Now, thanks to Sustainability Committee (SusCo) co-head Jessica Hensel ’21 who spent the past year compiling concrete data on Hopkins emissions, some of these solutions will soon be a reality on The Hill.
In response to questions for this article on Hensel’s numbers, Hopkins Chief Operating and Financial Officer David Baxter announced in an email to The Razor on 25 February, that this summer, over 1,450 lighting fixtures in five buildings will be upgraded and retro- fitted to efficient LED lighting and the boiler in Baldwin Hall will be replaced with a more energy efficient one. Additionally, in January, the Board of Trustees approved undertaking an environmental and sustainability study for the campus which will likely kick off in late summer.
This is when Hensel realized the need to commit to a larger data collection project. “I wanted to get a better understanding of where we produce our emissions and what areas would be most effective to focus on to decrease emissions.” To aim for larger reductions, she said it was essential to first look at the numbers.
One of the largest sources of carbon emissions that stuck out to Hensel was the commute to Hopkins and transportation. Hensel said she observed that even in pre-Covid years, many students commuted by car rather than by bus. “Of course our geographic diversity as a school is fantastic, it makes Hopkins what it is, and I’ve always appreciated that, but it has its negatives when it comes to carbon emissions.”
Hensel began speaking with English teacher and SusCo Faculty Adviser Brad Ridky and Baxter, as well as other administrators in the Business Office about the transportation methods students take to get to school. Hopkins transportation involves a large amount of car travel, buses, trains, and even a few flights. These flights are for school trips, such as the Guatemala trip, or for alumni events.
Hensel was sent records for flights but as for daily transportation numbers, Hensel was on her own. “That was a lot harder,” she said. First, she had to find the routes for all the buses. To do so, Hensel spoke with member of the Community Safety team David DuBois, who walked her through all exits at which each bus stopped. She then used maps to route Hopkins to the exits and calculate the total mile count the buses covered.
Next, Hensel used four online calculators to get the conversion from each bus type to a CO2 emission for the distance covered. Her total calculated value for commuter bus emissions was 240,030 pounds of CO2 emission per year.
On March 3 last year, Hensel and her fellow SusCo Heads, Julia Kosinski ’21 and Kate Collier ’21, sent out a school-wide survey on how individuals commute to campus. Hensel explains that all SusCo Heads individually pushed for each advisor group to fill out the survey and received responses from one-third of the school.
Hensel grouped the data by grade level/faculty and calculated the proportion of those who commuted to school by car, bus, public transportation, and foot. She then used that proportion and the size of each grade level/faculty to calculate a school-wide estimation of how the Hopkins community travels to and from school.
According to the results, 10.9% of results were from faculty members, 16% seventh graders, 10.4% eighth graders, 20.6% ninth graders, 17.4% tenth graders, 16.4% eleventh graders, and 8.3% twelfth graders. See numbers pictured in graph “Transportation Distribution by Grade, 2020” (Graphic A) for more information on comparisons between each grade.
Hensel’s estimation shows that 67.6% of the Hopkins community commutes by car, 25.8% ride the bus, 5.4% walk, and 1.2% use a different mode of transportation, such as MetroNorth trains (Graphic B). According to the survey results and Hensel’s calculations, roughly 64% of the Hopkins community do not carpool and 36% drive with at least one other Hopkins student or faculty member.
In addition to off-campus Hopkins emissions, Hensel gathered data regarding on-campus school emissions. Hensel began by examining one of the major sources of on- campus emissions: natural gas consumption. The majority of Hopkins natural has usage comes from winter heating.
Natural Gas is a fossil energy source that contains methane, CO2, and water vapor. According to the US Energy Information Administration, 117 pounds of CO2 are emitted per million British thermal units (Btu) of energy. Maintenance sent Hensel the total natural gas consumption numbers for the school from 19 October, 2019 to 20 October, 2020 in CCFs. One CCF equals the volume of 100 cubic feet (cf) of natural gas. The conversion from CCF to Btu is 100 cubic feet (CCf) of natural gas equals 103,700 Btu. This means for every 1 CCF, or 103,700 Btu, 0.1037 pounds of CO2 are released.
“When comparing each building, it’s hard to come to amazing conclusions based on the data because each building uses energy differently” Hensel said. Heath and the Athletic Center are especially difficult to examine, leading to Hensel’s decision to identify these buildings as outliers. “Their use is so different from all the other buildings that it wouldn’t make sense to compare them since we don’t have a way to isolate how much natural gas goes towards heating the pool and kitchens versus the rest of the building.”
In order to determine how effective a heater is, you have to compare CCFs per square foot. She reported the square footage of the main buildings on campus, excluding the Athletic Center and Heath, are as follows, Baldwin/Calarco: 47,190; Thompson: 37,400; Malone: 24,680; Lovell: 14,560 (Graphic C).
Hensel found the CCF totals, excluding the Athletic Center and Heath, to be: Baldwin/Calarco: 23,184; Thompson: 11,502; Malone: 12,392; Lovell: 5,782 (Graphic D).
