Jersey’s desalination plant cost more than £600,000 this year – and a climate change expert warns bills could rise with hotter and drier summers.
The machine, which makes drinking water from the sea, was turned on in July in “exceptionally dry” weather ahead of a ban on hoses.
The desalination plant ran for 77 days and cost £616,000.
Jersey Water said the plant was funded by customers but was unrelated to next year’s rate increase.
After heavy rains, which raised reservoir levels, the plant, which costs £8,000 a day, has since been deactivated.
Jersey Water said the plant’s running costs had not been “discounted” in next year’s 6% rate increase, equivalent to around £23 a year.
However, it said a “specific adjustment” may be required in the future if it needs to be used more frequently or for longer periods of time.
Prof Liz Bentley, CEO of the Royal Meteorological Society, said desalination was “one element” of dealing with drought, especially for an island nation.
“Desalination is very expensive and there are also environmental costs.
“There is energy use to remove the salt from the water and that contributes to more greenhouse gases in the atmosphere.”
She predicted “hotter, drier summers” ahead and said the “extreme” summer of 2022 in Jersey would be considered “typical” by mid-century.
Describing the process as “expensive financially and environmentally,” she said it would be important in the future to look at renewable energy sources for plants like those in Jersey.
Jersey Water’s annual report for 2018 stated: “The relatively low storage capacity of the reservoir combined with the island’s reliance on rainfall means that Jersey’s water resources are particularly susceptible to periods of drought.”
In 2021, the factory at La Rosiere on the southwest coast of the island was used for just 14 days on a “performance trial”, costing around £112,000.
Between 2011 and 2018, the plant, powered by Jersey Electricity, was not needed due to drought. It was then used in 2018 and 2019 to replenish water supplies.
A spokeswoman for Jersey Water said the cost of operating the desalination plant and the loss of revenue from the hose ban “have not been factored” into the rate increase.
She added that they would be “funded from reserves in this case” – paid by customers.
She said the factory would “remain shut down for the foreseeable future” but that they would “monitor closely” and review if necessary.
“Going forward, we will probably start the pre-treatment phase every year to make sure it’s ready to use when needed.”
On future rate increases, she added: “Specific adjustments may be required in the future if the desalination plant operates more frequently or if the run time is extended.”
There are no permanent staff in the factory, but engineers are there daily to supervise its operation.
The Jersey Government is the majority shareholder of Jersey Water.
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