Manhattan’s largest rooftop solar array is about to come online

Developer Siemens overcame design obstacles to build the Javits Center rooftop solar system, which also includes a 3.5-megawatt indoor battery.

A technician installs solar panels on the Javits Center, with the Empire State Building in the background. (Office of Governor Hochul)
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In a place as densely populated as New York City, plenty of obstacles stand in the way of installing solar arrays: limited space, the shadows of skyscrapers, and the need to work around existing water towers and other building equipment. To build Manhattan’s largest rooftop solar project yet, developers had to get creative. 

Some 1,400 solar panels now glimmer atop the Javits Center, a huge convention hub that overlooks the Hudson River. Siemens, the German technology giant, is building the 909-kilowatt installation, along with a 3.5-megawatt battery system housed in an interior room that will store excess solar energy.

Last week, during Climate Week NYC, a team from Siemens strolled the sun-blasted rooftop to get a look at the nearly completed project.

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Visitors expecting conventional rows of solar panels might’ve been surprised to find a floating checkerboard instead. The unique layout was necessary because the roof is already occupied by some three dozen HVAC systems and a lush, green carpet of sedum — a hearty plant that can absorb stormwater runoff and helps keep buildings cool.

So Siemens built solar canopies that hover over the boxy, gray HVAC units. The arrays themselves are shaped like puzzle pieces to accommodate air blowing from the systems’ vents. Custom racks from Inhabit Solar are bolted to narrow concrete curbs that weren’t originally designed for the task. Computer simulations showing how future high-rises could affect the amount of sunlight hitting the roof further informed the design — the skeletons of skyscrapers-to-be already loom across the street.

An older photo shows the 909-kilowatt solar installation when it was still under construction. (Governor Hochul)

The landmark project at the 3.3-million-square-foot convention center comes as distributed solar is proliferating across New York state. Residents, communities and businesses have so far installed a total of 4 gigawatts of solar arrays, putting the state on track to exceed its goal of adding 6 gigawatts of distributed solar by 2025, according to the office of New York Governor Kathy Hochul (D).

We are laser-focused on the battle against climate change,” Hochul said at a September 21 press conference at the Javits Center. She added that the building’s unique solar-plus-battery system is setting an example for other urban commercial buildings of how to be on the cutting-edge of our clean energy future.”

The Manhattan installation is also part of Siemens’ broader efforts to reduce greenhouse gas emissions from enormous multiuse buildings, Ruth Gratzke, the president of Siemens Smart Infrastructure U.S., told Canary Media. She said the company aims to transform today’s convention centers from passive structures into high-tech, digitally controlled spaces that can minimize energy consumption, improve indoor air quality and avoid the perils of arctic-cold conference rooms.

Globally, buildings account for nearly 40 percent of all energy-related carbon dioxide emissions, according to the United Nations Environment Programme. That figure includes operational emissions — created by burning fossil fuels to light, heat and cool buildings — as well as emissions generated by the building construction industry.

At the Javits Center, Siemens set out to not only reduce the building’s substantial electricity bills but also improve its resilience during emergencies. Along with hosting big events like the New York International Auto Show and Comic Con, the facility has served as a distribution site for relief supplies after 2012’s Hurricane Sandy and as a temporary field hospital in 2020 during the initial outbreak of Covid-19.

In case there’s a brownout in New York City, you can at least run rudimentary services in this building and keep it safe,” Gratzke said. That’s really the driving force behind this.”

A large metal HVAC unit covered by a solar panel platform
Siemens' partner Inhabit Solar built custom racks to hoist the solar canopies above existing HVAC units. (Maria Gallucci/Canary Media)

In 2019, the New York Power Authority, the state’s public utility, selected Siemens to design and install the solar-plus-battery system, which is expected to offset more than 1.3 million pounds of carbon emissions per year — equal to taking 262 cars off the road. The clean-energy project is now owned and operated by Calibrant Energy, a joint venture between Siemens and the financial services company Macquarie Group. Under their agreement, the Javits Center will pay Calibrant for the electricity the installation provides.

As Gratzke peered over the field of solar canopies, she explained that, while installing the panels was tricky, building an indoor battery system — the first of its kind in the state — has been a formidable challenge on its own.

The high-capacity battery system will sit inside a parking-garage-like room that engineers have designed with multiple layers of protection, including insulated walls and emergency systems to squelch any flames or contain any leaking gases. The project required obtaining special permits and waivers from city and state agencies, as well as the Fire Department of New York. The last of those are expected to be finalized in the coming weeks.

Along with installing solar panels and batteries, Siemens has developed a real-time monitoring system to optimize the performance of those technologies. That includes tapping the system to power the Javits Center when Manhattan’s power demand is at its highest, helping to reduce strain on the electric grid.

When you look at cities like New York, and you look at convention centers, everybody needs to meet sustainability targets,” Gratzke said. Gesturing at the solar-studded rooftop, she added, This is one very elegant way to get it done.”

Maria Gallucci is a clean energy reporter at Canary Media, where she covers hard-to-decarbonize sectors and efforts to make the energy transition more affordable and equitable.