The solar panels would take a big chunk out of the monthly electric bills, which currently run more than $29,000 a year at one of the facilities. But whether the savings will show up on customers' bills is uncertain.
"It's too premature to even try to predict that," said Robin Street, manager of the Sanitary District.
Both plants need to be upgraded to meet new Chesapeake Bay TMDL -- or total maximum daily load -- requirements, and any savings on electricity will likely be offset by the costs of chemicals and equipment, he said.
A preliminary study on the plant upgrades is under way, and Street said he has asked engineers to look at adding the solar energy systems in the new designs.
The plants have plenty of room for solar installations, because years ago the Sanitary District purchased enough land to accommodate future expansions, Street said.
But the new federal restrictions placed on sewage treatment plants as part of the effort to clean up the Chesapeake Bay means neither plant will be able to expand, leaving lots of grassy space that need to be maintained.
"I said, 'Let's quit buying lawn mowers and put in a solar field,' " Street said.
The systems will probably not be supplying power back to the grid because that would require more expense.
"I'm just trying to keep it simple," he said.
However, the plants would still need to be able to pull power from the grid at night and on cloudy days.
The Sanitary District's electric bills first skyrocketed several years ago after the plants were first upgraded for biological nutrient removal, Street said.
The next upgrade will be to enhance nutrient removal, which will probably cause another increase, he said.
The Sanitary District also operates two sewage treatment plants on Smith Island, but Street said he is not planning to install solar panels at either one.
Officials are now considering abandoning the plant in Tylerton and pumping sewage to the Ewell plant, which will be upgraded.
While there is no room at the Ewell plant for solar panels, Street said it might be possible to install a wind turbine there instead.
The Sanitary District isn't alone in looking for ways to lower costs at sewer plants that are becoming increasingly more expensive to operate.
In Crisfield, city officials are working toward building a wind energy system to power the Seventh Street sewage treatment plant, which also has enormous electric bills.
The 750-kilowatt turbine will be financed with a $4.8 million grant from the Maryland Department of the Environment.
City officials recently agreed to borrow $35,000 on an interim basis to pay for an impact study to make sure the system will be compatible with the power grid.
The turbine is expected to produce more electricity than the plant needs, so the city can sell the excess back to the grid.
In December, an engineer for the project reported that preliminary design work for the turbine had been completed.
Final design work was expected to take about three or four months, with construction to start later this year.
SOURCE: http://www.delmarvanow.com/article/20120331/SH01/203310328
No comments:
Post a Comment