Solar power becomes mainstream but stays quite a challenge. How do I install PV panels properly? Won’t they be carried away with the upcoming storm? Is there any alternative to railings? Is it worth buying? Keep breathing, I got your back covered – here is an ultimate guide on how to mount solar panels on the roof.
Your decision on switching to “green energy” – wind, solar, biomass or other sustainable sources, – is a bear fruit. Not to forget about lowering energy bills (or, maybe someday getting rid of them!) you’re also deriving numerous health benefits. Living in a “green household’ reduces indoor air pollutions. Long term, this leads to less bronchitis, asthmas or cardiovascular diseases. And of course, your intention to generate electricity from the sun saves the environment of the planet and – in the end – helps us all.
- Active Time: 3-5 hours
- Lumen: 1,000; Color Temperature: Super Bright
I find it a quick and easy way to get as much close as possible to net-zero energy consumption. Even if you’re planning to be 100% on solar, I recommend to stay on-grid (i.e. not to disconnect from the local utility company). In this case, you can store the oversupply for later inside the grid and take as much as you need instead of buying batteries and accumulate the excess electricity at home. Also, I insist on the accurate planning: choosing a proper type of panels according to your budget, taking time to design a perfect solar kit considering climate, shading, roof orientation, etc., figuring out the “sun hours” (not the same as “daylight, can be calculated online depending on your location). There’ll be no other chance to re-think those steps so don’t you ever save on them!
I agree the constructors are pricey. Especially after you’ve already paid a fortune. For those who are familiar with a tool belt and a drill, installation won’t be tricky. Your first mounting might take a couple of days (in comparison, professionals can handle it in 4-10h). Here’s a list of what you’ll need while mounting solar panels on a metal roof (or any other type of roofing).
- allen key
- metal cutting saw
- ruler, tape measure, pen, marker, level, and other marking and measuring tools
- ladders, scaffolding (if needed) and fall protection equipment (obligatory)
People don’t take it seriously, but professionals insist that at least a team of two is needed to work on a rooftop. In case of a fainting spell or a heat stroke, your co-worker will be able to call for help. Also, two pairs of hands are usually better than one.
Before we get to the materials and supplies, let’s figure with what they call “mounting system” or “solar racking”. Basically, there are two types of them. Rail-based are the classics: PV panels are fastened to a guiding rail that holds them securely in place. This system has almost no limitations and suitable for any weather or roof type. Also, it allows more options considering the tilt (unlike rail-free, where you only have to follow the slope of the roof). At last, a rail provides a wider gap between the panel and the roof surface, so you can place any additional devices (i.e. solar micro-inverter, power optimizer, etc.)
As for rail-free systems, they are more compact, light-weighted and fit in one box. Fewer components to install means quicker and easier to handle. Also, if there is a lot of obstacles on the rooftop, rails won’t be the solution. Nevertheless, you should avoid rail-free mounting on a crooked roof or in the windiest regions.
There is a third option combining the previous two. A shared rail is when two rows of PV panels share one middle rail. Such halving brings us to fewer roof penetrations and speeds up the installation.
Most solar mounting systems have a list of common components:
- flashings – to protect your roof from leaks. These pads are usually made of galvanized steel, copper and aluminum, but also might combine with rubber or plastic. I tend to those light-weighted flashings (such as QB2, SolarFlash or E-Mount) which require one single bolt for installation.
- mounts (aka feet) – to attach the whole solar array to the roof surface with or without a rail. Most commonly come in L-shape. I crave for all-purpose SnapNRack L-foot, Unirac Solarmount and Pegasus Solar for their convenience and compatibility with most rail systems.
- rails – to form the PV array and hold it safely in place. Also, to hide the wires and special devices. Manufactured in aluminum, stainless steel, DIY-ed of wood. My choice is Power Rails which uses one single tool for faster bolt placement, and very versatile Ultra Rail.
- clamps – to put between two solar modules or at the end of the rail and hold them in place. I find EZ Standing Seam clamp and HQ clamps easy to install and very affordable.
Any other options?
Here’s the list of alternatives – in case you don’t want to poke a lot of holes through the roof.
- Ballasted mounting system uses weights, or ballasts, which act as supports and hold PV panels in place. In other words, there is a “tray” and multiple concrete blocks that press it down and won’t let fly away. Better use it on a flat roof. As an example, consider the EconoRack 2.0 that has only 3 components and a pre-attached roof protection mats made of rubber. Also, it has an option to customize the tilt angle and roof orientation.
- Anchored PR racking is another good way to minimize holes in the roof and avoid any potential leaks. It works on concrete roof slabs. The support frame is attached strictly to the slabs. While designing such a layout, you should minimize the number of penetration points and seal each one properly. I recommend KB Racking AnchorRack as an option. It’s fixed in its place with wooden screws and high-quality flashings. Also, it permits tilting and is very flexible in panel orientation.
