electric-boilers-a-green-alternative-to-heat-pumps-that-no-one-is-talkin

HydroNiCK

Just saw this article. Have any of you installed one recently?
https://theconversation.com/electric-boilers-a-green-alternative-to-heat-pumps-that-no-one-is-talking-about-170479

Jamie Hall

There is a reason no one is talking about it. Unless you live in an area with a very large fraction of "renewable" power -- that would be nuclear, wind, solar, hydro -- electric boilers are anything but green (same thing is true for electric cars, electric trains, whatever.

The problem, of course, is that most people -- and most journalists -- can't see past their front doors. The power has to come from somewhere, folks. It doesn't just magically appear on those wires. And that somewhere is fossil fuels much of the time. A really good fossil fuel power plant may have a thermal efficiency of as much as 40%. Then you lose a little in the power lines, so call it 33% thermal efficiency by the time it gets to the point of use.

Granted, the electric boiler is 100% efficient -- but the overall thermal efficiency of the system is stuck at that 33%.

A good modern boiler on either gas or oil is 85% to 95%.

Which one is greener?

The whole thing is very tiresome.

jimna01

I will give two very good reasons to continue to continue to ignore electric boilers. In the northeast United States we pay as much as 22 cents per kWh (9 cents generation, 12 cents per kWh for distribution). I would go broke heating my house with resistive electric heat whether that is a boiler, furnace or electric baseboard. Even a domestic water heater is economically a stupid idea where I live. The other issue is I live in an area where we can get extended power failures in the winter. Good luck running an electric boiler of either a generator or solar power.

Zman

This is exactly why I told my kids that if they want to get into the sustainability field, they must start with a science-based undergrad. We can't afford to have more imbeciles like that author walking around on earth professing to know something.

dopey27177

Electric boilers serve a purpose in some spas where steam or super hot hot water boilers cannot be used to heat a steam room or dry heat sweat bath.

These spas can afford to pay the high cost installations and electric for the enjoyment of their clients

As was said the efficiency of these units and the cost of installation and operation for heating and or making domestic hot water is so low and environmentally ridiculous that a normal person could never afford to operate an electric boiler even if the rates were only 10 cents a kilowatt.

Jake

Hot_water_fan

Electric boilers will have a place - they can be used for very small installations or to supplement other kinds of systems with very low capital (and very high operating) costs. It'll be a bit of minor role.
The technology that holds the most promise but with low development to date is air-to-water heat pumps. They would fill a niche and offer a way to ditch fossil fuels (on site) for hydronic systems.

Zman

If the grid ever gets above ~60% renewable, electric boilers will have a great role and be a smart choice for some clients. Right now, they cost more to operate and have a significantly larger carbon footprint than any other heat source.

JakeCK

Lots of talk about why electric boilers are a poor choice for primary heat without many numbers so let me provide some.

This past July was my highest electric bill at just under $200. I used 1305kwh. Now a btu can be converted to a kw, or a therm or any other unit of energy. So how many btu's could that 1305kwh provide at "100%" efficiency? About 4.45 mbtu's. Sounds like a lot? Not really. At design my house requires just over 60k btuh. If we had a full day of 5-10f outside I'd need about 1.5mbtus to heat my house. Now imagine a full week of that in January? In less than 3 days I could rack up an electric bill comparable to my highest in July. 

No thank you. 

They have their place but not as a primary source of heat.

Actually I had thoughts of using a small 6 or 9 kw electric boiler to help heat a large buffer tank during the day when I over produce. This because I get paid less for the watts I put into the grid than what I get charged for the watts I pull from it. But I'm still not sure on the cost/benefits. It could work for the shoulder season.

Zman

In some markets, the cost of resistive electric heat is similar to propane or oil. What bothers me is the assertion that it is greener. It simply is not....

JakeCK

Zman said:

In some markets, the cost of resistive electric heat is similar to propane or oil. What bothers me is the assertion that it is greener. It simply is not....

I was told by a former friend who lived by, I believe, Quebec that they used electric boilers around there. But only because hydroelectric is plentiful and electricity is as cheap or cheaper than fossil fuel. So yes exceptions exist but unless there are dramatic changes to our grid they are not a smart choice for the majority.

I'll be honest though I am holding off replacing my 30year old more than twice oversized CI boiler because there are a lot of changes happening in the world and I'd rather not sink the investment in a new boiler only to have there be large changes in the energy landscape. 

Zman

Any new or substantially remodeled project should be future-proofed by designing the emitters to use low temp water.
From there, you can adapt to whatever heat source makes sense at the time. There are very few alternative energies that perform well at high temp.
Solar thermal, heat pumps, condensing boilers, low grade nuclear (OK, I made that up, but I think it would) all required low water temps. Resistive electric heat is a band-aid for poor planning.

