How do most people heat water with solar panels and batteries?

[WorldwideDave]

I've used about five switchback runs of black polyethylene pipe on top of a 20-meter-long roof (nearly 100 meters of 3/8" pipe). When it's sunny, the water is hotter than one could take straight--must be mixed with cold at the faucet. At night, it's a cold shower. But when the sun shines, it's an awful good feeling knowing that the hot water cost nothing. Total investment for the system was about $60, with half that being the hot-and-cold faucet (rare for Thailand). The pipe is inexpensive.

Hot water run into a 5-gallon bucket would stay warm for several hours, for dipper baths.

While the 3/8" pipe heats quickly, I'd recommend the next larger size (or longer length) for a little more capacity. My pipe would give about five minutes of hot shower before starting to cool.

We do similar in Mexico for our house.
In USA I do that for pool heat but doesn’t move needle too much. Bigger pipes would if at slow rate like it is now. Anywhere from 5-11 degrees F difference between intake and output from roof. Cost was about 120 with pump.

 

[BarracudaBob]

It is a RHEEM XE50T10HS45U1

Performance Platinum 50 Gal. 10-Year Hybrid High Efficiency Tank Electric Heat Pump Water Heater

I replaced my water heater a few years back and kicking myself that I didn't put in a hybrid because that is one of the hottest rooms in the house. Guess where my batteries ended up

 

[robby]

I replaced my water heater a few years back and kicking myself that I didn't put in a hybrid because that is one of the hottest rooms in the house. Guess where my batteries ended up

Ehh I am not so sure about the Hybrids.
When they work they seem to work great but there are a lot of people having issues with them.

 

[BarracudaBob]

Ehh I am not so sure about the Hybrids.
When they work they seem to work great but there are a lot of people having issues with them.

I think i paid $350 for my water heater so it didn't make sence. They are a Heat Pump and they break down.

Here is an idea for you. My attic is well over 100F. How about a radiator, fan, and condensation trap.. I know a guy that heats his pool this way.

 

[MattMan119]

When you run this device do you shower and do laundry only when the sun is up, or have large battery bank?

I have +30kwh battery … I just used it like normal to see what it would use…

 

[BarracudaBob]

* Solar Attic Pool Heater in the Eco-$mart Catalog

Energy and resource efficient construction supply and remodeling. Free design consultation

www.ecosmartinc.com

 

[BarracudaBob]

So on a not so hot spring day I am wasting 10KW/H of sun with my batteries at 100%. if I could only.....

 

[BaylentheSky]

I have solar, so going with an electric water heater would be a no brainer. I went with the Rheem Pro Terra hybrid (heat pump) water heater after some research, and could not have been happier with the result. It consumes on average about 2-3 kWh per day for a household of 3 adults and 1 child.

 

[BarracudaBob]

If you don't live in a hurricane prone location the on the roof water heaters are a no brainer. They are prevalent overseas. They used to be in the US but went away.

 

[BarracudaBob]

I have solar, so going with an electric water heater would be a no brainer. I went with the Rheem Pro Terra hybrid (heat pump) water heater after some research, and could not have been happier with the result. It consumes on average about 2-3 kWh per day for a household of 3 adults and 1 child.

and cools the room that it is in.

 

[BarracudaBob]

Here is my biggest question.

 

[BaylentheSky]

and cools the room that it is in.

It's in my laundry room which is just few feet from my bedroom. Wondering if it's worth the effort to pipe that cold exhaust air into my room through the attic. Did you do anything with your free cold air?

 

[DPC]

wrong spot

 

[dougbert]

back in 2020 I implemented a water heater diversion load to heat water prior to my nat gas taskless, documented in MY BUILD THREAD

1st link

2nd link

3rd link

4th link

 

[WorldwideDave]

If you don't live in a hurricane prone location the on the roof water heaters are a no brainer. They are prevalent overseas. They used to be in the US but went away.

Very common in Mexico. Love them. 5-8 year lifespan. Most keep for 12-15 though.

 

[time2roll]

Related, although it wasn't solar-powered.

A German friend here in Thailand (sadly now passed) had an indoor pool.

Being German, he liked his pool warm and his rooms set to arctic!

