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This reads like an ad, but the following passage stood out > the average US home consumes about 889kWh per month, or about 29.2kWh per day I assume most of th

by adrianN 9mo ago

This reads like an ad, but the following passage stood out > the average US home consumes about 889kWh per month, or about 29.2kWh per day I assume most of that is HVAC? I use about 1500kWh a year, but I don’t need aircon and heating is district heating.

tzs 9mo ago
House heating is often a big part of that. But even without that most would use more than you are using. Based on the site you link in your profile and the links there it looks like you are in Germany? If so, it should be noted that the average German household uses in the 3000-3500 kWh range per year, and even the average one person household uses around 2000 kWh per year. In the US we are more likely to to use electricity for a couple of things than Germans are. For example in the US around 80% of households use a clothes dryer, and about 80% of those are electric. In Germany only around 40% of households use a clothes dryer. 4 loads a week for a year would would be around 600 kWh, so we are already up to 40% of your usage just from that. Water heating in the US is split pretty evenly between electric and natural gas, with a smaller number using propane or oil. The energy use label on my water heater says it should take about 350 kWh a year for a typical household. Google is telling me electric water heating is much much less common in Germany. I think those are the major non-HVAC things where Americans and Germans significantly differ on whether they use electricity or some other form of energy to accomplish the task. Take those out though and it is still hard to get down to your 1500 kWh a year. I'm the only person in my household, don't have air conditioning, and in those parts of the year where I don't need to use heating and it is not so hot that I need to keep a fan running to not feel uncomfortable, and it is not a laundry day (so no use of the dryer nor use of hot water for the washing machine) and I don't use the dishwasher (another user of hot water) the lowest 24 hour use I've seen has been maybe 7.2 kWh. If I could keep that up all year that would be ~2600 kWh. Add in a load of laundry a week and 2 or 3 uses of the dishwasher a week that would probably be close to 3000 kWh. Your 1500 kWh a year would be 4.1 kWh per day average, so 3 kWh a day less than my minimum days. I suspect that a significant part of that difference is due to my water heating, from one or two hot showers a day. One thing I've got that you almost certain do not is a well with an electric pump. I don't have a meter on my water, but I'm pretty sure it is under 100 gallons a day. One shower and a few toilet flushes with both an efficient shower head and an efficient toilet should be way under that, and drinking/hand washing/teeth brushing is not more than a few gallons. I don't know the actual power used by the pump, but if it used the maximum power circuit it is on is rated for it would only use around 0.3 kWh a day. My fridge is just average on efficiency, but it is only using about 0.4 kWh a day. I assume you too have a fridge, so I doubt the fridge accounts for a significant difference. My computer stuff (M2 Mac Studio, 27" 5k monitor, 24" second monitor, powered speakers, powered USB hub, 4 bay Thunderbolt drive enclosure with 4 SSDs, network switch) is using 1.78 kWh per day. The cable internet gateway is another 0.35 kWh per day. I assume you also have a decent computer setup so not sure if there is much difference here. Oh, I just remembered one thing I had that was using more power than I expected in those summers when I saw usage as low as 7.2 kWh a day. I was not putting my A/V receiver in standby. I had assumed that when it was not actually playing the power usage would be very low, but apparently that's not the way these things work. It turns out it was using about 50 W all the time. That's 1.2 kWh a day! I only actually play stuff an hour or two a day, so that was about 1.1 kWh a day of wasted energy. No I have it on standby when not in use (0.07 kWh per day) so I may get down to 6.2 kWh on non-laundry/non-dishwashing days in 2026.
- adrianN 9mo ago
  I actually only use a laptop that maybe draws 50W peak. The FritzBox uses maybe 10W peak and I turn it off when I sleep. Warm water is probably the main difference between my household and the average German, since I get it via district heating not electricity.
Jtsummers 9mo ago
