Home Electrification: There's not a lot to do, and it doesn't have to be hard (Part 1)

Home Electrification: There's not a lot to do, and it doesn't have to be hard (Part 1)

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As we roll further into this decade, we will undoubtedly accelerate our collective endeavor to stop constantly working to extract gross sticky goops and explodey gasses out of the ground, spend more effort purifying and refining that gunk into products that we then promptly set on fire to just get a moment’s work out of... before we’re forced to do it all over again. Because, ya know, we set fire to it.

It’s gone now. Luckily, we have this amazingly flexible electric infrastructure out there which, while today does still do a fair bit of burning stuff to keep the lights on, is doing that less and less. We have these technologies that you build one time and then! They make electrical energy for decades just because they exist! And yeah they’re trickier to manage, which is a problem we’re actively working on, but every passing year breaks a new record for renewables generation, and that’s pretty neat.

And wouldn’t ya know it, most things we do today which involve setting fire to something have an electric alternative, including everything you do in your home. The catch, because there’s always a catch, is that those alternatives take work to deploy. So in this video, I’d like to discuss what’s needed to electrify the typical American home. It may seem like a daunting task, but it doesn’t have to be; we have some pretty slick tricks up our sleeves. This video is the first of two parts.

Here, we’ll mostly be talking about how energy management innovations can sidestep the headache of a service upgrade. In part two, we’ll discuss alternative appliances which can make the switch even easier, and we’ll also go over some potential solutions to dealing with power outages in an all-electric home. Three quick notes before we start: First, I’m going to be focusing on the American home because, y’know, me live there, but the fundamentals are generally the same no matter where you are. Second, I’m not going to go into operating cost comparisons here as that’s a very local consideration. But I will just point out with a hint of snark that in case it has escaped you the prices of fossil fuel products have gotten pretty dang volatile lately, meanwhile electric technologies continue to get cheaper and more efficient. And lastly, in a similar vein, I’m deliberately not talking about the stuff that needs to be done to the power grid.

You don’t need to write-in about that — we all know that’s a big challenge ahead of us, but that work is happening as we speak. I’m here simply to talk about the work that needs to happen in your home to make setting fire to stuff just to live your life a thing of the past. And the good news is that in many ways, it already is.

The vast majority of the stuff you use and rely on is electric: from hair dryers to air fryers, curling irons to waffle irons, your refrigerator, deep freeze, that extra fridge you have in the basement, coffee maker, panini maker, microwave oven, toaster oven, your air purifier, your computer, your phone, your internet modem, your TV, your game consoles, lava lamps, videocassette recorders - all that stuff plugs into the wall and gets power that way. They even — get this — they even make cars now that plug-in. Something tells me this electricity business is really catching on! In fact it’s caught on so well that entirely-electric homes are quite common! They’ve been the norm for decades in some parts of the country. However, particularly in colder regions, many millions of homes are out there which currently rely on combusting a fuel somewhere inside them to provide heat. You, like me, may very well live in one of those homes. Sometimes the fuel is the scented methane we like to call “natural” gas, or it could be propane, fuel oil, maybe even wood or if you’re feeling particularly old-school coal.

That is in fact still a thing in some parts. Although homes which burn fuels almost always have access to electricity, too, they still very much rely on those fuels to function. And that presents some challenges to completely electrifying those homes. How many challenges, you ask? Four.

4. Seriously, it’s just four. At most. And that’s the really good news here. Unless you’ve got something fancy like a gas fireplace or a garage heater, maybe a grill, you only have four things which might use one of those fuels.

♫ sudden game show music ♫ And they are... Your furnace! (or boiler if you’re of that persuasion). Your water heater! Your kitchen stove! And lastly, get ready Europeans, here comes another weird American thing, your clothes dryer! Yeah. We do that here.

Look! New LG tumble dryer… hooked up to a gas line! A very good and normal practice! But that’s really it. Your heat source, your water heater, your stove, and your dryer are the only four things we have to contend with. And many homes, especially if they use a fuel that's not natural gas, already have the electric version of one or two of those. Maybe even three.

