LED Lighting Saves Kilowatt Hours Every Day

Last winter Yestermorrow partnered with Efficiency Vermont's RELIGHT program to undertake a comprehensive lighting audit of our facilities and we are now finally seeing the results in our electric savings. We worked with lighting designer Donna Leban to inventory all the lighting fixtures in our main building, both inside and out, to determine what fixtures, lamps (bulbs) and controls would help to save on our electric bill. Initially, I wasn't sure that there would be much potential for savings, given that we already were using florescent fixtures exclusively and the building is in use pretty much 24-7. However, we did suspect that the lights in our woodshop were on nearly all the time and were using a lot of electricity, and we knew that there was room to improve the quality of outdoor lighting (most student visitors know it gets pretty dark here at night!). After going through the building with Donna, we identified four different potential outcomes for each fixture: 

1) Replace fixture with new LED fixture

2) Re-lamp (replace with screw in LED bulb)

3) Add controls (motion sensor or daylight sensor)

4) Leave as-is (this was recommended in low usage areas and/or places where the existing T-8 florescent tubes already had good manual controls)

At the end of the day we ended up with 47 new fixtures (mainly in the dorm area), 89 new bulbs (half LEDs and half reduced-wattage T8s), and 9 photo sensors and occupancy sensors, installed by our friends at Middlesex Electric. In addition, the light quality in the dormitory and woodshop has dramatically increased.

According to the team at Efficiency Vermont, we can expect to save over 10,000 kWh annually. in 2014 our total electricity consumption was 53,599 kWh so we can expect to save about 19% of our annual bill, and reduce the amount we have to purchase from the grid by about half (we currently produce 64% of our electricity on campus with our photovoltaic trackers), saving about $1,400/year. After factoring in the incentive provided by Efficiency Vermont, we expect about a 6 year payback on this investment.

Looking back on our bills for August and September, compared to the previous year, we saw a 17% drop in electricity use in August, and a 9% drop in September. It will be interesting to keep tracking the savings over the coming years as part of our environmental footprint analysis. Next up: installing LEDs in our outdoor workspace tents.