How distributed energy resources contribute to a more resilient grid
Recent extreme weather has prompted fresh thinking on the subject of grid resiliency. Part of the solution lies with the proliferation of distributed energy and how it can be harnessed for that purpose. Juan de Bedout, Chief Technology Officer of GE’s Grid Solutions business, spoke to Decentralized Energy about his company’s approach.
As Chief Technology Officer, de Bedout is responsible for designing and producing world-class products to help create a more efficient and reliable grid system. Prior to this role, Juan served as the Technology Director for the Electrical Technologies & Systems organization at GE Global Research.
Juan de Bedout, Chief Technology Officer of GE’s Grid Solutions
The most visible, recent sign of how modern grids can be affected by extreme weather came with the devastation of Puerto Rico in September. A lot of temporary power operators were called into action, when the grid succumbed, and much of the country is still without power.
“Hurricane Maria took out infrastructure at such a scale that 95 per cent of the people were without power and even a month later 88 per cent of the island was without electricity. That’s the world we are heading into and we must think differently about how we architect the grid so that it doesn’t leave people for days, weeks and even months without electric power.”
Much thought is now being applied to how to use new and existing energy resources on the ground, and offset some, if not all, of the power issues that plague post-storm regions.
“What is exciting is the ability to control these resources in a more optimal way, to balance variable resources like solar photovoltaics with demand response and energy storage for example. It’s also about facilitating a more cost-effective deployment of those distributed energy resources (DER).”
GE has been perfecting its microgrid tech over the years, with one of its stand out performers being the Philadelphia Navy Yard. Bedout’s team have been applying what it has learned to prolonging the time a microgrid can operate after a storm event.
“We have developed building distribution automation coupled with fault detection, isolation and restoration. When you consider those two technologies you now can build a large distribution system. If a storm passes through, you can identify the healthy portions and the damaged parts of the circuit very quickly and use it to restore power.”
One US utility that benefited from this was NSTAR (now incorporated into Northeast Utilities), who enabled resilience for healthy portions of the grid post-large storms. The company could ship power through alternate lines and then have the ability to more fully serve the portions of the circuit that could be enabled to power.
“It’s technically difficult. When you start reconfiguring circuits there can be concern about voltage but a cool thing about this technology is it takes it into account.”
“NSTAR used our system to restore healthy portions of the circuit after a major eventsin less than an hour. Take Tropical storm Irene in 2011 – that system had 6,000 power interruptions and half of those were fixed in less than an hour. That’s what we’re looking for.”
The recent damaging storm that tore through Puerto Rico saw both GE and its partners attempt to facilitate the complete restoration of the grid. The work there is ongoing and more strategic thinking is now necessary. Puerto Rico lies in an area of the world, where such weather events are not rare, and with the impact of global warming, the ferocity and frequency involved is unlikely to diminish.
“Our energy consulting group (power systems consulting team inside GE’s grid business) is working with Puerto Rico and helping them to envision how their system architecture would work going forward.”
“Resiliency is a key topic. Making sure some substations are hardened for heavy winds and that you have the right presence of distributed resources so that you can form microgrids to restore portions of the circuit, at least critical power. They are in the initial stages in helping them think through long term plans.”
Why has the Puerto Rico case been so much about reactive and so little about proactive up to now? Part of the issue lies in how the grid is sited on the island.
“You really want to rearchitect the system – essentially Puerto Rico today has most of its generation on the south of the island and a lot of the load is on the north of the island and when the transmission is wiped out connecting those two you have a big problem so it’s about thinking about that policy differently.”
“There could be higher proportions of DER in the northern part of the island where most of that load is for example. This is where we build more resilience into the system but it’s a different architecture.”