Speaking of three, dryers, water heaters, and stoves don’t vary all that much from home to home so installing the electric versions of those things is pretty straightforward. The only thing that’s gonna need much customization is your heat source, and that’s not exactly a new reality anyway. So… if there’s only four things to tackle at most… why is this difficult at all? Well, those four things all need a lot of electrical power to operate - significantly more than can be provided by a standard household outlet. But that’s no problem, right? Everybody’s got access to 240V in their electrical panels, so just run new wires and Bob’s your uncle! Well, sure, that’s something that’s gonna need to happen (if we assume conventional appliances, stay tuned for part 2!) but the lack of the appropriate circuits going to those appliances isn’t the only problem. There’s also one of capacity.

That’s the real show-stopper, here. Many homes that lean on gas appliances to do the heavy-lifting don’t have enough electrical power available to make all those electric things work. Except, uh, they do. Almost always. Conventional wisdom says they don’t, but conventional doesn’t always mean correct. But first, one last side-note.

I promise, this is the last one. I should address here if you haven’t already gathered that so far I’ve been talking about single-family homes, and, well, that’ll continue to be the case as we go on. Multi-family buildings will face many of the same challenges for electrification, but there are just so many different ways that they can be set up. For instance, lots of apartment buildings have big central boilers that distribute heated water to radiators, but others have fairly conventional furnaces with central air conditioning in each unit, and others still have packaged air conditioners which already provide electric heat.

And that’s before we get into water heating which may or may not be centralized. Setting aside all that wonkiness, retrofitting those buildings is outside the responsibility of tenants or a collective responsibility in the case of condo ownership. So while I’d like to talk beyond single family detached housing, other situations are just way too complicated to get into, your mileage will vary, see store for details, let’s get back to the capacity problem.

Alright, so generally, a home built here will have either 100A or 200A electrical service. Those aren’t the only two options available, but they’re the most common by far. If you have 200A service, you don’t even need to be watching this video - your home can easily be all-electric right now, assuming it’s not a McMansion. But oodles of homes, even pretty big ones, only have 100A service.

And this was a perfectly rational choice back in the day. Gas appliances usually need some electricity to operate, but that’s just for running blowers, pumps, igniters, and control boards. They get their heat energy from the fuel they burn, so they don’t really tax your electrical system at all. When all your appliances which could be gas are gas, the only big electrical demand in your home is air conditioning, and even if you need a real big honker of an AC unit, you’ll have at least 50 or 60 amps left for your lights and whatnot. And that’s more than plenty.

However, electric appliances like heaters, stoves, and dryers have to convert electricity into heat and that takes a lot of power. To give you some sense of their power needs, a conventional electric water heater pulls 18-24 amps when it runs. A clothes dryer pulls pretty much the same when you’re using it.

And a 3-ton air conditioner when it’s running? Well there’s another 20 amps right there. Just those three devices pull perhaps 65 amps. And a conventional electric range can pull up to 50A. Switch that guy on for dinner and now we’re at 115 amps! Which is too much! We’ll trip the main breaker every time we make dinner, so I guess we have no choice but to arrange for an expensive and disruptive electrical service upgrade.

But hold on a minute. Did you catch the little qualifiers I kept sneaking in there? When it runs. When you’re using it. And up to. 100A electrical service still allows you to pull up to 24 kilowatts (!) from the grid, and that’s a lot of power! Way more than you almost ever use.

On average, US households consume 1.2 kilowatts. Which only 5 percent of that. Now obviously, that’s an average. Over the course of a day, power consumption goes up and down depending on what you’re doing at any specific time. But that is the key - time.

We’ve got lots of it to play around with. Most of the time, our homes are just sipping power from the grid. Heck if you’re away from home on a mild day without the need for heat or air conditioning, assuming you didn’t leave any lights on, the only electrical loads are your fridge and internet modem. And those are tiny! Even if we add up all the vampire loads from your smart... whatevers, we’ll draw maaaaaybe 2 amps. Unless the fridge happens to be in a defrost.

