The Pros and Cons of Going All-Electric
With no building background at all I have been quite interested in better building practices, building science and the likes when we have decided to build our own custom home. I wanted to go Passive House if we could afford it but at the moment we are not quite there yet, so trying to do the next best thing given our budget constraints – to just build the best house we can with our resources.
One of the top priorities of this build is good indoor air quality (due to medical issues). Somehow somewhere through my research I learned that going all-electric is the way to go. Now that we are in the forefront of the house project steps (major decision making – picking exact materials and systems we want to use in the house) I am not quite sure whether going all-electric is the best fit for us and need some feedback and/or advice. This is a slab-on-grade, 1-story, 2400 sf house.
We aren’t going to use a PV system (though that idea was appealing to me). What are the pros and cons of going all-electric vs typical mix of electric and natural gas to power various equipment/systems in the house? If we are going to go all-electric we would probably need a generator of some sort as we would be totally incapacitated during a long outage. We recently went through the horrible TX Deep Freeze 2021 two months ago and thankfully our rental has a gas-operated stove so it was a lil bit more manageable than if we couldn’t cook food like normal. Which leads me to another question, natural gas hookup ready for generator use. If we are going to do that, then maybe just be ok with a combo of electricity and natural gas operation inside the house.
Unfortunately I do not remember what article(s) I read that led me to want to have an all-electric house but I suppose we were going to do that because of less risk of gas emissions from natural gas use in a pretty tight modern build. We are also planning to being more energy efficient in the choices of windows, appliances, etc.
Your help would be greatly appreciated.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
A tight home, in terms of "air tightness" (which is usually what is meant by a "tight home"), is a benefit to air quality since it gives you better control. With a tight home, you can use an HRV or similar to control the air transfers with the outdoors, and you can filter the intake air. With a leaking home, the air leaks tend to overwhelm whatever you're trying to do, so any filtration efforts you make are reduced in effectiveness due to the unfiltered air coming in through the leaks. I'd try to build a tight home regardless of any other issues you're considering -- there are no downsides to building a tight house.
The biggest concern with gas appliances and air quality is combustion products from either NON-vented gas appliances (which should be avoided), or non-sealed combustion appliances. A naturally aspirated hot water heater, for example, has a draft hood that pulls some indoor air and exhausts that out with the combustion gasses while running. This has the potential for back drafting, when combustion gasses "back up" into your home. Back drafting is a Bad Thing. In a tight house, you can actually have MORE chances of problems with a naturally aspirated water heater.
Sealed combustion gas appliances have their own air supply lines from the outdoors, so the combustion gasses go out one line, and supply air comes in on another. Sealed combustion appliances don't have any effect on indoor air quality. Sealed combustion appliances also tend to be higher efficiency units.
I'm not a big fan of the push for "all electric", especially in areas where a large percentage of the electric supply is sourced from natural gas fired generation (which is the case in much of the country these days). If you do go all electric, you're going to be looking at heat pumps since electric resistance is NOT a good option for large-scale space heating.
Gas or all electric, you're still stuck when the power goes out. Most gas appliances can't operated without a source of electricity to at least run their blowers. I wouldn't put "I'd need a generator" down as a negative for an all-electric home, since a home with gas is likely to be completely inoperable without electricity too. The difference is that a home with gas may be able to get by with a smaller generator than an all-electric home would need.
If you get a generator, natural gas is usually the best fuel source (easy, endless supply as long as the pipeline is working, etc.). As I understand it, a lot of the issues in the recent Texas storm was due to a natural gas shortage, so that could potentially impact your ability to run a generator. Most natural gas generators can also run on propane, but you'd need to have the supply in place to have that option, and it takes a surprising amount of propane to operate a generator for a long period -- a typically BBQ tank doesn't go very far, and often can't vaporize enough gas to supply a generator anyway. Diesel ends up being a better option if you have a real issue with natual gas availability, but diesel is higher maintenance, and you have to refuel the unit periodically during an extended outage.
Bill
thanks for sharing, Bill. So does that mean as long as I pick sealed combustion gas appliances that we shouldn’t worry about backdrafting? We would be needing the whole she-bang since it’s a new build. We want to go with VRF, ERV system; does having a VRF still mean we need a separate furnace? For cooking we want to do induction range. Washer and dryer are electric.
