The Project at a GlanceDownload
|Empire State Realty Trust
|350 Fifth Avenue, New York, NY
|35,665 square feet
In 2011, LinkedIn Corp.—the world’s largest online professional network with more than 300 million members in over 200 countries and territories—decided to lease office space in the Empire State Building. It now occupies multiple floors, including the nearly 36,000-square-foot floor 22. When LinkedIn signed its initial lease, the Empire State Building was in the midst of a major energy efficiency retrofit and repositioning, which transformed it into a Class A high-performance building.
When the time came to design and construct its new space, LinkedIn decided to follow the Tenant Energy Optimization process—a proven, replicable approach that integrates energy efficiency into tenant space design and construction and delivers excellent financial returns through energy conservation.
|Floor 22 buildout||Projected results*|
|Annual electricity reduction||92,840 kWh2.5 kWh/SFkWh / kWh/SF|
|Total electricity savings over lease term||0.9 GWh25.0 kWh/SFGWh / kWh/SF|
|Adjusted incremental implementation cost||$97,910 total$2.63/SFTotal / SF|
|Total electricity cost savings over lease term||$153,000 total$4.11/SFTotal / SF|
|NPV of project investment||$22,917 total$0.62/SFTotal / SF|
|ROI over lease term||23%|
|Payback period (with incentives)||6.4 years|
Executing the Process
Design and Construction
|Companies and Roles|
Energy project director
|M Moser Associates
Energy consultant and modeler
|Empire State Realty Trust
One of the primary reasons LinkedIn chose to lease space in the Empire State Building was because of the building owner’s demonstrated commitment to sustainability. The 2011 energy efficiency–focused retrofit included a refurbishment of all 6,514 windows, installation of insulation behind all radiators, a chiller plant retrofit, new building management systems controls, new revenue-grade meters serving the entire building, and a web-based tenant energy management system.
LinkedIn’s lease required that the tenant improvement installation include certain lighting, plug, and cooling energy performance measures (EPMs) that produce a five-year (or shorter) payback. EPMs are technologies and systems that aim to reduce energy use through efficiency and conservation. They are also frequently referred to as energy conservation measures (ECMs).
LinkedIn’s electricity consumption is submetered, and the tenant pays for electricity based upon its actual electrical use. By choosing to locate in the Empire State Building and engage with a landlord who is deeply committed to improving energy performance, LinkedIn positioned itself to achieve high levels of energy efficiency compared with a typical New York office space.
Working collaboratively with the building owner, LinkedIn assembled a team of experts to plan and execute the Tenant Energy Optimization process, several of whom had been involved with the Empire State Building retrofit and had experience with the Tenant Energy Optimization process.
The energy project team outlined energy performance goals that aligned with LinkedIn’s overall corporate sustainability targets and developed an extensive list of EPMs to be considered for implementation in the final buildout. By reviewing energy performance models, incremental cost information, and cost savings projections, the team was able to choose a package of EPMs that would meet the energy and financial goals of the company.
The EPMs that were implemented in LinkedIn’s space on floor 22 include the following:
|Energy performance measure (EPM)||Target area||Electricity reduction||Annual cost savings||Incremental first cost||Simple payback|
|High-efficiency lighting (0.85 W/SF)||Lighting||38,168 kWh/yr12.9%kWh/yr / %||$6,479||$1,000||0.2 years|
|Advanced lighting (daylight harvesting, occupancy sensors)||Lighting||10,468 kWh/yr3.6%kWh/yr / %||$1,777||$80,090||45 years|
|No humidification of Intermediate Distribution Frame (IDF) room||Data center||6,657 kWh/yr2.2%kWh/yr / %||$1,130||$0 (avoided cost)||Immediate|
|Increase temperature setpoint in IDF room||Data center||(241) kWh/yr−0.1%kWh/yr / %||($41)||$0||Not applicable|
|As-designed HVAC*||HVAC||(7,995) kWh/yr−2.4%kWh/yr / %||($1,319)||$27,500||Not applicable|
|ENERGY STAR equipment||Plug loads||20,167 kWh6.8%kWh / %||$3,423||$0||Immediate|
|Occupancy sensor plug strips||Plug loads||25,615 kWh8.6%kWh / %||$4,348||$7,000||1.6 years|
Measurement and Verification
After completion of the buildout, the energy consultants returned to LinkedIn’s space to perform measurement and verification (M&V) to ensure that the implemented EPMs were performing as intended. Results from M&V—which took place over a ten-day period, once the space was fully occupied and operational—showed that the EPMs were operating as designed, but overall energy consumption was overestimated by approximately 40 percent in the original model. This difference was largely caused by overestimation of IT equipment load and the associated power required to cool the data center space. Building of extra data center cooling capacity to allow for intended growth in IT load is common. Once the original model was recalibrated to account for actual energy use, the EPMs associated with the cooling of the data center showed negative savings. LinkedIn’s experience illustrates the value of performing M&V to get an accurate energy profile of the leased space.
To further understand energy consumption and trends by end use, temporary data logging instrumentation was installed as part of the final phase of the Tenant Energy Optimization process. This was an extension of the two-week M&V period and allowed LinkedIn to extract energy-use data in more granular detail.