Then maybe it’s more like… five. At least until it’s done. Anyway, the point is we only draw large amounts of power when we’re actively doing stuff! Even heating and cooling, which is the largest energy expense of most homes, isn't a constant load. Extreme weather might make an HVAC system work really hard on rare occasions, but even when that’s happening we can work around it. The only practical limitation of 100A service is that you can’t run every high-power load in your home at the same time. That might sound like a bummer but I promise that you never actually need to do that.

Now before you start thinking I’m gonna give you a big flow chart on how to manage your energy use manually, rest assured that’s not where I’m going. But think about this for a bit. How often do you actually use your dryer? Probably on laundry day for a few hours, right? The vast majority of the time, that’s not an electrical load you have to consider. How about a water heater? Well, it will actively run when you’re using hot water and for a bit afterwards to recharge the tank, but once the tank is back up to temp, it hardly runs at all. Alright, and now let’s consider a standard electric range (which, by the way, just means combined cooktop and oven).

While one of those can pull 50A, it’ll only do that IF the oven is on and ALL of the cooktop burners are on, too, and at *full-power* So in other words, it never pulls 50A except for maybe a few seconds on Thanksgiving. Most of the time it pulls essentially nothing, but even if you’re cooking a complex meal and using all the cooktop burners, most will be running at reduced power or cycling on and off, same with the oven element once it's preheated, and so more realistically it pulls perhaps 25A - and again, that’s only when you’re using it. So obviously, if you’re just a little careful about what you do and when, you could have all the electric things without going through a service upgrade. You just gotta make sure all those big loads don’t come on at the same time.

Heck, you can even throw high-power electric car charging into this mix so long as you make sure the car can’t charge when other stuff’s going on. This might sound tricky to manage, but what if I told you that smart circuit breaker panels are now a thing? You might very well do what I did and go like this: [exasperated sigh] What‽ No! Stop it! That’s the silliest thing I’ve ever heard of. This IoT stuff is really getting out of hand. What could you po… oh. OOOHHHHhhHHhhHHHHhhHHH. Right now, your breaker box has one job: safely distribute power throughout your home.

The main breaker keeps you from overloading the wires going into your house, and the other circuit breakers keep you from pulling too much power on the individual circuits they protect. Some might even offer arc-fault protection and ground-fault protection, too. But that’s it. It won’t disable power to any circuits for any reason other than a fault, and then you gotta have Jimmy go reset it.

But what if it could selectively disable power to high-draw loads when required, and reconnect them later? Since all the power in your home goes through this thing, it could easily monitor which circuits are active and how much they’re pulling. With some pretty simple programming, you could have such a breaker panel divvy up those 100A across devices, keeping you from ever exceeding the limit, and all while prioritizing active circuits so you don’t even realize that’s happening. Span is one company offering smart load centers (that’s the technical term for breaker panel). They’re not paying me to talk about them, I was connected to them via a fan of the channel, but I did have a conversation to discuss the details of their product so I could better understand what it does and how people use it. At its core it's a breaker box like any other, in fact it even uses standard circuit breakers which remain the protective devices and allow for manual circuit isolation. But behind each circuit lies an additional switching device that the panel can control.

Plus, it monitors power at the individual circuit level, allowing you to determine exactly how much power is being drawn and where it’s going. Right now, Span’s main customers are folks interested in things like solar energy and battery storage integration who want to be able to track and optimize their energy production and use with the data the panel can provide. So, in other words, nerds! I say that with affection, of course, because that very much includes me. That’s very cool! But, part of that optimization is identifying low-priority circuits so they can be disabled in times of energy scarcity. That can extend your runtime when operating on stored energy, and thus lower the amount of storage you need in the first place. But not everyone is a well-off energy nerd who can afford solar panels, batteries, inverters, and all that jazz.

Most of us rely on the plain ol’ grid, and what excites me most about Span and products like it is that they can eliminate the expense of a service upgrade and bring complete electrification to far more people with far less work. Now I know not everyone will love the idea of smartifying your breaker box, but before you dismiss it let me illustrate the potential. Say you’ve got conventional electric everything — let’s even throw a 30A car charger in the garage — but you’ve only got 100A service. Conventional wisdom says this is a terrible idea and you’ll be tripping the main breaker constantly.

