September 01, 2010

You can't miss it -- 213 solar panels and a battery the size of a tractor trailer sit alongside one of Duke Energy's electric substations on Charlotte, North Carolina's Highway 51.

And that is intentional, said Paige Layne, Duke Energy's corporate communications manager. "We found because the solar panels are out there on one of the busiest highways in Charlotte, people call in and ask us about them."

The solar arrays, the battery and 100 customers now hooked up with free home energy management systems create a virtual power plant, capable of supplying a reliable source of clean energy when demand is at its highest. The three parts make up Duke Energy's McAlpine Creek project, one of the utility's pilot projects, which tests smart technologies that allow customers to monitor their daily electricity usage and to create an online "energy profile." The giant zinc bromide battery also allows the utility to store 500 kilowatts of solar energy that can be tapped into during peak times.

"It was a concept of taking an area and concentrating all the digital technologies in this area toward grid optimization," said Melanie Miller, the McAlpine Creek senior project manager.

Duke Energy, which serves approximately 4 million electric and 500,000 gas consumers in North Carolina, South Carolina, Ohio, Kentucky and Indiana, is making many investments to reduce demand and to make the grid more efficient, and McAlpine Creek is just one way to test a new idea.

"[Duke] is moving forward with complete grid modernization, so what we are testing and learning can be applied in other areas," said Miller.

In Cincinnati, Ohio, and Hendersonville, N.C., for instance, Duke installed what it calls intelligent "self-healing" switches on power poles to reroute power during an outage. The switches help to minimize the number of customers affected by power outages.

"If we can learn what it is that our customers want and find valuable and deliver that on a larger scale with distributed generation, we can get to a level of sustained energy efficiency," said Layne. "This can then help us to delay building power plants."

Through the McAlpine Creek pilot, Duke is learning about customer demand by the energy profiles it sets up through the utility's Web site. Duke Energy sends a pricing signal to participating customers when energy is in high demand, and is most expensive; customers can then choose to adjust their profiles accordingly to use electricity when it costs the least. When demand drops, Duke Energy again notifies its customers that they can return to their original energy preferences.

"For the past 100 years, we built the grid to deliver energy, and our way of responding was to forecast demand and build power plants to meet the need. As the game has changed, we have had to find ways to balance the affordable, reliable and clean. Energy efficiency is one of the cheapest ways of doing that," said Layne.

Residential Participants First

For the pilot, Duke Energy offered volunteers free energy management systems; to complete the digital communication, smart meters, intelligent sensors and communication nodes on utility poles were also installed. The utility gauged interest by asking customers served by the McAlpine Creek Substation to participate through a letter of invitation, said Miller.

McAlpine Creek was chosen "for its dense population and mix of residential, small business and commercial customers," she said.

Currently, the pilot only includes residential customers, but it will soon spread to multi-family housing units, apartment buildings and small businesses, and will include the incorporation of 2.3 kilowatts of solar energy on rooftops, plug-in electrical vehicle chargers and several different battery technologies.

"The pilot started last year, and since then we have gathered a lot of data on how customers are using the system," Miller said. For instance, the company can tell how actively engaged customers are by how often they interact with their energy management system and participate in high energy demand events. In its first year, the utility saw 5- to 15-percent reductions in energy savings during peak periods.

"We have opened McAlpine as a self-serve educational opportunity," said Layne. The McAlpine site is comprised of a walking path in front of the solar panels and informational booths to encourage residents to visit and learn more.

"If you go on to Duke Energy's Web site to sign up for online services, customers with digital meters can see their energy usage in increments from the day before. Consumers have never been able to know how much energy they have used until they get the bill. That information piece is so powerful," she said.

The utility is realizing a growing desire among customers to know more about how they are using their energy. This is why Duke Energy has an active YouTube stream where customers can learn about the company's smart energy initiatives, including the McAlpine Creek project, which is empowering customers to make smart energy decisions, and how intelligent sensors on power poles are helping to prevent power outages.

The utility will continue to gather data from the McAlpine Creek project through 2013, so that it can determine what it is that customers want and what will keep them engaged, if that's what they want to do.

"We know not all customers are going to want to play," said Layne, "but we can learn what they want and deliver tools, information and technology so that they can do that."

"[The pilot project] is really evolving as technologies are changing," said Miller, who noted that Duke is constantly issuing requests for proposals for new ideas to make the grid smarter. "We want to make sure we capture all the data and all the components work together as we add apartments, multi-family and small businesses to optimize what we need moving forward."

 

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Laurel Lundstrom