Headley et al., (1994), used a compound parabolic concentrating solar collector (CPC) of concentration
ratio 3.9 and aperture area 2 m* to power an intermittent solid adsorption refrigerator and ice maker using
activated charcoal (carbon) as the adsorbing medium and methanol as the working fluid. Up to 1 kg of ice at
an evaporator temperature of -6°C was produced, with the net solar coefficient of performance (COP) being
of the order of 0.02. Maximum receiver/adsorbent temperature recorder was 154°C on a day when the
insolation was 26.8 MJK’. Temperatures in excess of 150°C are undesirable since they favour the
conversion of methanol to dimethyl ether, a noncondensable gas that inhibits both condensation and
adsorption. The major advantage of this system is its ability to produce ice even on overcast days
(insolation - IO MJ/m-‘). There was excessive heating capacity in the system, and only 2% of the incident
solar radiation was converted to the refrigeration effect. The system as it stands is therefore not
economically viable. However, the cost of heating using the CPC is about half as expensive as the cost of
heating using electrical power. The CPC is therefore a natural candidate for industrial process heat
generatron in the temperature region 80” to 200°C