The humble water heater could be the savior of our energy infrastructure woes • Hacker News Board

Re: The humble water heater could be the savior of our energy infrastructure woes

#11

Post by [deleted] » Wed, Jul 07, 2021, 1:28 AM UTC

Retric wrote: post #3

ttyprintk wrote: post #2

I think these water heaters in question are actually hybrid units. They cool the surrounding room to maintain a temperature set point. In some places, colder room air and thus more condensation is not appreciated. A less-sophisticated approach is to put your tank heater on a timer. Think carefully before you do this. Does your tank heater have the capacity to keep the water hot for a full shower, until you’re back un…

Large insulated tanks of water are cheap. Sizing your house for a full week’s hot water is going to be cheaper than paying peak rates. That doesn’t help people today, but water heaters don’t last that long. Alternatively a tankless water heater provides both redundancy and instantly hot water.

[deleted]

Re: The humble water heater could be the savior of our energy infrastructure woes

#12

Post by cartoonworld » Wed, Jul 07, 2021, 1:29 AM UTC

ip26 wrote: post #9

cartoonworld wrote: post #4

Earlier quoted context omitted.

>A less-sophisticated approach is to put your tank heater on a timer. Think carefully before you do this. Do not do this without understanding the lifecycle of legionella pneumophila, or you will face a dramatic decrease in your quality of life. https://en.wikipedia.org/wiki/Legionnaires'_disease

Slightly smarter timers could fix this problem. Raise the tank to 140+ once a day, probably at 4am, and work that into the energy storage regime...

Another issue arises in that the bacteria can propagate throughout the system, repopulating the heater. Some have checkvalves, but I'm no plumber.

I urge great caution, although I'd wager you'd be fine, so long as you remain healthy.

Re: The humble water heater could be the savior of our energy infrastructure woes

#13

Post by kumarvvr » Wed, Jul 07, 2021, 1:36 AM UTC

xupybd wrote: post #5

"This approach can be deployed far faster than dam construction" Can we really manufacturer that many hot water tanks in less time than building a damn?

Absolutely. DAM construction is essentially sequential. You can't build the top without completing the bottom.

Manufacturing hot water tanks is trivial and highly parallelized.

Thousands of manufacturers for parts, all of whom can contribute to the demand.

Re: The humble water heater could be the savior of our energy infrastructure woes

#14

Post by otterley » Wed, Jul 07, 2021, 1:37 AM UTC

ip26 wrote: post #10

toomuchtodo wrote: post #6

Earlier quoted context omitted.

Yeah, timer or grid controlled water heaters are old and busted (especially with bacteria concerns due to a lack of in tank convection). New hotness are heat pump water heaters that are very efficient and can even add cool air to a conditioned spaces by their inherent operation. Electric vehicle charging orchestrated as large aggregate loads are what replaces “the humble water heater.” Tankless heaters are great if y…

Heat pump water heaters do seem promising... But many water heaters live in cold basements... Classic tanked electric is so cheap to make & operate, I have come to think they may always be with us. (Though certainly a heat pump water heater is an easy choice in the right climate)

"Cold" basements rarely fall below 50 degrees Fahrenheit/10C. There's plenty of thermal headroom below that for heat pumps to work. Heat pumps already work outdoors at below freezing. I don't think there's anything to worry about.

Re: The humble water heater could be the savior of our energy infrastructure woes

#15

Post by vl » Wed, Jul 07, 2021, 1:39 AM UTC

labster wrote: post #7

Retric wrote: post #3

Earlier quoted context omitted.

Large insulated tanks of water are cheap. Sizing your house for a full week’s hot water is going to be cheaper than paying peak rates. That doesn’t help people today, but water heaters don’t last that long. Alternatively a tankless water heater provides both redundancy and instantly hot water.

Large tanks are cheap, square feet of residential space are expensive. Tankless water heaters work well when powered by nat gas, but if you want electric it’s not great. I’ve been intending to do solar water heating, and convert from gas to electric, but the old heater gave out at the wrong time. So the current plan is build the solar and make a new place to move the electric tank into, then use the other tank for ex…

> The good news about climate change is that I never have to worry about the pipes freezing any more.

