Welcome to the Vicinity Energy Kendall green energy facility

We’re thrilled to welcome you for a tour of our facility.

Tour stops

Our operating philosophy

We operate using three guiding metrics: safety, reliability, and efficiency. Safety is our number one priority, and it is at the center of everything we do.  

District energy systems are akin to college campuses that have a central energy facility that distributes utilities throughout the campus. Vicinity employs the same sort of system, except our campus is a lot larger: we serve over 230 facilities in Boston and Cambridge. 

We utilize the combined heat and power (CHP) process at our facility to simultaneously produce power and thermal energy in the form of waste heat. CHP is one of the most efficient methods of producing steam – it can exceed 80% efficiency – and consumes far fewer units of fuel than if the two products are produced separately. 

While we provide steam and electricity, our main product is reliable energy. Our customers are all the major hospitals in Boston (MGH, Boston University, Boston Medical Center, Tufts New England Medical, Mass Eye and Ear Infirmary, and the Shriners Burn Institute), and we also supply a who’s who of biotech, commercial offices, and higher education customers in Cambridge and Boston.  

Along with these critical care customers are some unique clients the steam from this facility heats: the Ocean tank at the New England Aquarium, and at the end of the line in Cambridge is a candy manufacturer that makes Junior Mints.

Utility electrical substation

The interconnection substation is where local electric distribution connects with the electric grid. Our lines are shared from the back of the property to this substation, where electricity enters the public domain and the grid.

This substation is a key part of our electrification plan. As we electrify our operations, we’ll rely on this onsite substation to supply renewable electricity to power the three technologies we will use to produce carbon-free steam, known as eSteam™. Those three technologies are electric boilers, industrial water-sourced heat pumps, and thermal storage.  

Black start generator & forward reserve market turbine

This facility produces steam for customers and electricity to the grid and provides reliability for critical demands. If the area experiences a power outage, we kick in as a fast-start generator to keep those operations running. This is called a black start capacity plan.

That fast start generator is a simple jet engine, just like the plane you flew in on, except the jet engine is nailed down to the ground, and instead of taking off, it spins and generates electricity.

That jet can go from zero to 20 megawatts in 10 minutes. When prices are high in the summertime, or if there is a blackout, that’s the first unit on. It can start by itself unassisted and powers the main facility. This facility is one of the first facilities available to power the grid in the event of a blackout.

Thermal storage site

This open area will be where we’ll site our thermal storage, which can be either molten salt, hot rocks, or ceramic bricks. As the electric grid evolves and renewable power floods the area, we will leverage storage to supply our operations. Our intent is to buy renewable electricity when it’s economical and plentiful, usually overnight, use the inexpensive off-peak power, store it in the thermal storage medium, and then blow air over it and produce superheated air, discharge that into existing boilers to make steam and supply it to customers during peak usage times– typically around 4:00 to 6:00 in the morning when buildings are waking up. 

Carriage house high purity water treatment facility

The carriage house is one of the facility’s original buildings and predates our other infrastructure: it’s been here since the 1800s. This building is called the carriage house because it was used to store the equipment required to bring coal in and out of the city.  

In 1900, coal was primarily used as an energy source, so the facility was designed to burn coal, but that lasted for a very short period of time. Coal was soon converted to heavy oils and then to natural gas as time went on. Today, we use the efficient combined heat and power process to generate heat and electricity simultaneously.  

At one point in time, the carriage house was going to be taken down to construct a pure water plant, but the city protected it as a historical building. So, they kept the structure of the building and put the water infrastructure inside. 

Water tank

The demineralization tank holds ultra–pure water. Pure water is used in the steam production process to produce clean, food-grade steam. This food-grade steam is distributed to our customers for heating, cooling process use, and sterilization.

people in hard hats standing outside facility

Biogenic fuel storage

The biogenic fuel tank currently holds 1,000,000 gallons of waste cooking oil collected from local restaurants and converted into biogenic fuel. The oil is stored here and then used in the winter months at our Kneeland Street facility. We are in the process of permitting expanded use. 

