E is for Energy

Maybe you've heard about the energy chatter in Vermont's Mad River Valley. Or maybe not.

There isn't really a quick way to explain it. If I had to, I might start with localvores and the idea of "localizing" food production, then draw a parallel to the idea of doing the same thing with how we create the energy we use every day.

But I might also start with oil ... the fuel that drives our cars and heats our homes in New England, the one that underwrites ongoing shipments of Vermont soldiers to the middle east, the one that also spewed and destroyed the Gulf of Mexico last spring, and the one that can send an entire nation into full freakout mode when the price starts creeping up at the pump.

An important layer to add is the looming spectre of a nearby nuclear plant. But the ghoulish fright factor of Vermont Yankee isn't just the leaks and the obfuscated reporting and a historical lack of transparency: it's the hole in output that would result from a closed nuke plant. Turns out it's a big one.

And to put the frosting on the top, you've got your locals. A big batch of which work for local-ish renewable companies (Northern Power, NRG systems, AllEarth Renewables, Alteris), and another big batch of which are either pining for Howard Dean to run for president, or counting the days till Vermont secedes from the union and becomes a haven for dirt roads and legal weed. Around here, they like their tea green and put Hakkepalitas on their biodiesel jettas. And when renewable-friendly Obama won the nomination, they gathered at the local movie theater to watch the Daily Show cover the historic occasion.

It's a community that looks quite green on paper. But when it comes to local energy production, things are actually a bit more grey.

Three big events from the last six months have underlined the color change with a huge black Sharpie. One was the proposal to put an industrial wind farm on the valley's pristine eastern border. The second was the subisidy-fueled arrival of a few dozen "solar trackers" -- home-sized solar units that look sort of like the love child of a satellite dish and a drive-in theater movie screen -- along well traveled scenic routes. And the third was the town's realization that they had almost zero control over either (a handful of folks on the state's Public Service Board make those final decisions).

In the wake of those developments, things have got noisy around here. And organized. And occasionally somewhat pissy.

For the three of you who'll actually read this whole post, I think you'll agree with me on this: regardless of what side you're on in the renewable debate, emotion has been the main winner.

In other words, it's easy to find the line between those who love local renewable energy production and those who hate it. But it's hard to find somebody -- on either side -- who's arguing their point with actual information.

You might imagine how the lights went off in my head when I had the good fortune to not space out about last month's Planning Commission meeting. This was the one that featured a couple designers from the Vermont Energy Atlas, presenting the website and its snapshot of possible renewable energy output for each home and property in the state. And oh, it's got maps ... for solar, wind, hydro, geothermal, biomass and efficiency. It's also got graphs that can chart your home's solar potential, for example, against the average in the rest of the state. And it's got sliding scales that can help you figure out how long it'll take to pay off a home-based system, based on how much you're paying for electricity right now.

The more I watched the team poke around the Atlas, the more I realized that on a personal scale, it's tough to imagine a better tool for right here, right now. And what the Atlas didn't provide ... fortunately, the Atlas team brought that as well: a working draft equation for the total energy required to provide 100% of Waitsfield's electricity and transportation needs (heating oil wasn't included, alas). And according to this calculation -- which was more about the concept than promoting one energy type over another -- it would take solar panels on 211 acres of land to provide 100% of these energy needs in an ongoing, sustainable manner. (Note: solar was chosen "randomly" for this calculation. It just as easily could be wind or another renewable energy source).

It's a rough equation. But it's a start. And from this vantage point, a more educated, less emotional conversation can get moving about how much we're using in energy right now, and how much we feel is the right amount to offset in the future. Maybe we start with a very basic percentage like 10% and grow from there. Or maybe we get more aggressive right out of the gate.

But either way, it's progress.

Ok.... here are the stats if you can't read them in the slide.


