Yestermorrow Design/Build School in Waitsfield, Vermont offers over 80 hands-on courses per year in design, construction, woodworking, and architectural craft and offers a variety of courses concentrating in sustainable design. Now in its 35th year, Yestermorrow is one of the only design/build schools in the country, teaching both design and construction skills. Our hands-on 1-day to 3-week workshops, certificate programs and semester programs are taught by top architects, builders, and craftspeople from across the country. For people of all ages and experience levels, from novice to professional.

Thursday, May 05, 2011

A Solar Story

Late last April, here at Yestermorrow we took a huge step towards our goal of producing renewable energy on campus with the installation of a 28kW photovoltaic array. It wasn’t just a token demonstration project, this was a statement—seven tracking units each measuring 22 feet wide and 17 feet tall right out in front of our main building on Route 100. One year later, we were curious to see how the performance of the PVs matched up with our projections. The AllSun Trackers which we used on the project are designed to change their angle and their orientation throughout the day so they are always directly facing the sun. This means they produce up to 40% more energy than a fixed panel. Each of our trackers is projected to produce 5,640 kilowatt hours per year. Multiply that times seven units, and our anticipated production is 39,480 kWh per year.

The next question inevitably is… “so, how much did they really produce??”. Between April 20, 2010 when the trackers went online, and April 20, 2011 they pumped out 37,367 kWh – pretty close to our original projections! (You can check out the production day by day on the AER website at:

This is enough electricity to supply 74% of the demand for our main building (just over 50,000 kWh last year).

So what’s next? This year we’re hoping for more sunny days :) but we’re also looking hard at what we can do to reduce our electricity loads—remember, conservation always comes before efficiency and renewables. We’re working with folks from Efficiency Vermont and the Mad River Valley Localvolts to install a TED energy monitor so we can track our consumption patterns more closely and identify trends over time. We’re also using a Kill-a-watt meter to identify energy-sucking appliances and tools so we can plan future upgrades. And thanks to great state incentives, we’re also testing out some new LED light bulbs around different parts of the campus and looking into occupancy and daylighting sensors.

Learn more about Yestermorrow's eco footprint...


  1. I love the fact you can track and share the impact you're making using the AER website.

    If you don't mind answering, what is your projected return on the investment? I would love to get solar panels for my house here in Las Vegas, but it would take at least 10 years for the ROI. I was wondering if it is about the same time for your project.

  2. Hi Chris,
    One of the innovative things about the AER All Sun Trackers is that they offer a Power Purchase Agreement, whereby we put down a $1000 deposit, then promise to purchase all the power produced by the trackers on our property at market rate. They get all the state and federal tax credits and carbon credits because they own the panels. This is a 5 year contract and at the end of 5 years we can either purchase the trackers at a depreciated price, or sign another 5 year contract adjusted to the current market rate for electricity.
    So basically the up front investment on our part was practically nothing, and the expense is the same as what we would be paying anyway to the electric utility.

  3. Have you found the Kill-a-Watt to be easier than the TED thing? One looks easier on the site but I can't tell whether it is worth it to spend more.

  4. The Kill-a-Watt serves a different function than the TED monitor. The KaW is used for an individual appliance or unit if you want to see how much juice it uses over time (for example, you might plug in an older fridge to see how many kWh it uses in a week). You can move the KaW around to look at different electricity loads.
    The TED monitor looks at all the energy used in your building (or in our case, part of our building, since it goes by breaker panel). Instead of just getting a monthly bill from the electric company with the total kWh you are able to track your energy use minute by minute over a long period of time. FYI, this is the same functionality as the new "smart meters" which are starting to be rolled out across the country, which might make the TED monitors unnecessary.

  5. Sounds like the TED5000 isn't worth the extra $200 since it is not for a commercial use. Although after a little looking I think I'd rather get the Kill-a-watt EZ instead of the original kill-a-watt. Being able to add in my cost/kwH is worth the extra couple bucks.

    Thanks for your help Kate!

  6. To Chris Kerschner: Chris, let me ask you what your ROI is with your current utility company?
    When you choose to go solar, you not only at least HAVE a ROI, but you get to a place when you do not have a utility bill and very possibly income from the energy you produce. You can get this immediately when your energy consciousness grows as it will, when you go solar - no matter how savvy you are now. Some of us get carried away with it, as i have done and ended up purchasing 3x as many panels as i currently need because my awareness grew so much. I live 100% solar powered off-grid (wish i could share it back to the grid) and i cannot possibly use all the energy i make. I am so conscious now that i don't seem to be able to be wasteful. Just think about the state of the planet if 50% of the people did likewise! Even 30%! Think our carbon emissions would go down quickly? I highly recommend that you consider taking the step to move into solar. you will not regret doing so... The prices of solar panels are the lowest they have ever been, interest rates are super low & the price of everything else is the highest it has ever been...

  7. Kill-a-watt meters are available for borrowing at many libraries now-a-days.