As movement on federal greenhouse gas initiatives has basically flatlined during the Trump administration, more states have stepped up to establish targets for reduced use of fossil fuels in their electricity generation portfolios. Several states—notably, Hawaii, California and New Mexico—have gotten the lion’s share of attention for such efforts with fast-tracked schedules to eliminate fossil fuels in the next 25 years. However, Vermont’s largest utility recently announced a plan that could make the Green Mountain State the first in the nation to go carbon-free, or nearly so, as early as 2025.
Hawaii was the first to set a goal of 100 percent renewables (with a 2045 target date) in legislation passed in 2015. Last September, California Gov. Jerry Brown signed legislation committing the state to 100 percent carbon-free electricity by 2045. And in March, New Mexico passed legislation committing to the same goal.
Vermont, in contrast, seems to have come somewhat late to this effort legislatively. It only established its own renewable portfolio standard (RPS) in 2015. That legislation called for 55 percent of generation to come from renewables by 2017 and 75 percent by 2032. Ambitious as these targets are, however, individual utilities in the state are already outperforming the mandates.
In fact, by the time Vermont legislators had settled on the state’s RPS, the Burlington Electric Department—the state’s second largest utility, with approximately 42,000 customers —had already hit its own 100 percent renewables goal. Then, just this April, Mary Powell, CEO of the state’s largest utility, Green Mountain Power (GMP), committed her company to 100 percent carbon-free generation by 2025 and 100 percent renewable generation by 2030. GMP’s 265,000 customers represent approximately 75 percent of the state’s total. And carbon-free sources now represent about 73 percent of the current portfolio of the Vermont Electric Co-op (VEC), which serves approximately 32,000 members.
Like every state, Vermont has unique advantages and disadvantages in its effort to reduce and eventually eliminate its dependence on fossil fuels for electricity generation. Its biggest advantage is its own hydropower resources and its transmission links to Canada’s even more significant hydropower supplies. So, in 2018, hydropower was anticipated to support 60 percent of GMP’s power sales and 36 percent of Burlington Electric’s sales. Additionally, in 2018, nuclear made up about 27 percent of GMP’s power supply, which, when combined with hydro and other renewable sources, enables the company to claim its current supply is 90 percent carbon-free.
Another big advantage for Vermont utilities is the state’s vast biomass resources—specifically, trees. Burlington meets its 100 percent renewables goal thanks to its 50-megawatt (MW) McNeil Generating Station, which supplies 36 percent of the utility’s electricity. Wood chips used as fuel for the plant are largely sourced within 60 miles of the plant as a byproduct of an active timber industry.
However, categorizing biomass as renewable is controversial for many environmentalists, some of whom also point to considerable carbon emissions in such plants’ operation. Proponents, however, contend that, at least in the McNeil station case, biomass creates a carbon-neutral virtuous circle of sorts, with carbon emissions taken up by the next generation of trees planted to replace those that have been harvested.
In terms of disadvantages, Vermont faces a bit of a transmission bottleneck, especially in the north of the state, where wind resources are high and property costs are low. VEC is the primary utility in the area known as the Northeast Kingdom, and its transmission system has already been strained with the addition of the 63 MW Kingdom Community wind farm. This facility periodically curtails operations because the transmission infrastructure required to ship that power out of the region is simply too small for the job. Both wind and solar projects have been rejected in the last several years as a result.
In part to address such issues with new energy supplies, Vermont utilities, especially GMP, have jumped into battery-based energy storage in a big way. GMP is now ranked eighth in the nation in terms of total installed battery capacity, according to the Smart Electric Power Alliance. In addition to pairing several recent solar projects with on-site batteries, GMP also has a residential storage incentive program.
Customers participating in the plan get credits against their bills based on the storage capacity they make available to the utility during peak demand periods, when emissions-heavy, oil-burning peaking plants would otherwise have to be fired up. In addition to environmental benefits, this approach also has a financial upside. The utility says that being able to call on customer-sited storage during peak periods in July 2018 saved customers $500,000 over what operating the peaking plants would have cost.