Sealed combustion gas appliances can't backdraft unless you manage to cut a hole in them somehow :-) Sealed combustion is MUCH safer. Sealed combustion also has no way to depressurize your house or any of the other goofy things that can happen with the other systems.
If you're planning on using a VRF system with a heating function, then it can handle the heeding needs of the home without a furnace, assuming all the usual sizing and airflow needs are met.
Induction is great for cooking, just make sure all your pots and pans will work with the sytem. There are some "conversion" devices out there, which are basically steel discs that sit between your pot and the induction cooktop, but they're clumsy and remove some of the benefits of true induction cooking like very rapid heat up and cool down of the pot.
If you're trying for high energy efficiency, you may want to consider a heat pump clothes dryer. I'm assuming by "electric" you probably mean "electric resistance", but that's not the only option anymore.
Bill
From an economic and comfort point of view if is almost impossible to beat city gas. Generally the cost per BTU is the lowest and a gas furnace will deliver much warmer air to your registers.
If you have a power outage yes the gas furnace will not operate but a very small generator could power a gas furnace. You would need 5 to 7 times larger generator to run a defrost cycle on most heat pumps.
A sealed combustion water heater will not affect your indoor air quality but will not operate without electric power.
To improve you air quality use electric for indoor cooking and clothes drying and say no to real fire places.
If you are dealing with a lot of humidity you may want to have dehumidification system.
Other will disagree but I think an ERV is a great thing when you live someplace that is cold and dry outdoors for months on end and your home is tightly sealed and your indoor humidity is too high seeing a 80 ° temperature difference from indoors to out could be common. In your climate most days will less than 25° and all the air your outdoor air is loaded with humidity you are desperately trying to get rid of.
Since you are in TX you may want to watch the YouTube video of Matt Risinger as he deals with your climate.
https://www.youtube.com/channel/UCFCTrfb1JUJjs3Im8OZDtBw
Since city gas is no available at my home site we are almost totally electric. We love our induction cook top.
Walta
> a gas furnace will deliver much warmer air to your registers.
Do you have any data showing that this is a good thing? Say 130F air vs 90F air (which is still warm if it blows on you - which it shouldn't)?
I agree that indoor air quality is not effected by the choice of well implemented natural gas for space and water heating. It's outdoors that may suffer.
Beedigs,
It's probably worth considering how both buildings and the electric grid will change over the course of the life of your house. It's a safe bet to predict that dirty grids will become cleaner, and electricity will continue to make inroads on fossil fuels as the dominant form of energy for buildings, vehicles, equipment and tools.
if you decide to go with gas, it might be prudent to imagine how the house could be converted to rely on electricity if that transition comes quicker than we presently foresee.
Coincidentally, GBA reader Fred Frasch has written a strong data-backed article about the flip side of going all-electric, i.e. the cons. It will be posted on May 5. Keep an eye out. I anticipate a lively debate.
will do for sure! hope that article would get posted sooner lol :)
Here you go blowing up all my plans :)
????
I hope I can get a sneak peek on the article as we have a budget meeting before May 5th so maybe that article might sway me onto one side than the other :)
Hi beedigs,
As a heads up, my article deals primarily with emissions, including greenhouse gases, from electric power generation compared with natural gas. If you have a medical condition that prioritizes indoor air quality, that could tip the scale in deciding to go with electricity.
Fred
FWIW, The VT Electric Cooperative, which serves most of northern VT, is going carbon-free by 2023, and all-renewable by 2030 (getting rid of the nuclear portion). Some other regional electric suppliers are not all that far behind. The grid is getting cleaner everywhere. Right now we're at the tipping point. You're building a house and making decisions that will last for 20 years on the appliances and ideally 100+ years on the fundamental architecture. I can't imagine we'll still be burning dinosaurs for heat in another 20-30 years, let alone 100.
