Electrification Could Cut Global Energy Use in Half

Large swathes of the US have hours of uninterrupted sunshine all year round. With a battery, a residential owner may never need to pay an electricity bill for the lifetime of the system.

The energy transition to clean energy is to a cheaper energy future.

Fossil fuels are not only more expensive, they cause tons of health problems from their pollution, in addition to climate change.

Smoothing out household demand on the grid is the future.

You're also assuming time of use billing, I assume.

I don't disagree, btw - gas is cheaper than a heat pump for me also, which makes me sad. My only point was that you have to compare against them and not resistance heating. (That's slightly wrong - if I were to use a heat pump during the shoulder season and my boiler when it's colder it would be cheaper in operating costs but lose on capex)

Let's say you want to run a single shower at 2.5gpm, the water comes into the home at 55F (12.8C, pretty temperate!) and you want your shower at 100F (37.8C), so a 25C rise. 2.5gpm = 9.463 L/min = 158mL/sec. Water's heat capacity is 4.184* J/mL/degC, so the sustained thermal power you need to deliver is:

4.184 x 158 x 25 = 16.5kJ/s = 16.5kW

At 240V, 16.5kW would be almost 70A.

What makes a heat pump heater more efficient is that it multiplies the electrical power input into a larger thermal power output, by "borrowing" thermal energy from the surroundings. So you could get (for example) 15kW thermal power from 5kW electrical power. In practice the heater will be tanked, rather than tankless, for two reasons:

1. The effective power will probably be less than that.

2. That was an estimate to run just one shower and you might want to run more than that!

So the tank lets you buffer the power draw over time; there will be some thermal loss over time, but insulation is cheap, and it's hard to fight a 3-5x amplification from the heat pump.

* Yes, yes, per gram/K but 1mL of water is close enough to 1g for this.

You need to compare this against the average heating days for their location.

Water heaters are a "incandescent lightbulbs are 100% efficient in the winter" situation.

Where do you live, with what power company?

Though, at the prices and idiocy you are citing, you could probably just cancel your electrical service and get a big house battery. If they don't allow that, you could just stop paying your electric bill entirely. They'd cut you off the grid eventually, stop billing you. Good riddance, I suppose.

That would be correct, I had never heard of this. it seems extremely punishing and something I would hope your government regulators are trying to fix.

The problem for you isn’t electricity it’s your local laws favouring gas and the utility extracting wealth. 86 usd in fees is more then my entire electric bill has been in the summer (the monthly fees here are 15cad a month)

I imagine your per kWh cost is also much higher too

That said I still don’t think on your math entirely holds up. Ovens and electric elements (even more so for induction) do not just draw their rated power continuously. Once they heat up they drop to a much lower duty cycle like 50%. But that is besides the point now.

The difficult part is that as demand for petroleum products drop, they will get cheaper (at least initially). Electricity costs need to fall faster than oil prices as oil demand drops.

If you go back to GP’s comment you’ll see they accounted for generation and transmission.

They clearly separated the efficiency of the engines with the efficiency of generation and transmission.

The point stands. For the same amount of energy, EVs travel 3-4x the same distance. And you were really rude.

Sounds to me like you're the one unwilling to accept reality.

Have you watched the Don't look up movie?

(Also wow does running your kitchen toaster really cost thousands a month? Maybe move somewhere where power company is not trying to gouge you?)

But overall, here's average US consumption:

    Heating                  12000 kWh/yr (1400 watts)
    Hot water                 3000 kWh/yr  (340 watts)
    Cooling and refrigeration 1200 kWh/yr  (140 watts)
    Lighting                  1200 kWh/yr  (140 watts)
    Washing and drying        1000 kWh/yr  (110 watts)
    Cooking                   1000 kWh/yr  (110 watts)
    Miscellaneous electric     600 kWh/yr   (70 watts)

For example, evaporating a 40,000 L solution of calcium chloride brine can store 4.6 megawatt-hours(*) of thermal energy and release it in the winter by passing water vapour over the solution to dilute it. This can heat geothermal temperatures from 10°C to 27°C which can be used in in-floor heating.

But the big asterisk is that only 11% of that 4.6 megawatt-hours of that thermal energy being "stored" is held in the enthalpy of dilution, and 89% of that heat is coming from the enthalpy of vaporization, and acquiring water vapour in winter isn't so easy.

One would probably need a source of water and use geothermal heat to raise dry cold air temperature to the needed 10°C, while absorbing water vapour from a (relatively small) tank of water. The net result is more of a thermochemical heat pump rather than a thermochemical battery per se. But the point is that, other than some fans, this is not electrically powered.

Then there is the issue of storing such tanks safely underground, and more problems. Still, there might be some innovative solutions lying in this direction. For example, one can replace this open-loop system with a closed-loop vacuum system to boil water, but at the cost of far more complex and dangerous engineering.

Expect to pay $10-20k for the hole but it is common in large parts of the world.

Real question: As I understand, good insulation in your home helps two ways: Keep the heat inside in the winter, and keep the cold inside in the summer. Do I have that right? If yes, I understand there are lots of places in Australia with very light winters (or none at all), so they are mostly focused on cooling with A/C. Are you saying that installing significantly better insulation is not economically efficient for many Australia homes?

I mean, sure, and a tiny one won't work for a mansion. If you're somewhere that cold, you choose a heat pump that works in that temperature range.

Modern internal-combustion engines have 35% to 40% efficiency, with even efficiencies of over 50% for the very big 2-stroke Diesel engines used in ships.

Nonetheless that remains about half of the efficiency of electric vehicles and the energy efficiency of the latter can be greatly increased over this ratio by the recovery of the kinetic or gravitational energy, when braking or descending.

And so on.

P.S. Since I drive a stick, I coast a lot. I live in a hilly area, and have a pretty good feel for just how and where I can shift into neutral and coast. I also coast towards a red light with the goal of reaching the intersection just when it turns green. (Moving forward from a dead stop uses lots of energy.)

"Free" fuel for you just pushes the externalities elsewhere.

Pre-industrial revolution most people in my country own enough clothing for everyday and then maybe some extra stuff for "best" appearance like church. Making a shirt requires hours of labour from skilled workers. The machines eliminate one of those jobs ("hand" weaving, using a loom that you operate at human scale, replaced by enormous machine looms which produce much more fabric and much faster with far less human labour) and streamline others so that the price of a garment collapses. So people buy a lot more garments. You probably own enough clothes that you can wear different clothes each day for at least a week, likely more, and you think nothing of it.

Most people won't buy so many clothes that they can't even wear items once, but many get pretty close, and so worldwide we produce hugely more clothing per person than before the textile mills were first built.

The crux of Jevon's paradox is that you’re lowering the cost of revenue below the sale price.

If I can generate $10 a sale then I’ll do no sales if it costs me $11 . If gas drops from $4 to $2 then I’ll do as many sales as I can as $9 is less than $10.

And relying on trees is not a great idea either, look at Easter Island, lol.

(GPT has all the answers anyway, no need to ask me, I'm an old man with no issue and no stake in this stuff)