But if you assign priority levels to each of those high-draw appliances, a smart panel can prevent lower-priority devices from running when others are in use and eliminate that problem. Let’s say you arrange it like this: Your HVAC system always takes priority. Next is your stove. Then your dryer. Then your water heater. And finally, your car charger. That would be my recommendation, I think. With the panel constantly monitoring the total draw on your system, a hypothetical cold winter evening might look like this: Your heat pump is running hard and combined with all the other low-power draws in your home you’re drawing 40 amps from the grid.

You start making dinner, and switching on the oven plus a burner on the stove brings that up to 60 amps. At this point, since another large load like the microwave, water heater, or even just another cooktop burner might appear, your panel preemptively disables the car charger. You probably weren’t even charging the car anyway but we don’t want a surprise 30A showing up right now. So now, let’s say someone else in your home decides to start laundry while you’re cooking. Adding the dryer to the mix while cooking a meal with the heat running pushes you up to 80 amps - and at this point your panel takes further action, temporarily disabling the water heater.

Which, by the way, is a perfect load to kill as even if it stays off for several hours, the water in the tank will stay piping hot and you can still use it as you please. It’s literally a battery, just a hot and wet one. Once you’re done cooking, the panel recognizes the load from the stove has dropped off so it re-enables the water heater, re-charging that wet-hot battery (if needed). The car charger remains locked-out, though, as the higher-priority dryer is still in-use and the heat is still running.

Once the laundry's done, though, your car is free to charge again. I hope you see the potential here. This hypothetical home would have been at risk of tripping the main breaker, which is never fun, but disabling lower-priority loads prevented that from happening. Your breaker box can be more than just an energy distribution device — it can be a command center, too.

And all throughout this scenario it could send alerts to you to inform you of what exactly it’s doing. Plus, with deeper integration with appliances, we don’t even need to go all-or-nothing. As a matter of fact, Span offers an intelligent EVSE, or car charger, that can offer charging speeds as high as 48 amps when possible, and dynamically lower output when other demands in your home increase. So maybe you can’t charge quite so fast when you're cooking dinner, but you can still be charging. There’s still a lot more potential here, though.

Span and products like it are connected to the internet — though real quick they don’t necessarily have to be! I know plenty of folks will scoff at that and I brought this up in my conversation with Span. I’m leery of it being online myself. I expect we’ll eventually see some sort of local configuration option which is set-and-forget. Details TBD. However, remote monitoring can be quite useful.

For instance, it could tell you something is wrong with your heat while you're away. And with the proper incentives and permissions, a smart panel could also be an important strategy in so-called virtual power plants, which allow utilities to manage and balance power needs by, say, commanding water heaters to switch on when there’s excess power on the grid, or reduce demand in power emergencies in a more delicate fashion than “just shut entire neighborhoods off.” But that’s largely future stuff, and may I remind you before you write in with your dystopian hot takes, remember I said with proper permissions. I hear you, and understand you, but let’s be reasonable. Working together has some benefits, y’know.

Now, energy-managing load centers like Span are creating something of a new frontier. Electricians might look at you like you have three heads if you say "I want to install one of these so I can get electric everything with 100A service!" And that’s understandable. Electric codes dictate that load calculations be done to determine the minimum service level for a home based on what’s in it, and old calculations will generally not result in 100A being OK for an all-electric home. But the good news is that the code is adapting to these new load-side management solutions. It may take some time for knowledge of the solutions to spread to permitting offices, utilities, and other regulatory bodies, though, so that’s something to keep in mind. And hopefully I’m helping! Also something to be aware of is that if you’re looking to make any of the changes we’ve discussed so far, there may be incentives to do so.

That might be in the form of a rebate or a tax incentive, and that’ll vary depending on where you are and what else you might be doing. You’ll definitely want to consult with someone who knows those particulars, and for the record that is not me! But I don’t want you to leave money on the table. And finally, let’s now get into the weeds of the tricky thing that is building heat. Dryers, water heaters, and stoves can all easily be managed and installed as they’re just single objects without too much variation from home-to-home and climate-to-climate.

