Oh Canada! NB Power turns renewable energy into firm power

By Bob Gibson

Speaking at the opening session of the DistribuTECH conference in Orlando on Feb. 9, Michael Liebreich, founder of Bloomberg New Energy Finance, noted that 2015 marked the first time that renewable energy attracted more global capital than fossil fuel generation.

Clearly, he said, “those years when we could refer to renewable energy as ‘alternative’ are well and truly over.”

The catch, Liebreich said, is that adding clean but variable power complicates the business of delivering electricity.

“(Renewable energy) is not easy to manage,” he said. “But (given price trends) if it’s that cheap, utility after utility will have to buy at least some and figure out how to integrate it.”

In fact, the job of managing the impact of solar and wind on the electric distribution grid dominated DistribuTECH, reverberating across the conference’s 14 education tracks and more than 500 vendor booths.

Much attention has been paid to the technology tools — such as advanced inverters or battery storage — that can mask or mitigate the variability of renewables on the distribution grid. But conference attendees also heard about an alternative and potentially powerful approach now gaining traction — a modern twist on the art of load management, using control of the electricity load to turn variable renewable resources into firm ones.

Wind turbine in New Brunswick. (Photo courtesy of The Maritimes Energy Association)

New Brunswick (NB) Power, the government utility serving the Canadian province on the Atlantic coast, has the kind of renewable power problem that Liebreich was talking about. The Canadian Maritimes region — which includes New Brunswick, Nova Scotia and Prince Edward Island — has a rich wind resource. With the price of wind power falling to a very competitive level, the utility has added almost 300 megawatts (MW) of wind capacity in recent years, and much more is on the way.

But NB Power can’t count on wind to deliver power at the exact times customers want it. On cold winter mornings, the utility can see a 700-MW ramp in customer demand in a two-hour period. On a system with a 2,800-MW peak and limited fast-start generation options, NB Power is often forced to run expensive diesel and inefficient coal generation to cover the gap.

Through PowerShift Atlantic, an innovative load management program covering the three Maritime provinces, NB Power has launched a pilot program that found 3 MW of renewable firming capacity. Specifically, the utility uses a communications system that allows it to directly manage the heating, ventilation and air-conditioning systems of small and medium-sized commercial buildings, as well as the pumping equipment of municipal water systems.

“NB Power said to these customers, ‘You are now part of our renewable energy program,’ even though most of them had no renewables of their own,” said Bud Vos, CEO of Enbala.

The company supplied the communications system that shifts the utility’s customer load in real-time by following fluctuations both on the grid and from the fleet of wind turbines. The shifting and shedding of loads are automated and designed to be invisible to the customer, with no impact on comfort or operations.

Filling the gaps in variable generation

The control system turns the variable wind resource into a firm one by offsetting the difference between day-ahead wind forecasts and actual wind output on a 15-minute interval basis. It fine-tunes the energy use of the connected devices to respond to dispatch requests from the utility. This load reshaping is accomplished through measures such as preheating buildings ahead of a peak or modulating water pressure in the pipes at the water treatment plants.

“Our software models how we can use the customer-sited resources to fill the gaps that the system will see as wind output and overall demand changes,” said Vos. “We create a virtual power plant.”

The utility network sees the aggregated demand-side assets as a single, dispatchable resource that it uses to smooth the variability of the wind output.

“Now the utility dispatcher no longer chases wind. The wind has become a fixed asset,” he continued. “We’re on the other side chasing load.”

Read the SEPA-Black & Veatch report on “Planning the Distributed Energy Future” here. 

While the pilot includes only 30 commercial customers and 2,000 controllable devices, Vos said that the value of the demand management system will increase with the addition of more commercial customers and an expanded palette of devices. The list of potential power sources includes chillers, compressors, fans and motors, plus end-use loads such as electric water heaters on the residential side.

“We love load diversity. You don’t want all the devices to be acting at the same time, in the same place,” said Vos.

NB Power plans to increase its renewable energy — adding solar to its wind resources when the price is right — and shutter all its coal generation over the next 20 years. It is working on an integrated demand-side resource plan as a key part of its evolution away from fossil fuels.

Visibility, agility and customer engagement

NB Power’s pilot can also be seen as part of a broader trend, envisioning the utility of the future actively engaging customers in reshaping the resource base. Success depends both on advanced technology and on fresh ways of building customer awareness and buy-in.

“Our automated systems are increasingly using artificial intelligence to provide predictions accurate to a couple percentage points of the electricity demand that can be expected and the generation that will be needed,” says Brad Molander, technology evangelist at the National Information Solutions Cooperative, an information technology software firm that works primarily with electric cooperative utilities.

“The systems look both for patterns and for anti-patterns, the abnormalities that can help utilities be more precise with the rollout of a new program, or to determine whether a customer is on the right rate schedule,” he said.

Most progressive utilities “are not apprehensive about the growth of solar or other changes”, Molander said. “They are using it as an opportunity to engage with their consumers.”

Greater visibility of consumer energy use “allows the utility to be more agile in its thinking and in its operations,” he said. It also provides “an opportunity for the utility to get its consumers excited that they can make a difference, not just for themselves but in the communities where they live.”

Bob Gibson is the Solar Electric Power Association’s Vice President of Knowledge. He can be reached at [email protected].