In 2021, we started the first phase of our decarbonization strategy by using biogenic fuels in our Boston and Philadelphia facilities. We partner with a Boston-based firm that produces this fuel derived from waste vegetable oil and fats discarded by the food service industry. 

Rather than dispose of it as waste material, which winds up in landfills or clogs city sewer systems, we repurpose this discarded cooking oil into a renewable heating source and use it to produce energy. The use of biogenic fuels reduces greenhouse gas emissions by over 80% versus distillate fuel, improving local air and water quality.

Gas infrastructure

The primary fuel source used at the facility is currently natural gas. The yellow pipe coming out of the ground is the gas that is coming into the facility off the interstate pipeline at about 350 lbs. per square inch pressure, which isn’t enough pressure for what the machine needs. The gas then gets compressed up to about 475 lbs. per square inch (PSI), filtered, heated, and then filtered again, resulting in a very clean fuel that is run through our equipment.

Diesel tank

If we’re not using natural gas, we have an alternate fuel source to ensure reliability. In New England, the gas system can be very volatile, both in price and availability, so we must have backup fuel. 

Our backup fuel is ultra-low sulfur diesel. We can store 1,200,000 gallons of ultra-low Sulphur diesel fuel oil in the tank in front of us. 

In context, when the machine is at full load, it can burn about 16,000 gallons an hour of fuel. We can swap between fuels on the fly with no interruption of service. Stored in the tank is enough to last about three to four days, so we have plenty of fuel unless we have a super long cold snap. 

Electrical infrastructure

We deliver multiple forms of energy: we deliver steam to our customers in Boston and Cambridge and electricity to the ISO New England grid. Three large wires exiting the building carry up to 115 Kv of electricity. This is how the electricity leaves the facility and goes underground into the local utility substation. This will also be how we bring renewable power into the facility when we flip the switch and start importing 250 megawatts of renewable electricity for our electrification process.
people stading outside facility buildings

Combined heat and power (CHP) turbine & heat recovery steam generator

A key part of our operations is our combined heat and power turbine, as well as our heat recovery steam generator.  

To the right of this building is the Takeda building. Takeda is one of the largest biotech companies in the world, if not the largest. Their building was built around the same time as the combustion turbine was installed in 2001. It’s one of the first LEED platinum buildings in the US. Their building is powered by our facility, getting all of its thermal energy needs from us. 

Air intake on CHP building 

The combined heat and power (CHP), also known as cogeneration, building utilizes an air intake filter system with 1050 HEPA filters in the intake structure. The air filter is essentially a giant Dyson: we pull in very clean air and feed it into the machine.  

Heat recovery steam generator

This inlet is where electric generation ends, and steam production begins. As we said, we’re making electricity and heat. Heat is now exhausting out and about 950 degrees, and it’s entering the heat recovery steam generator, which is a large radiator that turns the exhaust heat into high-pressure steam. 

We’re very tightly regulated for all our emissions: air emissions, water temperature emissions, and noise emissions. Vicinity’s facility is regulated to what is called the best available control technology, or BACT.  

All the silver piping that you see is for nitrous oxide control. There’s a catalyst that converts the emissions as it goes through the piping, using ammonia from nitrous oxide pollutants to nitrogen and water vapor, and we end up with 2PPM of nitrous oxide coming out of the exhaust, from where we started at 30PPM of nitrous oxide.


Electric boiler #1

Right here is where we’re taking step one in our electrification process. On November 17th of this past year, we commemorated this step with Boston Mayor Michelle Wu, where she came in and took a sledgehammer and swung it at our decommissioned natural gas-fired steam turbine. She did an excellent job because now, all that’s left is a hole.

