In July of 2000, the Lake Source Cooling (LSC) Project was officially launched, becoming the United State’s first ever major deep water cooling system. Initiated by Cornell University, the project has successfully cooled down Cornell’s campus (as well as that of IHS!) for 20 years. It saves over 20 million kWh per year by using the depths of Lake Cayuga and has revolutionized the campus’s energy budget—reducing it by about 85 percent. LSC uses the chilled lake water for refrigerators, air conditioners, and biological incubators. Despite having relatively high name recognition with most Ithacans, the details of the project are lesser known and often misunderstood.
As can be seen from the drawing below, taken from the Cornell University website, the project functions on two loops: the open lake-water loop and the closed campus loop. In the former, lake water is taken from Lake Cayuga at 250 ft depth. In the closed campus loop, the cool water is pushed up the hill towards campus by the warm water going in the opposite direction as well as larger pipes so that there is less friction. In short, the water from the depths of Cayuga is brought up to the open lake water loop to the Water utility center, and from there pushed up to the campus by the closed campus loop.
At the time of the project’s initiation back in the late 1990s, public opinion towards the project was generally negative. Despite praise from environmentalists around the world, throughout the late nineties and until it was installed, there were consistent protests attempting to stop the project. Looking back though, the criticism was largely due to the lack of information and spread of misinformation about the new, expensive and transformative system. Many of the arguments raised concerns about the potential rise of phosphorus and nitrogen levels in the lake. The other misconception was that the warmer water returning to Cayuga would increase South Cayuga’s algae blooms and less-than-desirable swimming conditions. When, in fact, these conditions are mainly due to the number of rivers entering that part of the lake and climate change.
The southern part of the lake is also much shallower, and therefore more prominently displays the symptoms that the majority of the lake is experiencing. Phosphorus and nitrogen levels have increased and the prevalence of algal blooms has skyrocketed, but their causes are world-wide climate change and an assortment of reasons that have nothing to do with LSC.
The LSC project does extract phosphorus from the upper parts of the lake and brings the phosphorus down to the lower part of the lake when it returns—but the real issue is the source of the phosphorus, not that LSC is moving it. LSC isn’t pulling more phosphorus out of the bottom or causing more phosphorus to be released, but instead recycling what is already in the lake. The teams at Cornell stressed that the amount of phosphorus LSC is putting into the lake is the smallest fraction of a percent of the amounts that are shown coming from other factors and makes an almost nonexistent impact on warming lake temperatures. And
the benefits seem to dwarf the drawbacks: it saves huge amounts of energy and rids Cornell of former cooling systems that released huge amounts of the greenhouse gas carbon dioxide.
In 2021, analytics and new data from the past 20 years have shown that the problems that were once feared by activists have proven to be either nonexistent or on much smaller scales than previously thought or represented. Yet, in those 20 years, there has been no real systematic assessment of the current performance of LSC compared to the original plans, and outgoing public information has been slim. But this semester, a team of Cornell students are looking back on the 20 years’ worth of data and analyzing the real impacts from LSC.
Twenty years after LSC’s start, Cornell Professor Peter McIntyre launched an analysis of the project as a Cornell capstone class, a project-oriented, team-based class focused, in this case, on LSC. The class of majority Environmental Science majors has been split into groups, each focusing on a different side of LSC’s impact, such as greenhouse gases/energy budget, lake ecological impacts, economic return on investment, and community engagement. After speaking to the project’s founders in depth and analyzing data from the past 20 years, the students will be publishing their findings on the Cornell website for the public, to document the impact the massive project has made.
But the LSC has helped more than just Cornell. Back in the 1990s when Cornell was first drafting out their plans for the massive project, engineers were figuring out where to position the pipes and coincidentally, they ran into IHS. Quite literally. The route they had planned to take was down Gun Hill, along Lake Street and through Ithaca City Schools Property. Cornell couldn’t just venture into ICSD property without permission, and so the two institutions made a deal to let Ithaca High School in on one of the main benefits of LSC: air conditioning.
Now this might come as a surprise to IHS readers; as anyone who has spent more than a year in that building knows that the one thing most students can bond over is suffering through wild temperature fluctuations in the G-Wing. But there actually is air conditioning in the high school. When you go to the cafeteria, the library and the district offices (school board and Superintendent offices etc.) the temperature is controlled by LSC. The original deal was for the entire high school to be cooled, but this quickly proved too expensive and now the luxury is limited to just a few of the more important buildings. In fact, if you look around the back of the building near F and K, you will find a small brick building sitting by itself; this is where IHS connects to LSC. Although controversial in its inception, LSC has proven to be a boon for Cornell, the environment, and even a slice of IHS!
\Thank you to Professor Peter McIntyre, Professor Anurag Agrawal, Mark Nelson, and the Cornell student teams for volunteering your time to speak about Lake Source Cooling.