Solar Panels to Assist Heat Pump, Thoughts from those that may know?

[alarmguy]

Just curious if anyone knows. Truly.

Im almost certain it would not be worth it @ 13 cents kWh but ... maybe someone knows something.
What if I wanted a limited amount of solar panels on one south facing side of my house to just ONLY assist my heat pump operating costs.
House is almost finished and will be moving in a few weeks, barring any delays.
Heat Pump I am guessing is 3 to 3.5 Tons. I'll know more after the coming weekend but I am certain it must be around that number..

Does anyone have any clue how many panels would be needed, costs involved.
If I understand correctly there would be no government tax credit unless I did something more extensive?
This is just a hair brain thought of mine only if for some "out there" reason this would cost next to nothing to have done. Other than that I dont have interest, I dont know if I would be in the home long enough for a payback, I am talking about a very limited system, almost for the fun of knowing on hot sunny or cold sunny days the Heat Pump will be getting some assistance from the solar panel. Nothing more than that.

 

[JohnnyG]

Unfortunately, heat pumps could use the help at night. Not a great idea in my opinion. But if you have very cold but sunny days, different story.
The new breed of low temp heat pumps might be a better option.

 

[BMWTurboDzl]

Just curious if anyone knows. Truly.

Im almost certain it would not be worth it @ 13 cents kWh but ... maybe someone knows something.
What if I wanted a limited amount of solar panels on one south facing side of my house to just ONLY assist my heat pump operating costs.
House is almost finished and will be moving in a few weeks, barring any delays.
Heat Pump I am guessing is 3 to 3.5 Tons. I'll know more after the coming weekend but I am certain it must be around that number..

Does anyone have any clue how many panels would be needed, costs involved.
If I understand correctly there would be no government tax credit unless I did something more extensive?
This is just a hair brain thought of mine only if for some "out there" reason this would cost next to nothing to have done. Other than that I dont have interest, I dont know if I would be in the home long enough for a payback, I am talking about a very limited system, almost for the fun of knowing on hot sunny or cold sunny days the Heat Pump will be getting some assistance from the solar panel. Nothing more than that.

How many solar panels do I need for air source heat pumps? | EnergySage Blog

Air source heat pumps are an incredible investment in your home’s energy efficiency, but the energy savings don’t have to stop there. Powering your heat pump system with solar panels can maximize energy bill savings while decreasing your carbon footprint. But how do you size a solar system to...

news.energysage.com

 

[PandaBear]

Not sure how your grid pay you when the heat pump is on vs off (unless it is one of those inverter heat pump with variable load so it is constantly running even at low load like the Lennox), and whether you are getting snow when your heat pump works the hardest. I would imagine whatever helps you on the roof will also reduce the sun light that keeps your roof warm and your heat pump has to work harder to warm the house more.

I have been thinking about how can a new home benefit from a small amount of solar panel without sending electricity back to the grid (can draw from the grid when it is not sunny enough), and the only answer I can come up with is either battery storage, or some form of variable load inverter based appliances and some form of thermal storage (making ice). Also if there's a way to wire the solar output to the heating element of the resistance heat based electric dryer and run the tumbling drum longer at lower temp.

I am not sure today's appliance is as reliable as before if they are going more complicated like inverter heat pump based AC, fridge, dryer, and water heater. It will likely use up more of the roof top solar output without a huge whole house inverter or battery storage, but it will still have a lot of mini inverters on each appliance.

 

[AZjeff]

The panels put power into the grid in the daytime, you take it out when you need it. There are solar calculators for your location to estimate how much you can expect to generate. Knowing the estimated amount generated and the heat pump usage you can get a ballpark idea. Don't ask me to figure it out.

I don't think you're allowed to wire directly to the heat pump if that's what you're thinking. Maybe you can but it's going to be more complicated.

 

[brianl703]

You'd want net metering so you get a credit for what the panels generate during the day. Then you can use that credit to run your heat pump at night.

