New Orleans S&WB power complex suffers another setback as it nears completion

The Sewerage and Water Board has hit another snag in bringing its long-awaited power complex online, again delaying when it can finally replace old, unreliable power sources with modern electricity.

Steven Nelson, the S&WB general superintendent, said officials believe the mishap is an easily fixable wiring problem, although they are still investigating. 

“Our contractors are still looking into what looks most likely to be a wiring related issue, but it’s something that’s not of grave concern,” Nelson said.

The delay – however minor it may be – is the latest in a series of setbacks to impede a critical project already two years behind initial expectations. Nelson said he expects the complex to be running at full capacity by November, which is a month later than the most recent schedule announced last month.

After the originally anticipated 2023 timeframe came and went amid funding shortfalls and political feuds, the S&WB maintained the power complex would be running in time for hurricane season this year, which began in June.

That timeframe began to slip in March, when the S&WB announced a phased ramp up with the power complex running in limited fashion starting in July and full capacity by September. A setback in July and the most recent snag have now pushed the limited opening to the end of this month at the earliest.

Meanwhile, the water board on Wednesday announced another complication with its existing power sources. A decades-old turbine, known as T5, was knocked out of service because of a broken temperature sensor. Officials expect repairs to be completed within two weeks, as hurricane season intensifies. The water board still has enough backup power to run the drainage system, but the backup sources are also error-prone any additional outages could compromise the pumps. 

Turbines an issue

T5 is one of two primary power sources, capable of supplying about half the megawattage needed to run the system at peak demand. The other is a century-old steam turbine, known as T4, which also supplies about half the needed power. 

Eventually, the water board plans to retire both turbines as the power complex ramps up and charges the entire system. Other problems could arise if there are further delays to the power complex: Nelson said the Louisiana Department of Health is requiring the S&WB to shut down T4 by the end of December. 

The state Health Department did not provide additional information about that order by print deadline on Wednesday.

Nelson said he is confident the power complex will be operating at enough capacity to retire T4 in time.

“Turbine 4 will be less and less of an insurance policy, to the point where it becomes zero here by the end of the year,” Nelson said.

When the power complex starts running in its initial, limited capacity, it will provide about the same amount of power as one of the turbines, meaning it will be able to operate about half the system at peak demand. Eventually, the water board plans to retire both turbines as the power complex ramps up and charges the entire system.

Extensive testing

The roughly $300 million complex – total cost estimates have varied and ranged as high as $350 million – centers on a new Entergy substation that will feed electricity to drainage pumps that require an outdated frequency. Three frequency changers to adapt Entergy’s modern power to the ancient drainage pumps are the key to making the complex work.

Each frequency changer is designed to supply about half the power needed to run the pumps during the heaviest storms. The third is for backup, in case one of the others goes down.

Water board officials have recently stressed the importance of extensive testing to make sure the frequency changers are compatible with the pumps.

“We’re going to operate it with caution, understanding it’s a brand new piece of equipment that needs to be put through its paces,” Nelson said, referring to the first frequency changer.

Nelson said the hiccup this week came when the first frequency changer blew a fuse as it was connected to a small drainage pump. Once the frequency changer is shown to work with a small pump, it will be tested with larger pumps throughout the system, Nelson said. He said those tests, which should take about a week, will verify the frequency changer can be used.

“Real world testing scenarios” will follow, Nelson said, as the frequency changer is deployed during storms alongside existing power equipment. Testing on the other two frequency changers will come once the first is up and running.

Nelson said the time it will take to complete all testing on the frequency changers is hard to pin down, since that depends on getting enough rain storms to run them with various pump combinations. 

“What we need is a couple of inches over a couple hours, enough to where we get a lot of water in a canal, but it’s not stacking up on the street,” Nelson said.