That doesn't mean we shouldn't still be trying to electrify everything.
Engineers from NIST, the National Institute of Standards and Technology, have just published a study titled Gas vs electric: Heating system fuel source implications on low-energy single-family dwelling sustainability performance. Of course, this government-funded organization's research is paywalled so I am basing this on their summary, where they ask:
Engineer David Webb is quoted:
If you want to make your home as energy-efficient and green as possible, should you use gas or electric for your heating and cooling needs? Gas is the more eco-friendly option —for now— for an energy-efficient home in Maryland.
Fuel type is an important factor because heating and cooling accounts for a significant amount of home energy consumption. However, little research has been conducted looking at the impact of which fuel source is used, gas or electric, on achieving low-energy and low-impact goals.
Really? There is tons of research. But never mind. The researchers evidently ran 960,000 building design combinations and eight economic scenarios over a period of up to thirty years and guess what they found:
Under those criteria, the study results suggest that a natural gas HVAC system is currently more economical overall than an electric one for a code-compliant Maryland home. Although net-zero energy performance was achieved at the lowest cost using electric heating, it came with higher environmental impacts due to the emissions generated during its production.
“The overall economic benefit of natural gas was expected because, at this time, it is the cheaper fuel source in Maryland, costs less in dollars and energy expended to produce and transport, and carries a lower construction price for installation of an HVAC system which uses it,” Webb explained.
Well, yes. This is fundamentally the problem across North America; thanks to fracking, natural gas is cheap, so cheap that some companies are paying to have it taken away. Electricity in much of the US is still coal fired and is carbon-intensive. That is not telling us anything new. But wait, things may change:
Kneifel said that electric may yet become the better bargain and more eco-friendly option. “For example, as more power companies move to cleaner forms of electric generation, such as natural gas instead of coal, the environmental impact will lessen,” he explained. “Also, technology changes, such as cheaper and more efficient solar energy and HVAC systems, should help make the use of electricity more cost-effective.”
Well, yes again, this is what everyone in the environmental movement has been calling for. And they say they ran projections out thirty years! By then we have to be off natural gas completely. If you bake in natural gas now you are stuck with it, but if you go electric it gets cleaner every day as the grid gets cleaner. I asked Nate Adams, AKA Nate the House Whisperer, what he thought of this study and his first reaction was "Oy, this is not helpful."
HVAC systems last 15-20 years, so ideally we ask what’s likely to happen by 2035-2040? Will renewables drive down electric costs 20-25% as Dr Chris Clack projects in MN? Will natural gas stay at record lows? How much cleaner is the grid going to be? Can you buy clean juice at the same cost in your market to make it an obvious choice today? NIST’s conclusion seems to be based on straight line rates of change rather than the geometric changes that are not only likely but required.
But to be fair and balanced, Nate and I both have an axe to grind here, and take the stance that we have to Electrify Everything! Also, none of our comments are based on reading the study itself, because we refuse to pay Elsevier for a study that American taxpayers have paid for already.
I have asked the authors for a copy, and will update the post if and when I receive it.
UPDATE: On reviewing the study, which the authors graciously sent me, nothing much changes. In fact, it gets a little worse, reading : "For example, use of natural gas presently leads to fewer GHG emissions (given current electricity fuel mixes) – however, it could lead to increases in other environmental inputs." The electricity fuel mix is in flux all over the world, and even in Maryland people can buy green power if they want to pay a bit more. It seems nuts to project one bit of the USA to the entire country. They do acknowledge this later, but it kind of makes the whole study pointless, it is just one window at one time in one location. Then they also are comparing "two Maryland state code-compliant homes" when it is obvious that if you are going to build a house that runs on expensive electricity, you should be building way above code. The researchers do acknowledge that things are changing:
Additionally, several underlying assumptions in the current analysis change over time, potentially leading to changes in the relative sustainability performance of alternative building designs. Building construction costs and materials environmental impacts, energy costs and fuel mixes, and the cost and efficiency of solar PV all are changing. Future research must account for theses dynamics to remain current and accurate over time.
But I think that brings the entire value of the study into question. If you build a house with gas now, you are locking it into gas for a very long time. If you build an ultra-efficient all-electric house now, it gets greener and greener as the grid's energy mix improves. If you build to the highest, most advanced construction now, you are future-proofing it no matter what it runs on. Which is why they should really go back to the results of the initial study of the NIST House.
It should also be noted that they based all this on their Net Zero Energy Testing Facility in Maryland, which was supposed to be your typical suburban 2,709 square foot house on a giant lot. They said when it was built, “We think that by demonstrating that it’s possible to have the home design you want, with the energy efficiency you want, we’ll help speed the adoption of energy-efficient technologies and net-zero homes.” I called it a high tech robotic green dinosaur, because it assumed that life in suburban America could continue unchanged, if we just made it a little greener.
And what's even funnier is that after a few years of studying this house, with every high-technology system they could throw at it, they concluded that all that high tech smart stuff was superfluous and it was the basic dumb stuff that made a difference.
The most important difference between this home and a Maryland code-compliant home is the improvement in the thermal envelope—the insulation and air barrier, says NIST mechanical engineer Mark Davis. By nearly eliminating the unintended air infiltration and doubling the insulation level in the walls and roof, the heating and cooling load was decreased dramatically.
This new study is no different, it seems to have been done with blinders, with no clue as to what is happening in the world, how whole countries are trying to get off gas, how electric generation is getting cleaner everywhere in the world, even the in the USA. As with the NIST house they modelled, I just don't know what they were thinking.