'We need to maintain reliability,' says Yukon Energy about pause to microgeneration project

Yukon Energy says it's all for adding more solar power into the territory's power grid — but not if it destabilizes the system and increases the risk of outages.

The utility recently asked the territorial government to put a pause on a rebate program for people who install renewable energy systems, such as solar, at home and then feed their excess power into the grid. 

The government agreed, and is no longer accepting new applications to its microgeneration program until at least next spring while a study is done. Microgeneration projects that have already been approved or built are not affected.

Paul Murchison, vice president of engineering and capital projects for Yukon Energy, says the concern is keeping the power grid stable during the summer months when solar generation is at its peak, but demand for power is not.

"We're excited to see people's enthusiasm," said Murchison, referring to the number of Yukoners who have already installed solar panels at home and applied to the microgeneration program. 

"That's great, but what we've seen is stability issues on our grid because of this quick adoption and increased penetration of solar on our grid," he said.

Murchison said solar generation in the summer can fluctuate wildly, depending on cloud cover. That means Yukon Energy's hydro or diesel generators must be able to kick in quickly when solar energy suddenly drops off.

"So those units have to speed up and slow down. But what we started to see with sort of that stability issue, is the ability for them to quickly respond," Murchison said.

"So that's why we did ask the Yukon government to pause the program. We need to make sure we maintain reliability for our customers."

Murchison said the system has protection controls built into it. That means any serious instability can trip the system, resulting in power outages. 

"The system can trip to prevent damage, not only to people's equipment in their homes but to the electrical equipment that we have in our system," he said.

Murchison said a new grid-scale battery storage system — currently under construction — will help provide more stability to the system, but he said that's only part of the solution.

The grid-scale battery — estimated to cost $35 million — is mostly aimed at reducing the need for diesel generation during periods of peak power demand in the coldest, darkest months of winter.

Yukon is unique compared to many other places where microgeneration projects are connected to the grid, Murchison says. That's because the amount of solar energy, and the demand for power, varies so widely between summer and winter.