As they recently learned in Texas.

Re: The humble water heater could be the savior of our energy infrastructure woes

#16

Post by seized » Wed, Jul 07, 2021, 1:55 AM UTC

labster wrote: post #7

Retric wrote: post #3

Earlier quoted context omitted.

Large insulated tanks of water are cheap. Sizing your house for a full week’s hot water is going to be cheaper than paying peak rates. That doesn’t help people today, but water heaters don’t last that long. Alternatively a tankless water heater provides both redundancy and instantly hot water.

Large tanks are cheap, square feet of residential space are expensive. Tankless water heaters work well when powered by nat gas, but if you want electric it’s not great. I’ve been intending to do solar water heating, and convert from gas to electric, but the old heater gave out at the wrong time. So the current plan is build the solar and make a new place to move the electric tank into, then use the other tank for ex…

Climate change tends to mean more extremes, hot and cold (and windy). Southwest Canada is normally known for mild summers but it peaked over 110F last week. It was 95+F in my office.

So maybe plan accordingly just in case....

Re: The humble water heater could be the savior of our energy infrastructure woes

#17

Post by Retric » Wed, Jul 07, 2021, 1:57 AM UTC

labster wrote: post #7

Retric wrote: post #3

Earlier quoted context omitted.

Large insulated tanks of water are cheap. Sizing your house for a full week’s hot water is going to be cheaper than paying peak rates. That doesn’t help people today, but water heaters don’t last that long. Alternatively a tankless water heater provides both redundancy and instantly hot water.

Large tanks are cheap, square feet of residential space are expensive. Tankless water heaters work well when powered by nat gas, but if you want electric it’s not great. I’ve been intending to do solar water heating, and convert from gas to electric, but the old heater gave out at the wrong time. So the current plan is build the solar and make a new place to move the electric tank into, then use the other tank for ex…

A family of 4 is normally fine with a 60 gallon water heater. Doubling that to 120 gallons takes up roughly 1 extra square foot of floor space assuming a 6’ tall tank. If you’re living in Manhattan at ~1,500$/sf might be worth it to avoid peak rates, but just about anywhere else it clearly is.

Re: The humble water heater could be the savior of our energy infrastructure woes

#18

Post by s0rce » Wed, Jul 07, 2021, 2:01 AM UTC

Virtual battery, there is an interesting project to do a similar thing with aluminum smelters where you heat them and operate at full capacity off-peak and then during peak electricity usage you run slower. Since a smelter consumes so much power this can significantly level the grid usage.

Re: The humble water heater could be the savior of our energy infrastructure woes

#19

Post by s0rce » Wed, Jul 07, 2021, 2:03 AM UTC

otterley wrote: post #14

ip26 wrote: post #10

Earlier quoted context omitted.

Heat pump water heaters do seem promising... But many water heaters live in cold basements... Classic tanked electric is so cheap to make & operate, I have come to think they may always be with us. (Though certainly a heat pump water heater is an easy choice in the right climate)

"Cold" basements rarely fall below 50 degrees Fahrenheit/10C. There's plenty of thermal headroom below that for heat pumps to work. Heat pumps already work outdoors at below freezing. I don't think there's anything to worry about.

More of a problem is when your water heater is within your conditioned space envelope and in the cold months when you are heating your space the hot water heater takes that heat. Its not a huge issue but you do run the heater extra for the heat that's going into your hot water. If you've got an air source heat pump outside then its just an extra step.

Re: The humble water heater could be the savior of our energy infrastructure woes

#20

Post by nradov » Wed, Jul 07, 2021, 2:13 AM UTC

kumarvvr wrote: post #13

xupybd wrote: post #5

"This approach can be deployed far faster than dam construction" Can we really manufacturer that many hot water tanks in less time than building a damn?

Absolutely. DAM construction is essentially sequential. You can't build the top without completing the bottom. Manufacturing hot water tanks is trivial and highly parallelized. Thousands of manufacturers for parts, all of whom can contribute to the demand.

It looks trivial if you've never done it. If you actually try you'll see that manufacturing a safe, quality product at scale while turning a profit is extremely difficult.