# Run a Heat Pump on solar power



## protechplumbing

When competition drives the cost to the end user down to $2.50 per watt you will see systems on every roof.



naptown CR said:


> On a wholsale level We are down t about $2.00 per watt for panels. Still have to add in labor invertors O&P but we are now under $6 a watt in most cases.


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## Tom Struble

IMO state and local governments should be creating solar farms,where economies of scale come into play,instead of encouraging people to stick these things on their house


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## neolitic

tomstruble said:


> IMO state and local governments should be creating solar farms,where economies of scale come into play,instead of encouraging people to stick these things on their house


Less need for new grid
if things are decentralized.
Big arguments in the southwest
over routing power lines from
potential solar farms to population centers.
NIMBYism.....


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## hvaclover

tomstruble said:


> p.v. prices are only part of the equation the other part is how much will grid power be in 2020,the higher the cost of electricity the more cost effective p.v becomes


If the grid goes super high in cost I can see mfg charging more for Soar Cells.


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## Tom Struble

sigh...i guess we are all screwed then:shutup:


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## solarguy

neolitic said:


> Less need for new grid
> if things are decentralized.
> Big arguments in the southwest
> over routing power lines from
> potential solar farms to population centers.
> NIMBYism.....


Green path isn't.


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## solarguy

hvaclover said:


> If the grid goes super high in cost I can see mfg charging more for Soar Cells.


The cost is going to come down with thinline panels. As the grid cost goes up more panels will be sold and the cost will come down. Thinlines are coated and the material can be painted on.
If the government shifted from financing big oil to financing solar, in 20 years we would all be reaping free energy. We would use the power companies as a back up only for which they will charge a fee. Costs will come down as generators are abandoned.


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## solarguy

Of course the power companies will fight it tooth and nail.


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## Tom Struble

neolitic said:


> Less need for new grid
> if things are decentralized.
> Big arguments in the southwest
> over routing power lines from
> potential solar farms to population centers.
> NIMBYism.....


but why neo,don't they have power going there anyway?
and it wouldn't have to go directly to the population centers
just would have to go to a grid connection,sell it directly to the power company,like those cogeneration plants


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## solarguy

tomstruble said:


> but why neo,don't they have power going there anyway?
> and it wouldn't have to go directly to the population centers
> just would have to go to a grid connection,sell it directly to the power company,like those cogeneration plants


As population grows, so does the grid. Original housing had small boxes. As they are upgraded to take care of the new microwave or whatever, they consume more. Solar is not the ultimate answer, but it can decrease the impact.


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## hvaclover

The infrastructure does not exist for it and it will be too costly to revamp the whole nation.

People who wan t an can afford solar will do so. But for the masses I foresee 

either cleanl coal or nuclear.

I hate to see some and gloom but all I see are too many jobs that aren't coming back and a lot more people living below the middle class we have come to know.


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## solarguy

Fifteen percent would be a great leap and is doable. Google solar and see all the manufacturers, including some big players. The price will come down with technology. IBM has recently made some big jumps recently.


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## hvaclover

solarguy said:


> Fifteen percent would be a great leap and is doable. Google solar and see all the manufacturers, including some big players. The price will come down with technology. IBM has recently made some big jumps recently.


The industry will cull it self as all new technologies do as they come of age.

Back in the first quarter of the twentieth century there were over fifty domestic car makers. By the end of world war two there was only Studebaker, Ford, GM and Chrysler. I think everyone gets my drift.


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## Tom Struble

what infrastructure doesn't exist?


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## hvaclover

I'm imagining the whole nation on solar and wind generated energy including municipal and inter city and stat transit. The house hold and family car too.

But that's a pipe dream . Nobody is gonna foot the bill for that.


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## naptown CR

The infrastructure exists currently. the beauty of small generation plants on roof tops and houses is not only is the energy clean, but a big portion is saving transmission costs. I think I read somewhere that almost 20 percent of useable electricity is lost between the generation plant and end user. Small decentralized generation would also reduce the number of transmission lins that would need to be run.


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## Tom Struble

what about the use of pv to generate hydrogen for fuel cell use nap...any opinions?


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## Tom Struble

hvaclover said:


> I'm imagining the whole nation on solar and wind generated energy including municipal and inter city and stat transit. The house hold and family car too.
> 
> But that's a pipe dream . Nobody is gonna foot the bill for that.


your grand kids may have too


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## solarguy

hvaclover said:


> I'm imagining the whole nation on solar and wind generated energy including municipal and inter city and stat transit. The house hold and family car too.
> 
> But that's a pipe dream . Nobody is gonna foot the bill for that.


