Surgery and Healing in the Developing World - Dartmouth-Hitchcock

Establishing Electrical Power in Remote Facilities for Health Care
Figure 10. A 55-liter vaccine refrigerator (with 34-liter freezer) specifically for use with
PV power. The crated shipping mass for export is 91 kg. (Photo courtesy Sun Frost.)
mand while keeping a bank of batteries sufficiently charged to allow several days of
autonomy. The system would also have DC and AC outlets for discretionary
low-power equipment. Because an 800-watt system costs about US$ 6,500 installed,
many remote clinics will not be able to have all of the equipment in Table 1. While
the list in Table 1 is somewhat opulent, there are a number of PV-powered clinics
with similar equipment now in operation. Examples include four remote clinics in
Chocó Province on the Pacific Coast of Colombia. The inclusion of color TV and
VCR might appear superfluous, however they serve as important teaching tools for
community public health. At some clinics, TV/VCR community theaters also serve
as revenue generators to help support the clinic.
The design of the entire PV system places an emphasis on energy efficient versions
of all appliances. Repair services for a remote clinic are not readily available,
and PV-compatible equipment must be designed for long-term reliability as well as
energy efficiency. This adds to the initial expense but assures a system suitable for a
harsh environment. Of particular importance to the mission of the clinic are the
vaccine refrigerator, lamps, and water purifier system, all of which are available in
high-efficiency versions specially designed for use with a PV system. An excellent
list of photovoltaic equipment manufacturers and contractors is found on the Internet
at www.seia.org. (Click on “Buy Solar”.) Most of these companies have local representatives
in various developing countries.
The World Health Organization distributes product information sheets available
on the Internet that describe vaccine-related equipment suitable for remote
clinics. 7 The WHO recommends that PV-powered vaccine refrigerators have their
own dedicated modules, separate from the array that supplies power to other appliances
in the clinic. This is to minimize the likelihood that an accidental overload
from other appliances in the clinic might deplete the battery bank and subsequently
cause a failure in the cold chain.
Several companies make rugged PV-dedicated vaccine refrigerators. Most of them
also have an ice-making capability so that they can be used to store tissue samples
and freeze ice packs. Two models, in particular, are discussed here. One is the Model
RFVB-134a manufactured by the Sun Frost company (Fig. 10). This unit has a
55-liter refrigeration compartment and a 34-liter freezer compartment that can hold
12 kg of ice. It is specifically designed to run off a 12-volt battery which is charged
by a PV system. Under the conditions of 2 kg ice production per day and an ambi-
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