Subject: It is possible to add a substance to water to decrease the boiling point?

During electrical generation, water is boiled to turn the 
generator. It is possible to add a substance to water to decrease 
the boiling point? Is there anything done to the water to 
increase the efficiency of the power plant? Would it help to 
increase efficiency by reducing the boiling point of water or use 
another liquid with boiling point much lower than water to 
replace water? I had thought about using some low boiling point 
liquid like alcohol but I think they are too dangerous to be used 
in the power plant. They can explode easily due to the high 
temperature in the power plant.

Re: It is possible to add a substance to water to decrease the boiling point?