JakeCK

I'm still wanting to replumb my whole system to utilize a buffer tank and microzones. One of my thoughts was to run pex and the transfer plates between the floor joists for downstairs. That would be over 700sq ft of floor. This in addition to keeping the ci rads and lots weatherization upgrades.

Hot_water_fan

In some markets, the cost of resistive electric heat is similar to propane or oil. What bothers me is the assertion that it is greener. It simply is not....

@Zman Not necessarily: New York State has emissions of .415 lbs/kwh, which makes electric resistance 36% lower emissions than oil, about 23% lower than propane and similar to natural gas (+5%). It'll vary based on the location and is subject to change as the grid changes. Obviously a heat pump is an 2x-4x improvement over all of these figures, but there's a small place for electric resistance.

Jamie Hall

That figure for New York included the contribution of the Indian Point nuclear plant -- which closed three months ago. It provided about 25% of New York's power -- at 0 emissions. It doesn't have that any more... now what's the figure?

GroundUp

Electric resistance heating is not, has never been, and will probably never be "green" unless somebody can convince the gubmint that nuclear power is the answer. With that said, the end cost to the user is often less costly in systems with smaller heat loads. I am in an area where dual fuel systems are very common and those rates are 5-7 cents per kWh versus 10-15 standard, depending on the provider. With that, I have installed well over 100 electric boiler systems in the past couple years versus maybe 20 gas systems because they're more cost effective and reliable. Green? Absolutely not. But the end cost to the consumer is definitely lower for most anything under about 40,000 BTU at design- in my neck of the woods. With the cost of gas skyrocketing this year, the numbers are almost scary. I just figured out as system for a gentleman last week who requested an electric boiler for a large building with a 118,000 BTU design heat loss. I thought in my head that there was zero chance it'd be more cost effective than LP, but actually penciled out the numbers and with current pricing, the electric boiler over a 20 year span would hypothetically save him just shy of $8000. I am installing a 36kw unit for him in a few weeks.

JakeCK

GroundUp said:

I just figured out as system for a gentleman last week who requested an electric boiler for a large building with a 118,000 BTU design heat loss. I thought in my head that there was zero chance it'd be more cost effective than LP, but actually penciled out the numbers and with current pricing, the electric boiler over a 20 year span would hypothetically save him just shy of $8000. I am installing a 36kw unit for him in a few weeks.

I can believe it with LP. And the fact he requested that specifically makes it sounds like he had already done the math too.

Jamie Hall

Sometime some years back I penned a comment, more or less as follows:

The job of the heating professional, or in fact any engineer, is to determine what the client needs and then provide the client with the optimum solution to the needs, taking into account safety, operating constraints (do you have maintenance?), operating costs, capital costs, and so on.

Note that this is not necessarily the theoretically best solution. It is the best solution for that client's needs, at that time, and in that situation. The two are not always -- in fact frequently are not -- the same.

It is NOT, repeat NOT, the job of an engineer -- or heating professional -- to be an advocate for this solution or that one, for this technology or that one. That is the job of a salesperson or a politician.

I could -- and have -- written sermons on the general topic, but not here or now. Leave it at the above, and think about it.

Solid_Fuel_Man

What is green? 

Let's see.....

Solar? Where do the rate earth metals come from....and who is manufacturing the panels and their real world lifespan? Manufacturing footprint? 

Teslas? Where are the batteries coming from, are they recyclable, and what on earth is making those kWh? 

Biomass? Well an arguemant can be made here, but most green people dont like forestry in general.......just have to use blow downs and let forest fires roar.....

Wind? What is the real world lifespan of a wind turbine, what resources are used and how much carbon is emitted in their lifecycles? 

Using phase change refrigeration? As a licenced and long time refrigeration tech, all I can tell you is that every.....and i mean every ounce of refrigerant that goes into any air source heat pump has been or will be emitted to the atmosphere. I've fixed more leaks in those than any other refrigeration system. Outdoor coils, indoor coils, line sets, stupid flairs, a few EEVs, a compressor or two, chang over valves. I've changed them all. I dont know how R410a does in the atmosphere, but some has been in a few people's homes. 

I'm mixed on nuclear, I think if we really put our minds to it and left the regulation out of it for the design of a reactor and plant. Then made sensible regulations that are not 1970 we could move to a nuclear grid. But not in the current state of nuclear.

hot_rod

Solid_Fuel_Man said:

What is green? 

Let's see.....

Solar? Where do the rate earth metals come from....and who is manufacturing the panels and their real world lifespan? Manufacturing footprint? 

Teslas? Where are the batteries coming from, are they recyclable, and what on earth is making those kWh? 

Biomass? Well an arguemant can be made here, but most green people dont like forestry in general.......just have to use blow downs and let forest fires roar.....

Wind? What is the real world lifespan of a wind turbine, what resources are used and how much carbon is emitted in their lifecycles? 