He had a stainless-steel heat-exchanger made by a local fabricator so he could warm the pool using the waste heat from the aircon. It worked well as his pool was invariably like a sauna.

I'm afraid I have no details whatever about the heat exchanger arrangements

Yes heat-pump pool heaters are everywhere. Just set it up in your living room. Puts the heat in the water and blows cold air into the room. Heat exchangers are now going titanium for even better corrosion resistance.

 

[CaliSunHarvester]

Gas furnaces and gas water heaters will be illegal to install in California 1/1/2027. That's 22 months away. I have a couple of gas w/h in storage (new in box) for my rentals. They won't be for sale much longer.

Retail prices in the article are hilarious

Collins: Gas water heater ban begins in 2027 - San José Spotlight

On March 15, 2023, the Bay Area Air Quality Management District banned gas water heaters starting in 2027 and gas furnaces beginning in 2029. This will affect the majority of homeowners in the area, so we as an association are actively trying to inform homeowners of the upcoming changes. While...

sanjosespotlight.com

 

[LydMekk]

Insulated 200liter tank with 2.5kW element. Timer so it is only on from 08:00 to 18:00. Stays warm until morning, no problem.
I would not run tankless with solar, no.

 

[dougbert]

Gas furnaces and gas water heaters will be illegal to install in California 1/1/2027. That's 22 months away. I have a couple of gas w/h in storage (new in box) for my rentals. They won't be for sale much longer.

Retail prices in the article are hilarious

Collins: Gas water heater ban begins in 2027 - San José Spotlight

On March 15, 2023, the Bay Area Air Quality Management District banned gas water heaters starting in 2027 and gas furnaces beginning in 2029. This will affect the majority of homeowners in the area, so we as an association are actively trying to inform homeowners of the upcoming changes. While...

sanjosespotlight.com

time to sell and move out of state

 

[time2roll]

time to sell and move out of state

Time to raise the rent.

 

[CaliSunHarvester]

time to sell and move out of state

Yeah, that would be one hell of a 1031 exchange. I cannot imagine selling the homestead. I got rid of 10 apartments right near the peak though, late 2021, and exchanged to Texas.

Our place here (Santa Cruz) is on a steeper downslide than the rest of the state. Especially the city limits should be avoided.

 

[Norwasian]

I've used about five switchback runs of black polyethylene pipe on top of a 20-meter-long roof (nearly 100 meters of 3/8" pipe). When it's sunny, the water is hotter than one could take straight--must be mixed with cold at the faucet. At night, it's a cold shower. But when the sun shines, it's an awful good feeling knowing that the hot water cost nothing. Total investment for the system was about $60, with half that being the hot-and-cold faucet (rare for Thailand). The pipe is inexpensive.

Hot water run into a 5-gallon bucket would stay warm for several hours, for dipper baths.

While the 3/8" pipe heats quickly, I'd recommend the next larger size (or longer length) for a little more capacity. My pipe would give about five minutes of hot shower before starting to cool.

I should add that the only way to do those pipes is to keep them all ascending, no vertical roller coasters....and especially no spiral loops (unless you have a pump strong enough to overpower the inevitable vapor lock in the pipes). In my case, I added a couple of risers with valves at the top just to bleed off stray air bubbles. I could open the valves from time to time if the water seemed sluggish.

 

[Madcodger]

We put a 50 gallon heat pump water heater in the mechanical room, with the inverters. So as they produce heat, it gets moved into the water. We have never had it set for anything but heat pump only mode. With two people, we've never run out of hot water.

 

[SomethingAppropriate]

Yeah I have a tankless on demand and it’s not the best for solar. It pulls between 8-15kw depending on the flow rate. But I also have an ev charger that pulls 12kw so I had to size for both.

So you dont use hot water when you are charging your car?

 

[Banjoman]

80 Gallon Heat Pump Water Heater.. with two kids and the wife it does switch to heating elements and yeah it pulls around 5400 watts if it needs to recover/recharge quicker than normal. When running in heat pump mode you are good to go for a long time on battery power. I am going to need to add more battery capacity to keep up when it kicks into what it calls high demand mode and turns the elements on.