I live in Austin, in an all electric home. Heat pumps for heating / cooling work very well here as heating is almost a non issue (well except for a week or so this year :) ) I'm also about 3/4 of a mile for Matt Risinger's new build. I have a heat pump water heater, that works very well for two people and as an added benefit does some cooling of the garage. As others have stated gas cooking is the biggest culprit in indoor air quality. If you are outside of a city with some acreage, a propane tank is a good way to maintain a generator for those very few times you are out of electricity. For me, any backup generator is not feasible as I'm inside the city, small lot, and no gas in the neighborhood. I live in a tract home that I have virtually rebuilt. All exterior walls have been gutted to the studs, penetrations sealed with foam, slab to sill sealed with polywall liquid flash, rock wool insulation, R-zip with all penetrations sealed with liquid flash (zip 2.0) and new high efficiency Pella wood and fiberglass windows. The majority of my energy usage is my 750 gal hot tube and 2000 gal koi pond.
nice! With lumber prices being this high right now we just do not have a lot of wiggle room to accommodate more things into add-on insulation or better materials (Zip R vs regular Zip) ...still need to figure out how to up my R values for the roof and the walls to meet more ideal R values...I wonder how your electric bill looks like generally with your energy-efficient, all-electric home.
On an annual basis I average about 1500 KWH/month. When I run my hot tub the 11 KW electric heaters can really spin the meter. So a lot of my power consumption is not coming from my house. I'd look into solar but lot is too shady, which is nice, and I"m not cutting down trees to put solar panels on my roof.
For comparison though, I have neighbors without hot tubs, ponds, pools and keep their AC's above 75 F (my wife thinks anything above 74 is too hot) in the summer and still have much higher energy bills.
Our circumstances are so different that I am sure it is not comparable, but on the off chance it's useful to someone, we have a nearly all electric house (water heater is still gas), in Seattle, about 2400 square feet, two-story, mixed degree of air tightness/insulation, and we use about 8500 KWH per year, or just over 700 a month (way more in the winter, way less in the summer).
Up here in Zone 6, I am working on a spreadsheet that models the cutover point of where gas becomes more economical than electric. Somewhere between 7f and 13f gas becomes more economical based on the overall energy output which translates to December, January and February. This is why I am in favor of air to water heat pumps as they work down to -13f.
William,
Higher operating cost for a small percentage of the year doesn't necessarily mean more expensive. I'm in the land of cheap gas and expensive electricity, once you add in ancillary costs such as gas meter fee, yearly cost of heat pump works out to about the same as natural gas.
Air to water or air to air doesn't effect this math, same compressor technology making the same temperature air or water. There are a number air to air system rated for -22F operation. Anything hydronic is fun to design and tweak but does add a lot of cost without much benefit in most low load homes.
> Air to water or air to air doesn't effect this math
I disagree somewhat. Air to water allows storage which allows time shifting which should increasingly effect electricity cost. It also allows the avoidance of operation during cold nights and hot afternoons (which provides better COPs). It can also be combined with rooftop PV, often avoiding increasingly unfavorable net metering sell rates.
This is a green building forum. People should be considering more than just their direct $ costs. And preparing for a cleaner grid (but how fast this will happen is debatable and variable).
In many areas, the on-peak/off-peak price differences have been reduced, often by a LOT compared to what they were a few decades ago. This has made energy storage technologies like ice chillers much less cost competitive. I think this is dissapointing, not just because I've always thought the technology is cool (literally :-), but also because load balancing is a Good Thing. This shift has changed how I have to design some things because we can't plan to low-cost nighttime rates the way we used to.
People don't need to get hung up on net-metering, either. PV can work just fine as a peak shave system, especially in combination with time of day electric rates (you DO still save money this way, just not as much as before). Solar peak output lines up with the typical peak grid load, so you can "shave" off your peak load during the day. This means no more "net zero", but so what? You still reduce your energy costs, you still reduce grid load, you just don't have the plus and minus columns on a spreadsheet. I've never considered net metering, or the lack of it, to be a huge problem on the technical side for solar.
I agree there are other things besides just costs to consider, but it's also important to not completely disregard costs. Oftentimes excessive costs associated with a "green" technology relative to something else are a sneaky way of telling you that you'd be better off spending that extra money in a different way. More insulation might result in a lower overall energy use compared to a heat pump, for example (I didn't calculate anything, that's just a hypothetical to make a point).
Sometimes when people go in search of a green home, they focus too much on a few small items instead of looking at the entire system. The best results come from looking at the system as a whole, which is usually both most economical AND most green, since you're getting the most from the least resources that way.