- No-drill mounts stick to the roof surface by the very strong adhesive layer. There’re two reasons it’s not as popular as it could be are. First,the price. For a 100 watts panel you’ll need 4 feet. When it comes to more than 150 W panel, you need to buy 8. Secondly, the glue doesn’t adhere properly to rubber roofing, old-fashioned types of tiles and shingles. If you’re looking for such mounts, pay attention to Renogy Corner Bracket mounts or Sticky Feet RV mounts – they allow creating any tilt, and all you need to do is to find a piece of flat and smooth surface to stick it onto. For a slope roof, think of the Solar Pod Crown.
Yes, we can!
Without further ado let’s learn how to install solar panels step by step. This is easier than you think!
Find the perfect placement for your panels, depending on wherever they will receive the most sunlight. It could be on one or both sides of your roof, closer to the middle or the edges, etc. Avoid any roof objects and shaded areas. Establish the proper scheme by marking the distances between your panels and considering their configuration. For this, measure the distance between the holes pre-drilled in your specific panel. That number means you should place the rails on exact same distance apart.
Think of the tilt. The best option is to adjust it seasonally (2 or 4 times per year).
Determine the tilt depending on your latitude and:
- for fixed panels:
- if you are below 25 degrees (including 25) the tilt equals the latitude number
- from 25 till 40 – add 5 for each extra 5 degrees up to 40 (at 25 make it 30, at 35 make it 40)
- more than 40 – add 20 to your latitude number
- for tracking panels:
- add 15 degrees to your latitude for winter
- subtract 15 degrees for summer
Check for any damages of the roof surface. Remove, repair or replace any broken pieces. This might not only hold the solar array in place but will also prevent potential leaks.
Set up the scaffolding. Make sure everything is secure and safe. In case the house isn’t too high, use the safety belt and the safety cable. Attach the roof anchor to the top rafter so you’re able to tie yourself and prevent from sliding off. Use the safety harness all the time you spend on the rooftop.
Mark out the actual solar array on the roof surface. Keep in mind the rafters: use an initial blueprint to locate them or use a stud finder. Working on a metal roof is even easier, just follow the existing fixing points and screws.
It doesn’t seem so easy to find any rafter even with a blueprint in front of you. Make a “pilot hole” where you suggest the rafter is located. Leave the drill bit inside the hole. Then get to the attic and take a look at it: measure how far from the actual rafter it is, then go back to the rooftop. Take the drill bit out and seal the hole. Make a mark using your measurements. Be sure your next hole will be located exactly where it has to be!
Drill holes into the rafters watching them not to split. Basically, you’ll need 2 holes for each mount. Skip this if you are on the metal roof – just take some of the screws out on the required distance from each other.
Replace them with bigger ones. Install the flashings and the mounts. If needed, use a sealant to make watertight and airtight to prevent corrosion.
Time to install the rails. Place them parallel to each other following the marks and the plan. Start with the bottom one and move upper till the roof ridge. Secure your rails with screws and then cut to size to get rid of any excess. If needed, use a rail joiner to put them together. Add a finishing touch – place end caps on all the rails to bring more aesthetic.
Attach and power up!
To the point of no return of our manual on how to install solar panels by yourself. Position the first module, adjust it with the clamps, then repeat the process for the next panel. Insert the mid-clamp in between and fasten all the cap screws. Make sure there is a sufficient gap between the panel and the roof to bring in the air circulation (this will keep your system cooler in warm weather and produce more energy). Now interconnect your panels and connect the complete array to your inverter.
How to clean solar panels on the roof? Even funnier than you imagine! Most solar panels become self-cleaning during stormy weather. Light snow typically doesn’t stick to their surface and melts away as fast as it lands. Heavier snow covers the panels just like an ordinary roof. If there is the sun within a couple of days you’ll face tiny “snowslips” from above as those panels clear themselves. In other case take a roof rake with a long handle and wipe the excess snow. If your house is way too high, then yes, there will be a bit of climbing and balancing on the rooftop so maybe it’s time to call the professionals.
During the warm and dry season, there is a layer of dust and pollen which causes less energy production. I recommend manual cleaning. Use a garden hose to spray water directly to the surface and let the water drain.
Hopefully, this didn’t seem tricky for you. After you’ve finished make sure to do all the required paperwork (this here might be a bigger pain than any construction works!) You’ll need to feel up several forms for regulatory and safety reasons. Not to forget, send a notification to your electric company that they have to install a new meter for you – so you might receive credits for any excess electricity you export.
Haven’t you decided yet? Solar panel kits for homes are becoming more and popular so the price goes low. Will your house be the next going solar? Think about it and let me know in the comments below what your opinion is. As for me, I wish you luck at starting your own green household tomorrow. And let there be sunshine over your roof!