https://www.eia.gov/energyexplained/use-of-energy/electricity-use-in-homes.php https://www.eia.gov/energyexplained/use-of-energy/electricit... - This shows a breakdown. HVAC is not the most [edit: as in majority, it has the largest share though], but it is a significant amount. Also my household is apparently well below average (though still higher than you) for the US and our region in the US.
sixothree 9mo ago
30 kWh per day sounds about right. I have resistive heating and holy heck is it expensive in the winter months, which are short and mild. I plan to replace it soon. But yes, most of that would be heating and cooling single family homes. Many built during a time when insulation was an afterthought. Now homes are well insulated, but they are larger.
- toomuchtodo 9mo ago
  Do you intend to replace your resistive heat with a heat pump?
  - sixothree 9mo ago
    Yes. Its mild enough here that none of the typical concerns even matter. The house has natural gas connected, which is exceedingly cheap, but why would I.
thebruce87m 9mo ago
In Scotland it looks like I use 10kWh minimum (not in), 20kWh on a “normal” day and more when I charge the EV. Family of 3 in a Bungalow. I’d love a system like this to charge on my cheap overnight tariff and use during the day. Solar just isn’t worth it here.
- laurencerowe 9mo ago
  I think it would just about break even on an economy 7 night rate saving about 17p/kWh shifting load to the overnight rate. (Might save more on a smarter tariff.) A 12kWh system costs £5880 including VAT. Assume 95% round trip efficiency and 80% cycle each night gives savings of £565 annually. That's about the same as the cost of a loan at 5% for the total amount paid back over an estimated useful life of 15 years. This assumes it doesn't need servicing in that time and you can DIY install. I don't know whether home systems like this will get much cheaper as the batteries themselves probably only make up about 20% of the system cost. There are huge economies of scale for utility scale storage with all in project costs now down to $125/kWh meaning 12kWh would cost just $1500 rather than $6600 for this home system. So I wouldn't be confident the price differentials between day and night rates will remain as high over its expected lifetime.
  - thebruce87m 9mo ago
    My night tariff is 6.67p/kWh compared to 28.36p/kWh for daytime. I don’t think these differentials will last either but I do like the idea of smart charging when there is too much wind. I suspect these grid storage systems currently being built won’t handle these peaks and will be designed for the average case so there will still be periods of cheap electricity. My supplier already controls my car this way and charges it on a schedule it defines each night and also ad-hoc during low demand. There is also some benefit to have a backup system for when the power goes out which happens a few times a year.
    - laurencerowe 9mo ago
      I pretty much agree. There seems a clear economic case to install enough grid storage to smooth out within day variations but that will fill up during multi-day windy periods so there will certainly still be periods of cheap electricity just not every day. That likely means you'll still be able to charge your car cheaply most of the time but it probably makes home battery investments less attractive since you might only get 100-200 opportunities a year to charge it cheaply instead of 365, halving the annual savings. But then given so much of the cost of a home system is in the inverter and control unit maybe it will become economic to buy several days consumption worth of batteries.
deleted 9mo ago
[deleted]
estimator7292 9mo ago
A lot of us live in older homes without good insulation. Somewhere in the mid 1900s we simply forgot that "plaster interior wall directly on brick exterior wall" does not provide insulation. 1920s era homes are even worse, single hung windows in wooden frames, no insulation, no conception of managing airflow. Modern homes are much more efficient, but they're a bit impractical to buy these days, and are increasingly built so shitty that their lifespan is less than their inhabitants.
- kyleee 9mo ago
  It’s a double edged sword - that draftiness and inefficiency can be surprisingly effective at preventing rot
LazyMans 9mo ago
Can confirm. HVAC https://imgur.com/a/yI2AX6D https://imgur.com/a/yI2AX6D
jmgao 9mo ago
> I use about 1500kWh a year, but I don’t need aircon and heating is district heating. That's 171 W on average, that's about the same as my refrigerator (~150 W on average).
- adrianN 9mo ago
  I have two refrigerators that use about 200W when the compressor is running. It is not running all the time though.
Marsymars 9mo ago
> I assume most of that is HVAC? I use about 1500kWh a year, but I don’t need aircon and heating is district heating. I wouldn't expect so - I have gas heating and no A/C and I average around 700 kWh / month.

