Toledo Edison shut down a 900 kilowatt wind turbine installed at Clay High School in May because it is missing a trip switch that would prevent backfeeding of electrical energy to and from Edison’s substation.
“The turbine is perfect,” said Dean Sandwisch, business manager for the Oregon City Schools District. “Edison is requiring a shut down switch that would stop the turbine from operating and backfeeding into the system in the event of an electrical mishap, such as a lightning strike. And we’re working to accommodate Edison.”
Backfeeding, technically known as “islanding” would be a “rare event,” said Sandwisch.
|The turbine sits idle. (Press photo
by Ken Grosjean)
“If something were to happen with the substation, there’s a very remote possibility that our wind turbine would be producing at the exact same level as the substation,” explained Sandwisch. “And Edison wouldn’t be able to tell and it would feedback onto the lines and cause damage to equipment or cause danger to people working on the line.”
The 285-feet wind turbine, which generates electricity by wind and is expected to provide power to Clay High School, is backed by $4.5 million in bonds underwritten by the Toledo-Lucas County Port Authority. The school board last year signed an agreement with SUREnergy, the general project contractor who guarantees savings on electric costs from the first month of operation under a 15-year lease to own finance package.
Sandwisch, Toledo Edison, and SUREnergy have met many times since the turbine was shut down to discuss the matter. But no one can agree on what should be done to get the turbine up and running. That’s because the Direct Transfer Trip switch costs $200,000, according to Sandwisch, who believes the part is unnecessary.
“We now have to put this switch in that gives a signal from the substation to shut off the turbine. But it would shut down anyway within a second should there be a problem. So it’s kind of a redundant system. There would be a one in a trillion chance of it backfeeding. The wind turbine is designed to shut down once there is any variance in the system. This type of turbine is in six locations throughout the country and nobody requires this part. So there’s a little frustration,” said Sandwisch. The switch, he added, was not required for the two wind turbines installed at Eisenhower Middle School this year.
Debbie Paul, the external affairs manager for Toledo Edison, said the switch is a necessary safety feature.
“The turbine that they have at Clay is huge – the largest of its kind on our system. It really needs to be on a wind farm. That’s what it was designed for - not for a distribution system. Either system could backfeed into the other when a generator over-commits and pushes energy back into the system. We have guys working on our system every minute of every hour of every day. To think a line is de-energized when it’s energized – that’s a huge safety risk on our part.”
The switch is not required for the two turbines at Eisenhower because they are not that big, she said.
“Bottom line is, the people they bought it from, SUREnergy, have not met all the requirements they obviously had to have before the turbine can run. They need the Direct Transfer Trip switch on that generator because it protects not only our system and our employees, but it also protects the investment in their windmill. I know we’ve been going round and round with this. I know the school is under some heat because it’s not operating. But at the same time, the contractor should have done his due diligence before he installed. Technically, they never got a Permit to Build from us to connect to our system. Normally, that is required all up front. But SUREnergy’s paperwork was really late,” said Paul.
The Direct Transfer Trip switch should have been in SUREnergy’s plans, she added.
“Should have been, but was not,” she said.
Edison denied a request from the district for a temporary operating permit to run the turbine until the matter could be resolved, said Paul.
“We can’t run that risk. Nor should they - they’re at risk of damaging a multi-million dollar generator,” she said.
SUREnergy and TAS Electric, the electric subcontractor for the wind turbine, proposed a wireless trip switch that would be much cheaper to install, according to Sandwisch.
“Edison’s switch was incredibly expensive and not very reasonable. They wanted $200,000 to hardfire that switch – in other words, basically run a wire from the turbine to their substation, then install the switch. The wireless switch is only 10 percent of the cost of the switch that Edison wants,” said Sandwisch. “It was tested two weeks ago and it performed wonderfully – above minimum standards.”
Sandwisch said SUREnergy is responsible for the cost of installing the part.
“It won’t cost anything to the district,” he said.
Paul said the wireless trip transfer system proposal is under review by an Akron engineering group that monitors generators throughout Edison’s system.
“We’re committed to making this thing work, no matter what. But we’re not going to let it work unsafely,” she said.
SUREnergy did not return calls to The Press for comment.