Let's Talk Solar Panels on your House

I'm a solar panel seller. A few months ago a spam company buy a lot of equipment. And they have the question about a roof. So.. little faq about it. I hope it will be helpful.

What happens if my roof needs replacing now or in a few years?
If you need a new roof now and also want solar be sure to add flashable mounting brackets before laying a shingle roof.  These brackets provide the highest level of protection from leakage when attaching to a shingled roof.   Or if you’re considering standing seam metal roof no roof penetration is needed.  Alternatively if you know you’ll need a new roof in 8 or 10 years, but you want solar now, you could consider a pole mount, or a ground mount instead of a roof mount thus, there’s no need to have the panels removed from the old roof and put back on the new roof.

What about hail, will it break the panels?
Solar panels are actually very strong, break resistant and can withstand some pretty harsh weather. 

Regard, Daniel

I actually canceled my appointment with the solar people after thinking about they told me on the 2nd phone call.

My local utility does "Net Metering" they will knock off the $$$ for the power I generate use.............but not beyond that. So let's say my electricity bill would normally be $150 for that month. But my solar panels produced $300 "worth" of electricity. 

I have a $0 for the electricity bill that month, but my utility just received $150 of free power production they sold to another customer. 

Doesn't seem quite right to me.

z31maniac said:

I actually canceled my appointment with the solar people after thinking about they told me on the 2nd phone call.

My local utility does "Net Metering" they will knock off the $$$ for the power I generate use.............but not beyond that. So let's say my electricity bill would normally be $150 for that month. But my solar panels produced $300 "worth" of electricity. 

I have a $0 for the electricity bill that month, but my utility just received $150 of free power production they sold to another customer. 

Doesn't seem quite right to me.

Check into how that works.  In my state, our utility has to square up with us on an annual basis.  

I will follow up and ensure that's how it works. 

But this is how the solar company explained it to me and why they said they look at your last year of kwH usage and build the system to average out the costs, but not too big so you aren't giving away free power. 

I assume (and we know about assuming), that they wouldn't tell me it was this way if it wasn't. It seems like adding extra capacity wouldn't cost *that* much more once you already have the crew out there, installing up on the roof, connecting to the grid, etc.

bummer! I'm getting ready to call for some quotes because of this thread as well.

In reply to z31maniac :

man, berkeley that!   i'd cut a cash deal to my neighbor and power their house from my production before i'd let the utility steal my excess.   either that or i'd leave the lights on 24/7.

I never looked at my excess as a money maker.  I sized the system to be roughly even, and then I see it as knowing what my energy costs will be.  No rate hikes in the future.

And when I want get an EV I can add capacity and fuel that for no extra cost.

TVR Scott said:

I never looked at my excess as a money maker.  I sized the system to be roughly even, and then I see it as knowing what my energy costs will be.  No rate hikes in the future.

And when I want get an EV I can add capacity and fuel that for no extra cost.

Not a money maker, but let me give you an example of the usage because of the AC system in OKC where I live.

May through September, we averaged 1500-1650 kwh per month. In November through February, that drops to around 450 kwh (we have natural gas for heat and water).

So even though the sun is at a lower angle, since I have no shade in the backyard, I suspect my system designed to hit $0 during the summer (the expensive months) would be generating plenty of free, excess power for OG&E during the non-peak electricity months. Or it would be small enough that I'm paying for the solar panels and some electricity during the summer. 

My initial goal, was buy an array large enough (that yes I'm taking out a loan on it) but that I never have an electricity bill. It seems ridiculous that the power company just gets to keep for free any excess power you produce.

z31maniac said:

TVR Scott said:

I never looked at my excess as a money maker.  I sized the system to be roughly even, and then I see it as knowing what my energy costs will be.  No rate hikes in the future.

And when I want get an EV I can add capacity and fuel that for no extra cost.

Not a money maker, but let me give you an example of the usage because of the AC system in OKC where I live.

May through September, we averaged 1500-1650 kwh per month. In November through February, that drops to around 450 kwh (we have natural gas for heat and water).

So even though the sun is at a lower angle, since I have no shade in the backyard, I suspect my system designed to hit $0 during the summer (the expensive months) would be generating plenty of free, excess power for OG&E during the non-peak electricity months. Or it would be small enough that I'm paying for the solar panels and some electricity during the summer. 

 

My initial goal, was buy an array large enough (that yes I'm taking out a loan on it) but that I never have an electricity bill. It seems ridiculous that the power company just gets to keep for free any excess power you produce.

No kidding--do they take that free to them electricity and give it to folks in need? I doubt it. Straight to the balance sheet.

z31maniac said:

My local utility does "Net Metering" they will knock off the $$$ for the power I generate use.............but not beyond that. So let's say my electricity bill would normally be $150 for that month. But my solar panels produced $300 "worth" of electricity.

Edit:  Nevermind, looks like OK's "Oklahoma's Energy Cooperative" does do net metering by the month, not the year.  Doh!     Deleted my previous links.

Here's what that website says:

What happens if I produce more than I use in a month?

