$$\text { An OTEC system operates with a warm reservoir of } 23 ^ { \circ } \mathrm { C } \text { and a cold }$$

$$\text { An OTEC system operates with a warm reservoir of } 23 ^ { \circ } \mathrm { C } \text { and a cold }$$ reservoir of $5 ^ { \circ } \mathrm { C }$ . Calculate the mass of water (vapor) flowing through the evaporator needed to generate $1 \mathrm { MWh }$ of electricity. Assume a $90 \%$ conversion from mechanical to electrical energy.