Solar Hot Water - Frequently Asked Questions
What provides back-up heat if the solar hasn't provided enough?
We often recommend an in-tank electric element. It is affordable and simple and it lets you shut your boiler off for the summer. You might be thinking, "Isn't electricity a really expensive way to heat hot water?" True, but the reality is that it will only be needed for a small amount of heat each year, so it doesn't add up to much money. More importantly, you will save money by being able shut off your boiler during the summer. This is a really important point because that boiler will run 95% of the summer in standby, keeping itself hot, just for that 5% of the time it is actually heating the water in your tank.
How much does it cost? What Incentives are available?
Check out our incentives page to learn more about the cost.
What is a typical installation timeline?
How does a solar hot water system work?
Check out our How it Works page to learn more.
Does it work during the winter?
YES! If you have ever been in a greenhouse when it is cold and sunny or cool and over-cast you know it can still get pretty toasty warm. Solar hot water panels are way better than greenhouses--a lot of sophisticated engineering goes into them.
What is the life span of a solar hot water system?
Your solar hot water system will easily last 25 years. Spartan Solar provides a one year warranty on parts and labor. The panels and tanks we use typically have ten year warranties.
What maintenance does a solar hot water system need?
A properly designed and installed system requires very little to no maintenance. We recommend a checkup every 5 years to make sure that everything is working well. Also, just like with any system in your home, a periodic quick observation on the owner's part is always a good idea. Is it making an unusual noise? Does the pressure gauge indicate a proper amount? Easy stuff.
Can I heat my home with solar hot water?
Yes, but it might not be as easy as you think. Many people who have radiators think, "I heat my house with hot water, let's heat that water with a solar hot water system." Sounds like a good idea, but what isn't obvious is that the temperature required to make those radiators effective is around 160 degrees F. Although solar hot water systems routinely generate temperatures that high during the summer, it only happens once every week or so during the winter.
On the other hand, radiant heat uses much lower temperature water, typically 90-120 degrees F. This is a much better match for solar hot water. There are also radiators that utilize "low temperature" hot water. These radiators can be retrofitted into your home. For residential solar hot water space heating, one can expect to install anywhere from 6-16 panels.
How many panels do I need?
For a 1-3 person household, we usually recommend a 2 panel domestic hot water system. Three panels if the household has 4-6 people.
Solar hot water space heating can be anywhere from 6-16 panels.
What is the difference between solar hot water and solar electric (PV)?
These are two entirely different ways of generating energy from the sun. Solar hot water has fluid passing through the panel and back down into the basement in order to collect energy in the form of heat. Solar electric (PV) panels use a special silicon material to generate electricity. If you see a solar system on someone's roof and it has a dozen or more panels it is almost certainly solar PV. Whereas, if there are 2-4 panels, it is probably solar hot water.
I am thinking about installing solar electric panels (PV) and using electricity to heat my hot water. How does this compare to solar hot water?
You will need anywhere from 6-12* solar electric (PV) panels in order to provide the energy needed to heat hot water with electricity as compared to 2 solar hot water panels. Those additional PV panels will cost anywhere from $6,000 - $12,000. Essentially, the solar hot water system ends up being cheaper and pays off faster.
Another consideration that might be helpful for some folks: The carbon footprint of using PV to heat water is higher than a solar hot water system. Each panel has a lot of aluminum in it, and, it turns out, that aluminum has a very high carbon footprint. Also, the thing that makes PV do its thing, the blueish silicon crystals that we all see, are manufactured through an energy intensive baking process. So, if environmental stewardship is a concern, you may want to use 2 solar hot water panels rather than 6-12 PV panels to heat your potable water.
* 12 if you are using a standard electric hot water tank, 6 if you are using an air source hot water heat pump like a GE Geospring to heat your water.
I have an older solar hot water system that needs service, what should I do?
Many of the systems that were installed in the 1980's are starting to see the end of their life span. We will certainly be able to fix your system, but, like an old car, there is no guarantee that another part won't break in the near future. If you live in Massachusetts, and you are eligible for the tax credits, the most economical choice is almost always to install a new system.
I see some people covering up their solar hot water panels during the summer. Will I need to do that?
Definitely not. There was a time where we didn't have the technology to prevent the glycol solar fluid from over-heating. If you happen to have one of these older systems, we recommend installing a new computer controller that will prevent the glycol from over-heating saving you from covering the panels.
How large are the panels?
Think a sheet of plywood--roughly 4' x 8'. On commercial jobs we might use 4' x 10' panels.
Will the solar system raise my property taxes?
Residents of Massachusetts: Not for 20 years after the installation date. Residents of Vermont: It depends on the municipality.
