There’s an upside to all the rain I hear we’re having in Oregon: We don’t have to consider building a desalinization plant so we can use ocean water to supply our towns.
A plant like that is being built next to an electric generating station on the Pacific Coast Highway in California’s Huntington Beach. I read about this project, by a company named Poseidon, when I tried to learn more about the generating station, whose steam stacks I’ve been riding past the last few days.
The stacks have been landmarks since 1958 and their days seem to be numbered. The gas-fired power station, run by AES Corp., is undergoing a huge retrofit to meet environmental regulations and make it more efficient. Instead of using seawater for cooling, it will be air-cooled, and its stacks will be replaced by shorter ones. The stack replacement will happen around about 2020, according to a report the Orange County Register updated in 2013.
The remodeled plant will use new technology allowing it to start up and shut down within minutes so it can compensate for fluctuations in power produced from wind and solar. With the old equipment it would take hours, the company says.
The desalinization plant next door is supposed to be finished in 2018, one online publication says. Using the same intake pipe now used by the power plant, the installation will suck in 124 million gallons a day from the ocean and produce 50 million gallons a day of drinking water, or about 8 percent of what Orange County needs. (What happens to the other 74 million gallons I have no idea. Maybe it’s used up in the conversion.)
Domestic water in this area now comes from the Sacramento Delta, the Colorado River and from wells, and because of the long drought there isn’t enough of it. So you can see how de-salting seawater makes sense despite the enormous expense.
We have our own water issues in Oregon, but least we’ve not had to try to solve them by looking to the sea. (hh)
I’d think if the salt gets too concentrated, there would be a greater likelihood of salt deposits on the boiler/evaporator tubes. That results in more down time for expensive cleaning.
There could be other restrictions such as salinity/temperature limits for discharge to the ocean.
The desal plant uses reverse osmosis. There’s no chemical reaction, just what amounts to a filter. The 74 million gallons per day would return to the Pacific along with the salt from the 50 million gallons per day that becomes potable water.
The new equipment is pretty spiffy — gas-fired turbines driving generators, with the turbine exhaust feeding a heat recovery steam generator (aka HRSG) which in turn feeds a steam turbine that spins a generator. High efficiency, flexible, very good turndown. Uses the cleanest commercially-available fuel.
One piece about the old plant contained a child’s comment about the stack plume. It looked like a cloud factory. Kids, gotta love ’em
Thanks for the explanation. (hh)
Sounds overly complicated when all you have to do to a RO filter is pump water through it.