But what heats your home can be any number of things and also depends on the size, age, and condition of your home. And let me start with that - I’ve said it before in other videos, but a key thing we need to be doing is building envelope upgrades to reduce the need for heating and cooling energy in the first place. More insulation and better windows and doors will go hand-in-hand with building electrification, as the less heating and cooling you need, the easier it is.

Luckily some incentives are starting to roll out which you should look into if they’ll be helpful for you, but for the purposes of this video, we’ll assume your home is already reasonably well-insulated. Now there is one thing I know for sure, and that is that what you’re gonna need to efficiently heat your home with electricity is a heat pump! With one of those bad boys you can spend 3 kW of power running the pump and get 9 or even 12 kW of heat energy out of it. They're the closest thing we have to free energy and that’s why they’re cool as beans. Check out this video of mine if you want to know how exactly they work. But what precisely getting a heat pump will look like depends a lot on what currently heats your home.

If you have a forced-air furnace, you’re probably in an ideal situation. Especially if you currently have central air conditioning, because that means you already have a heat pump! It might only pump one way because why spend the $50 on a reversing valve when gas is cheap? But you’ve got a 240V circuit already going to the outdoor condensing unit. That’s a huge leg-up and there’s tons of housing here in the US set up precisely this way. That’s good. Even gooder is that cold-climate air-source heat pumps continue to get better at operating in frigid temperatures.

Heat pumps that work effectively below -10°F are just around the corner from domestic manufactures, and, uh, already here from Asian manufacturers but nobody tell the likes of Carrier or Lennox, it might hurt their feelings. Anyway, once those are commonly available, the same circuit that currently runs your air conditioning can also run your heat. It may need to be bumped up in size depending on your specific situation and heating needs, though. The more daunting challenge for electrification is how to manage resistive backup heat. When it gets so extremely cold that a heat pump can’t work effectively, or even just to provide backup in the case of a mechanical issue, good ol’ fashioned heating elements will step in.

That could be as simple as some space heaters strategically placed around your home, but most people appreciate a more permanent option. In a home with ducted, forced-air heating, so-called heat strips in the air handler can switch on when needed turning that air handler into a giant hair dryer. There’s just two problems: first, well there’s another circuit you'll need to run. Your furnace has graduated and needs more juice. And second, it might need a LOT of juice. In a large home, the heat strips might suck down 20 kilowatts.

That’s 83 amps right there. In one thing. However, and I cannot stress this enough, heat strips are rarely needed when you have a heat pump. Already in many climates they’re basically only there to aid in defrosting the heat pump and to provide a backup in case the heat pump fails - in fact many thermostats will refer to heat strips as “emergency heat.” And if you live somewhere it hardly ever dips below freezing, you can probably just skip them altogether. So the heat strips are not something we should expect to operate frequently and as heat pumps develop and get better at working in extreme cold, they’ll become less and less necessary.

Resistive backup heat is just that - a backup. Keep that in mind as we continue with this discussion. Of course, we still need to plan for having that backup but, hot take 20 kilowatts of heat strips is probably rarely necessary, especially if we do insulation retrofits like we absolutely should. As a piece of anecdata, my mom and dad live in a pretty large four-bedroom ranch-style home that’s about 15 years old.

Including the finished basement, they have 3,500 square feet of conditioned space. A decent chunk. And their house is all-electric, but for some silly reason they don't have a heat pump. They have entirely resistive heat, and what they call the “furnace” is really an extremely cheap air handler with a contactor for its blower motor and two beefy contactors for the heat strips.

The thing's hilarious, it has no logic circuitry in it at all, the thermostat is the only control mechanism and when it calls for heat there’s a big “THUNK” and then the lights get a bit dimmer and it delights me in its crudeness! Anyway, the heat strips in their air handler are indeed of the 20 kilowatt flavor. See, there’s two 10 kilowatt doodads in there. But even when it’s extremely cold outside, their home has no trouble at all staying warm. Over this past Christmas it was stupid cold and pretty windy, and on December 23rd it never even broke zero degrees Fahrenheit outside.