Bill
Agreed, try to look at all components and alternatives, $ cost and environmental cost.
> Solar peak output lines up with the typical peak grid load
But not in California, Hawaii and increasingly in other places. Prepare for a world with cheap/clean sunny/windy period electricity.
> I am working on a spreadsheet
I encourage you to add a column for the often ignored cost of environmental damage.
I was not clear in my post - the average low point for Zone 6 is 7F - so well within a cost effective range of a heat-pump. In doing the math - a Natural Gas Boiler is hard-to-justify economically. when it may really only be needed 14-days out of the year. A small 9 KW 3-stage water heater has a lower up-front design cost and implementation cost.
It is better to spend the money on air sealing and insulation rather that on NG to heat the house.
Gas will remain in the mix of power generation in Texas for decades. That being said Texas is in a good location for taking advantage of solar. So what I would do is design/orientate the house so that is it "solar-ready". I would let your intended air tightness goal determine whether or not you want a gas or induction range as well as the location/type of mechanicals.
I don't know about the need for generator. A well insulated house should be able to get by for a couple of days w/out power.
I am attaching an image of the build site with its orientation. We are wanting to build this as an all-electric home to achieve great indoor air quality and avoid emissions from gas-operated fixtures and/or appliances. The only thing is that it would be nice to be able to cook during extreme weather occurrences and power outages.
https://blogs.scientificamerican.com/plugged-in/so-what-direction-should-solar-panels-face/#:~:text=In%20Texas%2C%20the%20current%20structure,demand%20as%20hard%20as%20possible.
2014 article. Not sure how much of it applies today.
'... In Texas, the current structure of compensating for the energy produced by solar panels incentivizes south-facing panels. However, what utilities really want are west-facing panels to hit peak demand as hard as possible. Given the limited daily solar resource, the market calls for something in the middle. ..'
Depending on your local gas and electric costs, going all electric can have some significant financial benefits. Where I live gas is deregulated and while the per therm costs is fairly low, there is a +/-$30 per month base charge for natural gas delivery. In the non-heating seasons even with gas water heating, cooking, and clothes dryer we will use only a few dollars worth of gas but pay the monthly charge. If the electric costs are low enough, and if you have time of use pricing, going all electric can provide significant cost savings, plus you eliminate the cost of installing gas lines in the house. I am on a time of use plan that increases electric costs weekdays June through September and reduces the rates significantly the rest of the year. Since I use heat pumps my winter heating costs are very low. I also have an even lower overnight rate which allows me to charge my Leaf for next to nothing. A standard electric or heat pump water heater and induction range are the last items to install to eliminate the need for gas. There is the issue of the cleanliness of electricity generation, but most utilities will sell you solar power for a premium, easing your conscience. High performance heat pumps produce hotter air than standard efficiency models, avoiding the cold air issue some people experience.
we are in hot and humid TX so probably more concerned of needing cold air in the hot summer than heating for the winter.
One point that I think gets overlooked in these discussions of efficiency is the IAQ concerns that come from having a gas appliances within the building envelope. Carbon monoxide as well as other products of combustion seem like an unnecessary risk at this point with the efficiency of the alternative electric technologies. I can understand the desire for fuel diversity in power outages, but I think as houses get tighter that gas usage can be quite dangerous in those power outages if you are reliant on an electric unit for ventilation at the same time. Personally, I have had a few instances of CO detectors going off and it is quite unsettling knowing there is potential for acute effects from something you can't see or smell, but also reading more into the low level long-term exposures make me think twice about having or planning gas appliances within the home.
Sealed combustion gas appliances don't have indoor IAQ issues. Things like gas cooktops, and especially unvented indoor gas fireplaces, do. I would never have one of the unvented fireplaces in my own home.
Bill
In an ideal world I would agree. That requires the equipment to be installed properly and for it to be maintained to keep it in that state throughout the lifespan. I am not sure how many people have their equipment inspected that diligently or install low level CO detectors for earlier detection of issues. Just from my observations and experience I wouldn't be surprised if sealed combustion appliances contribute more to IAQ issues than they should.