Only part of the solution. Geothermal, ocean wave power reclamation will also play their small part.Eventually we will eat away at the focus on fossil fuels piece by piece.


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## Tinstaafl

As much fun as it is to dream about cheap bountiful energy either on or off the grid, we all know that's not going to happen any time soon. But something we've all lived through, and I expect the trend to continue, is that most of our toys consume far less energy than they used to.

High energy prices will continue to reinforce that trend, as cost-conscious consumers will generally try to purchase low-usage products, and even modify their lifestyles to a certain extent for the same reason.

I predict that technology in general will continue to have a much larger effect in terms of reduced consumption, rather than any substantial gain in production.


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## Tom Struble

i agree Tin but those power reducing technologies will really help to make p.v. shine....so to speak:whistling


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## Tinstaafl

Hey, Tom?

Don't give up your day job. :laughing:


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## Tom Struble

what day jobarty:


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## Tinstaafl

:laughing::thumbsup:


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## Electric_Light

naptown CR said:


> The saga continues with education.
> 
> What the discussion here is is about Photovoltaics. the generation of electricity from light.
> There is not a heat factor involved other than the law of physics that states that with a rise in temperature the resistance of a conductor is increased.


Someone mentioned cold temperature improves PV performance. It also just happens to be that high available solar radiance energy usually coincides with high ambient temperature. 



> 90% of all photovoltaic systems pay for themselves in 4-5 years after we factor in the incentives.


It's basically not self-sustainable yet, economically if it depends on other people paying for it (i.e. subsidy). There's also not enough neutral source(i.e. not coming from PV contractors) data supporting your claim.



> The panels are warranted for performance for 25 years and have a life expectancy of 30 years.


Warranted by who and how certain are you that the said company will be in business 25 years from now?



> The other major component is the inverters and are generally warranted for 10-15 years depending on the brand and type. My common inverter is warranted for 15 years and has an estimated time before failure of 300+years.(Don't ask me how they came up with that but thats what they claim) That time frame is immaterial to this conversation.


What they claim and what happens in real life are two different things. In real use, its subject to surge, lighting impulse, etc. They probably don't factor in things that might happen in a real life. Auto body usually lasts decades, assuming you don't crash it. 



> Lets limit it to the average heat pump warranty which is 5 years.
> Now lets factor in the semi annual service that is not required on a PV system vs say 100-200 twice a year or annually for a heat pump.


How long does the battery bank last and what does it cost to replace them? If they're not sealed, they'll require maintenance as well. If you were to include solar panels to be covered from hail damage, would that increase your home insurance premium? If so, did you factor that into cost? I believe there are quite a few case studies on IEEE eXplore on battery maintenance cost on telecom company batteries and it costs them quite a bit.



> So now your heat pump that costs say for the sake of numbers $5000 and saves them 500 per year on their fuel bills vs their old heat pump.
> So raw numbers at 5000 divided by 500 = a 10 year payback.


What bank lets you borrow $5,000, pay back $500 a year for next ten years and not a dime extra? Unless the old system was already in need of replacement anyways, the only cost that should be considered in PBP calculation is the cost difference of expensive energy efficient type vs the normal (and possibly non heat pump) system though, then the cost of spending the extra money on higher efficiency model instead of spending elsewhere. If it had to be financed, then the interest expense has to be deducted from savings accordingly. 




> Now subtract the annual maintenence of say in the middle 300 per year
> so $500 savings-300 maintenance=200 actual savings 5000 divided by 200 = 25 year payback
> the system is only warranted for 5 years
> What's the average life span on a heat pump" 20 years is pushing it in my book but I have seen them last that long.
> 
> Now which is the better value.


I thought the thread was about using PV to run heat pump, so I don't see how you can compare the two that are supposed to operate together.


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## naptown CR

tomstruble said:


> what about the use of pv to generate hydrogen for fuel cell use nap...any opinions?