Using phase change refrigeration? As a licenced and long time refrigeration tech, all I can tell you is that every.....and i mean every ounce of refrigerant that goes into any air source heat pump has been or will be emitted to the atmosphere. I've fixed more leaks in those than any other refrigeration system. Outdoor coils, indoor coils, line sets, stupid flairs, a few EEVs, a compressor or two, chang over valves. I've changed them all. I dont know how R410a does in the atmosphere, but some has been in a few people's homes. 

I'm mixed on nuclear, I think if we really put our minds to it and left the regulation out of it for the design of a reactor and plant. Then made sensible regulations that are not 1970 we could move to a nuclear grid. But not in the current state of nuclear.

Nuclear plants need fuel also. It is mined, shipped and processed with diesel and coal fired electric plants. Clean coal probably

But the harder sell for the public is how to handle the waste. It has been piling up for years in temporary storage facilities around the country. No permanent home on the horizon. Allegedly some of theses underground facilities are leaking radioactive fluids into the ground, rivers and seas?

If you can harvest your fuel in your yard and burn it cleanly, wood and biomass, that may be the greenest.
The cleanest, greenest fuel it that which has not been combusted or consumed.

Larry Weingarten

Hi, Going with what Bob said, efficiency is likely the greenest technology out there. It just isn’t sexy 🤪

Yours, Larry

hot_rod

Even Texas doesn't want it! But they handle a lot of the radioactive fracking fluids on the east side, I have a friend in that business.
https://www.texastribune.org/2021/09/10/texas-nuclear-waste-ban/

JakeCK

Fusion to the rescue? 

Hot_water_fan

Electric resistance heating is not, has never been, and will probably never be "green" 

It’s all about trade offs. The sources solar, wind, oil, coal, gas all have emissions no one denies that. It’s about how they emit relative to each other that’s important. Same with the end use - electric resistance can be green in some situations and not others.

mattmia2

I don't think it is as clear with vehicles. internal combustion engines have similar to worse thermal efficiency to electricity generation and transmission but there is the ability to use regenerative braking. The energy normally lost to braking is much of the energy consumption in conventional vehicles.

JakeCK

The regenerative braking is impressive. Also the cost of ownership is just simply less both because of the cost of fuel vs electricity and the cost of maintenance. There is simply a lot less stuff on an EV to break compared to an ICE. Hundreds vs thousands of components.

https://www.caranddriver.com/features/a37419238/pikes-peak-mountain-2021-porsche-taycan-4s/

Jamie Hall

Actually on vehicles I'm sort of on the fence. It is true that there are fewer things to break on an EV. However once they are broke -- particularly the wiring and the computers (40 or 50 of them -- or more) they're broke, and at the prices they go for you might just as well take a long drive off a short pier. Even the dealerships -- if you can find one -- can't fix all of them. Whereas with my daily truck there isn't anything on there I can't fix with a box of tools and a good ear and a few cheap parts.

My truck happily goes 400 miles on a tank of gas, and "recharges" in 10 minutes (counting getting coffee).

It used no exotic, environmentally damaging minerals in its construction.

The car in the family -- a US built diesel -- goes 700 miles on a tank of fuel. I can't maintain it, but it doesn't require all that much (a computer did die on it once -- a 75 mile tow and a bit over a thousand for the part, but covered by warranty).

JakeCK

The part about computer parts is true for any new vehicle. I have a bluetooth obd2 dongle I use for diagnostics on my 13 f150. You REALLY don't want to know what I can do to my truck with that from my couch with the software I have.

Also with my 36ga tank my gasser can go over 700 too. Or about 300-350 with the camper on it. 

Jamie Hall

Just don't leave that dongle attached, @JakeCK , and be careful who is hanging around the neighbourhood with a scanner when you are using it... anything you can do anyone else can do, too, if they get into the system.

JakeCK

At least with it being a 13' it isn't connected to the internet via the cell network. Some university students hacked a jeep compass years back over the internet and took complete control of it. I've also read about cases where it has been possible to hack into a vehicle through the TPMS. That did require the hackers to be with in several feet luckily. 

Jamie Hall

JakeCK said:

At least with it being a 13' it isn't connected to the internet via the cell network. Some university students hacked a jeep compass years back over the internet and took complete control of it. I've also read about cases where it has been possible to hack into a vehicle through the TPMS. That did require the hackers to be with in several feet luckily. 

The latter is by far the easiest way to steal a modern car. Folks do it quite regularly. Several feet turns out to be a considerable distance with the right equipment...

jumper

High temperature radiant can make one comfortable quickly. At lower air temperature. So electric resistance can be practical. A ski chalet, for example, requires full power for short periods of day. And if electricity comes from windmills that generate regardless of when we need it, then First Law energy efficiency is not entire story.