Get the right size transformer for your future electric load
Going green can be a slippery slope—in a good way. It’s great to invest in emission-free devices, especially when they contribute to quality of life and cost less over the long term. What’s important is making sure you have the transformer capacity to power your new devices, both now and several years from now.
Electric vehicles, heat pumps, and heat pump water heaters have entered the consumer mainstream, with reliable performance and more affordable options. They’re also easier to buy with plentiful purchase incentives and the promise of savings over time.
These electric devices also minimize the environmental impacts of heating, cooling, and transportation, especially in WEC territory, where power is 100% renewable and generated close to home, and whose members have long prioritized clean energy. It’s no surprise, said WEC Products and Services Director Bill Powell, that WEC members are replacing old combustion devices with electric ones. WEC encourages it.
But about a third of WEC members’ transformers are just 5 kVA (or kilovolt-amperes—a measurement unit of the total amount of power a system uses). Increasingly, that’s not enough power for members’ desired or future electric load. These 5 kVA transformers are the legacy of past decades’ regulations, before the state’s sources of electric power were as clean as they are today. At that time, Vermont encouraged utilities to conserve electricity, and to use those smaller, more electricity-efficient transformers.
Over the last few years, Powell said, many members trying to add net metering, Type 2 electric vehicle chargers, or other devices have discovered that their rising electric power need, or “load,” is too much for a 5 kVA transformer. Not only have members discovered they need new transformers, but transformer shipments were held up during the global supply chain crunch caused in part by the COVID pandemic. Recently, Powell noted, the shortage started to ease, and WEC has begun to receive transformer orders again with a degree of reliability.
That leaves a long list of WEC members eager to make a lot of electric improvements. Powell, whose tenure at WEC is longer than 30 years, noted that he used to see a request for a larger transformer come in maybe five times a year. “The pace and frequency is now daily,” he noted.
And that slippery slope of going green? It’s real: a member who upgrades one device is far more likely to upgrade another, said Powell.
“What the member and the Co-op wants to avoid is doing it twice. Do it once and future-proof your location,” advised Powell, meaning set yourself up with a transformer that may be larger than you need right now, but that will accommodate your future power needs. “Thoughtfully anticipate what you want to do over time, and that’ll give us a sense of what you’ll need over time.”
Powell has seen cases in which a member requests a transformer upgrade—but then continues to add devices that draw a lot of power, and just a year or two later, needs another upgrade. That’s a situation you want to avoid.
How it works
A transformer is the device, often attached to a utility pole, that changes the electricity traveling on single- or three-phase distribution lines to a lower voltage safe for regular home and business power use. Nicknamed “cans” for their shape, they come in a range of kVA capacities: 5, 10, 15, 25, 37.5, 50, 75, 100, and beyond.
Most of WEC’s transformers serve one household each—this is a rural, sparsely populated territory. Some “joint-use” transformers serve multiple homes: for example, a group of camps on a pond.
If there is more electric demand on a transformer than it can support, it overloads the device. “A fuse that opens on an overloaded transformer causes a big bang and an unplanned outage,” described Powell. “Please don’t add load without telling your electric co-op about it first, because the consequences of overloading a transformer are expensive and inconvenient.” Members who cause an outage are responsible for the costs of repair—which can exceed $1,000.
Plan ahead: WEC’s Load Sheet
In order to tell WEC about your planned upgrades—and to get in the queue for a new transformer, should you need one—you’ll need to submit a Load Sheet. This is a document that helps WEC assess what size transformer members need to meet their current and future electric needs. Accuracy is important, and the sheet specifically requests information about future project plans.
With your electrician’s help, you can take care of your current and future to-do lists. Call them to evaluate your capacity before you purchase or install new devices, said Dave Kresock, WEC’s Director of Engineering and Operations. “This is when members should have their electrician complete the load study and fill out the Load Sheet.” Your electrician will also let you know if you need to make any upgrades to your home’s service entrance or other electrical infrastructure in your home before you install any new load.
So tell your electrician about your future plans, and ask them to fill out the Load Sheet on your behalf. If you’re installing a Type 2 charger now, but budgeting to build out a cannabis grow operation over the next two years, you will want a transformer that can support it.
Overall, members adding electric load is evidence of members changing from oil burners to heat pumps, for example, and other upgrades that use renewable electricity. That’s better for the environment and, when it means more power purchased from WEC, it’s better for the health of the Co-op and the members who own it. When the Co-op’s financial margins exceed the cost of doing business, members receive capital credits proportional to the amount of power they purchased—and that shows up as an annual credit on your bill.
Plan Ahead Resources
WEC’s Load Sheet is available online. You may also request one by calling 802-223-5245.
To access the Load Sheet online:
- Visit wec.coop, scroll down to Helpful Documents, and scroll down to the New Construction header to find the Load Sheet PDF.
- Alternatively, enter washingtonelectric.coop/Document-Center and scroll down to the New Construction header.
Direct link to the Load Sheet: https://www.washingtonelectric.coop/wp-content/uploads/2023/06/Load-Sheet-06-2023-1.pdf
For information about incentives, visit EfficiencyVermont.com and search for “IRA Savings Calculator.”
Direct link to the savings calculator: https://www.efficiencyvermont.com/blog/how-to/how-much-money-can-you-actually-get-in-clean-energy-incentives