In Part 1 of this series, we defined Net Zero and discussed why a building must be all-electric. In Part 2, we discussed the lab-specific space conditioning and exhaust challenges related to safety and fume hoods. However, going Net-Zero has impacts beyond just lab air; we’ll discuss those here, in Part 3.
What effect does being all-electric have on building systems?
The visible impacts are surprisingly small. Some of the most important effects are behind the scenes: for example, no gas appliances mean less exhaust, so shaft sizes can be reduced. Similarly, heat-pump space conditioning means that you only move air around for ventilation, so for any spaces which were previously conditioned by blowing hot or cold air around, duct sizes (and shaft sizes) are reduced.
What about electrical infrastructure?
It’s normal to read all this about all-electric buildings and imagine upgrades to the electrical system, all the way to increasing the service size from the utility company. In fact, most all-electric buildings don’t need to increase electrical connection size at all. Why? Because most buildings already have all-electric cooling in the summer. Since cooling is (usually) a larger load than heating, the electrical connection the building has is already more than enough to handle the heating load in the winter.
But isn’t electricity more expensive?
Yes – but no. (It’s complicated.)
Yes, per unit of energy, it costs more to buy a unit of electricity than a unit of energy in the form of gas or oil. However, electrical building systems are so much more efficient than gas-fired ones that the price per unit of heat in the building is actually very close.
As I write this in 2021, the price to condition a building that is all-electric is somewhere around 10% more than the price to condition a building that’s a conventional gas/electric combination. However, the price of electricity has been quite steady over the last couple of decades, while the price of gas has varied quite a bit. It’s near a historic low now, but not very long ago, it was more than double the current price. So while electricity looks just a bit more expensive now, it would have been a much cheaper choice for many of the last 20 years and is likely to be cheaper again in the future.
What if you can’t predict the price of electricity? What if gas is cheap forever?
It’s certainly hard to predict the price of anything in the future. However, there’s a different financial consideration, which you have probably heard of under the name “carbon tax”. Put very simply, it’s a fine you pay for dumping smoke into the atmosphere. Think of it as a fine for littering.
While carbon taxes are just beginning to be implemented, they are growing rapidly, and it’s no surprise that science-friendly states and cities where so many labs are located are the same ones who are farthest ahead on passing these laws. In the future, it’s likely that even if gas is cheaper to buy, it will be more expensive to burn.
Doesn’t the utility company just burn gas (or coal) to make electricity anyway?
It’s true – most of the electricity generated today is created by burning fossil fuels. But that’s today: it’s changing rapidly. In my home state of Massachusetts, the portion of the grid powered by renewable sources is climbing 2 or 3% per year, just because it’s cheaper to build and operate. That growth is accelerating; it’s not hard to look ahead and see an all-renewable grid.
When that happens, an all-electric building powered by the grid will instantly be Net Zero, with no solar panels insight. In short: it’s possible to produce electricity in a Net Zero way; it will never be possible to burn gas in a Net Zero way.
What about emergency power?
If you’re wholly dependent on electricity, it’s important to have a good backup. Right now, battery technology has come a long way: not just in electric cars, but even utility companies are building giant battery farms to provide grid-scale backup during blackouts. It’s entirely realistic to talk about building-scale battery backup.
Still, some science requires the kind of peace of mind that comes from a backup system that is completely separate. In those cases, building a natural gas generator is not a bad solution. Yes, it sounds like it undermines everything I’ve writing in this series: burning natural gas in a Net Zero building! But if a building is all-electric except for one or two days per year when the power is out, that’s 99.5% Net Zero operation. If we reduce our pollution by 99.5%, I’d call that a very good accomplishment.