I'm able to turn my water heater off twice a week without a noticable difference in the water temperature. I wish there was an easier way other than flipping the circuit breaker.
The humble water heater could be the savior of our energy infrastructure woes
91–100 of 258 posts
Re: The humble water heater could be the savior of our energy infrastructure woes
#92In Northern Europe heat pumps are now pretty much standard for new homes. They reduce heating bills quite dramatically compared to other technology. In particular if combined with solar power. One big advantage is that they can also be run in reverse so you could cool the house in summer (although you might need a special heat pump to do this, especially to separate from the hot water). In areas where it gets very co…
> One big advantage is that they can also be run in reverse
I don't get why this is an advantage. That's just plain old air conditioning, which is genreally considered to be a wasteful, energy guzzling luxury in colder climates.
The heat pump hype is a bit puzzling to me. Here's a TreeHugger article which puts it better than I can: https://www.treehugger.com/why-are-there-so-many-fist-pumps-...
Re: The humble water heater could be the savior of our energy infrastructure woes
#93Earlier quoted context omitted.
Heat pump water heaters mentioned in the article are better for efficiency. They typically use half the energy of a normal water heater. And they cool the air around them, so if you live in a hot area they save more.
And if you live in a cold area, you get no efficiency advantage, pay more, and probably eventually leak coolant with a GWP of 2088.
I live in a cool place. This winter we had extended periods of -20C. Heat pump efficiency drops, but still stays above 2. SCOP (for year round average for heating coefficient of performance) units sold now are better than 5.
Also, if you are worried about the refrigerant leaking, you can sacrifice a little bit of efficiency and buy a unit using CO2 as a refrigerant with a GWP of you know: 1.
I think the biggest problem here for leakage are random construction dudes cutting the pipes when they demolish or remodel homes. If only they could gather the gas in the outdoor unit before, all of it would be saved.
Re: The humble water heater could be the savior of our energy infrastructure woes
#94This is old technology, I'm surprised the US hasn't already implemented it. They have been remote-controlling water heaters in New Zealand and Australia since the 50s. Just a simple relay installed in each house that responses to extra frequencies on the power lines in the 160-1600hz range. It's called ripple control, for obvious reasons. Each home gets assigned to one of several channels in each area so they can hav…
About half of the US uses natural gas for water heating - its substantially more efficient than burning said gas (or coal) to generate electricity, then using the electricity to heat water.
Re: The humble water heater could be the savior of our energy infrastructure woes
#95Most newly built electric cars have a 50+ kWh battery. Imagine if smart meters could use _that_, regardless of where the car is currently parked and plugged in. 50kWh is in excess of what most households use in electricity on most days.
This will be the case in the next couple of years. Wall boxes are inherently smart (that is, controllable). So as a sink, the concept works somewhat already. But most cars won't be empty all the time. Also as source the 50kWh will only be usable as an emergency backup for the owner of the vehicle and only if they have the infrastructure to consume directed current. No one will let their own battery drain for the grea…
> No one will let their own battery drain for the greater good
Agreed. That’s why you‘ll get adequately paid for the energy sucked out of the battery in the evening when everybody starts cooking and energy prices on the market spike.
The big problem we have right now is that we want to get rid of coal and gas, but they are currently absolutely necessary for serving peaks occurring when wind power and solar lie flat. Vehicle2grid could be the solution - a giant distributed battery. I think if you charge 40kWh in the day with cheap solar, and sell it for 5x the price in the evening or morning, that would more than offset the battery degradation (which is way less of a problem than initially suspected, especially when charging and discharging slowly). A big battery could make you a couple of bucks every day.
Re: The humble water heater could be the savior of our energy infrastructure woes
#96Most newly built electric cars have a 50+ kWh battery. Imagine if smart meters could use _that_, regardless of where the car is currently parked and plugged in. 50kWh is in excess of what most households use in electricity on most days.
50kWh can cover about two to three weeks for me. Unless you use electricity for heating, you don't really need all that much.
That’s impressive.
We don’t use electricity for heating (heating and warm water are powered by community heat), and need 11kWh per day on average, excluding the EV. The EV adds another 5.5kWh per day.
Re: The humble water heater could be the savior of our energy infrastructure woes
#97In Northern Europe heat pumps are now pretty much standard for new homes. They reduce heating bills quite dramatically compared to other technology. In particular if combined with solar power. One big advantage is that they can also be run in reverse so you could cool the house in summer (although you might need a special heat pump to do this, especially to separate from the hot water). In areas where it gets very co…
> One big advantage is that they can also be run in reverse I don't get why this is an advantage. That's just plain old air conditioning, which is genreally considered to be a wasteful, energy guzzling luxury in colder climates. The heat pump hype is a bit puzzling to me. Here's a TreeHugger article which puts it better than I can: https://www.treehugger.com/why-are-there-so-many-fist-pumps-...
Good heat pumps aren't of the air conditioner type. Our heat pump uses two 60m deep drilled holes. Thus heat exchange happens in the ground, which is always more or less 10 degrees Celsuis.
Heat exchange in the house happens through floor heating. So during a hit summer, the reverse capability just pumps the cold water through our floors (controlled for the dew point) and the warm floor water into the ground. That, combined with controlled ventilation over a physical heat exchanger, keeps the warmth out. Or, during cool seasons, the warmth in.
Our heat pump uses about 1 Kwh electricity (from ecological resources like water or wind only) to generatev3 to 4 Kwh of heating. Without producing carbon dioxide. Airflow based heat pumps are less efficient, and more noisy outside, of course.
Re: The humble water heater could be the savior of our energy infrastructure woes
#98Earlier quoted context omitted.
We have an under-sink unit that has hot water ready 24/7. After hooking it up, I noticed it increased our monthly bill by about $15. I bought a used Wemo plug for $10 and set it to only be on for 3 hours in the morning and 3 hours at night. Now we have hot water at any of the times when we actually would want it, and we aren't wasting money/energy to keep hot water on tap 24/7.
Make sure to set the temperature really high if you don't run it continuously or you risk breeding Legionella.
Appreciate that; it's practically boiling.
Re: The humble water heater could be the savior of our energy infrastructure woes
#99I'm able to turn my water heater off twice a week without a noticable difference in the water temperature. I wish there was an easier way other than flipping the circuit breaker.
Re: The humble water heater could be the savior of our energy infrastructure woes
#100Earlier quoted context omitted.
The problem is the cool water in the pipes. A typical solution is recirculating the water so that it stays hot. (I have a gas tank heater and the faucets far away take a bit to warm up, because of the water in the pipes)
Are recirculating systems safe? Those have to be designed to prevent microbial build-up. I'm thinking of Legionnaire's disease.
We have a solar (parabolic vacuum pipes) water heater which provides 95% of our annual hot water needs, backed up by gas.
The heat is stored in a layered and heavily insulated 300 liter tank.
The water delivered to the tap isn't actually from the tank, but it's just fresh water heated instantly and on-demand through a heat exchanger which is part of the storage tank.
No need to worry about stale hot water with such a system.