Ocean-water desalination only uses 10 to 15 percent more energy than importing water here from Northern California and the Colorado River. And because West Basin is also expanding current water recycling and conservation efforts, the overall energy use will actually be less as the Water Reliability Program is implemented, even with ocean-water desalination.
West Basin is committed to making its water supply portfolio “carbon neutral” when compared to imported water. West Basin will use green energy to make up any difference in energy use between importing water and desalting water. West Basin was one of the first agencies to install a solar system at its facilities. The Edward C. Little Recycling Facility uses solar power to save 10 percent of its peak energy needs and reduce CO2 emissions back to 1990 levels. In addition, West Basin’s ocean-water desalination project will use new energy-efficient membrane filters, high-efficient pumps and an energy-recovery device that reuses some of the plant’s process energy.
West Basin is committed to environmental stewardship with a responsible ocean water desalination facility and minimizing all energy required to produce the water. West Basin is committed to evaluating all types of energy sources including powering the facility by 100% renewable energy sources such as wind and solar. West Basin will evaluate all the options through the Environmental Impact Report(EIR) process.
No, ocean water desalination plants today do not need to be next to or co-located with power plants. More and more power plants are going to air cooling systems so it there no benefit to co-locate an ocean water desalination purification plant with a power plant. - See more at: http://westbasindesal.org/energy.html#sthash.cINTW7rw.dpuf
West Basin and the water industry typically quantify energy required for different water sources in kilowatt hours(kWh) required to produce one (1) acre-foot(AF) of water. One acre-foot of water is the water required to fill once acre with one foot deep of water. West Basin’s proposed full scale facility is estimated to use approximately 4,200 kWh/Acre-Foot of water.
West Basin and the water industry typically quantify energy required for different water sources in kilowatt hours(kWh) required to produce one (1) acre-foot(AF) of water. One acre-foot of water is the water required to fill once acre with one foot deep of water. The table below compares the energy requirements for West Basin’s water supplies.
|Water Supply||Energy Required (kWh/Acre-Foot)|
|Ocean Water Desalination||4,200|
|Indirect/Direct Potable Reuse||1,500-2,000|
|California State Water Project||3,5000|
|Colorado River Aqueduct||2,500|
Desal uses about 10 to 20% more energy than importing water here from Northern California. To counter that we are looking for less expensive power and renewable power. Keep in mind, by expanding our recycling and conservation programs, and adding about 10% of our future supplies from desal (20 MGD) we will actually lower the District’s carbon footprint over existing energy use without desal. Additionally, we are testing several energy saving devices, including new RO membranes with nano technology, energy recovery devices which reuse 42% of the reverse osmosis pressure as well as variable speed pumps and optimizing our operations to save energy. Attempts will be made to offset desal energy use with green energy, however, it should be noted that 10% of the power for our recycling plant comes from solar power, so I guess you could say that our Water Reliability program, of which desal will be a part, is already using green off set energy.