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Great thing about heating water, is that it stays hot after you’ve heated it. Water heating is basically the poster child for “demand-response” technologies. Y

Great thing about heating water, is that it stays hot after you’ve heated it. Water heating is basically the poster child for “demand-response” technologies. You can easily heat your water a few hours earlier than normal with basically no consequences to the user. But you need to get reasonable smart about modelling people water usage, as people don’t tend forget or forgive a cold shower.

practicemaths 2y ago
What about tankless water heaters? You can eliminate greenhouse gas emissions for heating and be more efficient with energy usage overall.
- adgjlsfhk1 2y ago
  tankless heaters use slightly less energy, but they use it in a really annoying way. the optimal design for a heavily renewable grid is a heat pump water heater with a tank
  - blitzar 2y ago
    The optimal design for a heavily renewable grid is solar water heating a tank in home whenever the sun shines, falling back on a heat pump water heater with a tank.
    - practicemaths 2y ago
      That's for maximizing energy efficiency. Tankless I think might be a tad bit more easier and cheaper to implement than this. Regardless the point is eliminating the use of natural gas in heating water is itself a benefit.
    - organsnyder 2y ago
      That's only optimal if you know you'll need 100% of the heated water (or have a way to store it). While photovoltaics are going to be less efficient than direct water heating, you can direct the energy to other uses if you don't need more hot water.
      - bluGill 2y ago
        Large tanks of water are about the cheapest way we know of to store energy. Batteries store more energy, but are extremely expensive.
        organsnyder 2y ago
        Yes, but that only matters if we can easily consume that energy. If we need the hot water, then that's easy—no conversion loss. Otherwise, it gets trickier, especially in a small-scale setting like a home.
        bluGill 2y ago
        All homes use at least some hot water for showers. In many climates they can use a lot of energy for heating which means a very large tank could be useful in winter.
        Gibbon1 2y ago
        I read a study looking at the difference between tankless and tank water heaters. Summary the more hot water you use the smaller the win is for tankless. Other thing I've read and seems true is gas and heat pump water heaters cost about the same to run. I installed a heat pump unit five years ago. Works okay for two people. If you had three teenage girls and a wife that likes baths a tankless would be a better choice.

practicemaths 2y ago

What about tankless water heaters? You can eliminate greenhouse gas emissions for heating and be more efficient with energy usage overall.

adgjlsfhk1 2y ago
tankless heaters use slightly less energy, but they use it in a really annoying way. the optimal design for a heavily renewable grid is a heat pump water heater with a tank
- blitzar 2y ago
  The optimal design for a heavily renewable grid is solar water heating a tank in home whenever the sun shines, falling back on a heat pump water heater with a tank.
  - practicemaths 2y ago
    That's for maximizing energy efficiency. Tankless I think might be a tad bit more easier and cheaper to implement than this. Regardless the point is eliminating the use of natural gas in heating water is itself a benefit.
  - organsnyder 2y ago
    That's only optimal if you know you'll need 100% of the heated water (or have a way to store it). While photovoltaics are going to be less efficient than direct water heating, you can direct the energy to other uses if you don't need more hot water.
    - bluGill 2y ago
      Large tanks of water are about the cheapest way we know of to store energy. Batteries store more energy, but are extremely expensive.
      - organsnyder 2y ago
        Yes, but that only matters if we can easily consume that energy. If we need the hot water, then that's easy—no conversion loss. Otherwise, it gets trickier, especially in a small-scale setting like a home.
        bluGill 2y ago
        All homes use at least some hot water for showers. In many climates they can use a lot of energy for heating which means a very large tank could be useful in winter.
        Gibbon1 2y ago
        I read a study looking at the difference between tankless and tank water heaters. Summary the more hot water you use the smaller the win is for tankless. Other thing I've read and seems true is gas and heat pump water heaters cost about the same to run. I installed a heat pump unit five years ago. Works okay for two people. If you had three teenage girls and a wife that likes baths a tankless would be a better choice.