Some six months later, we successfully deconstructed the turbine, generator, and condensers and ended up with this hole. This will house a 42MW electric boiler that will be put in place of the turbine beginning this year. The installation will be completed next year, marking the start of our electrified steam journey with carbon-free eSteam™. 

When the electric boiler enters service in 2024, we will repurpose the same wires that the generator used to send out power, to take in power to the electric boilers. At that time, we’ll procure electricity from renewable, carbon-free energy sources such as wind, solar, and hydro to generate eSteam™, our carbon-free renewable energy product. 

Boston-based life sciences developer IQHQ will be Vicinity’s first customer to utilize eSteam at their developments in the Fenway neighborhood at 109 Brookline and the Fenway Center Phase 2. Under the agreement, IQHQ’s 305,000-square-foot office and laboratory space 109 Brookline Avenue will use 100% eSteam™ for heating—making it one of Boston’s first entirely carbon-neutral buildings.

IQHQ is also pursuing eSteam™ at its Fenway Center development, a mixed-use, transit-oriented life science campus located at the western gateway to Boston. Fenway Center will include nearly 1 million square feet of commercial office and lab space built over the Mass Pike.

Turbine deck & control room screen 

There were originally three turbines in the turbine hall here. There was turbine #1 that’s no longer here, turbine #2 has been decommissioned, and at the far end is turbine #3.  

At the far end of the turbine hall is the back-pressure steam-driven generator. It does not use the river for condensing, and all the generated steam goes through the back-pressure steam turbine. The generator generates another 25 megawatts of power, and the 200% exhaust steam is sent to our customers. 

In this area, there is also a control room screen that we view in several places throughout the facility to monitor aur operations in Boston and Cambridge. The screen displays some key performance indicators for steam generation, electric generation, backup capacity, and more. 


In this section, there are three power boilers that are all of the same construction. These boilers are hung from the ceiling, starting on the 7th floor, all the way down to the first floor, so we can walk underneath them.

Combustion turbine

We house our combustion turbine in the turbine hall, and this is where we generate 200 megawatts of electricity. 

To do so, the hot exhaust gas is passed out through a heat recovery steam generator (HRSG). The electric generator is coupled to a GE7FA Combustion turbine. In the HRSG, we capture the waste heat to make more steam and send it to the other buildings to produce more electricity. 

Heat pump complex

Our power boiler #1 has been decommissioned and will be removed to make way for the industrial-scale heat pump complex we’re installing in collaboration with MAN Energy Solutions, a Germany-based energy equipment provider.  

The heat pump complex is anticipated to be operational by 2028 and will be one of the largest of its kind in the U.S. The heat pump will lift energy from the Charles River and use it to preheat water for the new electric boilers, improving the overall efficiency of the system. 

An additional stage of heat pumps can be used to directly generate steam for export to customers. These large-scale, high-lift heat pumps can accomplish higher efficiencies than commercial heat pumps but require the use of refrigerants that are not suitable for individual buildings.  

Upper view of heat pumps

Our power boiler #1 goes up about five stories and will eventually be torn out to make room for our industrial-scale heat pump complex. Once installed, the heat pump will run about 6 to 7 stories from the front to the back of the building. 

River water intake

When we put in our heat pump complex, we will use existing infrastructure to take heat from the river to turn it into steam and send it out to our customers.

There will be two intake structures to bring this water in, and the infrastructure already exists. One structure is a 7-foot tunnel underneath the building, and the second is further down along the canal. Both will pull about 70,000 gallons of water an hour into the facility to feed our heat pumps and then discharge water back into the river across the street, a little cooler than we brought it in.

The Charles River has always faced the issue of heating up in the summertime, so our heat pumps will provide an environmental benefit to the river as well by cooling it down a few degrees.

Facility history

Interestingly, there are three facilities here, but the original facility is the yellow brick building built in the 1940s. This building contained three 1300 PSI power boilers and was constructed as a coal-fired Rankine cycle facility, which means the power boilers drove over condensing turbines. The facility used the river for cooling as part of the original design. 

