That’s a perfectly normal number for any home that isn’t very new and perfectly insulated.
My 37sqm appartment needs approximately 5000 kWh in natural gas per year, 876 kWh last December, so 28 kWh per day on average. The building is admittedly old and not perfectly insulated but it’s also not a log cabin out in the open in Finland, but instead a flat enclosed within 3 other flats in the middle of cosy, never below -8C Germany.
21 kWh in a log cabin in Finnland actually seemed pretty low to me. It’s sort of obvious OP is using a heat pump and the cabin must really be absolutely tiny.
It’s an easy conversion - 1 kWh is equal to 3412 Btus. In Germany, both electricity and natural gas are charged in kWh. I know a fair bit about energy measurement if you have any questions.
So given that most gas furnaces (at least in the US) operate at 90-95% efficiency, does that mean 20 kWh of resistive electric heat (as measured on the bill) provides similar heat to ~11 kWh of gas?
Great question. When it comes to utility billing, efficiency doesn’t factor at all. Just like with electric billing, the utility company gives zero shits about what you do with your energy. They just bill you for everything you use.
Utility companies keep track of the volume used in cubic meters and convert it to kWh using the formula…
Volume (in cubic meters) • Calorific value (usually around 37-42) • 1.02264 (correction factor) ÷ 3.6 (conversion factor to kWh) = kWh
The calorific value accounts for the varying energy density of natural gas caused by its inconsistent composition. The correction factor accounts for the effects of the average temperature and pressure at the property on gas volume measurement. 1.02264 is standard for most locations but would be different if the location is extreme, like the high elevation of Machu Picchu.
What sucks about gas heating is some of the heat energy released leaves with the exhaust. The heating efficiency varies depending on the unit but is generally 90-95% for newer units but as low as 50% for older units. While 90-95% doesn’t seem bad, electric heat pumps achieve efficiencies that exceed 100%, even as high as 300+%.
Cubic meters (or another similar measure of volume) is what I’d expect. It’s the conversion to an unrelated and theoretical (since it’s not actually being converted to electricity) unit that confuses me. I presume it’s to make it easier to compare electric vs gas heat, but the variable efficiency of burning gas and the existence of heat pumps ruin that.
kWh is a unit of energy. Regardless of whether it is in the form of electricity or from burning fuel. So it is actually very related, and much more useful than a measurement of volume I’d argue. The measurement is of course done in m³, but then a conversion factor based on several factors is used to convert to an actually useful unit.
A m³ of gas really could be anything depending on pressure, temperature and constituents.
(Brace yourself for Much 'Merica) Several gas utilities I’ve had in the USA measure natural gas CCF, which is 100 cubic feet (at some standard temperature/pressure), which happens to be almost exactly the same as a Therm, or 100,000 BTU.
I live in a desert climate and I have an all electric two bedroom, two bathroom, attached home. The unit has an area of 109sqm. Over the course of the year my monthly average is 622 kWh. This includes times where I run the roof-mounted air conditioning unit all day and its 46C outside. It actually becomes hotter when the sun goes down before getting cooler again because the ground absorbs heat during the day and it radiates back out to space at night passing through the city. I only use air conditioning for 4.5 months a year, the rest of the time I open the windows and use fans.
2022 Average: 622.6667 kWh or 20.755
2022 Air conditioning months average (June - September): 828 kWh or 27.625 daily
2022 Non air conditioning months average (including May which is partial): 519.625 kWh or 17.320 daily
The daily numbers lose some fidelity because I’m lazy and divided the averages by 30.
This is my total energy usage including my hot water heater, two computers, TV, electric stove, often used oven, lighting, fans, and various small appliances. You figure that the rough average air conditioning energy usage is the difference between the daily averages or 10.304 kWh per day and 309 kWh per month
Considering urban development where I live is nearly water neutral and I have a mix of solar power and natural gas generation, it is funny to me because people in northern parts of my country tell me about how where I live must be somehow more unsustainable than where they do. My region also grows a significant portion (read 90% of the total) leafy green vegetables they eat year round.
That’s a perfectly normal number for any home that isn’t very new and perfectly insulated.
My 37sqm appartment needs approximately 5000 kWh in natural gas per year, 876 kWh last December, so 28 kWh per day on average. The building is admittedly old and not perfectly insulated but it’s also not a log cabin out in the open in Finland, but instead a flat enclosed within 3 other flats in the middle of cosy, never below -8C Germany.
21 kWh in a log cabin in Finnland actually seemed pretty low to me. It’s sort of obvious OP is using a heat pump and the cabin must really be absolutely tiny.
