DIY Solar Metal Roof – Part 1: Planning & Budgeting

Solar panels are VERY cheap now (2017) and it only makes sense to own a solar roof, as opposed to leasing / PPA, which are a total scam. This summer I will be putting a metal roof on my house and as much as 12-14 KW of solar panels. What I plan to achieve with this is the following:

1. Completely eliminate my very high electric bill: I pay over $0.20/kwh to a horrible Eversource (which bought National Grid and increased Massachusetts electric prices by over 40%!
2. Have too much solar electricity production: I plan to add a Mini-Split ductless HVAC system to part of my house that is very cold, and my forced hot air does not properly work in that section. Mini-Split is a heat pump system that runs on electricity, and is very efficient. Right now I pay $120-180 / month to heat that section with space heaters, and it’s still cold. Mini-split will make it warm there, and will use 1/2 the electricity!

   I also plan to switch from Gas drier to Electric drier, so I won’t be using gas to dry clothes. All this appliances will run off solar electricity, produced by my massive panels array!

3. Use Net-Metering to accumulate solar electric credits in the summer, and use them in the winter: Since I don’t use AC in my house, or use it very little, my summer usage is minimal (under 300 KWH per month), so all my peak summer production will be saved as credits and used in the winter for heating, etc.
4. Have Battery Backup Power: I want to install Tesla Power Wall or similar, to have a backup plan for when/if power goes down. I don’t want to have a backup generator because it’s very expensive ($6000-10000) and uses fossil fuel. Instead I will have an always-charged battery backup system that can get you through the day on mild usage!
5. Have Electric Car Charging: I’ve wanted an electric car or at least a plugin hybrid for many years. Now it’s becoming a reality, except for one little problem 🙂 I have a big family (4 kids) and there are not many options for 7-seat electric vehicles. Keeping my fingers crossed, hoping Mitsubishi will finally introduce it’s Outlander PHEV, which is extremely popular in Europe. Seriously, there it’s the #1 selling SUV 🙂

Here is what my roof looks like – south-facing side:

So big goals/plans. How do I plan to achieve all this, how much it will cost, and how long it will be paying for itself? Let’s review the budget and return on investment.

If you have done Solar PV installs before, please let me know if I missed something, or any good tips for me and our readers. This will be my 1st ever solar job, so I really need all the help I can get. Leave your feedback in the comments section below

Replace the roof BEFORE installing Solar Panels

Here is a video of a failed roof after Solar was installed. PV panels and racking had to come off because of leaks just 2 months after it was originally put on:

Solar PV system costs and ROI in 2017 – basics

As I said in the beginning – solar is VERY CHEAP now. How cheap? Let’s see.

I can buy THAISUN 320W Poly 72 cell for $0.354 per watt (sold in full pallets of 23 panels). I will need 2 pallets or 46 panels (extras I can use on my future RV Solar Roof). That is $5211 total for 14720 WATTS of solar panels. So we can safely subtract 10% for losses, and also another 5% for diminishing production in the first 2 years. After first 2 years efficiency loss stabilizes at 1% per year.

So Let’s say my max production will be 12512 Watts. In my town, we get about 961 hours of sun per year (according to Google Solar Project) or 2.63 hours per day. However I do believe it’s more like 3.5 hours per day or 1277 hours per year.

This means that my 12.5KW systems (after losses) can produce 12013-15969 KWH of electricity per year or at least 1000 KWH per month! It’s more than enough for my house… For 99% of homes in US for that matter!

1000 KWH is equivalent of about $200 electric bill, which I run in the winter. If I will have excess electricity, I can just add more electric appliances (such as more Mini Split systems) for heating, to reduce my gas heating costs. Maybe even an electric water heater!

Solar PV system costs planning

Solar PV Panels: So we have $5211 for solar panels. I may find better prices, because I have several friends in the solar industry, working on large volumes with suppliers.

Inverters: I’m still undecided which inverters to use, but most likely I will NOT use mini inverters, because if one dies, I’ll have to go on the roof, which can be dangerous in my case (very steep metal roof – 15/12 pitch, with solar panels on it). So I will most likely use string inverters – three at 5KW each. I will do this in case one dies, it’s less expensive to replace a 5KW unit vs 15KW

I can get a SMA SB 4000US-10 (4KW inverter) for $667 ($567 after credit) or SMA SB 5000US-11 (5KW) for $788 ($688 after credit). So lets say three 5KW units at $688 each, will be $2064.

Update: As you can see the deal on inverters and solar panels expires today – March 15, 2017 (oddly enough on the day when I wrote this). However, similar deals run all the time, from multitude of suppliers. Therefore I will not run out and buy these things today. I do need to measure everything and have an exact layout of my roof and panels, before buying anything. I feel very confident these prices will be available again!

Racking / Mounts / Wiring / Other small control units: I haven’t picked out exactly what I will use for, but I estimate this to be under $0.15 per watt… more like $0.12 per watt or $1500-2000. I will be using either S-5 clip or similar but cheaper option (which there are many) to attache racking to the ribs on my standing seam metal roof.

Why Metal Roof: I don’t need to replace my roof now, but it would be stupid to put new solar panels on a 12 year old roof. I know that most people do it, but they are not thinking. Roofs go bad after 12-20 years. WHEN your roof starts to leak, you will have to REMOVE and REPLACE your solar PV system, which costs $5800-7500 (excluding cost of new roof)! Complete waste of money, especially when you as homeowner have to pay that bill.