When the combustion turbine was put in, they needed to bridge the two systems to make it a combined cycle plant. Today, all the systems are tied together across the bridge ahead of you, so steam, electricity, condensate, and all auxiliaries are shared between the two plants. 

In 1900, coal was primarily used as an energy source, so the facility was designed to burn coal, but that lasted for a very short period of time. Coal was soon converted to heavy oils and then to natural gas as time went on. Today, we use the efficient combined heat and power process to generate heat and electricity simultaneously. 

Because district energy is fuel agnostic, these systems can utilize any fuel source to generate steam. Over the years, our facilities have pivoted as more sustainable fuel sources have become available, and we’re continuing this legacy. 

Kendall Square neighborhood & history

Energy goes out through two different steam lines from our facility — one is over the Longfellow Bridge. If you’ve ever seen a movie filmed in Boston, you’ve likely noticed an iconic shot of the Longfellow Bridge.  

The second steam line comes out of the plant and goes past the Cambridge Parkway, the Museum of Science, and into the city of Boston that way. 

The canal behind our facility used to be used for commerce, running all the way up into the city. Barges would come up through the canal, and they would deliver coal, oil, and other goods into the city of Cambridge. With the decline in coal, the canal was truncated and is now primarily used recreationally, with residents canoeing and kayaking.  

When our facility was built, the city required this boardwalk to be installed for pedestrians and public use. We maintain the boardwalk to this day, and it’s used frequently by the public.  

JFK history & NASA

In the 1960s, John F Kennedy, originally from Cambridge, set the ambitious goal of going to the moon. He famously stated, “We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard.” 

And so, to achieve his goal, he needed to develop a space authority, known today as NASA. In 1964, Kendall Square became home to NASA’s Electronics Research Center (ERC) and supported NASA’s electronics research during the Apollo era and served as a graduate and post-graduate training center. 

The ERC needed power, and our Kendall facility was the perfect location to house all the materials necessary to accommodate NASA’s Kendall Square operations. The red portions of our building were originally boilers that we used to power the NASA campus. However, when JFK was assassinated, the next president Lyndon Baines Johnson didn’t have an affinity for Cambridge; he was from Texas, and began to move NASA to Houston. 

Kendall Square neighborhood evolution

Kendall Square has undergone many changes since the 1800s. The area was initially very industrial, whereas today, it’s home to the world’s leading biotech and research facilities. 

One of the first customers of the original facility was a woven hose and rubber company that produced fire hoses and ink stamps and ink, as well as the candy manufacturers along Main Street.  

In the sixties, these industrial companies gave way to technology. For example, the Polaroid Corporation was founded right here in Cambridge by Edwin Land and George W. Wheelwright III in 1937.  

Edwin H Land Blvd, named after the inventor of the polaroid camera, Edward Land, runs behind our facility. At the time, the invention of the Polaroid camera was groundbreaking – the company built an empire from that idea and employed research and university graduates to build it. In the ‘80s, with the advent of digital photography, the company all but evaporated. However, biotech later reinvented the area using the same model and university brain power to find cures.  

At the end of the line is a company called Cambridge Brands, the only place in the world that makes Junior Mints! The factory produces 15 million Junior Mints a day.

Often, visitors to Kendall Square cannot believe an operating energy facility is located in the area. The truth is, however, that this neighborhood looked a lot different when our facility was built in the 1940s. Today, the city has built up around our facility, and you can live and work in what used to be an industrial area of Cambridge.

As Kendall Square has evolved, our facility and reliable steam service have remained constant. While some processes and fuels have changed, Vicinity has provided thermal energy for Boston and Cambridge for almost 100 years. Leveraging this rich history and existing infrastructure, our facility is the most viable means to quickly and effectively decarbonize the buildings we serve in the near future.

Want more information?

Learn more about how Vicinity is electrifying our facilities, starting with our Kendall facility, today.