ENERGY EFFICIENCY
The Empire State Building Retrofit Project
An experiment that showed that by spending ~2% of its GDP on energy efficiency, New York City could lower its emissions by almost 35%.
What is the problem with big buildings?
Big buildings, unsurprisingly, use a lot of resources to accommodate the large number of people that live or work inside. They use a lot of electricity, gas, water, space, and whatnot. The problem is, that with the usage of that magnitude it also becomes easy to waste. And that simply means a lot of unnecessary emissions that can be avoided.
New York City has emissions higher than the country of Switzerland, and buildings account for almost two-thirds of it. Half of those emissions come from just 5% of the buildings.
This wastage can not only be because of the design of the building itself but also because of its inhabitants who may not all think about, let's say, using tap water wisely. While the latter is mostly an awareness and behavioral issue, the former issue can have many reasons. Maybe the developers were unaware of the technologies available; maybe the economics didn't tie up; or, maybe the developers used the best options of their time but the building is just too old now.
This post will talk about the third reason, and how an almost 100 years old building retrofitted itself to make itself more cutting-edge than most modern structures.
The Empire State Building, New York
The Empire State is a 90-year-old building, constructed at a time in 1930 when not much thought went into making buildings energy efficient. It could have easily remained just another old building with a legacy, but its owner Tony Malkin had different plans.
Built at the peak of the great depression in 1931 the building signified hope for the American people. At a time of another crisis, climate change, he [owner] wanted the building to again signify hope and lead in sustainability.
Malkin assembled a team of experts and gave them the task of retrofitting the landmark. He only had one simple requirement — while trying to maximize carbon reduction, each measure should pay itself back in five years.
In 2008, the building was approved to have a wide variety of upgrades at an estimated $550 million, out of which $93 million were spent on all energy-related retrofit measures.
But why retrofit?
Measures taken by the project team have been described below, but first, why retrofit a building? And what did it help the Empire State building and its management achieve?
The Empire State Building project was taken up to prove the economic feasibility of energy efficiency retrofits for a large commercial facility. After all, if a 90-year-old building could make a strong business case out of it, the younger ones most probably can. The amount it spent on energy efficiency measures paid itself back in 3.1 years through energy bill savings. The results still serve as a benchmark for other commercial projects of its size.
It is estimated that 80% of buildings that will exist in 2050 have already been built. This makes retrofitting existing buildings an important part of the solution.
Some of the major ways in which retrofit benefitted the building are:
- The new windows along with more efficient office equipment reduced the building’s peak cooling load by a third. Not only did this reduce the pricey demand charges, but the existing chiller could also then just be retrofitted instead of replacing it with a bigger-sized system saving an investment of $17 million.
- Overall, the energy consumption dropped by almost 40% resulting in an annual savings of $4.4 million on bills. This led to an equivalent drop in carbon emissions of roughly 7000 tonnes per year. To put that in perspective, the average US home emits 7.5 tonnes of carbon per year.
- ENERGY STAR certification every year since 2010 helped the building attract more tenants, as it would mean lower energy bills for them. The new indoor space also offered more comfort from better heating and windows, and improved air quality. It is estimated that the rent premium for green buildings can range between 3–9%.
If every building in New York City followed this example, the city could save enough energy to shut down New York’s largest power plant, take 11 million cars off the road, and avoid emitting an amount of carbon that would require at least 240 million trees to filter. It might cost an estimated $20 billion for all large commercial buildings to do what the Empire State has done, but this is just ~2% of New York City’s GDP.
Retrofit Measures Undertaken
Once the plan was approved in 2008, the organizations managing the project — Johnson Controls, JLL, and Rocky Mountain Institute — got together to examine the building systems and their energy requirements. Out of almost 60 actions they could have taken, the team analyzed the business value and GHG reduction potential of each and chose the following 8 measures.
For financial viability, it was also important to look at each measure not in isolation, but with a 360-degree view of everything. The integrated nature of the ESB project ensured that the benefits of each solution spilled over to the other which overall helped avoid or lower the individual investments and reduced the payback period, just like the example of the chiller mentioned in point #1 above.
Over time, many other measures were taken up to make the building more sustainable like upgrading to faster elevators with regenerative braking; replacing water fixtures with low flow variants to save water and reduce pump load; and replacing the flashy exterior lights with LEDs. An excellent illustration of the changes can be seen here.