Yet, even keeping the interior a comfortable 68 degrees, the thermostat only called for heat for 15 hours. Yes, that’s a lot, but clearly they’ve got a huge margin for error. They’d be completely fine and still have some margin left with only 15 kW of heat strips.

And as it turns out, that’s exactly what they have! Each 10 kW heat strip unit is actually made of two 5 kW heating elements, and one of them happens to be burnt out, meaning they really only have 15 kW and that’s been the case for who knows how long. But wait! There’s less! Those heat strips are constantly cycling on and off thanks to a limit switch whenever the heat's running. I don’t know if that’s normal behavior or if their blower speed is set too low or something but each one is only on about ⅔ of the time. So in reality, their home only has ⅔ of ¾ of 20 kW. Or 10 kW of heat output. And that 10 kW was only needed for 15 of 24 hours on an extremely cold day.

Yeah, their home is fairly new and well-insulated, but it’s also no passive house. They’ve got old-fashioned double-hung windows everywhere and other than some extra attic insulation, the house is basically just built to the code minimums of the day. Yet we know exactly how much heat output it actually needs to stay warm in the coldest weather we get, and it’s nowhere near 20 kW.

It’s actually more like… six or eight tops. By the way, this sort of data-logging is a really valuable thing smart thermostats provide. You can use it to find out just how oversized your heating system is, which around here they almost always seem to be by a factor of 2.

But anyway, circling back to the smart breaker panel, even if you truly need some big ol’ heat strips for your home (which again, I cannot stress this enough, that should only ever be necessary on rare occasions) Well, we can still manage that load so long as we’re clever about it. Say we had 15 kw of heat strips and the smart breaker panel that could power-limit them in chunks of 5 kilowatts. That would mean that should you need to, you can throttle the heat output rather than just shut it off entirely. So when other loads like the water heater or stove threaten to push you over 100A, we can just knock off 20A from the air handler which will reduce output slightly but still provide you with heat.

And of course when those other loads disappear, we can send the full amount back to the air handler. We like to pretend 100A is not a lot of power but folks - it really is. We just have to use it wisely. So far, I’ve been talking about what homes that currently use forced-air furnaces and central air conditioning will need to do to electrify themselves. That’s a huge amount of housing here, but it’s definitely not universal.

You might have a boiler which makes water hot and pumps that around to radiators throughout your home or perhaps an in-floor heating system, and that might also produce domestic hot water for bathing, too. There are heat pumps which are designed to replace boilers, but they’ll be a bit more work. You’ll need to run a new circuit to an outdoor unit, plus new plumbing and whatnot. And if that’s the situation you’re in, you may want to look into ductless mini-splits which can also provide cooling in the warm months.

As far as what you’ll do for your backup emergency heat... ah, I’ll let you be creative. We’re pushing into half-hour territory but there’s still a lot more to talk about. So far I’ve discussed what it would take to swap your conventional gas stuff for conventional electric stuff, and how we can use energy management to make that possible with limited electrical supplies. But that’s still a lot of work.

Thanks to the miracles of heat pumps and batteries, though, we can avoid much of that work. In part two, I’ll talk about heat pump water heaters, clothes dryers, and stoves with batteries. We’ll also discuss options for dealing with power outages. There will be a clicky thing popping up right about now which’ll take you there once it’s ready.

But for now, thanks for watching. ♫ divvied-up smooth jazz ♫ Just those three devices pulled per… Nyyaaagh! But hang on a minute. But hang on. But hold your horses. But hang on, though. [laughs] OoohhhHHHHhHHHHHhhH OoohhhHHHHHHHhhH OoohhHHhHHHHHhhH Your HVAC system always takes priorit[eh] … why am I running out of vocalization before the end of “priority?” Your HVAC system always takes priorit[eh] Why is that happening? Priorit[eh] …thing we need to be doing is building envelope upgrades to reduce the need - should I keep that in? I’ll start over.

So one of my favorite things about electricity is playing around with load limits and things like we've been talking about here. It's helpful not only in the individual home, but also to the broader grid. The more we can spread periods of high-demand out, the easier managing everything becomes.

There's a lot of.... potential there.

2023-03-07 02:15

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