Reducing peak energy demand key to size of future Duke plant

While almost everyone agrees that reducing overall electricity consumption offers environmental and economic benefits, it’s the amount of power used by our community at times of peak demand that will determine the capacity of Duke Energy’s planned upgrades at the company’s Lake Julian power plant, according to speakers at a panel discussion on WNC’s future energy needs on Feb. 3.

Organized by Leadership Asheville in conjunction with UNC-Asheville’s Office of Sustainability, the event provided an opportunity to hear from Duke Energy’s Director of Integrated Resource Planning and Analytics Glen Snider on the subject of the planning methods and assumptions on which Duke bases its projections for future energy needs in this region.

In November last year, Duke Energy announced that it was abandoning a previous plan to build a new, 45-mile transmission line to bring power into the region from upstate South Carolina. Local residents and governments had expressed widespread opposition to the plan, submitting over 9,000 comments to Duke Energy. At the same time, Duke detailed a new approach.

Duke’s revised Western Carolinas modernization project will replace existing coal-fired units at its Lake Julian plant with two new 280 megawatt generating units fired by natural gas. As part of the plan, Duke is also seeking regulatory approval from the North Carolina Utilities Commission for the construction of a third gas-fired unit to be built in 2023 to provide additional capacity for times of peak demand, contingent on trends in power usage between now and then.

Environmental groups such as MountainTrue and the Sierra Club have focused their recent advocacy on efforts to eliminate or delay the construction of the third proposed generation unit. Many of the speakers at a public hearing on Jan. 26 in Asheville asked the Utilities Commission to deny or delay approval for the third unit.

At the Feb. 3 panel discussion, Duke’s Snider explained that three tenets guide the electricity provider’s planning: reliability, cost and environmental impact. “We have to balance these priorities,” Snider said. “It’s not an option to pick and choose between them.” With its Western Carolinas modernization project, Snider explained, the company is looking at needs not just in the Asheville area, but also in the entire western region and in the adjacent Carolinas region (which encompasses the Charlotte area).

Snider said that peak demand in WNC occurs during the cold months. And Duke must serve the region’s needs regardless of the weather conditions. “We can’t say that we can’t serve you if the temperature is four degrees rather than 12 degrees. So we have to have capacity for peak plus reserve,” Snider explained.

Sonia Marcus, panel moderator and Director of Sustainability at UNC-Asheville, noted that the region experienced its highest-ever electricity demand of 1,200 megawatts in January 2015. Average power demand for the region is 550 megawatts, according to Marcus.

A Duke Energy information sheet details peak demand trends:

Since 1970, peak power demand has more than tripled in Duke Energy Progress’ Western Region. Ensuring power reliability was particularly difficult during the winters of 2014 and 2015, when peak demand was 30 percent higher than in 2013. Over the next decade, continued population and business growth is expected to increase overall power demand by approximately 17 percent.

A snowbound Jim Spencer, Director of Engineering for New Belgium Brewing Company, addressed the gathering from Colorado via live videoconferencing. Spencer outlined a component of the FortZED initiative — a collaborative effort between New Belgium, the city of Fort Collins, Colorado State University and other partners — which used a U.S. Department of Energy grant to implement programs that resulted in a city-wide peak energy load reduction of over 30 percent.

Spencer explained that technology tools allowed the FortZED partners to predict and monitor peak grid usage. “We looked at ‘how does our peak usage influence the overall grid?'” he said. Based on that analysis, New Belgium was able to time its operations so that it is not “colliding with the grid peak.”

When its operations come online in Asheville, New Belgium anticipates undertaking similar efforts here. “In the big picture, it’s challenging to align our demand-reduction efforts with the time when it would be most meaningful,” Spencer observed. Speaking of the role Duke Energy must play, he continued, “It takes larger leadership to make that happen.”

Another panelist, Joan Walker of MountainTrue, said that many programs for reducing business and consumer demand already exist, including differential pricing for energy use during times of peak demand. Another Duke initiative is the Power Manager program, which allows residential customers to let Duke cycle air conditioning units on and off during peak periods in exchange for bill credits. These and other Duke programs will pay bigger dividends, Walker continued, if Duke works with community partners like MountainTrue to identify and remove barriers to participation.

Walker also said she’s a “big believer in good, old-fashioned weatherization.” Much of our area’s housing stock is older and lacks sufficient insulation and other conservation features. Providing incentives and programs to support improving the efficiency of the existing housing stock could “really impact peak demand,” she said.

Snider agreed with Walker, but reminded the audience that all Duke Energy programs must be approved by utility regulators.

In response to a question about the role of renewables in Duke’s modernization plans, Snider said that the utility has committed to a minimum of 15 megawatts of solar generation capacity at the Lake Julian site, along with a minimum of five megawatts of utility-scale storage capacity. Those commitments are important, he continued, but they don’t really address concerns about reducing the load at peak demand times.

“Our peak time is seven a.m. The sun is not up then,” Snider said. “Storage right now is expensive and it has problems — but it has promise.”

The bottom line? It all comes down to partnering with local government, community organizations, businesses and other stakeholders to reduce peak demand, Snider said. ” That third plant is going to be needed if we don’t change our current trajectory.”