Transitioning to Renewable Power: An Expert Describes What it Might “Look Like”

By Guy Page

How many in-state, renewable power plants would it take to generate five percent of all energy used in the state?

This isn’t just an academic question for energy policy wonks. The State of Vermont has hitched its wagon to the star of 90 percent renewable power by 2050, and is pulling mighty hard to build more wind turbines, solar farms, and other renewable power generators. And some Vermonters are pushing back just as hard.

There’s no lack of spirited debate, but sometimes it’s hard to find good, solid facts. On February 7, the State of Vermont’s Director of Energy Policy and Planning, Dr. Asa Hopkins, performed an important and very informative public service as he addressed the Vermont Energy Generation Siting Policy Commission at a public hearing in Montpelier. Using “just the facts, ma’am” tone and detail, Dr. Hopkins described what a five percent increase in Vermont- generated renewable electric power would look like.

Hopkins emphasized that there’s nothing magic about five percent. It’s just one intermediate step from the 23 percent renewable energy level of 2010 to the 90 percent goal of 2050. He also clarified that electricity is a third of Vermont’s total energy sector. Heating and transportation, both more heavily dependent on fossil fuels, account for the other two-thirds. The state energy analyst described several possible paths to increasing total energy by five percent solely through instate renewable power generation:

  • Using large wind only, the state would need to generate 288 megawatts (MW), equal to 96 three- megawatt turbines. That is 4.6 times the capacity of the Kingdom Community Wind project.
  • Using solar only, the state would need to generate 576 MW (5.4 square miles – half the size of Burlington or 1.3 times the size of Barre City), equal to 262 2.2 MW solar generators – the maximum size allowed under the state’s “standard offer” subsidized power program. Hopkins himself liked it to placing slightly more than one 2.2 MW solar plant in every town, city, and gore in Vermont.
  • Using small hydro only, the state would need to generate 173 MW, almost twice the estimated capacity available from powering 300 of the 1200 existing dams. Hopkins noted that the federal permitting process for small hydro can be lengthy and complex.
  • Using biomass (woodchips) only, the state would need to generate 139 MW, which would require an additional 1.1 million tons of fuel per year. At present, Vermont now uses 1.5 million tons/year total.

Dr. Hopkins noted that the expected reduced demand through conservation will cancel out the projected annual growth in demand for electricity. There is a notable exception: when demand for electricity rises by one-third due to the transition to plug-in electric vehicles. Energy conservation can’t keep up with a power demand spike of that size. At that point, Vermont ‘s power supply would need a real boost.

Vermonters know, more than we knew several years ago, the challenges that wind and solar projects present. We are developing opinions of a future of renewable power, based on our actual experience. Dr. Hopkins’ scenarios may help some of us inform those opinions. Knowing what we know, do we want five more Lowell Mountain wind projects, or solar farms everywhere, or hundreds more small dams, or heavier harvesting of woodlands in and around Vermont? Or an energy buffet of smaller servings of “all of the above?” For others, the answer might be “none of the above.”

Two years ago there was just a single ridgeline wind facility, now there are four. Solar power production on rooftop homes, on large buildings, and in pastures are on the rise. Plug-in car registrations grew 57% in 2012, but only to 188 in total.

Can we build (and afford) enough renewable power? If we can, do we want to? These are questions that Vermonters will continue to debate. But with the help of Dr. Hopkins’ illustrations, at least we can better understand what the finished work might look like.

One thought on “Transitioning to Renewable Power: An Expert Describes What it Might “Look Like”

  1. I don’t see in Guy Page’s article where Dr. Hopkins accounts for the base load necessary to support the intermitent wind and solar. Always and forever in some “cloud”? Also, how do the numbers change with the loss of uability from off peak generation?

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