Solar System to Run Electric Pool Heater Off Grid

[LosFelizGirl]

I can't believe I haven't been able to find any info on youtube about running an electric pool heater, w/ a separate solar system to power it (off grid).
The only thing I have found is how to run a "heat pump" w/ solar. A heat pump is a different kind of heating technology. Anyway, anybody have any info? I need to start at the very beginning on this.

 

[sunshine_eggo]

Heat pump is 5-6X more efficient than direct heating.

What heater?
How many Watts?
How many hours/day?

 

[WindWizard]

I am effectively heating our 17500 gallon in ground pool using solar. I use the solar panels/batteries to power the pump and then 10 solar hot water panels to heat the pool. I also have a solar heat system built in the roof area. Pool water gets up to 87 and my wife is happy.

The solar hot water panels are fairly easy to obtain. A number of people have them mounted on their roof and remove them to replace the shingles and then put them for sale on marketplace or craigslist. It is a lot more effective using solar hot water panels than any other way.

 

[LosFelizGirl]

Heat pump is 5-6X more efficient than direct heating.

What heater?
How many Watts?
How many hours/day?

Hi. Thanks for your reply. I don’t know the answers to your questions. I need to learn about it more, what my options are, which electric heaters are the fastest, how many panels it will take for certain heaters, etc, that’s why I said I have to start at the very beginning. The only thing I know is a heat pump takes too long compared to an electric heater. This is for an Airbnb, can’t use heat pump.

 

[sunshine_eggo]

Hi. Thanks for your reply. I don’t know the answers to your questions. I need to learn about it more, what my options are, which electric heaters are the fastest, how many panels it will take for certain heaters, etc, that’s why I said I have to start at the very beginning. The only thing I know is a heat pump takes too long compared to an electric heater. This is for an Airbnb, can’t use heat pump.

You need to determine how much energy you need to heat the pool. Until then, there's no point in researching solar.

 

[efficientPV]

An Airbnb, so it has to be able to be run by idiots. There are ways to do this, but they are not suitable for the general public. Given that water and electricity don't mix well, I wouldn't want to be opening myself up to potential liability.

 

[Quattrohead]

I can't believe I haven't been able to find any info on youtube about running an electric pool heater

Because no one in their right mind would do it.

 

[LosFelizGirl]

You need to determine how much energy you need to heat the pool. Until then, there's no point in researching solar.

Well there you have it! I would only have learned this if I researched solar. Thanks, looking up my pool size today.

 

[Mattb4]

Direct sun warming of water circulating in black piping set in the sunshine gives you much more heating than indirect use of a 20-23% efficient solar panels to an electric heater and than to the water. What you would use solar panels for is to power the circulating pump.

There are many manufacturers of solar pool heaters.

Solar Swimming Pool Heaters

Solar water heaters are cost competitive with other types of water heaters and have low annual operating costs. Find out if they are a good option ...

www.energy.gov

 

[SilverbackMP]

There’s a reason most off grid folks have propane for or other sources (geothermal, wood, etc) for heating. They might use electric hot water water in the summer for a “dump” load but they almost never do in the mid fall to though early spring.

Might be able to get away with it in a lower latitude desert climate, but the solar hot water tubes directly in panels makes a ton more sense.

 

[dcg9381]

I can't believe I haven't been able to find any info on youtube about running an electric pool heater, w/ a separate solar system to power it (off grid).
The only thing I have found is how to run a "heat pump" w/ solar. A heat pump is a different kind of heating technology. Anyway, anybody have any info? I need to start at the very beginning on this.

I also agree, not a great idea unless you've got a specific use case. You can easily heat pools with solar power, direct thermosyphon heating rather than convert DC high voltage DC power to lower voltage DC, then lower voltage DC back to AC power. Never mind that batteries are expensive and will need to be replaced eventually

I've run thermosyphon water heater systems before in my home with backup electrical heat. Works great... But pools are a LOT more simple.

What part of the country are you in and what are you trying to accomplish?

 

[LosFelizGirl]

Because no one in their right mind would do it.

Well then I would like to find out why. When I don't understand something, I ask a lot of questions, it's really the only way to learn.

 

[LosFelizGirl]

Because no one in their right mind would do it.

I also agree, not a great idea unless you've got a specific use case. You can easily heat pools with solar power, direct thermosyphon heating rather than convert DC high voltage DC power to lower voltage DC, then lower voltage DC back to AC power. Never mind that batteries are expensive and will need to be replaced eventually

I've run thermosyphon water heater systems before in my home with backup electrical heat. Works great... But pools are a LOT more simple.

What part of the country are you in and what are you trying to accomplish?

I'm in a part of the country where gas is super expensive- Palm SPrings, CA. My gas bill for January 2023 was $2700. YEs, you read that right. My house is an airbnb. In the winter guests heat the pool to 90 degrees for day use and use the spa day and night. Our $50 additional pool/spa heat fee has always covered our gas bills, but not anymore! My goal is to supplement the gas heat w/ electric during the day. For example, use the gas to heat the pool up fast and then maintain the temp w/ a separate electric heater, powered w/ an off grid solar system that only feeds the electric pool heater. Meaning, it will have nothing to do w/ my main electric panel in the house. I figured this would relieve me of using gas during the sunny days in the winter to maintain the temps.
My pool is small w/ an attached spa separated by a wall (see pic)
Pool measurement: 10' X 35' 3 feet to 6 feet deep
Jacuzzi measurement 10' X 5'

 

[LosFelizGirl]

There’s a reason most off grid folks have propane for or other sources (geothermal, wood, etc) for heating. They might use electric hot water water in the summer for a “dump” load but they almost never do in the mid fall to though early spring.

