How hydrology could help power grid evolution
As distributed resources change the way electricity flows through the power grid, energy researchers are borrowing a concept from hydrology to study how the increasingly complex system works.
The US Department of Energy is preparing to award $10 million in grants for research related to “energy discharges”. The term may conjure up images of small wooden buildings housing whirring generators, but it’s actually a play on the watershed concept.
A watershed is a geographic area where all water flows into a common outlet, such as a river. An energy shed then examines how energy is created and consumed in a defined area. The DOE’s definition, borrowed from a 2016 report by John C. Evarts, is “an area in which all energy consumed is supplied there”.
“It’s a very multi-faceted, multi-layered concept,” said Austin Thomas, co-author of a paper on energy sheds published last year in Energy Research and Social Science. “There is still some flexibility and ambiguity in its definition.
Thomas’ article uses a broader definition: “The geographic area that contains the land, infrastructure, people, benefits and environmental impacts related to final energy consumption.”
Application of the concept could be particularly useful now that more and more communities, states and regions are moving away from reliance on centralized fossil fuel generation facilities in favor of energy sources more distributed renewables.
“Understanding the implications of more local generation can lead to a more efficient and resilient power system,” the DOE’s Office of Energy Efficiency and Renewable Energy said in its description of the funding opportunity.
“The DOE recognizes that the future of energy is not the past of energy,” said Gretchen Bakke, a senior fellow at the Institute for Advanced Sustainability Studies and a participant in the energy shed workshop at Last year. “They are trying to figure out how to involve local communities and working around public services in their current form, to experiment, but also to come up with real pragmatic plans. How big should a hangar be, what should be the production capacity, how would all of this work together.
The concept “digs deep into the location issues associated with energy,” said Paul Hines, vice president of electrical systems at Energy Hub, which develops distributed energy management software. “When you buy energy, it comes from many different sources on the grid, with impacts in all of those places. How can we understand the territorial impacts of our energy choices? Although many details are unclear, systems are needed to coordinate distributed energy resources and enable people to participate.
Breaking down large energy systems on a regional or national scale into smaller energy basin areas could help “understand the trade-offs between producing and delivering energy within that boundary versus importing or exporting energy to or from that region,” said Clayton Barrows, a member of the Grid Operations Planning Group at the National Renewable Energy Laboratory.
Under the DOE funding opportunity, power pools proposed for investigation must be confined to a “discrete geographic area” in which renewable energy sources supply a large portion of the demand, but in which the constraints of network capacity limit additional generation deployment.
The service area should also have a significant deployment of interactive smart meters, an essential data collection tool.
In addition to gathering information on resilience, reliability, affordability and sustainability, energy shed projects are also expected to address issues of equity and inclusion, including job creation, exposure environment and transparency.
“Today’s energy system was not built with the needs of rural and urban communities in mind equally, or with consideration for climate change or low-income communities,” Thomas said. “So what is the direction of the future? And what are the shortcomings of existing systems? »
One of the biggest points of disagreement and ambiguity around power shedding is how to set the boundaries – what do you include or omit? For example, Thomas said, you could reasonably group all of the New England states into one power pool, because they’re all on the network run by ISO-New England.
But if you include the natural gas used to generate electricity and take into account where that fuel comes from, you have to expand the limits, because the gas is not produced in any quantity in the region, he said. .
Importantly, an energy shed is not the same as an energy island or a microgrid, both of which are designed to operate individually, Bakke said.
“It’s not like we’re going to live in these little energy capsules and not be connected to each other anymore,” she said. “If you get an energy shed that meets 80% of a particular community’s needs, the remaining 20% will be balanced from the outside.”
The DOE plans to fund two to five projects. Winners will be announced in September.