by adrianN 9mo ago

tzs 9mo ago

House heating is often a big part of that. But even without that most would use more than you are using. Based on the site you link in your profile and the links there it looks like you are in Germany? If so, it should be noted that the average German household uses in the 3000-3500 kWh range per year, and even the average one person household uses around 2000 kWh per year. In the US we are more likely to to use electricity for a couple of things than Germans are. For example in the US around 80% of households use a clothes dryer, and about 80% of those are electric. In Germany only around 40% of households use a clothes dryer. 4 loads a week for a year would would be around 600 kWh, so we are already up to 40% of your usage just from that. Water heating in the US is split pretty evenly between electric and natural gas, with a smaller number using propane or oil. The energy use label on my water heater says it should take about 350 kWh a year for a typical household. Google is telling me electric water heating is much much less common in Germany. I think those are the major non-HVAC things where Americans and Germans significantly differ on whether they use electricity or some other form of energy to accomplish the task. Take those out though and it is still hard to get down to your 1500 kWh a year. I'm the only person in my household, don't have air conditioning, and in those parts of the year where I don't need to use heating and it is not so hot that I need to keep a fan running to not feel uncomfortable, and it is not a laundry day (so no use of the dryer nor use of hot water for the washing machine) and I don't use the dishwasher (another user of hot water) the lowest 24 hour use I've seen has been maybe 7.2 kWh. If I could keep that up all year that would be ~2600 kWh. Add in a load of laundry a week and 2 or 3 uses of the dishwasher a week that would probably be close to 3000 kWh. Your 1500 kWh a year would be 4.1 kWh per day average, so 3 kWh a day less than my minimum days. I suspect that a significant part of that difference is due to my water heating, from one or two hot showers a day. One thing I've got that you almost certain do not is a well with an electric pump. I don't have a meter on my water, but I'm pretty sure it is under 100 gallons a day. One shower and a few toilet flushes with both an efficient shower head and an efficient toilet should be way under that, and drinking/hand washing/teeth brushing is not more than a few gallons. I don't know the actual power used by the pump, but if it used the maximum power circuit it is on is rated for it would only use around 0.3 kWh a day. My fridge is just average on efficiency, but it is only using about 0.4 kWh a day. I assume you too have a fridge, so I doubt the fridge accounts for a significant difference. My computer stuff (M2 Mac Studio, 27" 5k monitor, 24" second monitor, powered speakers, powered USB hub, 4 bay Thunderbolt drive enclosure with 4 SSDs, network switch) is using 1.78 kWh per day. The cable internet gateway is another 0.35 kWh per day. I assume you also have a decent computer setup so not sure if there is much difference here. Oh, I just remembered one thing I had that was using more power than I expected in those summers when I saw usage as low as 7.2 kWh a day. I was not putting my A/V receiver in standby. I had assumed that when it was not actually playing the power usage would be very low, but apparently that's not the way these things work. It turns out it was using about 50 W all the time. That's 1.2 kWh a day! I only actually play stuff an hour or two a day, so that was about 1.1 kWh a day of wasted energy. No I have it on standby when not in use (0.07 kWh per day) so I may get down to 6.2 kWh on non-laundry/non-dishwashing days in 2026.

adrianN 9mo ago
I actually only use a laptop that maybe draws 50W peak. The FritzBox uses maybe 10W peak and I turn it off when I sleep. Warm water is probably the main difference between my household and the average German, since I get it via district heating not electricity.