Since panels generate more energy in summer than they do in winter, and your energy needs in winter maybe higher than in summer, the credit you get for the excess energy produced in the summer can be used in the winter when your panels don't produce as much.

 

[Rhymingmechanic]

If I remember right, Alarmguy is talking about a house on the North Carolina coast, not far from the SC border. That might be be relevant to the replies.

 

[eljefino]

You may be able to boost your in-house electricity usage without backfeeding to the grid. Depends a lot on your codes, rebates, incentives, and power company cooperation as well as what sort of inverter you get.

There will be baseline loads in your house like the internet router that run all the time. I'm not sure why you want to "budget" your power for one specific item. The inverter should help you geek out by seeing current and historical kilowatt production.

You can also use solar for domestic hot water, should be in a good spot for that. Absent of any incentives this was until recently, and possibly still, the best ROI. And they make heat pump water heaters that, by coincidence, dehumidify the basement or wherever you set it up.

 

[Rhymingmechanic]

From a quick reading of this page, there doesn't appear to be a minimum threshold to get a tax credit.

https://www.energy.gov/eere/solar/homeowners-guide-federal-tax-credit-solar-photovoltaics

I don't know a lot about the details, and there's sure to be a lot of variation by location, but Eljefino makes some good points about the other things that would be powered besides the heat pump. Depending on the arrangement and whether you have backup power already, a solar system could keep your fridge running during the inevitable power outages. Solar could be a good selling point if you don't stay in the house, too.

 

[Snagglefoot]

Your panels will not be “ off the grid” so you won’t be powering your heat pump directly but in your head you can make that assumption. Your panels will reduce the amount the heat pump is drawing from the grid and the best bang for the buck will be in the summer when the heat pump is operating as an air conditioner and the panels are getting maximum solar insolation.

 

[Snagglefoot]

Just curious if anyone knows. Truly.

Im almost certain it would not be worth it @ 13 cents kWh but ... maybe someone knows something.
What if I wanted a limited amount of solar panels on one south facing side of my house to just ONLY assist my heat pump operating costs.
House is almost finished and will be moving in a few weeks, barring any delays.
Heat Pump I am guessing is 3 to 3.5 Tons. I'll know more after the coming weekend but I am certain it must be around that number..

Does anyone have any clue how many panels would be needed, costs involved.
If I understand correctly there would be no government tax credit unless I did something more extensive?
This is just a hair brain thought of mine only if for some "out there" reason this would cost next to nothing to have done. Other than that I dont have interest, I dont know if I would be in the home long enough for a payback, I am talking about a very limited system, almost for the fun of knowing on hot sunny or cold sunny days the Heat Pump will be getting some assistance from the solar panel. Nothing more than that.

Roughly about 12 panels will deliver 4,000 watts and and will power the heat pump if it was a sunny clear day for 5 or 6 hours. Maybe someone more local can comment on payback. If 12 takes up too much space you could try 8 for at least 2400 watts to power a high SEER rated unit.

 

[alarmguy]

The panels put power into the grid in the daytime, you take it out when you need it. There are solar calculators for your location to estimate how much you can expect to generate. Knowing the estimated amount generated and the heat pump usage you can get a ballpark idea. Don't ask me to figure it out.

I don't think you're allowed to wire directly to the heat pump if that's what you're thinking. Maybe you can but it's going to be more complicated.

No, I understand how panels work completely.
I was just wondering if there was a possibility of it being inexpensive to put a minimal amount of solar panels on the southern part of my roof that would supplement the energy that the heat pump draws.
I’m not really interested in selling power back meaning it could be a true minimal system that might be cost-effective over a short period of time producing enough power to supplement the heat pump during the daytime
The cost of power is so cheap and my time in this house may not be all that long. I wouldn’t want to invest a lot of money.
Somebody posted a calculator in this thread, and it was a help. I think it would be far too costly to make it work.

That was really the reason for my post since I didn’t know anything about any rebates, but I’m assuming it would need to be a robust system that supplies more than I’m willing to spend.

