TechNet-21 - Forum

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  1. Pat Lennon
  2. Cold chain equipment
  3. Tuesday, 21 May 2019

In January 2019, PATH and the Solar Electric Light Fund (SELF) partnered with the government of Senegal to evaluate a smart energy management device attached to certain solar vaccine refrigerators that would enable health workers to use electric devices in areas with limited or unreliable power. Called an energy harvest control (EHC), the device consists of a smart switch that takes excess power generated from solar panels already powering the refrigerators and safely allows the energy to be used for devices such as lights, fans, mobile phones, and some medical devices. The EHC configuration varies by solar direct drive (SDD) refrigerator manufacturer, but each device can access the excess energy, including through USB ports or 12 VDC sockets. The evaluation is taking place in four health posts in the Meckhe and Tivaouane districts of Senegal.

To date, three EHC devices have been prequalified by the World Health Organization (WHO) Performance, Quality and Safety (PQS) process—two SDD refrigerators with a built-in EHCa,b and one stand-alone systemc paired with a specific SDD refrigerator.d,e

The need for better electrification

One study found that of the 11 countries surveyed in sub-Saharan Africa, on average more than one-fourth lacked any access to electricity and close to three-fourths lacked access to a reliable supply of electricity.1 Electrification is a health equity issue—87 percent of those without electricity live in rural areas.2 Studies in Uganda demonstrated that access to midwives and electricity at health facilities had great impact, reducing the maternal fatality rate during emergency obstetric care by as much as 80 percent.3,4

Our goals for the EHC evaluation

The evaluation in Senegal will assess whether these EHC devices:

  • Perform according to the WHO PQS specifications in a real-use setting.
  • Are acceptable and useful to end users.
  • Have any unanticipated positive or negative effects on the health system.

Better health care through energy harvest control

This evaluation is a step forward in revolutionizing primary health care at the lowest levels of health systems. With the power provided by the EHC, health systems have improved options for:

  • Communication. The ability to charge cell phones, remote temperature monitoring devices, and other small communication devices supports facilities to keep in touch with patients, share data with higher-level facilities, and order supplies.
  • Management of health emergencies. Devices such as lights (for emergencies or births that happen at night)5 and neonatal ultrasound Dopplers for emergency obstetric care are prime examples of how EHC can enable better health care in hard-to-reach areas.
  • Access to health care. By decreasing the amount of time health workers spend away from health facilities charging their devices, health staff can be more available for patient care.
  • Quality of service: Patients must have a high degree of trust in their health centers to rely on them for their health needs, and that trust is either validated by receiving the proper care or broken through negative health interactions associated with a lack of basic equipment. Something as simple as basic lighting can help foster patient trust and improve perceptions regarding the reliability of their health system—and increase the likelihood that patients will seek help when needed.

Preliminary feedback from health workers

Users have had a positive response to the electricity provided through the EHC.

A head nurse noted, “Now they [health workers] get light at night when women are giving birth or when they have urgency—instead of using candles, light from mobile phones, or flashlight lamps.”

Users generally appreciated the extra power, used some of the study-provided loads, and charged additional loads like mobile phones and radios. The community had more positive perceptions regarding the health services provided by facilities as a result of the EHC devices.

“From the EHC project,” noted one head nurse, “we now have medical material to better diagnose our patients, especially pregnant women (fetal Doppler, otoscope).”

Next steps

We expect to have results from the evaluation in June 2019, and funding has been identified to expand this study to evaluate more EHC devices preparing for PQS pre-qualification. Future work could include market-shaping activities, expanded implementation, and testing and evaluation of equipment that can be used with an EHC.


PATH acknowledges and appreciates the leadership shown by Steve McCarney in bringing EHC technology to market and his long-time role as champion of solar power for use in low-resource health care facilities.


Steven Diesburg,



a. See

b. See

c. See

d. See

e. See



1. Adair-Rohani H, Zukor K, Bonjour S, et al. Limited electricity access in health facilities of sub-Saharan Africa: a systematic review of data on electricity access, sources, and reliability. Global Health, Science and Practice. 2013;1(2):249–261.

2. United Nations Department of Economic and Social Affairs (UNDESA). Analysis of the Voluntary National Reviews Relating to Sustainable Development Goal 7 - 2018. Geneva: UNDESA; 2018.

3. Mbonye AK, Mutabazi MG, Asimwe JB, et al. Declining maternal mortality ratio in Uganda: priority interventions to achieve the Millennium Development Goal. International Journal of Gynaecology and Obstetrics. 2007;98(3):285–290.

4. Mbonye AK, Asimwe JB. Factors associated with skilled attendance at delivery in Uganda: results from a national health facility survey. International Journal of Adolescent Medicine and Health. 2010;22(2):249–155.

5. Suhlrie L, Bartram J, Burns J, Joca L, Tomaro J, Rehfuess E. The role of energy in health facilities: A conceptual framework and complementary data assessment in Malawi. PLoS One. 2018;13(7):e0200261.

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