Gas ranges are for all intensive purposes maintenance free. The IAQ concerns are really not an issue. The issue is the expense with making sure a typical 30" range has a range hood and sufficient air. It's all about doing it correctly.
I can see where you are coming from, but I think practically the implementation doesn't support that conclusion. I would point to a multitude of studies that show gas ranges produce higher levels of emissions into indoor environments. (this article seems to cover the topic well: https://www.vox.com/energy-and-environment/2020/5/7/21247602/gas-stove-cooking-indoor-air-pollution-health-risks) I agree this can be mitigated with proper ventilation - if the occupants use it. In reality, I think many houses only have recirculation range hoods and many people only use the hoods if they are doing something smelly not realizing there are other IAQ issues. Finally, if the OP would like to use the range a a backup heating source in a power outage - I would think that becomes very risky as any ventilation system would not be functioning due to the power outage. Opening windows could mitigate that issue as well, but that would likely defeat the effort to heat the house.
@Aaron.
The risk associated with fuel type is overstated. Typical fearmongering used as justification to ban a fuel type (Nat Gas). The real health issue is PM2.5 which btw per the study linked in the article has essentially no bearing on fuel type but everything to do with how food is prepared. Going electric, induction won't solve the PM2.5 emissions problem so some sort of ventilation strategy is required.
What's next? Banning indoor cooktops?
https://www.osti.gov/biblio/1172959
To provide clarity on the original OP question and my previous response - my preference if the backup is your concern is to utilize the gas for a generator only. If that is a likely occurrence, it might be worth the extra expense for you to hard pipe that generator to a supply otherwise a propane tank and connected generator might be more cost effective as a backup if it is more unlikely/frequent to happen.
And, in the case of an event that limits gas supply as well as electricity, a propane tank is a more effective backup.
Hi,
I am in the process of starting a slab on grade house build where natural gas is not an option since it is not serviced in my area outside of the city which left us with all electric or include some propane appliances.
We went to all electric because propane, while still a bit cheaper, has additional cost such as tank rental/purchase, tank recertification and delivery charges. The other factor is we plan to add solar panel at some point down the road.
In our area we do lose power but it only seems to be a handle full of times per year and rarely do they last more then a day. For those reasons, I purchased a slight larger, 9400 watts, tri-fuel generator that I will be using during the construction phase but it will serve as my backup power once construction is completed.
For heat, we went against most opinion and included a wood stove to supplement our heating in Ottawa, Canada since we have 23 acres wooded lot and it will also serve as the backup heating during power outage.
Arnold
can u pls share the brand and model of your generator and how much it costs pls? honest question, why would u need a generator for construction? is it the norm to use generators during construction in Canada?
It's pretty common to use generators for at least the early stages of a new construction project. The reason is that the electric service doesn't get installed until further into the build, and temporary power, if requested/available, is often behind schedule. You don't want your framers waiting on the electric company...
BTW, for anyone considering a propane-fueled generator, the tank will likely be bigger than you'd think. A propane tank has to be able to boil off enough gas (propane is liquid inside the tank, at least until the tank is nearly empty), and it has to be able to do that at the lowest outdoor air temperature you expect to see. This often means you'll need a significantly larger tank than you'd need if you planned only to have a tank sized based on runtime. If you undersize the tank, you'll starve your genset for fuel, and that can damage the engine if it runs lean. Best case the genset will just shut down.
Nearly any natural gas backup generator can also run on propane with a small conversion, if even that (some just need a small adjustment). I like the Kohler units for residential backup myself.
Bill
I bought the Firman Model: T07571 that was on sale at Costco Canada. The sale price was $756.98 CAD down from the regular $1,199.99 CAD which is likely still on the expensive side for you guy in the USA.
https://www.firmanpowerequipment.com/shop/t07571/
As Bill mentioned, electrical service isn't installed at the early staged and my property is rural so I can't easily pull an extension cord from a neighbour.
The propane option is nice to have but it will be the backup fuel chose for me since like most, I'll have a BBQ tank laying around I can use if I run out of gas.
Arnold
You may find that a BBQ tank doesn't help much. Some BBQ tanks are flow rate limited, and will starve a generator for that reason. Other times, the BBQ tank can't vaporize enough gas to supply the generator. Running the generator lean can be a problem for the engine.