“If you look at CCFs per building, you see that Baldwin is extremely high compared to other buildings. And if you look at the size of Baldwin, it’s the highest, but it’s not that much higher than Thompson” Hensel said. The reason for this disparity is that Thompson is a much newer building and has
a more efficient heating system.
Hensel measured how much emissions could be reduced if the CCFs per square footage of Thompson were applied to Baldwin. Based on her numbers, Hensel calculated 8,671 CCFs per year would be saved.
“Even if you got the same heater that Thompson has and installed it in Baldwin, it might not get the exact mathematical outcome, but it should come pretty close, or even better, because the technology now is even better than when we built Thompson” Hensel noted.
Baxter announced Hopkins will in fact be replacing the Baldwin boiler this summer. The boiler which is 25 years old also services the Calarco Library. According to Baxter, the new boiler is approximately 15% more energy efficient than the current one. “So we expect to see a meaningful reduction in natural gas consumption needed to heat Baldwin and Calarco Library,” said Baxter.
Hopkins now also plans to upgrade 1,457 light fixtures in Baldwin, the Calarco Library, Heath Commons, Lovell Hall, and the Malone Science Center to more efficient LED (light-emitting diode) lighting. Currently these buildings use fluorescent, compact fluorescent, incandescent, or, in Malone, high pressure sodium lighting.
He said these upgrades are expected to reduce annual energy consumption by over 240,000kWh. This would be an approximately 11% reduction in campus-wide electricity consumption for all purposes.
Baxter also highlighted the upcoming Trustee-approved environmental and sustainability study for the campus which could collect more information on emissions and solutions. “We are likely to kick this off in the late summer and hope to include the Sustainability Committee and other student voices in the process in the fall. I am excited about the prospect and grateful to the Trustees for the green light.”
Aside from a new heating system for Baldwin, Hensel said SusCo’s main solution to reduce carbon emissions should be to install solar panels. “Going solar would be better than an offset because it’s a permanent solution, versus offsetting, which is temporary and must be done each year.”
As covered in a previous Razor article, “The Past, Present, and Future of Sustainability at Hopkins,” by Aaron Gruen, Baxter commented on the issues involved with installing solar panels on campus, “Hopkins has investigated solar over the years. A number of solar companies, consultants, and salespeople have reached out to Hopkins. I have met with several of them and this topic has been reviewed at the Trustees Building & Grounds Committee. In each case, the analysis focuses on the Athletic Center (built in 1985) and secondarily Lovell (build in 1959). These two buildings make the most sense as they are large expanses of membrane roofs. In each conversation, I have been told that the economics require that a 20-25 year easement be granted to the solar company. That is, these panels would need to be in place and the building largely unaltered for the entire period. Unfortunately, the two primary candidates for solar are also the two buildings in the Master Plan slated for significant renovation and expansion. As such, Hopkins simply cannot contractually commit now that those roofs will be unaltered for 20-25 years. The exact timing of these renovations is tied to fundraising.”
Thus, Hensel believes SusCo’s third best solution to combat CO2 emissions, after solar panels and replacing Baldwin’s heating system, is for the school to pledge to offset transportation-based carbon emissions. “We targeted carbon offsets because Hopkins doesn’t think we are in a place to in- stall solar panels and we felt that offsetting was the next best solution that fit with the administration’s priorities.” An offset solution would entail that Hopkins tracks our school’s annual CO2 emission due to transportation and purchases an offset for this amount of CO2.
According to Hensel, using the transportation numbers above, offsetting these emission sources would amount to roughly ~$8,250 for cars (1,649,924 CO2), ~$1,200 for buses (240,030 CO2), and ~$950 for flights (189,437 CO2) for the 2020 school year.
A potential fourth solution, Hensel explains, would be to purchase 100% renewable energy through green energy supplements through Hopkins’ energy provider, United Illuminating. She said Ridky calculated that this would cost Hopkins approximately $16,000 per year.
Finally, Hensel suggested a Renewable Energy Certificate as a fifth possible solution. A Renewable Energy Certificate is an offset of the nonrenewable portion of our energy, replaced with renewable energy. Hensel estimates this would cost Hopkins roughly $11,500 per year.
Hensel also researched the sustainability efforts of other private schools in Connecticut. Greens Farms Academy has a 2.28 kW solar panel installation and is planning to build another solar array on the gym roof. King School, in 2014, established a plan to reduce energy by 50% over 5 years and gives preferential parking and car-sharing programs for carpools. Finally, Greenwich Academy has installed 27.6kW of Solar panels.
Hensel adds, “We as a school have a greater responsibility to be sustainable due to our large number of commuters that come from far distances and our community’s resources. We have already implemented a lot of fixes to increase energy efficiency... But in the future as more solutions come out, it will be the most impactful to adopt large-scale, permanent changes, versus doing the easy fix every couple years.”