All-electric vs. natural gas in Zone 2
I’m building a house in Houston, Texas. It will probably be a ‘pretty good’ house – dense pack cellulose and exterior rigid foam installation with an encapsulated attic and targeting an ACH50 of <3 with an ERV system for ventilation. I will have a sizeable solar PV array on the roof – 6-8 kw so I have been debating whether to use natural gas as in my current house for multiple appliances or go all electric. Pros and Cons as I see them are: Benefits all electric: No standing monthly charge of $25 for gas since consumption is below threshold 9 months of year Avoids backdraft/air quality issues Heat pump better sized on small AC unit than furnace Induction cooktops offer similar performance to gas stoves Air heat pump hot water heater cools surrounding area – could be put in garage or encapsulated attic where cooling will be beneficial 9 months of the year Solar PV offsets large proportion of consumption Don’t have to run gas lines around the house – pays for some of the increased cost of hot water/induction etc Drawbacks: Electrical equipment more complicated and less reliable – don’t want repairs every 5 years Natural gas good for resale based on general consumer knowledge Gas dryer is great! Gives back up functionality if electricity goes down – Hurricanes are a potential risk in this area Anything I might have not considered here? Anyone else had to make this choice in a cooling driven climate? Anyone had bad experience with reliability of newer electrical units vs natural gas ones? Appreciate your experience. Markus
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Markus,
It sounds like you have analyzed this well. My conclusion is that all-electric is the way to go -- especially if you intend to install a PV system.
Green builders who look at our current climate crisis, and who want to be part of a global transition away from fossil fuels, generally lean toward all-electric homes equipped with PV.
I have no idea why you prefer a gas dryer to an electric dryer, by the way. When you open the door, the clothes are dry, no matter which fuel was used to dry them.
And it's simply untrue that "electrical equipment is more complicated and less reliable" than gas equipment. I've had a balky gas-fired tankless water heater from Bosch that has driven me crazy for years -- it has a pilot light that doesn't want to stay lit. Makes me wish I had a dumb-as-a-rock electric resistance water heater.
-- Martin Holladay
Make sure you put in all the connections, pipings, ventings, for natural gas, yes for resale value. Just don't use it yourself.
And yeah, gas dryer is great! And so is a gas range. Also, that $25 is a regressive tax for 12 months, not just 9 months.
Thanks for the feedback, I think I have garnered the impression on electrical equipment mostly being down to the high failure rate of electronic control boards I have seen. Both my fridge and oven died within a couple years from this and control panel failure seems to be an issue on air pump hot water heaters and induction cooktops as well.
On a side note if going for a air pump hot water heater do you think it would be most beneficial in garage or attic? Attic is main house envelope but obviously creates more of an issue if it leaks and I have to be careful around sound proofing for the attic floor so it isn't intrusive to the bedrooms.
Thanks,
Markus
I'd aim for at least 1ach50. It's not that hard to do. And induction cooktops give you all the benefits of gas, plus none of the IAQ issues. I've used both, never thought I'd give up gas, but now much prefer induction. We have a heat pump dryer that works well, with the bonus of no hole in the wall.
As for functionality in a power outage, you'll still have no gas heat or AC without electricity. As for cooking, you can use the outdoor grill in a pinch.
If I were putting pv in today, I'd look into battery storage for backup. It won't run the whole house, but you can get by with a single 10 kwh battery, using pv to recharge it during outages.
I disagree with Anon. For resale, people want to be comfortable. They are less likely to care about what fuel keeps them comfortable. Skip the cost of running gas pipes all over the place and build a nice right house, well insulated, heated and cooled with efficient heat pumps.
I'm not sure if or when it will be coming to the ERCOT region, but since FERC Order 745 has been blessed by the US Supreme court last year, companies aggregating electric water heater loads in to demand response programs and ancillary grid services markets can make enough to pay homeowners. A "smart" or "grid-aware" water heater can be as good or better investment than a heat pump water heater in some markets. The controls and the number of moving parts are a lot simpler than for a heat pump water heater. So far ERCOT doesn't have a capacity market to bid into, but high value frequency & voltage stabilization services are there.
One such aggregator operating large fleets of residential water heaters as a "virtual powerplant" in the PJM grid region is Mosaic Power:
https://mosaicpower.com/
Texas has some of the most creative and competitive electricity markets in the US- somebody will surely be tracking when & how aggregated distributed resources can make money there, but it may take some digging to find it. Some local utilities might have demand response programs to limit or avoid high spot market energy pricing too, even if the grid operator isn't running a more far reaching market. Being entirely within a single state the ERCOT grid isn't much affected by federal interstate electricity market rules established by the FERC, but as more connections to neighboring grids & markets get built that is likely to change.
