Extreme weather in both Texas and Florida has tested the newest smart grid deployments made by utilities. With many smart grid advocates citing resiliency and recovery as major benefits, some utilities have been praising their uptimes – while others seem to have been caught short of the mark.
Hurricanes Harvey and Irma thrashed Texas and Florida, respectively, with flooding and high winds responsible for most of the damage. Irma killed power supply to some 6.7m homes in Florida (10m people), with Florida Power and Light (FPL), the largest electric utility, saying it had seen an unprecedented 5m customer outages. Hurricane Sandy knocked out power for 6.2m people, in comparison.
FPL has begun the process of rebuilding its smart grid, which it completed in 2013 after a $3bn investment. With $200m of that funding coming from the Department of Energy’s 2009 Recovery Act, FPL proved the capabilities of the smart grid approach in 2016 – when it managed to restore power to 99% of its customers within two days of Hurricanes Hermine and Matthew, winning it awards from the Edison Electric Institute.
But Irma was on another scale entirely, and FPL is not going to repeat that success – owing to extensive damage to core components in the distribution network that weren’t knocked offline in Hermine and Matthew. If Irma is an anomaly, then the likes of FPL should be able to weather future storms, and use their smart grid tech to bring power back much more quickly than conventional methods – which involve extensive manual inspections and site visits to troubleshoot hardware.
However, if storms like Irma become more commonplace, then smart grid upgrades will need to find new ways to avoid mass outages. In the run-up to such storms, most stores are depleted of their gasoline-powered electric generators, as homes know they will have to generate their own electricity when the grid’s supply goes offline.
Battery storage could provide an alternative here, especially if they were installed inside homes as part of a grid’s upgrade program – using the battery to store electricity when there is over-supply and the price is cheap that can be used later on to help the utility buying electricity when the price has risen. In the build-up to a storm, these batteries could be topped up, so that the home would have a reserve to use inside the home – until the grid comes back online.
Many utilities are exploring grid-scale storage, as a way of accommodating the varying generation outputs of renewable sources like solar and wind, but whether utilities decide to push the storage closer to the customer (and actually inside their homes) remains unclear. There doesn’t seem much enthusiasm for such an approach, although some consumers are exploring the model – especially if they have solar panels on their roofs.
Home storage, or storage units that are located inside multi-tenant buildings or residential blocks, could provide an answer for post-storm outages, providing they withstand the winds and flooding. Negotiation software will be required to ration the reserves between users on the sub-network, but such a system could help keep lights on, food refrigerated, or cooling fans running. Air conditioning is likely too power intensive to be supported, unfortunately.
As for other IoT technologies that could help the recovery process, drones could provide a much faster way to check on the integrity of infrastructure like power lines – allowing a technician to check far more lines or towers than they could if they had to drive to each asset.
FPL President Eric Silagy said “we’ve never had that many outages. I don’t think any utility across the country has. It is, by far, the largest in the history of our company. This is unprecedented.” Silagy later told Bloomberg that “there is no way to engineer against a storm of this kind of magnitude.”
After that statement, VP Communications Rob Gould said that the east coast of Florida could expect the standard power restoration roadmap, but that the west coast would require a ‘wholesale rebuild.’ Gould said “this is going to be a very, very lengthy restoration, arguably the longest and most complex in US history.”
By all accounts, FPL was well prepared for a storm. Each year, it has to file a storm preparedness document with the state, and that it had begun integrating systems based on the experience of Hurricane Sandy – such as flood sensors in substations, which could keep downtime to a minimum. But due to Irma’s destructiveness, FPL’s preparations could not stop the outages.
The smart grid technologies here should provide a quicker recovery process. The amount of data they can generate and pass back to control applications and dashboards should mean that utilities like FPL are better able to assign workers to assets in an efficient manner. Even the smart meters at the customer locations can quickly tell a utility if they need to visit a street or block.
Being able to remotely connect to an asset should let an operator see if it is online and functional, with the asset able to tell them what, if anything, is wrong. That could mean a tech is sent there with just the right part to bring the substation or power line back onto the grid, or simply prevent a wasted visit to an asset that is working correctly.
And it seems that some of the tech proved its worth in Irma. On those substation flood detectors, FPL’s Silagy said “frankly those saved three or four days of work and millions of dollars’ worth of equipment that would have had to be replaced rather than simply re-energized,” – allowing the substation to shut itself down if water is detected, instead of being flooded and shorting out.
In Texas, CenterPoint used its Fault Location, Isolation, and Service Restoration (FLISR) to tackle outages via automated distribution circuit switches, which can be activated remotely from a control center. However, FLISR systems aren’t designed to deal with hurricane-scale problems, and complicating matters are the floodwaters that didn’t recede immediately.
Next generation distribution equipment is being built to be more resilient to hurricanes and flooding, which might allow utilities to better protect them by installing them underground – something that isn’t really possible in Florida, due to the labyrinthine network of water ways that make digging cable trenches extremely cost prohibitive.