So I’ll install a lifetime metal roof, and never have to worry about leaks, ice dams, etc! And standing seam offers a great mounting surface for solar racking, without any penetrations!

My cost for metal roof: So I will not be paying retail 😀 … I will have to pay my guys to tear off old shingles, and for the dumpster. I figure $50-60/square + $400 for dumpster. My roof is about 24 squares, single layer, easy tear-off. So about $2000 to remove old roofing.

I will use GAF Deck Armor underlayment – 3-4 rolls $215 so $645 – $860.

Metal panels will run me about $1.20 per square foot for 24 Ga Kynar painted steel. I would love to use aluminum instead, but will have issues with expansion / contraction, because my panels will be over 25 feet long. So steel it is! With accessories and all, I figure $2 / square foot or $4800-5000 for materials.

I my labor cost should be another $1500-2000, which includes me working along my guys.

So my total metal roof cost will be $8700-9700 or $3.50 – $3.88 per square foot for NEW METAL ROOF! This is definitely not retail pricing which is about $8-12 per foot!

You can use our calculator to estimate metal roof cost.

Electrician cost: I can fix many things around the house, but electricity is not my thing. So to hire an electrician I budget about $1500-1800. This guy will know exactly what he is doing, as I will borrow him from one of my solar friends.

Extra costs: If you look at my roof, it’s covered in shade. There are 6 trees I will have to cut down, and since I will have another 3-5 trees in the back to remove, I expect to pay $250-300 per tree, without stomp grinding. I will do stomps myself, by renting a machine from home depot for $170.

So for the 6 trees that block the sun, it will be $1500-1800 🙁

I will also budget another $1000 for unforeseen circumstances.

My total budget for Metal Roof, Solar PV and tree removal:

So we have $5211 for PV panels, $4000 for inverters, racking, etc, $1800 for electrician, about $10K for the roof, $1800 for tree removal and $1000 for extras.

I’m taking higher numbers, so it would look better when all is done, and I’ve saved a grand or two 🙂 My total budget for this is $23811.

Excluding the roof, my solar budget is $13811 or just about $1/watt … OMG I just realized how CHEAP solar PV is now. Ok, so $1/w may be very low, but I don’t see it going over $1.2 per watt. So even if we add 20%, we are still at $16573.

Sure this does not include installation, because most of that work I will do myself, but just consider that 7 years ago, people were paying $6-7 per watt installed. Trust me, installation does not cost $3.5 per watt, because in my case it would be $51520 just for install 🙁

Solar PV ROI, or how long until I own this system free and clear:

Right out of the gate, I will get 30% off my solar costs as federal tax credit. That is $4143 in credits, bringing my solar cost down to $9668. I will also get some Massachusetts solar rebates. I’m not sure what they are right now, but I think another 15% of the total solar cost. But let’s not include them now, to have a more clear picture.

Since I will be saving $200/month in electric costs, that is $2400 per year. Therefore it will take me just about 4 years to have this system pay for itself. If we include metal roof in this calculation, my repayment will be 8 years, which is still VERY good, and is about 12.5% annual ROI.

Now something that is difficult to calculate now is the reduction in my gas bill (because I will supplement heating the addition with FREE electricity, so inevitably gas usage will be reduced). I also did not figure in the cost of Mini Split heat pump, which is about $3000 for my addition, and if we through that into the mix, my repayment will be 9 years and 7 months.

But I can’t really include the metal roof into the total, because at some point I’d have to replace it anyway, and it’s not part of solar pv system – it’s part of the house. Therefore we have about total cost of $13000 (solar + heat pump) with $2400 per year payback, which is about 5.5 years to get my money back, and then have TOTALLY FREE electricity in my home, much more comfortable addition, and a lifetime metal roof! Also, as said before, I don’t include State Solar Rebates in this calculation, so my payback period will be even shorter!

Final thoughts, scheduling the projects, buying solar panels and roof, etc

As you can see, there are many unknowns, but they won’t have massive effect on the bottom line. At most 10% impact on total cost.

Scheduling such massive project is difficult, especially that i’m still doing some inside remodeling. So first order, is to cut the trees sometime in April 2017, when tree removal guys are still slow. Then, I will begin doing the roof. Tear-off and underlayment will be done sometime in May, and metal roof installed in late May or early June. Then it’s just me installing raking and solar panels in late June / early July. Then road trip / vacation with family, then Mini Split heat pump in either July or August. Hopefully I can follow this schedule :).

What I’m most concerned with is connecting my PV system to the grid, and setting up net metering. When you have a solar contractor do this for you, all these things are taken care of. In my case, I hope the electrician will know what to do. Otherwise it will be a ton of bureaucracy and calls to the dreaded Eversource.

I also would like to have some type of solar monitoring system added, and I don’t know too much about that. I suppose I will also have to do a lot of reading.

I will have many more blog posts, covering this project, as I’m sure it would be very interesting to many of you – my loyal readers.

In future posts, I will outline and show everything that I do, as well as go over costs, and hopefully no budget overruns 🙂

When it is all done, I will have a detailed Step by Step DIY Solar PV guide that homeowners can follow to save an average of $2-3 per watt on your new solar install. Since most common arrays are 5-6KW, the saving would be $10-18K … not chop change by any means.

If you have done Solar PV installs before, please let me know if I missed something, or any good tips for me and our readers. This will be my 1st ever solar job, so I really need all the help I can get. Leave your feedback in the comments section below