Smarter Grid Solutions (SGS), a clean energy software firm, has developed five methods that could double the capacity available for solar panels, wind turbines and other distributed energy resources (DERs) to connect to individual electricity substations.
Using the company’s ANM Element software product, utility companies can monitor the amount of power generated by solar photovoltaics, wind turbines and other renewable energy devices connected to their substations in real-time and react to spikes in output and network loading.
“Each of these solutions applies a real-time export limit to specific DER, thereby providing a set of potential solutions to utility planners and DER developers by creating additional grid capacity and headroom to ease interconnection problems. This, in turn, speeds up clean energy deployments and saves substantial amounts of money for all stakeholders,” says Pete Maltbaek, general manager at SGS North America.
“We believe that the application of these solutions to specific interconnection challenges, identified by screening analysis, in combination with other smart grid and flexible operation solutions, provides utilities with a much-enhanced toolkit for DER integration,” he adds.
Monitoring at the edges of the grid in this way allows utilities to take a much more nuanced approach to managing their networks, enabling them to dial down output from renewables only when local output threatens to breach agreed operational limits at or near specific substations, rather than adopting a grid-wide approach.
Major utilities in the U.S. and Canada are using SGS’s ANM Element platform, and it is widely deployed in the U.K., including at Scottish Southern Electricity Networks, SP Energy Networks and U.K. Power Networks.
This interconnection and hosting capacity approach allows ANM Element to tackle five major challenges when balancing supply and demand at substations:
- Current: monitoring circuit loading means DER output is limited only at the moments when the current, power or output-to-demand ratio requires it
- Voltage: monitoring the point of connection or upstream voltage levels allows the re-dispatch of DER as required to maintain voltage within the required thresholds
- Backfeed: managing the DER output to fit within substation backfeed limits to avoid or defer large capital expenditure on substations and speed new DER interconnections
- Flicker: using flicker measurement, the contributing DER is re-dispatched only when flicker is a live problem rather than inhibiting the interconnection completely, or over-curtailing generation export
- Ground fault limits: limiting DER output only at times when a risk is presented by specific fault conditions that can increase zero-sequence voltage contributions and subsequent overvoltage
Using grid edge control software to protect substations from ground fault overvoltage could cost a 10th of the price of expensive physical upgrades while allowing a 100% increase in DER hosting capacity, notes the company.
Photo: SGS’ About web page