When the Covid-19 pandemic hit New York City, visits to the Empire State Building fell 95 percent and nearly 200 tenants asked to defer their April rent payment. Despite being largely vacant, the building’s energy usage only declined by 28 percent. So, what explains this?

Mostly, it’s “vampire energy” usage, which is basically a bunch of stuff that is plugged into a wall socket but isn’t actually doing anything. The Empire State Building is actually a model of energy efficiency, and it has reduced it’s overall consumption by 40 percent in recent years through a comprehensive plan that looks a wide array of methods and opportunities to reduce its carbon footprint. They even have a plan for vampire energy:

Some tenants also use an automated system to control power use. At night and on weekends, the system will shut off designated power outlets, preventing “vampire energy” consumption by devices that are left plugged in.

The building saves $4 million on energy costs over what it was paying a decade ago, but sitting empty for two months has provided them with more insight on how even greater efficiencies can be produced. A lot of it can be emulated by homeowners. Unless we’re Mitt Romney, we probably can’t install elevators that produce energy when they brake, but we can install better insulated windows and reflectors that keep more radiated heat in the house. If made available, we could all benefit from an automated system that cuts power to select devices that are not in use.

With any luck, the Empire State Building will become a model for large buildings across the planet and become a big part of the climate change solution, but homeowners can play their part, too.