Tuesday, May 14, 2013

The 90% Solution: What 90% Renewables Would Look Like in Vermont

What going to 90% renewable energy would do to Vermont’s landscape

In 2011, the Vermont Department of Public Service published a Comprehensive Energy Plan (CEP) for Vermont’s future. The CEP states that Vermont will get 90% of all its energy, including the energy we use to drive our cars and heat our homes, from renewables by 2050.  There’s another section titled “25 by 25”, meaning that Vermont should get 25% of its energy from renewables by 2025.  There are no concrete directions or roadmaps for accomplishing either of these goals.

In a hearing before the newly formed Energy Siting Board, one woman stated that the CEP was a collection of slogans, not a plan.  She was correct. Nevertheless, it does represent the goals Montpelier has made for our state, they are acting on it, and we have to take it seriously. I am attempting to see how we could possibly meet these goals, and to answer the question what does moving to 90% renewable energy – or trying to – really mean? In particular, what impact would it have on our natural environment and signature Vermont landscape?

Here’s the reality: If we are going to build enough renewables to generate 90% of our energy needs, we will have to devote much of our state land resources to the cause of energy production.

Renault ZE  electric car
Consider that to “get away from fossil fuels” we will have to convert to mostly electric vehicles and electric heat-pump heated homes. How much more electricity will we need?  Right now, Vermont uses 6000 GWh of electricity per year.  For the “renewable” future, my preliminary estimate is that we we will need at least three times this much, or 18,000 GWh. In an op-ed in the Valley News, Charles McKenna, a Sierra Club member and retired engineer, estimated Vermont would require 15,000 GWh. (He was making the case for building renewables quickly.) In short we’re looking at a lot more electricity generation. What are the renewable options for obtaining this power?

Let’s take wind turbines. Most people are immediately struck by how big the things are. A 3 MW wind turbine has blades that sweep the entire area of a football field.  The Vestas at Kingdom Community Wind (Lowell Mountain) have blades that sweep 112 meters  (367 feet). Why so big?  Because wind is not energy-dense.  Think about it: a windy day can blow some trash around, but the wind usually can’t lift even a tiny dog and blow it around.  If you want to make electricity with wind — enough electricity to make it worth the trouble to put in a transmission line — you have to capture a lot of wind. So, you build turbines that sweep more than the area of a football field.

Solar and Wind at Lempster NH
To make 18,000 GWh of electricity, my rough estimate (I’ll have more detailed numbers ready for publication later this spring) is that Vermont would need to build 140 wind farms with the approximate output of Lowell Mountain’s 21-turbine facility. According to the National Renewable Energy Laboratory web site and other comparisons, 21 turbines of this size would usually cover 5 miles of ridgeline.  These 140 wind farms would use 2,240 industrial turbines over 700 miles of ridgeline. Lowell claims to use only 3 miles of ridge line: in this case, ”only” 420 miles of ridgeline would be required for the turbines. However, not all ridges have wind as good as Lowell, so more turbines would probably be needed. Keep in mind, the entire state of Vermont is 158 miles long and 90 miles across at its widest.

If we do move to a 90% renewable energy portfolio, much of Vermont’s high country would need to be sacrificed to meet the CEP’s goals. Still, that wouldn’t cover the electricity we would need, because sometimes the wind doesn’t blow.

Logs at Springfield NH
biomass plant
What about solar? A 2.2 MW solar facility was recently installed in White River Junction. An area of 15 acres was cleared for this facility. Do to our northern locations and frequent cloud cover, this can be expected to generate only 2,755 MWh or 2.8 GWh per year. Making 18,000 GWh per year with solar would require 6,700 such facilities or 100,000 acres of solar installations. They would cover an area approximately one-fourth the size of the Green Mountain Forest. And, of course, they would not provide any power when the sun isn’t shining.

Biomass? It is difficult to calculate the wood required by biomass plants. Using information from the McNeil and Ryegate biomass plants gives different results from calculations based on wood heat content and power plant efficiencies. Basically, making 18,000 GWh with wood biomass will require between 8 and 14 million cords per year. In contrast, the current wood harvest from Vermont is about 1 million cords per year.
At the Springfield plant

How much forestland does, say, 12 million cords represent?  Estimates of a sustainable wood harvest vary from 0.5 to 2 cords per year per acre. Assuming one cord per acre, we would need 12 million acres to be devoted to wood for the biomass power plants. The total area of the state of Vermont is 5.9 million acres, of which 4.6 million is forested.

Any (or any combination) of the above mentioned options necessary to meet a 90% renewable policy would have a tremendous impact on the look and feel of Vermont for generations to come. Tourism plays a very important role in the economy of this state, and a pristine and rural landscape is an important part of the Vermont brand. We really have to decide if “90%” is worth its tremendous cost to our environment. (And to our pocketbooks. Electricity made from renewables costs two to ten times as much as standard “grid” electricity. We can expect Vermont’s electricity prices to double or triple, if the CEP is actually put into effect.)

People who are against large-scale renewable energy development are often ridiculed as NIMBYs.  However, they may simply be aware that achieving renewable-energy goals will have huge effects on Vermont’s landscape and ecosystem, and they don’t want that to happen.  In other words, people opposed to renewable developments are often true environmentalists. It is time to reject the impossible goals of the CEP, and implement only the renewables that are reasonable and cost-effective for the citizens of our state.


This is a preliminary version of the Vermont Land Use report that George and I are writing for the Ethan Allen Institute.  This post first appeared on the Ethan Allen Institute site.


jimwg said...

It's insane. All this panic-rush for "renewables" and razing the environment to get your juice when you already have a clean low-profile plant already faithfully chugging along. Fear is one blind implacable steamroller over reason. and fact, that's for sure!

James Greenidge
Queens NY

Bill said...

18,000 GWh is 2.05 GW-years. By coincidence, this is just about the output of two AP1000s, allowing for downtime. Of course the footprint of such a nuclear plant would be a modest multiple of the current plant.

The Lowell Mtn. wind farm is expecting to have a capacity factor of 33%, producing about 186 GW-h (=21.2 MW-yr). If so, a hundred copies would do.

Meredith Angwin said...


Thank you for your thoughtful note.

Green Mountain Power does indeed claim a 33% capacity factor for wind for Lowell, but it also says that the existing Searsburg facility has a capacity factor of 20-25%. Capacity factors claimed by developers and actual measured capacity factors after installation can be quite different. I used 0.29%, which is the average capacity factor for the U S fleet for the past six years, according to Willem Post's careful searching for actual capacity factors:
Post article

Here's Wind Action Group and capacity factor by state: WInd Action East Coast wind energy capacity factors average below 30%.

You might also see Hallquist's guest post on this blog, where he notes wind curtailment on the local grid. Hallquist is the CEO of Vermont Electric Cooperative, which has contracted for some of the power from Lowell Mountain.


Capacity factors for wind can be argued about endlessly, but I see no reason to accept Green Mountain Power's optimistic projections as given.

And yes, two nuclear plants would have much less impact! Thank you for that comment.