5 ms·

> In some climates and energy grids, switching from things like incandescent to LED causes a greater environmental impact How would that be the case?

jhugo 4y ago
5x 100W light bulbs is 0.5kW of heat output which your heating system doesn't need to supply. Switch to LED and your heating system will need to supply that extra 0.5kW. In a climate where you are almost always running heating, this makes the benefit of switching to LED much smaller, and considering that they are much less environmentally friendly to produce, it may even tip the scale the other way.
- gregable 4y ago
  Yes, but. There are few places that need heating 100% of the year and fewer people living there. During the non-heating hours/days, that's just waste heat. Depending on where the bulbs are located, they may be emitting into a ceiling cavity that exits the building's envelope more quickly than the location of the heating coil. Some bulbs are actually outside the building. And of course, the heating system can supply 0.5kW for less than 0.5kW of power with heat pumps or (net including generation and transmission) natural gas.
- post-it 4y ago
  Resistive electrical heating is typically the most expensive heating option available, at least here in Canada. A heat pump uses much less power to provide the same amount of heat, and fossil fuel heating (gas in the west, oil in the east) is often much less expensive than electric.
- D13Fd 4y ago
  This really only applies where the heat is frequently so low that heat pumps cannot function. Antarctica, or maybe Siberia or northern Alaska. Beyond that, heat pumps are still much more efficient than direct electric heating. Also, if you have air conditioning at any point in the year, those incandescent lights are just going to make your air conditioner work that much harder.
aperson_hello 4y ago
It used to be the case. The energy cost of production was massively higher in their early days and if the waste heat was used, there wasn't a net energy savings. Not so much anymore, especially when increased lifespan is taken into account (it's at least at parity at this point).
gigel82 4y ago
Reminds me of the story of the LED traffic lights that freeze in winter, thus needing an additional heating solution (making them more expensive / error-prone and even less energy-efficient during cold weather): https://www.popularmechanics.com/technology/infrastructure/a20703748/led-traffic-lights-freezing/ https://www.popularmechanics.com/technology/infrastructure/a...
- gregable 4y ago
  That was once true but it's no longer a real issue: https://youtu.be/GiYO1TObNz8 https://youtu.be/GiYO1TObNz8
nybble41 4y ago
If you live in a climate where it's too cold for heat pumps to function, and rely on electrical (resistive) heating instead, the "waste" heat from the incandescent bulbs offsets the power needed for heating almost 1:1. Replacing those with LED bulbs wouldn't reduce your power requirements at all (you'd just run the heaters more) and the LEB bulbs require more energy and exotic materials to manufacture.
- brnt 4y ago
  Is there such a thing as too cold for heat pumps though? They drop in efficiency, sure, but still beat resistive heating. Modern ones are still going to be 300% efficient down to -20C or so. With a resistive pre heater I don't see how they'll ever not be more efficient than resistive heating.
  - BizarroLand 4y ago
    My heat pump is a Trane heat pump from 2018 and it goes into emergency heat mode when the temps are below 36, which is off and on for most of the winter. I wonder if I should have it serviced to make sure it's working correctly.
    - deleted 4y ago
      [deleted]
    - deleted 4y ago
      [deleted]
    - bcrosby95 4y ago
      It's partially a function of your heating demands. My sister's emergency heat mode would run all the time in her town house. But she installed a giant insulating curtain over one of her leaky sliders and now it almost never needs to run.
      - BizarroLand 4y ago
        That seems more like she improved her insulation, decreasing her heating needs rather than addressing the temperature cutoff for a heat pump. I still like the heat pump because in the summer my power bill for cooling a 2600 sq ft home is about $50/month, and in the winter I do have a wood burning stove that I can run to heat the house when the temps are below 36. That and recirc mode on the fan unit can keep my power bills to a minimum.

jhugo 4y ago

5x 100W light bulbs is 0.5kW of heat output which your heating system doesn't need to supply. Switch to LED and your heating system will need to supply that extra 0.5kW. In a climate where you are almost always running heating, this makes the benefit of switching to LED much smaller, and considering that they are much less environmentally friendly to produce, it may even tip the scale the other way.

gregable 4y ago
Yes, but. There are few places that need heating 100% of the year and fewer people living there. During the non-heating hours/days, that's just waste heat. Depending on where the bulbs are located, they may be emitting into a ceiling cavity that exits the building's envelope more quickly than the location of the heating coil. Some bulbs are actually outside the building. And of course, the heating system can supply 0.5kW for less than 0.5kW of power with heat pumps or (net including generation and transmission) natural gas.
post-it 4y ago
Resistive electrical heating is typically the most expensive heating option available, at least here in Canada. A heat pump uses much less power to provide the same amount of heat, and fossil fuel heating (gas in the west, oil in the east) is often much less expensive than electric.
D13Fd 4y ago
This really only applies where the heat is frequently so low that heat pumps cannot function. Antarctica, or maybe Siberia or northern Alaska. Beyond that, heat pumps are still much more efficient than direct electric heating. Also, if you have air conditioning at any point in the year, those incandescent lights are just going to make your air conditioner work that much harder.

aperson_hello 4y ago

It used to be the case. The energy cost of production was massively higher in their early days and if the waste heat was used, there wasn't a net energy savings. Not so much anymore, especially when increased lifespan is taken into account (it's at least at parity at this point).

gigel82 4y ago

Reminds me of the story of the LED traffic lights that freeze in winter, thus needing an additional heating solution (making them more expensive / error-prone and even less energy-efficient during cold weather): https://www.popularmechanics.com/technology/infrastructure/a20703748/led-traffic-lights-freezing/ https://www.popularmechanics.com/technology/infrastructure/a...

gregable 4y ago
That was once true but it's no longer a real issue: https://youtu.be/GiYO1TObNz8 https://youtu.be/GiYO1TObNz8

nybble41 4y ago

If you live in a climate where it's too cold for heat pumps to function, and rely on electrical (resistive) heating instead, the "waste" heat from the incandescent bulbs offsets the power needed for heating almost 1:1. Replacing those with LED bulbs wouldn't reduce your power requirements at all (you'd just run the heaters more) and the LEB bulbs require more energy and exotic materials to manufacture.

brnt 4y ago
Is there such a thing as too cold for heat pumps though? They drop in efficiency, sure, but still beat resistive heating. Modern ones are still going to be 300% efficient down to -20C or so. With a resistive pre heater I don't see how they'll ever not be more efficient than resistive heating.
- BizarroLand 4y ago
  My heat pump is a Trane heat pump from 2018 and it goes into emergency heat mode when the temps are below 36, which is off and on for most of the winter. I wonder if I should have it serviced to make sure it's working correctly.
  - deleted 4y ago
    [deleted]
  - deleted 4y ago
    [deleted]
  - bcrosby95 4y ago
    It's partially a function of your heating demands. My sister's emergency heat mode would run all the time in her town house. But she installed a giant insulating curtain over one of her leaky sliders and now it almost never needs to run.
    - BizarroLand 4y ago
      That seems more like she improved her insulation, decreasing her heating needs rather than addressing the temperature cutoff for a heat pump. I still like the heat pump because in the summer my power bill for cooling a 2600 sq ft home is about $50/month, and in the winter I do have a wood burning stove that I can run to heat the house when the temps are below 36. That and recirc mode on the fan unit can keep my power bills to a minimum.