Should your DG system generate more electricity than you use during the month, the excess energy simply flows back to the power grid. OEC does not credit your account or reimburse you for the excess generation. Regardless of the DG system’s production, OEC will bill you for the customer charge, currently $0.83 per day for residential accounts.

That sucks.

Yep, the good 'ol boy system in OK is ridiculous.

It's a crock of E36 M3.

In reply to z31maniac :

The seasonal energy use you're describing will probably make solar work out strongly to your benefit.  My solar production is far higher in summertime than in winter.  See this graph of production at my house since 2016:

Because of the higher sun angle and the longer day, you'll get lots and lots of power to cover your big A/C bill.  Then in winter it'll drop off and you'll not be wasting extra power. 

Sounds ideal, actually. 

You could even take it a step further and have the panels tilted to face the summer sun more directly.  Though anymore, panel tilting can end up being more expensive than just an extra panel.

As far as shifting some of your winter energy toward solar friendly, there are electric heat pumps and water heaters.  I'd love to move to electric-warmed radiant floor heat.  Induction cooking would also shift some energy to use up some of that solar production.

Food for thought, anyway.

I would think if your power use is low enough that you could sell power back, a solar system would not make economic sense (cost benefit payback).

(You of course could be doing it for other then pure economic reasons)

In reply to TVR Scott :

That's good to know, I didn't think the production would drop off that hard in the winter.

As for the HVAC and water heater, both are less than 2 years old from the house being renovated. They are mid-level brands so hopefully they will be reliable and cheap to maintain for the next 5-8 years.

Our range/stove is an electric glass top.

aircooled said:

I would think if your power use is low enough that you could sell power back, a solar system would not make economic sense (cost benefit payback).

(You of course could be doing it for other then pure economic reasons)

Yeah, according to my installer, you'll never pay off a panel selling back to the electric company.  Even in a perfect situation with yearly net metering like here in CT, on the years I get any back at all it's only ~$75-$100, because the electric co will only pay you the going wholesale rate for kWh, which means you're competing with any coal, oil, natural gas, wind, etc. major producer, and you're probably only getting paid $.05 per kWh or so.  General rule of thumb is that on >50% of the years, you'll get enough to pay off a few months of connection fees, and on slightly less than 50% of the years you'll have to pay in a few bucks more. That's how you know you have the proper sized system for your house.

TVR Scott said:

In reply to z31maniac :

The seasonal energy use you're describing will probably make solar work out strongly to your benefit.  My solar production is far higher in summertime than in winter.  See this graph of production at my house since 2016:

Because of the higher sun angle and the longer day, you'll get lots and lots of power to cover your big A/C bill.  Then in winter it'll drop off and you'll not be wasting extra power. 

Sounds ideal, actually. 

You could even take it a step further and have the panels tilted to face the summer sun more directly.  Though anymore, panel tilting can end up being more expensive than just an extra panel.

As far as shifting some of your winter energy toward solar friendly, there are electric heat pumps and water heaters.  I'd love to move to electric-warmed radiant floor heat.  Induction cooking would also shift some energy to use up some of that solar production.

Food for thought, anyway.

Is yours a roofmount or ground mount?  I don't have quite the variation that you do, although I'm ground mounted which I've read is good for 5-20% better overall efficiency depending on where your roof is pointed:

If I'm reading your chart right, looks like you're at about 1/3rd your generation in January vs. August.  Whereas I'm in the 48%-range.

In reply to WonkoTheSane :

Yeah, we drop to between 1/3 and 1/2 at the seasonal low.  Mine is roof mounted.  East side roof, which probably has some effect.

My monthly totals are very dependent on how much snow we get.  Like last March was one of our highest production months ever and we had very little snow.  This March we had several big storms and the total is a lot lower.

I definitely agree with you that selling excess power back to the power company will never be a mad money-making scheme.  Best to buy what you need and not much extra.  The nice thing about modern solar systems is that they scale up very easily.

As an update of sorts...

We're a few months into running the system and so far it's been great.  Our monthly electric bill is now just $15- the monthly fee charged by the electric company for the meter and service.  

Something I wasn't quite clear on until recently was the concept of SRECs.  Basically, solar credits we get as a non-utility generator.  We just got a check in the mail for the SRECs generated over the past 5 or 6 months, which worked out to about $90.  So that paid for all those months' worth of electric company fees (at $15/month).  

The monthly payment for the solar system is about $75.  Which is zeroed out by the savings on the bill (which was usually around $100 or so, pre-solar)

And since we're consistently generating more than we use, at the end of the year when the electric company settles up with us, we'll get a check then.  Which will basically be just gravy on the top of everything else.  

How many watts of panels do you have?

California has made them mandatory on new construction starting in 3 months.  This includes rebuilding homes damaged by fire.  I personally know at least a dozen people that lost their homes in the fires last year in Paradise, CA that will not be able to afford to rebuild their homes.  Their insurance will cover replacing the house, but will not pay for the solar panels.  The added expense is enough that leaving makes more sense.  I guess they all could have been lying, but that seems unlikely to me.

