In 2007, Williams set a goal of reducing greenhouse gas emissions to 10% below 1990 levels by 2020. Each year since 2007 we have decreased our emissions through conservation and burning cleaner fossil fuels at our central heating plant. As of fiscal year 2010, Williams is over 60% of the way to our emissions goal.
These emissions were approximately 21,000 metric tonnes eCO2 in 1990/91. They increased to approximately 31,000 metric tonnes in FY05 due to added buildings and increased energy use in existing buildings. Concerted efforts to reduce energy consumption and emissions starting in FY07 have lowered annual emissions to 23,136 tonnes in FY10.
Our central heating plant is designed to burn either residual oil (#6) or natural gas. In the past residual oil has been less expensive and supplied most of our winter heat. Natural gas emits about 35% less greenhouse gas per heating unit than residual oil, and in light of our emissions goals, Williams has made the choice to primarily burn it. In FY10, 96% of heating fuel used was natural gas, compared to 43% in FY07.
Conservation has also played an important role in decreasing greenhouse gas emissions. Total campus energy use has decreased 13% from the peak in FY05. Since 2007, Williams has invested over a million dollars in installing energy efficient lighting, occupancy sensors, variable frequency drives and efficient motors and fans. These projects have taken place in buildings across campus, but special attention has been given to Morley Science Labs. MSL is the single largest user of electricity on campus (accounting for over 10% annually), and likely consumes a similar proportion of campus heating energy.
In addition to installing energy efficient equipment, Williams has also asked members of the college community to participate in energy savings. During the past two Winter Breaks, we closed the campus and shut down buildings as much as possible. We encouraged students, faculty and staff to turn off and unplug all lights, refrigerators, printers, computers, etc. before leaving. Building temperatures were turned down significantly. Williams saved an estimated 528 tonnes of emissions in the 10 days of the 2009/2010 shutdown.
While the progress so far has been very encouraging, many challenges remain. The first round of energy conservation projects represent the “low-hanging fruit” Additional projects are being identified that may be more challenging to implement or produce savings at a lower rate. These projects will require continued commitment to resources (both capital and personnel) to accomplish them.
The increased proportion of natural gas used at the heating plant represents a large portion of the decrease in emissions. Similar (or lower) levels of emissions from the heating plant (whether through burning of natural gas or some other relatively clean fuel) are necessary in future years if Williams is to meet its goal, and it may be difficult at times to balance emissions with economic concerns.
Only a small portion of Williams’ total energy (<1%) comes from renewable sources. One or more large-scale renewable energy projects will likely be necessary to reach the emissions goal. As we approach that goal, established in FY07, Williams may wish to consider whether deeper emissions reductions are warranted.