Electric_Light said:


> Someone mentioned cold temperature improves PV performance. It also just happens to be that high available solar radiance energy usually coincides with high ambient temperature.
> 
> One of those statements is true. Cold temperatures do increase performance due to lower resistance through the panels and associated wiring. The solar radiance is no different during the winter than the summer. Under certain curscustances cah be higher due to the fact that the earth is 3 million miles closer to the sun during the northern sinter and reflected light from snow. There are differences in angle of incidence on a fixed array for varying times of the year. the main difference is the length of day between sumnmer and winter.
> 
> 
> It's basically not self-sustainable yet, economically if it depends on other people paying for it (i.e. subsidy). There's also not enough neutral source(i.e. not coming from PV contractors) data supporting your claim.
> 
> Go to the The DOE website
> 
> 
> Warranted by who and how certain are you that the said company will be in business 25 years from now?
> 
> I would hope that companies like Sanyo, BP, Panasonic, Kyocera, will still be around, They have been for a while.
> 
> 
> What they claim and what happens in real life are two different things. In real use, its subject to surge, lighting impulse, etc. They probably don't factor in things that might happen in a real life. Auto body usually lasts decades, assuming you don't crash it.
> 
> That statement above is riduculous However All arrays are grounded and tolerant to anything but a direct lightning strike. What else out there is warranted for that. (except maybe lightning rods)
> 
> 
> How long does the battery bank last and what does it cost to replace them? If they're not sealed, they'll require maintenance as well. If you were to include solar panels to be covered from hail damage, would that increase your home insurance premium? If so, did you factor that into cost? I believe there are quite a few case studies on IEEE eXplore on battery maintenance cost on telecom company batteries and it costs them quite a bit.
> 
> There are no batteries in most system so this point is moot.
> There is generally no increase in insurance costs for installing solar. the panels are generally rated to withstand 130 MPH winds and 3/4" hail.
> 
> 
> 
> What bank lets you borrow $5,000, pay back $500 a year for next ten years and not a dime extra? Unless the old system was already in need of replacement anyways, the only cost that should be considered in PBP calculation is the cost difference of expensive energy efficient type vs the normal (and possibly non heat pump) system though, then the cost of spending the extra money on higher efficiency model instead of spending elsewhere. If it had to be financed, then the interest expense has to be deducted from savings accordingly.
> 
> Correct. Interest is not factored in however financing is available and at a 6% interest rate that still leaves a 10% or better return on investment. ROI is even better if there is no financing. Generally between 15-20%
> 
> 
> 
> I thought the thread was about using PV to run heat pump, so I don't see how you can compare the two that are supposed to operate together.


Well you're right that's how it started and evolved into the discussion we are having now.


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## Electric_Light

naptown CR said:


> Correct. Interest is not factored in however financing is available and at a 6% interest rate that still leaves a 10% or better return on investment. ROI is even better if there is no financing. Generally between 15-20%
> 
> Well you're right that's how it started and evolved into the discussion we are having now.


What data is there to support this claim? Are you including the opportunity cost of cash, which includes returns on it from investing elsewhere? 

Do your figures subtract at least the treasury bond rate from the gains when calculating the ROI? 

ROI is basically zero or negative unless you can surpass the NPV at the time of PBP compared to that of equivalent length treasury bonds. Cash in box is losing value and something that gains value at the same rate as inflation is gaining nothing. 

As far as insurance, if damage to PV system won't be covered and must be added specifically, the premium increase must also be deducted from ROI.


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## hvaclover

Electric_Light said:


> What data is there to support this claim? Are you including the opportunity cost of cash, which includes returns on it from investing elsewhere?
> 
> Do your figures subtract at least the treasury bond rate from the gains when calculating the ROI?
> 
> ROI is basically zero or negative unless you can surpass the NPV at the time of PBP compared to that of equivalent length treasury bonds. Cash in box is losing value and something that gains value at the same rate as inflation is gaining nothing.
> 
> As far as insurance, if damage to PV system won't be covered and must be added specifically, the premium increase must also be deducted from ROI.


MY GOD WHAT HAVE I DONE?

fROM A QUIET RANT I HAVE CREATED A MONSTER:blink:


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## solarguy

> What bank lets you borrow $5,000, pay back $500 a year for next ten years and not a dime extra? Unless the old system was already in need of replacement anyways, the only cost that should be considered in PBP calculation is the cost difference of expensive energy efficient type vs the normal (and possibly non heat pump) system though, then the cost of spending the extra money on higher efficiency model instead of spending elsewhere. If it had to be financed, then the interest expense has to be deducted from savings accordingly.


