From 2011-2015, California experienced an extreme drought. According to some paleoclimatologists, this drought was the most severe in the past 1200 years. Because water use for thermoelectric power generation is one of the largest uses of water world-wide, one means of reducing water use in California is shifting electricity generation to systems that consume less water. Although California imports much of the electricity it uses from other states, there is still a substantial amount of electricity generation that is done in-state, and this offers opportunities for water conservation.
a) Using the data provided in the Table below, estimate total water usage associated with electricity generation in California. Identify the type of electricity generation that uses the most water per MWhr and the type of electricity generation that uses the largest total amount of water.
b) If all electricity generation in California were to switch to natural gas and the water intensity of electricity generation (I water/MWh) remained the same, how much would water usage be reduced?
c) If the average municipal water use is 100 gal per person per day (36,500 gal/yr), how many people could be provided with water with the savings identified in part b? (1 gal = 3.81)
Fuel source Water used in extracting fuel Water used in generating electricity Electricity generated in California
- (liters of water per MWhr of elecetricity generated) (liters of water per MWhr of elecetricity generated) (MWhr)
Natural gas 24 737 76,082,000
Coal 96 1895 3,692,000
Nuclear 212 1817 36,586,000
Wind 0 4 2,418,000
Thermal Solar Source: 0 3975 681,000