The U.K. may have taken the crown as Europe’s fastest-growing solar market last year, and it’s set to double its share of renewable energy to meet its 2020 carbon reduction goals. But that growth could be choked off by a grid that can’t handle any more distributed energy.
Or, to be more precise, the country’s 14 distribution network operators (DNOs) lack the data to know whether or not they can allow new solar and wind power without expensive grid upgrades at the point where they’re being interconnected. Think of it as a problem similar to the one that Hawaii’s utilities are facing in bringing lots of new distributed generation (DG) on-line, only on a much bigger island.
In April, DNO Western Power Distribution announced it will close the grid in the country’s southwest to new renewable projects for three to six years while it upgrades its infrastructure. Likewise, U.K. Power Networks maps show that large parts of eastern and southeast England’s grid have almost no capacity, The Guardian reported last month.
While infrastructure upgrades are certainly necessary in some places, the U.K.’s Solar Trade Association complained last month that DNOs and renewable developers are “missing basic information because we don’t have an assessment of how much actual capacity is left” on specific portions of the country’s grid.
That’s where new smart grid technologies might be able to help, by collecting data on the grid edge. That could help DNOs figure out just where their low- and medium-voltage grids can take on new wind and solar systems, versus where they’ll need upgrades.
Take the two projects that grid sensor vendor Tollgrade Communications has been working on for DNOs Western Power Distribution and Scottish Power Energy Networks. Both are being funded by the Low Carbon Networks Fund run by the U.K. Office of Gas and Electricity Markets (OFGEM), which has called for “network companies to take creative approaches to connecting generators without costly network upgrades” as part of the country’s new energy regulatory regime, known as RIIO.
“OFGEM has really been pushing the U.K. utilities through the 2020 initiatives, and in their most recent RIIO filing,” Erik Christian, vice president of smart grid for Tollgrade, said in an interview last week. “They have a lot of customers that are trying to hook right onto the distribution grid. But the DNOs are having trouble in how to facilitate this queue of customers.”
Tollgrade’s first project with WPD is known as Project FALCON (Flexible Approaches for Low Carbon Optimised Networks). It's “based on gauging the power capacity to avoid building new generation plants,” he said. “They see this as the necessary precursor to a massive distributed renewables rollout. But they just don’t know right now where the areas are that they have constraints, where the areas are that they can hook DG onto the distribution grid, and where they have excess capacity.”
Tollgrade’s Lighthouse powerline sensors are being deployed to bring visibility into these “dark” portions of WPD’s power grid. “That allows them the ability to see in real time if they have extra capacity in that area of the network, or if they need to build redundancy into that area of the network,” he said. “They’re looking at how many interconnections they can hook onto the grid, and what’s the fastest way they can get their customers onto the grid with distributed generation.”
The second project with Scottish Power Energy Networks is dubbed ARC, or Accelerating Renewable Connections. It’s also looking at collecting data to determine where local grids can or can’t handle new interconnections, much like Project FALCON, Christian said. But beyond that, “they’re looking at using Tollgrade Lighthouse sensors for active management of their distribution grid,” he said.
Specifically, Tollgrade’s sensors will be delivering data to U.K. startup Smarter Grid Solutions (SGS), one of a number of companies creating distributed energy resource management software (DERMS) to collect and analyze data coming from renewable generation sites, building energy systems and other grid-edge sources. That data is then fed to underlying grid control systems, to allow them to make real-time decisions based on the ups and downs of wind and solar power coming onto the network.
Tollgrade is working with SGS on several projects on the Scottish islands, which have to balance power from large-scale wind farm with imports and exports to the mainland via undersea cables. “They’re trying to see if they can possibly sell energy back to the mainland and monitor that interconnect point,” he said.
At the same time, SGS has built a software tool for Scottish Power, dubbed OCAT, or Online Curtailment Analysis Tool, to allow project developers to “point and click” their way to finding capacity on the distribution grid. It’s also working with Silver Spring Networks and Alstom Grid on the Flexible Plug and Play project, which is directing £9.7 million ($16 million) toward connecting an array of distributed resources to manage wind and solar resources in Cambridgeshire.
Christian noted that both projects Tollgrade is working on are still in their early phases. But “one of the interesting takeaways we learned from our customers is that they have extra capacity in a lot of areas that they didn’t realize they had, where they’re able to install and hook up distributed generation quicker than they thought.” Conversely, “in other areas, they found out that where they thought they had extra capacity, they didn’t -- and hooking up more distributed resources would have been a bad thing.”
In either case, traditional grid modeling tools aren’t really designed to calculate the constant fluctuations of wind and solar power on the grid, he said. “The distribution grid is becoming so dynamic that it’s becoming impractical to take a few pieces of data, and then infer mission-critical information,” he said
This is the same imperative that is driving investment into technology to collect, analyze and share data for renewables-rich regions across the globe. California utilities are being asked to share their grid data with distributed energy providers as part of the state’s distribution resources plan proceeding, and Hawaii’s utility regulators are asking its utilities for the same kind of integration with third-party energy companies like SolarCity and Enphase.
New York’s Reforming the Energy Vision initiative envisions the state’s distribution utilities taking on the role of distributed service platform providers to manage the interplay of customer-sited renewable energy and utility grid operations. Europe has dozens of projects working on similar challenges, ranging from region-wide energy balancing to local distributed energy integration.