Might be able to get away with it in a lower latitude desert climate, but the solar hot water tubes directly in panels makes a ton more sense.

Thanks for your reply.
My gas bill for January 2023 was $2700. My house is an airbnb. In the winter guests heat the pool to 90 degrees for day use and use the spa day and night. Our $50 additional pool/spa heat fee has always covered our gas bills, but not anymore! My goal is to supplement the gas heat w/ electric during the day. For example, use the gas to heat the pool up fast and then maintain the temp w/ a separate electric heater, powered w/ an off grid solar system that only feeds the electric pool heater. Meaning, it will have nothing to do w/ my main electric panel in the house. I figured this would relieve me of using gas during the sunny days in the winter to maintain the temps. I'm not interested in storing energy in batteries.
My pool is small w/ an attached spa separated by a wall (see pic)
Pool measurement: 10' X 35' 3 feet to 6 feet deep
Jacuzzi measurement 10' X 5'

 

[Bluedog225]

Interesting case. I think you are going to find that solar water panels are much more efficient.

 

[LosFelizGirl]

Heat pump is 5-6X more efficient than direct heating.

What heater?
How many Watts?
How many hours/day?

Interesting case. I think you are going to find that solar water panels are much more efficient.

 

[LosFelizGirl]

@Bluedog225 I was under the impression that solar water panels can't get the pool that hot. I have to maintain a 90 degree pool temp in the winter, and 102 for the jacuzzi. My house is an airbnb, this is what I have to supply.
My goal is to supplement the gas heat w/ electric during the day. For example, use the gas to heat the pool up fast and then maintain the temp w/ a separate electric heater, powered w/ an off grid solar system that only feeds the electric pool heater. Meaning, it will have nothing to do w/ my main electric panel in the house. I figured this would relieve me of using gas during the sunny days in the winter to maintain the temps. I'm not interested in storing energy in batteries.
My pool is small w/ an attached spa separated by a wall (i attached a pic in other replies)
Pool measurement: 10' X 35' 3 feet to 6 feet deep
Jacuzzi measurement 10' X 5'

Attachments​

 

[sunshine_eggo]

@Bluedog225 I was under the impression that solar water panels can't get the pool that hot.

Incorrect.

Sun hitting a solar panel - 80% is absorbed and radiated as heat where <20% is use to generate electricity.
Sun hitting a solar water panel - 100% is absorbed as heat and something around 50-60% of the heat is transferred to the water.

$2700 sounds outrageous. This really needs some context. Does the house also run on gas?

Have you considered a retractable pool cover that might help retain both the water and heat?

If you can determine how much gas was consumed in maintaining the pool's temperature, you can estimate how much electrical energy might be needed to offset that.

 

[dcg9381]

I'm in a part of the country where gas is super expensive- Palm SPrings, CA. My gas bill for January 2023 was $2700. YEs, you read that right. My house is an airbnb. In the winter guests heat the pool to 90 degrees for day use and use the spa day and night. Our $50 additional pool/spa heat fee has always covered our gas bills, but not anymore! My goal is to supplement the gas heat w/ electric during the day. For example, use the gas to heat the pool up fast and then maintain the temp w/ a separate electric heater, powered w/ an off grid solar system that only feeds the electric pool heater. Meaning, it will have nothing to do w/ my main electric panel in the house. I figured this would relieve me of using gas during the sunny days in the winter to maintain the temps.
My pool is small w/ an attached spa separated by a wall (see pic)
Pool measurement: 10' X 35' 3 feet to 6 feet deep
Jacuzzi measurement 10' X 5'

You're in an area with a lot of sun. The reason "why" you don't do it the way you're suggesting is that it's expensive AND inefficient compared to direct solar heating of the water which can be easily done on your roof (much cheaper than PV) and with a simple pump. You would be shocked at how much heat you can get into water with moderate sun.

Yes, you CAN do it the way you want to do it. But if you're expending $2.7K per year on gas, we'd need to convert that to energy use and then design a PV solar system that can produce that kind of power. As $2.7K is probably just under my total electrical bill for the year, I'm guessing that a PV solar system - and associated batteries, probably $50k DIY, easy. Expect $100k+ turn key.

 

[LosFelizGirl]

Incorrect.

Sun hitting a solar panel - 80% is absorbed and radiated as heat where <20% is use to generate electricity.
Sun hitting a solar water panel - 100% is absorbed as heat and something around 50-60% of the heat is transferred to the water.

$2700 sounds outrageous. This really needs some context. Does the house also run on gas?

Have you considered a retractable pool cover that might help retain both the water and heat?

If you can determine how much gas was consumed in maintaining the pool's temperature, you can estimate how much electrical energy might be needed to offset that.

Sorry about the lack of context. My home is an airbnb in Palm SPrings, CA. Guests heat the pool up to 90 degrees and the jacuzzi to 102 in the winter. Before gas prices skyrocked here a normal bill with this usage would be about $900. Anyway, the bill is directly correlated to the pool and jacuzzi heat. The ammout of therms consumed for that huge bill was about 550. The only other thing that runs on gas is stove and heat in the house. Heat in the house isn't used that much though.