Why are you measuring natural gas in kWh? How do you even measure that as such?
It’s an easy conversion - 1 kWh is equal to 3412 Btus. In Germany, both electricity and natural gas are charged in kWh. I know a fair bit about energy measurement if you have any questions.
This is fascinating to me. How does it factor efficiency, since gas needs to be burned?
Energy is energy regardless of what unit is used to show it. so 3412 BTUs always equals 1kWh.
You do an efficiency calculation after, average gas blower is about 90% so you’d end up with 3070 BTUs or 0.9kWh of heat energy.
It does not factor efficiency at all.
The bill does not care about efficiency.
To turn gas to electricity assume 50% efficiency. 2MWh of gas = 1MWh of electricity.
So given that most gas furnaces (at least in the US) operate at 90-95% efficiency, does that mean 20 kWh of resistive electric heat (as measured on the bill) provides similar heat to ~11 kWh of gas?
It would equal about 22kWh of gas, since gas isn’t 100% efficient like electric heat is.
Great question. When it comes to utility billing, efficiency doesn’t factor at all. Just like with electric billing, the utility company gives zero shits about what you do with your energy. They just bill you for everything you use.
Utility companies keep track of the volume used in cubic meters and convert it to kWh using the formula…
Volume (in cubic meters) • Calorific value (usually around 37-42) • 1.02264 (correction factor) ÷ 3.6 (conversion factor to kWh) = kWh
The calorific value accounts for the varying energy density of natural gas caused by its inconsistent composition. The correction factor accounts for the effects of the average temperature and pressure at the property on gas volume measurement. 1.02264 is standard for most locations but would be different if the location is extreme, like the high elevation of Machu Picchu.
What sucks about gas heating is some of the heat energy released leaves with the exhaust. The heating efficiency varies depending on the unit but is generally 90-95% for newer units but as low as 50% for older units. While 90-95% doesn’t seem bad, electric heat pumps achieve efficiencies that exceed 100%, even as high as 300+%.
Very common in countries that use the metric system (ie literally everywhere except the USA). It’s measured either in kWh or in m^3
Cubic meters (or another similar measure of volume) is what I’d expect. It’s the conversion to an unrelated and theoretical (since it’s not actually being converted to electricity) unit that confuses me. I presume it’s to make it easier to compare electric vs gas heat, but the variable efficiency of burning gas and the existence of heat pumps ruin that.
kWh is a unit of energy. Regardless of whether it is in the form of electricity or from burning fuel. So it is actually very related, and much more useful than a measurement of volume I’d argue. The measurement is of course done in m³, but then a conversion factor based on several factors is used to convert to an actually useful unit.
A m³ of gas really could be anything depending on pressure, temperature and constituents.
(Brace yourself for Much 'Merica) Several gas utilities I’ve had in the USA measure natural gas CCF, which is 100 cubic feet (at some standard temperature/pressure), which happens to be almost exactly the same as a Therm, or 100,000 BTU.
Yeah, even firewood can be (and not uncommonly is) measured in kWh
My meter measures it in m3 and my supplier, knowing the exact caloric value of the product they’re selling, tells me in kWh on my bill.
edit: m3 of course not 2 lol
Just because I love numbers
I live in a desert climate and I have an all electric two bedroom, two bathroom, attached home. The unit has an area of 109sqm. Over the course of the year my monthly average is 622 kWh. This includes times where I run the roof-mounted air conditioning unit all day and its 46C outside. It actually becomes hotter when the sun goes down before getting cooler again because the ground absorbs heat during the day and it radiates back out to space at night passing through the city. I only use air conditioning for 4.5 months a year, the rest of the time I open the windows and use fans.
2022 Average: 622.6667 kWh or 20.755
2022 Air conditioning months average (June - September): 828 kWh or 27.625 daily
2022 Non air conditioning months average (including May which is partial): 519.625 kWh or 17.320 daily
The daily numbers lose some fidelity because I’m lazy and divided the averages by 30.
This is my total energy usage including my hot water heater, two computers, TV, electric stove, often used oven, lighting, fans, and various small appliances. You figure that the rough average air conditioning energy usage is the difference between the daily averages or 10.304 kWh per day and 309 kWh per month
Considering urban development where I live is nearly water neutral and I have a mix of solar power and natural gas generation, it is funny to me because people in northern parts of my country tell me about how where I live must be somehow more unsustainable than where they do. My region also grows a significant portion (read 90% of the total) leafy green vegetables they eat year round.