Jtsummers 9mo ago

https://www.eia.gov/energyexplained/use-of-energy/electricity-use-in-homes.php https://www.eia.gov/energyexplained/use-of-energy/electricit... - This shows a breakdown. HVAC is not the most [edit: as in majority, it has the largest share though], but it is a significant amount. Also my household is apparently well below average (though still higher than you) for the US and our region in the US.

sixothree 9mo ago

30 kWh per day sounds about right. I have resistive heating and holy heck is it expensive in the winter months, which are short and mild. I plan to replace it soon. But yes, most of that would be heating and cooling single family homes. Many built during a time when insulation was an afterthought. Now homes are well insulated, but they are larger.

toomuchtodo 9mo ago
Do you intend to replace your resistive heat with a heat pump?
- sixothree 9mo ago
  Yes. Its mild enough here that none of the typical concerns even matter. The house has natural gas connected, which is exceedingly cheap, but why would I.

thebruce87m 9mo ago

In Scotland it looks like I use 10kWh minimum (not in), 20kWh on a “normal” day and more when I charge the EV. Family of 3 in a Bungalow. I’d love a system like this to charge on my cheap overnight tariff and use during the day. Solar just isn’t worth it here.

laurencerowe 9mo ago
I think it would just about break even on an economy 7 night rate saving about 17p/kWh shifting load to the overnight rate. (Might save more on a smarter tariff.) A 12kWh system costs £5880 including VAT. Assume 95% round trip efficiency and 80% cycle each night gives savings of £565 annually. That's about the same as the cost of a loan at 5% for the total amount paid back over an estimated useful life of 15 years. This assumes it doesn't need servicing in that time and you can DIY install. I don't know whether home systems like this will get much cheaper as the batteries themselves probably only make up about 20% of the system cost. There are huge economies of scale for utility scale storage with all in project costs now down to $125/kWh meaning 12kWh would cost just $1500 rather than $6600 for this home system. So I wouldn't be confident the price differentials between day and night rates will remain as high over its expected lifetime.
- thebruce87m 9mo ago
  My night tariff is 6.67p/kWh compared to 28.36p/kWh for daytime. I don’t think these differentials will last either but I do like the idea of smart charging when there is too much wind. I suspect these grid storage systems currently being built won’t handle these peaks and will be designed for the average case so there will still be periods of cheap electricity. My supplier already controls my car this way and charges it on a schedule it defines each night and also ad-hoc during low demand. There is also some benefit to have a backup system for when the power goes out which happens a few times a year.
  - laurencerowe 9mo ago
    I pretty much agree. There seems a clear economic case to install enough grid storage to smooth out within day variations but that will fill up during multi-day windy periods so there will certainly still be periods of cheap electricity just not every day. That likely means you'll still be able to charge your car cheaply most of the time but it probably makes home battery investments less attractive since you might only get 100-200 opportunities a year to charge it cheaply instead of 365, halving the annual savings. But then given so much of the cost of a home system is in the inverter and control unit maybe it will become economic to buy several days consumption worth of batteries.

deleted 9mo ago

[deleted]

estimator7292 9mo ago

A lot of us live in older homes without good insulation. Somewhere in the mid 1900s we simply forgot that "plaster interior wall directly on brick exterior wall" does not provide insulation. 1920s era homes are even worse, single hung windows in wooden frames, no insulation, no conception of managing airflow. Modern homes are much more efficient, but they're a bit impractical to buy these days, and are increasingly built so shitty that their lifespan is less than their inhabitants.

kyleee 9mo ago
It’s a double edged sword - that draftiness and inefficiency can be surprisingly effective at preventing rot

LazyMans 9mo ago

Can confirm. HVAC https://imgur.com/a/yI2AX6D https://imgur.com/a/yI2AX6D

jmgao 9mo ago

> I use about 1500kWh a year, but I don’t need aircon and heating is district heating. That's 171 W on average, that's about the same as my refrigerator (~150 W on average).

adrianN 9mo ago
I have two refrigerators that use about 200W when the compressor is running. It is not running all the time though.

Marsymars 9mo ago

> I assume most of that is HVAC? I use about 1500kWh a year, but I don’t need aircon and heating is district heating. I wouldn't expect so - I have gas heating and no A/C and I average around 700 kWh / month.