Advanced transmission technologies designed to maximise the use of existing transmission lines could help the US bring more renewables capacity online without having to wait for new grid infrastructure to be build.
States such as Kansas and Oklahoma could bring more than double the wind and solar generation capacity online that could be connected otherwise, according to a study cited by Jay Caspary, vice president of Grid Strategies, during a panel discussion at the Clean Power 2021 virtual summit.
The two states currently have 9.2GW of wind in the transmission queue – projects that already have an interconnection agreement — along with 260MW of solar. Kansas and Oklahoma have strong wind resources and large existing wind fleets — 7.3GW and 9.6GW respectively, according to Windpower Intelligence, the data arm of Windpower Monthly.
Overall, Caspary said that three technologies — advanced power flow control, dynamic line ratings and topology optimisation — could enable the region to integrate an additional 5.2GW of wind and solar capacity.
The report, a case study of how grid-enhancing technologies (GETs) could unlock the grid in the Southwest Power Pool area, was conducted the Brattle Group for the Watt Coalition, of which Grid Strategies is a member.
The US’s Federal Energy Regulatory Commission (FERC) is planning discussions later this year to consider incentives to promote the use of GETs, including dynamic line rating (DLR), which allows transmission lines to carry more capacity by calculating ratings based on real-time measurements of line temperature, wind speed, tension and sag rather than relying on fixed, worst-case assumptions. DLR has already been deployed worldwide and in pilot projects in several US transmission regions, including PJM, New York, Colorado, Minnesota and Texas.
Nationally, the use of GETs could deliver carbon emissions cuts equivalent to taking 20 million cars off the road, Caspary said. More than $5 billion in yearly production cost savings could be achieved across the US. Regionally, the annual benefits for Kansas and Oklahoma, according to the report, include $175 million in production costs savings and avoiding 3 million tonnes of emissions.
Terron Hill, director for US transmission asset development and policy at National Grid, told the summit that the utility is piloting GETs in New England. Their deployment is a boon given the aggressiveness of the region’s renewables goals, he explained, and considering that New England is densely populated with scant green space and minimal room for new transmission right of ways.
Amanda King, director of strategic transmission planning at Minneapolis-based Xcel Energy, said her utility has analysed GETs and projected that they could offer a 10-20% improvement in renewables interconnections.
A 500MW wind project could save $80 million and five to seven years in development time by using grid-enhancing technologies, suggested Mark Freyman, general manager for the Americas at GET specialist Smart Wires. “There is a clock ticking — these technologies can be a bridge while we are building out the transmission we need,” he said.