Toebra said:

California has made them mandatory on new construction starting in 3 months.  This includes rebuilding homes damaged by fire.  I personally know at least a dozen people that lost their homes in the fires last year in Paradise, CA that will not be able to afford to rebuild their homes.  Their insurance will cover replacing the house, but will not pay for the solar panels.  The added expense is enough that leaving makes more sense.  I guess they all could have been lying, but that seems unlikely to me.

While I'm not a fan of government mandates in most cases, and don't know the particulars of what's going on here specifically, I can say that, based on my experience, the net monthly cost to add solar was effectively $0.  This is based on the reduction in my monthly electric bill roughly equaling the monthly payment on the solar loan I took out.  So they're either lying, didn't really research the costs and reduction in power bill as a result of going solar, or simply didn't want the gubmit telling them what they had to do.  

z31maniac said:

I will follow up and ensure that's how it works. 

But this is how the solar company explained it to me and why they said they look at your last year of kwH usage and build the system to average out the costs, but not too big so you aren't giving away free power. 

I assume (and we know about assuming), that they wouldn't tell me it was this way if it wasn't. It seems like adding extra capacity wouldn't cost *that* much more once you already have the crew out there, installing up on the roof, connecting to the grid, etc.

You are not quite getting it. Basically the solar year will start around May 1. Each month you roll any credits over to the next month. But at the end of April the following year if you have any remaining credits you lose them. This was designed around photovoltaic production rates: you will likely generate some credits during the summer, then use them up over the winter. 

Jcamper

Coming late to this party, but this is actually a topic that I know something about.  I was a certified Solar Site Assessor in Wisconsin back in the days before the utilities bought the public service commission who then quit funding the program.  We had a complex spreadsheet and methodology that would factor in a number of variables in a solar installation and output a bunch of good information - system output, payback period, etc.  There are a lot of factors that need to be considered in determining whether a solar install makes sense:

- System output.  Use the National Renewables Energy Labs (NREL) PVWatts calculator.  Unless it's been simplified since I last used it, there's a bunch of parameters that needed to be input - location, panel mounting type and direction if fixed, panel output, etc..  Bigger systems are more cost effective since the BOS (balance of system) costs per watt decrease on bigger systems.  Any shade between 9am and 3pm will reduce the system output, and this should be evaluated with a solar analysis tool which these days can be a smartphone app.

- How unfriendly is your utility and your state to end user owned PV?  Utilities would rather sell you electricity than have you make your own, or worse, sell it to them, especially at retail prices.  The rules vary radically by state, and more utilities are trying to put monthly minimums in place to "pay for the infrastructure", even though distributed solar at the low penetration levels we have actually reduce their costs due to needing less distribution infrastructure.  Likewise the deals on selling excess power you generate vary greatly by state.

- Are you buying or leasing a system installed by a third party (in states where that is legal).  If you are leasing, there's a third party that will need to make a profit so any savings on your bill will be shared with them.  On the other hand, they know the rules and handle permitting, etc. which simplifies the process.  If you are buying, it's up to you to find the best equipment at the best price and that's not a simple task.

- Rebates, incentives, and financing make a huge difference.  Federal and state rebates vary by both location and tax year and getting a significant tax credit can make the difference between a reasonable time to payback and never.  If you're financing you need to figure in the interest rate, and if not, the interest you'll be losing by tying your cash up in a fixed asset on the roof.

- Permitting and regulation.  How hard is it to get approval and how long does it take, and how much hassle is it?  Will your installed deal with this for you?

That's the brief version of what I used to do.  In Wisconsin, we were generally looking at a 15-20 year payback for the better sites.  The cost of panels has dropped radically - like by a factor of 3 in 8 years.  I'm hearing that in good locations like the southwest payback can be as quick as 7-10 years.  If I were younger and building a house, I'd probably go totally off grid with battery storage and a backup generator, mostly to smite the local utility.

In reply to volvoclearinghouse :

I take it your state isn't one of the 20 states that provide free solar panels?  
  Here in Minnesota  if your house qualifies  ( southern exposure roof  without shade during daylight hours) you get them installed at no cost to you.  You do pay for them with your excess energy. You are paid for that excess energy at last years residential rate. So the power company still makes a slight profit.  
  Where they come out ahead is they don't have to build a new power generating station and pay for the fuel for the projected 20 year life span of those panels. 
    Plus since your excess power  will be consumed locally with little/ no  transit loss there is enough there to make  worth while to the power company.  
    I should mention that part of a power company's "costs"  is the fund they set up to build that power station. 

frenchyd said:

In reply to volvoclearinghouse :

I take it your state isn't one of the 20 states that provide free solar panels?  
  Here in Minnesota  if your house qualifies  ( southern exposure roof  without shade during daylight hours) you get them installed at no cost to you.  You do pay for them with your excess energy. You are paid for that excess energy at last years residential rate. So the power company still makes a slight profit.  
  Where they come out ahead is they don't have to build a new power generating station and pay for the fuel for the projected 20 year life span of those panels. 
    Plus since your excess power  will be consumed locally with little/ no  transit loss there is enough there to make  worth while to the power company.  
    

You've brought up these "free" panels multiple times in the past and I've never been able to confirm any of it. Do you have a link, or any other info about who/what is providing this program?