 

[alarmguy]

Your panels will not be “ off the grid” so you won’t be powering your heat pump directly but in your head you can make that assumption. Your panels will reduce the amount the heat pump is drawing from the grid and the best bang for the buck will be in the summer when the heat pump is operating as an air conditioner and the panels are getting maximum solar insolation.

Yes exactly my thought process and all I would ever want but it seems like even that would not return any investment in a short period of time now that we see assuming it will still take 8 to 10 panels

 

[alarmguy]

From a quick reading of this page, there doesn't appear to be a minimum threshold to get a tax credit.

https://www.energy.gov/eere/solar/homeowners-guide-federal-tax-credit-solar-photovoltaics

I don't know a lot about the details, and there's sure to be a lot of variation by location, but Eljefino makes some good points about the other things that would be powered besides the heat pump. Depending on the arrangement and whether you have backup power already, a solar system could keep your fridge running during the inevitable power outages. Solar could be a good selling point if you don't stay in the house, too.

Yes tax credit on a small system is what interests me, not concerned about battery back up, power outages or anything more than efficiency of a small inexpensive system to generate some power a heat pump/ac would draw.
I’m quickly, realizing it probably will not interest me

 

[alarmguy]

You may be able to boost your in-house electricity usage without backfeeding to the grid. Depends a lot on your codes, rebates, incentives, and power company cooperation as well as what sort of inverter you get.

There will be baseline loads in your house like the internet router that run all the time. I'm not sure why you want to "budget" your power for one specific item. The inverter should help you geek out by seeing current and historical kilowatt production.

You can also use solar for domestic hot water, should be in a good spot for that. Absent of any incentives this was until recently, and possibly still, the best ROI. And they make heat pump water heaters that, by coincidence, dehumidify the basement or wherever you set it up.

The house is brand new, and COs being issued this week, not in any way, interested in investing any more money into it nor tearing up what we just built
After all everything is brand new and we’re talking about electricity that cost $.12-$.13 a kWh plus propane stove and hot water heat.
I appreciate your input, but as I posted, I was just curious if there was a simple cheap system with a good tax rebate that supplements some of the power that the house uses.
I’m realizing it was just a curiosity and pipe dream

 

[alarmguy]

Unfortunately, heat pumps could use the help at night. Not a great idea in my opinion. But if you have very cold but sunny days, different story.
The new breed of low temp heat pumps might be a better option.

The winters are pretty warm here, I was just mentioning the type of system, we never open the windows in the air-conditioning runs many many more months than the heat ever does.

 

[brianl703]

I’m not really interested in selling power back meaning it could be a true minimal system that might be cost-effective over a short period of time producing enough power to supplement the heat pump during the daytime

You still have to get set up for net metering; otherwise, you will be billed for any excess energy your panels produce, because the newer digital meters won't "count backwards" unless they've been programmed for net metering. They'll count the power you send back into the grid as power you've used.

Also there are regulations involving notifying your power company that have to be followed to comply with state law and power company rules.

 

[Snagglefoot]

In the city of Calgary, Alberta, Canada, solar panels are highly encouraged and you can have a solar panel system paid for by the city and then they add a payment plan to to the property tax, transferable to subsequent owners. One builder puts 8 panels on ALL new homes.

 

[alarmguy]

You still have to get set up for net metering; otherwise, you will be billed for any excess energy your panels produce, because the newer digital meters won't "count backwards" unless they've been programmed for net metering. They'll count the power you send back into the grid as power you've used.

Also there are regulations involving notifying your power company that have to be followed to comply with state law and power company rules.

Yes. guess I started this thread and didnt word it correctly. Im doing that in my post right below this one, unless someone posted before I finish, then it wont be right below! *LOL*

 

[Snagglefoot]

A friend had a 12 panel system put in for $6000 USD after a $3400 rebate with a projected payout of 8 years. It averages 4,000 watts and power is 10 cents per KWh.