other value chain actors through the storage of cold drinks, food, and other perishable items for later sale.

According to a recent study from the Efficiency for Access Coalition, the cumulative market potential for off-grid refrigerators amounted to USD 4.4 billion in 2018, and this figure could more than triple to USD 14.3 billion by 2030. However, refrigerators are one of the most challenging off-grid appliances to design and develop to be both energy efficient and cost-effective. A deeper understanding of the unique performance and design considerations for off-grid refrigerators is essential to catalyze necessary advancements in product design and accelerate market growth.

Laboratory test method development for the 2016-17 Global LEAP Awards

In 2016, the CLASP team launched the inaugural Global LEAP Awards Off-Grid Refrigeration Competition to identify and promote the world’s best, most efficient off-grid refrigerators. In many ways, off-grid appliances use similar technologies, components, and design considerations as those in developed on-grid markets. However, certain considerations for quality, durability and energy consumption differentiate refrigerators designed for consumers living in off-grid environments.

Refrigerator energy consumption is highly correlated to the environmental conditions. In hot and humid climates as found in primary off-grid markets in like sub-Saharan Africa and South Asia, higher ambient temperatures result in higher energy consumption. For refrigerators to meet the needs of off-grid consumers, the appliances must be highly energy efficient. Additionally, quality and durability are extremely important for off-grid refrigerators. Because of the high cost of refrigerators, deciding to purchase the appliance can be a huge investment for off-grid consumers. Ensuring the product will function properly and maintain a long lifespan protects consumers and their investments.

The Competition consisted of product testing by accredited laboratories for their energy performance, quality, and durability, and evaluation by a panel of off-grid market experts. The test method development process involved a technical working group of off-grid energy industry stakeholders, appliance manufacturers, policymakers, and test facilities.

To enable improved comparisons of off- and weak-grid appropriate refrigerators, CLASP and a consortium of product, market and test experts developed a unique test method to evaluate energy performance, quality, and durability of refrigerators. The initial test method leveraged existing international test methods – such as those by International Electrotechnical Commission (IEC) and World Health Organization (WHO) – commonly used to measure energy performance of on-grid refrigerators and off-grid vaccine refrigerators.

The Global LEAP Awards test method was slightly modified to better enable the evaluation of specific off-grid characteristics, including frequent opening and closing of refrigerator doors and higher internal temperature preferences.

Field testing

Later in 2017, as an expansion of the Global LEAP Awards Competition, all 36 products that successfully passed laboratory testing were shipped from the Netherlands to a selection of small retail shops across rural Uganda for field testing. For most of the Ugandan vendors, the introduction of these refrigerators marked the first time they were able to offer chilled drinks and food items in their shops. Field testing hence offered deeper insights into off-grid refrigerator use cases that are not possible to capture through lab testing alone.

“In field-testing, we were seeing user-behavior and user-error variables that impact product performance,” explained Elisa Lai from CLASP. “For example, one refrigerator that was very high performing in the lab was not showing great performance in the field. When we went to examine it, we realized there was a small gap between the refrigerator lid and the chest. The customer had left a tiny Styrofoam piece of packaging in the lid, assuming it was part of the refrigerator. That gap was leaking cold air and increasing power consumption over time.”

While domestic refrigerator users only open and close their refrigerators a few times a day around meal preparations and market trips, small business owners open their fridges more often to place in warm beverages and remove cold ones. During the day, these instances of heat exchange significantly impacted the refrigerator power consumption.

“When we initially designed the lab test methods, we set a reference temperature at 4°C, which is pretty standard food storage temperature for a household refrigerator.” explained Lai. “However, the retailers in Uganda did not really care whether or not their drink was at 4°C . On average, the beverage temperatures we measured in the field were somewhere between 8 and 10°C, and people were quite satisfied with these “warmer” drinks. From this experience, we questioned whether using an internal temperature of 4°C during lab testing is the right approach.”

With extensive insights on off-grid refrigerator use cases and consumer experiences, the Global LEAP Awards team had one important question: How can we use the lessons from field testing to revise lab test methods for the next round of the competition?

Field testing implications on lab testing

Although a critical component of off-grid refrigerator testing, field testing presents large logistical and cost challenges. Instead of implementing another round of field tests, the Global LEAP Awards team took the lessons from the 2017 field experience to revise the off-grid refrigerator lab test methods.

“We changed the temperature reference in this round to range from 4-8°C and added a completely new test measuring energy consumption differences between an empty fridge and a fridge full of water bottles,” Lai explained. “Now we are calculating that delta to see how much energy is needed to cool down a liter of water. It is not perfect, but it’s an indication of relatively how much energy the refrigerator would need to cool a certain amount of liquid.”

To simulate the retail use case where a shop owner constantly opens and closes refrigerators to remove cold beverages and replace with warm, the team introduced a load processing efficiency test. The purpose of the test is to quantify the incremental energy impact of user-related aspects of refrigerating appliance use, such as door openings and cooling of warm food and drinks. This data can be used in conjunction with closed door tests to produce a total energy consumption estimate that more closely represents actual use in different regions. Refrigerators that were able to reduce the temperature of the package with minimal energy were considered well-suited for off- and weak-grid environments.

For more on the lessons from the off-grid refrigerator field testing, check out the CLASP publication Catalyzing Technology Innovation in the Off-Grid Market Through Appropriate Product Performance Testing in the Lab and Field.

2019 Global LEAP Awards Off-Grid Refrigerator Competition

For the 2019 round of the Off-Grid Refrigerator Competition, CLASP worked with Re/genT test lab in the Netherlands, a lab that specializes in refrigerator testing, R&D, and supports European and international test standards for refrigerating technologies. Re/genT brought in their technical and testing expertise from the on-grid market and helped the CLASP team refine the test method for the off-grid context. “It can be challenging to find a good testing partner. The partnership with Re/genT combines both on-grid and off-grid market knowledge and makes our testing process even more robust,” says Lai.

After nearly 5 months of testing at the Re/genT test lab, twenty-one best-in-class products were recognized as Winners and Finalists of the 2019 Global LEAP Awards Off-Grid Refrigerator Competition on October 22, 2019.

One of the primary objectives of the competition-based, Global LEAP Awards infrastructure is to drive innovation and performance improvements in early stage product markets, and this objective was clearly demonstrated through the results of the 2019 competition. On average, the Winners and Finalists of the 2019 competition are 28% more energy efficient than those from the inaugural 2017 competition.

The 2019 Off-Grid Refrigerator Competition also included the first ever Global LEAP Awards innovation prizes focused on affordability. £100,000 in prize money was awarded to Devidayal Solar Inc. for Consumer Affordability, innovations that make it easier for diverse customers to purchase refrigerators, and to Youmma for Unit Cost Affordability, design innovations that lower the cost of manufacturing, assembling, and/or shipping.

All Winners and Finalists from the Off-Grid Refrigerator Competition are eligible to apply for Global LEAP results-based financing. Over the next seven months, approximately 6000 best-in-class refrigerators will be distributed across Bangladesh, Kenya, Tanzania, Rwanda, and Uganda as part of the program.

View the full list of Global LEAP Awards Winners and Finalists in the 2019 Global LEAP Awards Buyer’s Guide for Outstanding Off-Grid Refrigerators and check out the new off-grid refrigerator test method.

Learn about the development of the 2019 Global LEAP Awards Solar Water Pump Competition and test method.


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