A BBQ tank, even when it is enough to work for you, won't give you much run time. If you're expecing long outages, you'll want to have a larger tank on hand.
Bill
>" I wanted to go Passive House if we could afford it but at the moment we are not quite there yet, so trying to do the next best thing given our budget constraints – to just build the best house we can with our resources."
In Texas with better than code house designs the amount of natural gas used during a given month will often be below the cost of having the gas meter. Sometimes it's cheaper for low volume users to go with propane, which doesn't have a monthly charge, but that's still not likely to be the ideal solution.
A gas or propane furnace will almost always be oversized for low-load homes, leading to lower comfort. But all but the lowest load homes in Texas will require air conditioning. Rather than split AC + strip heat solution, a heat pump right-sized for the ACTUAL cooling loads (with some margin) will have more than adequate heating capacity, and is less likely to be ludicrously oversized for the heating load than a gas furnace. A right sized modulating heat pump doesn't have large startup surges, and can usually be run off a reasonably sized propane or gas backup generator, whereas with strip heat + split AC start up surges and high continuous strip heat loads can double or even triple the capacity requirements of the backup generator.
While it's still in the design phase, designing it with a service chase (or a plenum truss) to accommodate the ducts and air handlers BELOW the attic insulation increases efficiency, lowers the capacity requirements of the equipment, and reduces the amount of air-handler driven outdoor air infiltration, which allows much better control over indoor air quality. While plenum trusses & or service chases add to the framing cost, but makes air sealing easier & more reliable, and results in lower HVAC equipment & operating costs. See:
https://www.greenbuildingadvisor.com/article/use-plenum-trusses-to-keep-ducts-out-of-your-attic
https://www.greenbuildingadvisor.com/article/service-cavities-for-wiring-and-plumbing
In my area it costs several thousand dollars just to hook up a house to the natural gas mains on the street. YMMV. In new construction the foregone connection costs can usually be put to better use by going all electric.
While conventional armchair analysts as well as many power industry pros continue to believe that gas will still be a major player in ERCOT grid generation for decades to come, there is plenty of reason to believe that won't be the case. The capacity factors of EXISTING gas generators keep falling year on year, increasing their average cost, and the cost of solar, batteries and wind keep falling. (Capacity factor is the average actual output divided by the full output rating of the of the equipment.) Already it's cheaper to install 4 hours of battery and a solar PV array than than it is to build and maintain a gas peaker of equivalent output. When looking at the still rapidly declining cost curves, in wind & sun rich Texas it's likely that well before 2030 the ;all-in levelized cost of renewables + multiple-day battery storage will be below even the maintenance cost of a combined cycle gas generator, let alone any remaining capitalization cost + fuel cost.
The folks at the Rethink-X think tank have run the numbers for Texas, California, and New England for grid solutions that use ONLY solar + wind + batteries against real-world capacity factors and the learning curves of wind/solar/battery technology and found that many solutions not only exist, but that the least-cost solutions are cheaper than business as usual fossil & nuke grids. They anticipate that even existing gas & nuclear generators will become uneconomic stranded assets, and that building NEW gas plants would be VERY financially risky.
In the past few months Rethink-X has posted several short to medium length videos explaining their analysis in simplified terms. While there has been some pushback on that analysis, the fundamentals are still pretty strong. A basic overview lives here:
https://www.youtube.com/watch?v=PM2RxWtF4Ds
A discussion of the stranding of fossil fired assets lives here:
https://www.youtube.com/watch?v=YJ-HlykM1LU
A big +1.
Don't split hairs on operational costs of gas vs electric. Comfort is worth paying for, worry about what is happening 90% of the time.
Consider this logic.
If you are concerned about power outages the best thing you can do with a new house is insulate and air seal enough so the home remains livable (if not comfortable) through a rare outage. If you do this the loads become low enough that two things are likely true. First, the only way the to be comfortable the vast majority of the time is a variable speed heat pump. Anything gas will likely be too big and you'll regret it. Also, you'll get very efficient AC that is more likely to manage humidity and load matched heat from the same device. Second, properly sized, I doubt you'll be needing more than 24k capacity which means an inexpensive gas generator will run the heat pump and keep ventilation active.