Thanks for heads up on the water heater load management developments. I'll keep an eye on it as we get close to outfitting the house (which will probably be a year away). Texas does have quite alot of innovation in it's power markets so someone might well be trying something like that by then.
If you don't have gas it will lower the resale value of your house, good luck putting it in after the house is constructed.
Agree with Anon. Gas hookups will expand your pool of potential buyers especially if they don't want the PV array on the roof.
Just my opinion, but I think it makes no sense to spend money installing features you don't want, because some future buyer might want them. If it makes sense to use minisplits for heat and AC, installing ductwork for future gas heating, cooling and cooking doesn't make sense.
No one knows what a future buyer might want. And why wouldn't someone want pv?
People buy houses for a variety of reasons. However I can't see (nor have I ever experienced) a buyer passing up a well performing house because it didn't include provision for switching energy sources in the future.
By the nature of the content this forum attracts people interested in energy issues. The real estate market typically does so to a much smaller extent. I bet the absence of a walk-in closet in the master bedroom has more effect on the marketability of a house than gas stub-outs.
Yes, not convinced someone is going to want the home but not want the PV system. For the buyer attracted to the home the PV will be a selling point, not a distraction. Won't be visible from the street either. Discounted value of money over 10 years (estimated minimum ownership time) certainly limits attractiveness of upfront investment.
Anyone with a view of whether to put heat pump water heater in garage or encapsulated attic?
They won't pass on the house if it doesn't have gas, they just value it less. The higher end the house, the more it hurts the value. The inability to have a gas oven can often be a deal killer for high end homes. If this is a 100k house, you don't have to worry about this, people expect electric only at this price point.
You can find stories of home owner selling off the PV panels one by one during a home sale since the next buyer value it at less than 0. When in doubt, ask local real estate agents.
PS: not having ducts for force air HVAC will also hurt resale value, make sure you put it in even if they are unused.
What is the point of saving a few thousands in energy cost if you are losing hundreds of thousands down the road?
I've never met a cook who prefers a gas oven to electric. And once they use an induction cooktop, they all prefer them to gas.
I agree with Stephen. I've designed a lot of high-end kitchens and people who actually cook or bake prefer electric convection ovens. They have finer control and more even heat than gas ovens.
When it comes to cooktops, I always recommend induction, but I've had trouble convincing cooks (including my wife) to give up their $1000+ investment in All-Clad cookware to save on the order of $10 to $20 a year in energy use.
Reply to Michael: Your All-Clad cookware should work fine on an induction cooktop. My off-brand All-Clad clone works fine, as does cast iron. If a magnet sticks to it, it'll work.
Stephen, it is good to learn that most of All-Clad's line is compatible with induction cooktops: http://www.all-clad.com/Collections. Unfortunately ours (except for one piece) is their classic MC2 line, which is not magnetic. I'll change my sales pitch going forward, though--thanks for the info.
"Yes, not convinced someone is going to want the home but not want the PV system. For the buyer attracted to the home the PV will be a selling point, not a distraction."
Marc Rosenbaum thought that too but:
"One of the interesting twists in the sale of our old house was that I priced the solar electric system as an option, since it was an income generator, making $1,250 worth of electricity per year. Ultimately the house was purchased by our friend and next-door neighbor in the cohousing development. He is a staunch Tea Party Republican, and quite knowledgeable about investments and money — but solar isn't part of what the “drill baby drill” party wants to hear about. So he wasn’t willing to pay the $5,000 bargain price we established for the PV system. (A four year tax-free payback here!)"
https://www.greenbuildingadvisor.com/blogs/dept/guest-blogs/moving-new-house
"Anyone with a view of whether to put heat pump water heater in garage or encapsulated attic?"
Installing the HPWH in the conditioned attic is better from a whole-house efficiency point of view than putting it in the garage. A better-than-code house with a high SEER cooling system in Houston will have excess latent load to deal with. Installing the HPWH in the attic, inside the pressure boundary of the house reduces the latent load directly converting it to sensible heat inside the insulated tank, whereas a dehumidifier delivers it as sensible heat into the room air, raising the cooling load.
@Dana,
I'm convinced that one of the major political partys presently has a much bigger tendency than the other one to let facts be crowded out when the alternative is a simple message: "government bad, market forces always good". They don't seem to understand that the opposition party does not believe in the opposite of that, (or at least they shouldn't). The more reasoned approach is that both things should have their proper implementation and natural regimes in which they function best and have a proper sphere of influence. But that intrudes on the simple message that has been pounded into them by far right media sources ever since the fairness doctrine elapsed, and uncontrolled fake news over the internet. It has been allowed to short circuit reasoned thought and subtlety in analysis of everything.