* Population = 1,678

* ~12,500 miles/capita/year
(Source: Waitsfield Town Plan)

* 500 gallons/capita/year (@25mpg)

* 1 US gallon Gas = 114,000 BTU/gal
(Source: Wikipedia)

* 3,412 BTU’s/kWh
(Source: Wikipedia)

* 4.3kWh/day in VT meaning a 1kW solar array
(Source – National Solar Radiation Database, e.g., 5 – 200W panels, 4 – 250W panels etc.) will produce on average 4.3kWh/Day of power, amortized throughout the year with length of day, average weather conditions (snow, rain, cloudy days etc.)

Total transportation fuel?
1678 people * 500g/person/year = 839,000 gallons

Total kWh Equivalent
(839,000g * 114,000btu)/3412btu/kWh = 28,032,239 kWh (28,032 Mwh/year)

OFFSET SCENARIO 1: Ground Mounted Solar Offset (100%):

1 Mw array requires ~ 6 acres of land producing 1 Mw x 4.3h/day x 365 days/yr x 0.8 Derate Factor = 1,250 Mwh/yr:
(Source: Acres/1Mw array of RACK MOUNTED SOLAR (Not Trackers) from Alteris Renewables 200kW array in Berlin, VT on 1.2 acres & 1.2Mw array being built in Ferrisburg, VT on 7 acres; “Derate Factor” see NREL PVWatts Help - http://rredc.nrel.gov/solar/calculators/PVWATTS/derate.cgi for general discussion, I ended up using a value of .8 vs. .77 based on feedback from VT solar professionals, e.g., AllEarth Renewables, Alteris etc.)

For Transportation Fuels, 100% liquid fuel offset:
(28,032 Mwh/1,250 Mwh/yr) * 6 acres/Mw = 134 acres

For Electric Consumption (2008), 100% electric consumption offset:
(16,038 Mwh/1,250 Mwh/yr) * 6 acres/Mw = 77 acres

Total Offset for Electric & Transportation - Rough Estimate = 211 acres


  1. Great post Drew! Agreed a constructive conversation starts with a number like this. Glad to see to see it started. It would be good to understand how far into the 211 we are so far and keep tracking it. What are we at so far, maybe 10-20 acres out of 211? A few folks and I started a study of the energy consumption in the Mad River Valley about a year ago (see mrvenergy.org), but that was a bottom up process. I really like how these state averages short cut that whole process to get you to the 211 number. One other thing to consider: Instead of figuring out how to get to 211 acres of solar farm going, we could also consider trying to lower the number acres devoted to renewable energy generation through energy efficiency (e.g. more insulation, higher MPG) and energy conservation (e.g. drive less, turn down the thermometer). In any case, I love the number. There should be a big ass thermometer sign in the middle of town showing everyone how we are doing against this number until we lick this one.

    Thanks again,

  2. Jesse Stowell11:32 PM

    Great read. Only thing "missing" is our heating energy. (e.g. For my house 700 gal propane = 18737 kWh per year which over 3X our eletrical usage) I've always thought that the abstration created by different energy units when used for electricity (kWh), heat (BTU's, gallons of differnt fuels) , and transport (gallons) decrease our energy awareness and frugality.
    On that vein I would lobby for our "big ass thermometer" (YES!) to be measured in kWh per year. Different colors for the different types of energy usage (elec, heat, transport) Measuring in PV acres doesn't reflect the mix of efficiency and different renewables that can address the displacement goal.
    Wouldn't it be powerful to start a Valley Wide awareness movement about total energy footprint!?!? Bonus: Big users (Sugarbush) would have to step-up and show some progress in energy reduction. Could the MRV energy wiki support folks creating an account that logged their electrical and heating fuel usage and milage? Maybe GMP could automatically upload our usage if we gave permission. This would be on a volunteer basis of course...

    PS - 1 kW of ground mount solar probably doesn't produce 1250 kWh/yr. (A 3 kW solar tracker produces about 4200kWh. or 1400kWh/kW) 1 kW of ground mount PV in Vermont produces more like 1000kWh / year.