Around here the state and local jurisdictions cover a percentage as well. Interest free loans are available and are assed with your property tax. Being so the payoff comes in around 10 years. The panels are virtually indestructible from physical damage. I've been working on a friends property where we installed 25 year old panels to run his well. They are perhaps a little etched cutting down a bit on VOC. Very slight difference from the original readings.
Panels are rated under standard test conditions and derated for the actual conditions for where they will be used. Heat brings the rating down slightly. It is best to leave airspace under them. For the most part it is insignificant. Cold is the main enemy, increasing voltage beyond the ratings and must be accounted for in conductor sizing etc. They got it all figured out. These guys are geeks putting this stuff out.
As far as the heat pump, an energy efficient model might be more cost efficient than panels. That is the first place to put your money.


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## naptown CR

Electric_Light said:


> What data is there to support this claim? Are you including the opportunity cost of cash, which includes returns on it from investing elsewhere?
> 
> I will attach a return on investment for you to see
> No the opportunity of cash is not included. If cash were invested and were receiving a return that may be a factor however this would be a comparison on the rate of return. My example shows return on this investment only.
> 
> Do your figures subtract at least the treasury bond rate from the gains when calculating the ROI?
> 
> No see above
> 
> ROI is basically zero or negative unless you can surpass the NPV at the time of PBP compared to that of equivalent length treasury bonds. Cash in box is losing value and something that gains value at the same rate as inflation is gaining nothing.
> 
> As far as insurance, if damage to PV system won't be covered and must be added specifically, the premium increase must also be deducted from ROI.


Panels are covered on Homeowners policy's the same as roofing etc. I have not had a client have their rates go up for installing panels. But to answer the question if there were more premiums due this is not subtracted from the ROI.

One other thing the ROI does not take into account is the savings on utility costs. Since a savings canot be taxed it would be fair to add your tax rate into the savings as this would give the equivalent in income to provide that amount of increased discretionary spending.

The ROI is based on Maryland's laws, credits and grants. Your state and locality may vary. These are actual costs from one I sold recently.


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## hvaclover




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## protechplumbing

I have yet to see this mystery paintable PV film. Bet you can't show one working example of any such system in use right now. I call BS.



solarguy said:


> The cost is going to come down with thinline panels. As the grid cost goes up more panels will be sold and the cost will come down. Thinlines are coated and the material can be painted on.
> If the government shifted from financing big oil to financing solar, in 20 years we would all be reaping free energy. We would use the power companies as a back up only for which they will charge a fee. Costs will come down as generators are abandoned.


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## protechplumbing

Hydrogen is a nightmare to try to contain and transport. Impossible, no. HIGHLY improbable, yes.




tomstruble said:


> what about the use of pv to generate hydrogen for fuel cell use nap...any opinions?


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## Tom Struble

why? we do it with propane


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## solarguy

protechplumbing said:


> I have yet to see this mystery paintable PV film. Bet you can't show one working example of any such system in use right now. I call BS.


I was referring to the manufacturing process, not the application.


> the different manufacturing process is expected to enable much lower fabrication costs, as it is consistent with high-throughput and high materials utilization based deposition techniques including printing, dip and *spray coating* and slit casting.


http://www.energymatters.com.au/index.php?main_page=news_article&article_id=765
Perhaps "spray coating" might have been a better term.


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## protechplumbing

Google hydrogen embrittlement. That is just the beginning.

Also, propane can be stored as a liquid under relatively low pressure at room temperature. That's not going to happen with hydrogen so your energy density is going to go way down and that's assuming you can safely store and transport the stuff which you can't.

I'm a tree hugger. I have solar. There are many(in fact most) green technologies that you just have to acknowledge are bogus.


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## protechplumbing

Fair enough. I just get riled up when the "paintable solar panels" get brought up because it seems like I get at least 1 call a month from toothless red-necks wanting me to come out and install it for $.50 a watt 




solarguy said:


> I was referring to the manufacturing process, not the application.
> 
> http://www.energymatters.com.au/index.php?main_page=news_article&article_id=765
> Perhaps "spray coating" might have been a better term.


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## naptown CR

Protech
Being in central fla and a plumber I assume you do DHW?
Just curious who's equipment you use.


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## solarguy

protechplumbing said:


> Fair enough. I just get riled up when the "paintable solar panels" get brought up because it seems like I get at least 1 call a month from toothless red-necks wanting me to come out and install it for $.50 a watt


I wouldn't do it for under tree fiddy.
Hydrogen was hype.


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## protechplumbing

I use AET for DHW.

Go here if ya wanna see: http://www.protechplumbing.biz



naptown CR said:


> Protech
> Being in central fla and a plumber I assume you do DHW?
> Just curious who's equipment you use.


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