We often recommend an in-tank electric element. It is affordable and simple and it lets you shut your boiler off for the summer. You might be thinking, "Isn't electricity a really expensive way to heat hot water?" True, but the reality is that it will only be needed for a small amount of heat each year, so it doesn't add up to much money. More importantly, you will save money by being able shut off your boiler during the summer. This is a really important point because that boiler will run 95% of the summer in standby, keeping itself hot, just for that 5% of the time it is actually heating the water in your tank.
How much does it cost? What Incentives are available?
Check out our incentives page to learn more about the cost.
What is a typical installation timeline?
- If you are in Massachusetts and you are using a 0% interest HEAT loan to finance the cost of the system, installation will be about 3-6 weeks from the time you decide to move ahead. This allows for time for you to get a free energy audit (required for the HEAT loan), apply for the rebate and pull the permits, etc.
- If you aren't using a HEAT loan we can probably get started 2-3 weeks after we the initial deposit.
- Installation takes about 3 days.
- If you are in Massachusetts you can expect to see your rebate check 4-6 weeks after the final paperwork has been submitted.
How does a solar hot water system work?
Check out our How it Works page to learn more.
Does it work during the winter?
YES! If you have ever been in a greenhouse when it is cold and sunny or cool and over-cast you know it can still get pretty toasty warm. Solar hot water panels are way better than greenhouses--a lot of sophisticated engineering goes into them.
What is the life span of a solar hot water system?
Your solar hot water system will easily last 25 years. Spartan Solar provides a one year warranty on parts and labor. The panels and tanks we use typically have ten year warranties.
What maintenance does a solar hot water system need?
A properly designed and installed system requires very little to no maintenance. We recommend a checkup every 5 years to make sure that everything is working well. Also, just like with any system in your home, a periodic quick observation on the owner's part is always a good idea. Is it making an unusual noise? Does the pressure gauge indicate a proper amount? Easy stuff.
Can I heat my home with solar hot water?
Yes, but it might not be as easy as you think. Many people who have radiators think, "I heat my house with hot water, let's heat that water with a solar hot water system." Sounds like a good idea, but what isn't obvious is that the temperature required to make those radiators effective is around 160 degrees F. Although solar hot water systems routinely generate temperatures that high during the summer, it only happens once every week or so during the winter.
On the other hand, radiant heat uses much lower temperature water, typically 90-120 degrees F. This is a much better match for solar hot water. There are also radiators that utilize "low temperature" hot water. These radiators can be retrofitted into your home. For residential solar hot water space heating, one can expect to install anywhere from 6-16 panels.
How many panels do I need?
For a 1-3 person household, we usually recommend a 2 panel domestic hot water system. Three panels if the household has 4-6 people.
Solar hot water space heating can be anywhere from 6-16 panels.
What is the difference between solar hot water and solar electric (PV)?
These are two entirely different ways of generating energy from the sun. Solar hot water has fluid passing through the panel and back down into the basement in order to collect energy in the form of heat. Solar electric (PV) panels use a special silicon material to generate electricity. If you see a solar system on someone's roof and it has a dozen or more panels it is almost certainly solar PV. Whereas, if there are 2-4 panels, it is probably solar hot water.
I am thinking about installing solar electric panels (PV) and using electricity to heat my hot water. How does this compare to solar hot water?
You will need anywhere from 6-12* solar electric (PV) panels in order to provide the energy needed to heat hot water with electricity as compared to 2 solar hot water panels. Those additional PV panels will cost anywhere from $6,000 - $12,000. Essentially, the solar hot water system ends up being cheaper and pays off faster.
Another consideration that might be helpful for some folks: The carbon footprint of using PV to heat water is higher than a solar hot water system. Each panel has a lot of aluminum in it, and, it turns out, that aluminum has a very high carbon footprint. Also, the thing that makes PV do its thing, the blueish silicon crystals that we all see, are manufactured through an energy intensive baking process. So, if environmental stewardship is a concern, you may want to use 2 solar hot water panels rather than 6-12 PV panels to heat your potable water.
* 12 if you are using a standard electric hot water tank, 6 if you are using an air source hot water heat pump like a GE Geospring to heat your water.
I have an older solar hot water system that needs service, what should I do?
Many of the systems that were installed in the 1980's are starting to see the end of their life span. We will certainly be able to fix your system, but, like an old car, there is no guarantee that another part won't break in the near future. If you live in Massachusetts, and you are eligible for the tax credits, the most economical choice is almost always to install a new system.
I see some people covering up their solar hot water panels during the summer. Will I need to do that?
Definitely not. There was a time where we didn't have the technology to prevent the glycol solar fluid from over-heating. If you happen to have one of these older systems, we recommend installing a new computer controller that will prevent the glycol from over-heating saving you from covering the panels.
How large are the panels?
Think a sheet of plywood--roughly 4' x 8'. On commercial jobs we might use 4' x 10' panels.
Will the solar system raise my property taxes?
Residents of Massachusetts: Not for 20 years after the installation date. Residents of Vermont: It depends on the municipality.