Surgery and Healing in the Developing World - Dartmouth-Hitchcock

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82 Surgery and Healing in the Developing World
Table 1. Example of equipment for a PV-powered remote clinic
Power On-Time Daily Energy
Appliance Mode (Watts) (Hrs/Day) (Watt-Hrs)
Vaccine refrigerator/freezer DC 60 5-10 300 - 600
Ten 18-W fluorescent lamps DC 180 5-10 900 - 1800
UV water disinfector DC 60 1 60
Optical microscope lamp AC 15 1 15
Centrifuge AC 150 1 150
Suction pump AC 60 1-4 60 - 240
Autoclave DC 660 1 660
VHF 2-way radio DC 30 1 30
19-inch color TV AC 60 1-4 60 - 240
VCR AC 30 1-4 30 - 120
Application of a Photovoltaic System in a Remote Clinic
Figure 9 shows a schematic diagram for a complete photovoltaic system suitable
for a remote clinic. The system supplies DC power from the batteries and AC power
from the inverter. Table 1 lists the appliances that might be found in a relatively
well-equipped remote clinic 7 powered by the PV system in Figure 9. For this clinic
configuration, the total daily energy consumption is between 2300 and 4100
watt-hours. In many tropical locations, an 800-watt PV array could meet this de-
Figure 9. Schematic of a small PV system that supplies both DC and AC power. (From
Maintenance and Operation of Stand-Alone Photovoltaic Systems, Sandia National Laboratories,
1991.)