How To Install Solar Panels on Roof? How It’s Crucial To Understand!!

How To Install Solar Panels?

Accounting for the inadequacy of fossil fuels, solar PV panels as an alternative source of energy enables you to

– go off-grid or 

– keep the electricity bill down

Among the renewable energy sources (solar, wind, hydro, tidal, geothermal, etc.) solar generation is the most user-friendly system. 

This complex free technology can significantly power up your house. 

In this article, we shall explain “How to install solar panels step by step”.  

We’ll demonstrate connecting an array of solar PV panels; however, you can scale up the solar panels according to your demand, provided you maintain the procedures.  

If you’re thinking about installing solar PV panels for your home, but it is the first time you are into electrical installation, have no fear!

Here’s to a good start. We’ll cover the instructions on “How to install solar panels step by step” in detail for residential houses or offices. 

We will describe the steps you need to take and answer the following questions to ease your solar installation process. 

i. How do I know if my house is good for solar panels? 

Brief description of how do you hook up solar panels to your house

ii. do you have a roof that supports solar panels?

iii. How many solar panels does it take to run a house?

iv. What are the key elements of a solar PV system?

How To Install Solar Panels Yourself: An Easy Process

a) Solar installation planning

Calculating the power usage (load usage)

For proper solar installation planning, you have to know the performance parameters and your required wattage of solar PV panels. 

Calculate how much solar power (in kilowatt hours kWh) you require before starting the installation process. 

This assessment will decide the size of your solar system and ensure the solar charge controller and battery bank be properly sized. 

You can estimate your power needs with an arithmetic calculation. But if you want solar power to cover all your daily power usage you can just take the utility bill to know the required power. 

Assuming, your monthly requirement of power = 600 kWh on average.  

Thus, the daily requirement will be = 600/30 kWh

                                                   = 20 kWh

Divide this number with peak sun hours to get the required size of your array / PV system. 

Peak sun hours = The number of hours the solar irradiance remain 1000 watts/square meters/day

If you receive 5 hours of peak sun hours in a day, the size of your PV system needs to be = 20 kWh / 5 h

                               = 20,000 / 5 W

                               = 4,000 W

If you want to install 250 W solar panels, the required number of solar panels will be = 4,000 W / 250 W

                       = 16

b) Solar system components and materials to purchase

Now, let’s review the key components of a solar PV system.

Only a well-built solar system with quality components – solar modules, batteries, inverters, and charge controllers ensure long durability. A solar PV system if installed with inferior materials will cause you nothing but distress. Hence, every component of the solar PV system is critical.

Substandard components are threatening the sustainability of your PV generation. 

In this article, we’ll focus on how to install solar panels step by step with proper selection of solar system components.  

Whether you buy monocrystalline or polycrystalline solar PV panels, make sure they are of same wattage capacity from the same renowned manufacturer. 

You’ll need the following components for installing a roof-mounted solar PV system:

i. Solar array

ii. Mounting / racking kit & grounding system

iii. Inverter

iv. Cables 

v. Rails 

vi. Splices 

vii. Mid clamps 

viii. End clamps 

ix. L-feet or standoff 

x. Flashing 

xi. Grounding lugs 

xii. Grounding clips 

xiii. Tape Measure

xiv. Benchmark (style) Cutting Knives

xv. Ratchet Action Pipe Cutter

xvi. Hammer

Solar PV panels generate DC power from sunlight. As household appliances use AC power, we’ll use an inverter to convert the DC power into AC. 

The AC and DC cables will connect the inverter with the fuse box and PV panels respectively.

How to install solar panels at home: detailed description

You must be aware of the following things before we get to “How to install solar panels step by step” at home.

a) How do I know if my house is good for solar panels?

You’ve to assess a few things to know if your house is good for solar panels. The effectiveness of solar PV panels varies with the shape and size of your roof. 

You should consider 

  • The possibilities of shading 
  • Space requirement (square meters) of the solar PV panels 
  • Weight of the solar PV panels 
  • Mounting / Racking system / frame
  • You may install solar panels on the roof (flush mounting), ground, or poles. Wherever you install the solar PV panels you must eliminate the possibilities of shading and mount the panels on the roof following your regional building codes and ordinances. 
  • Try to keep plentiful space from the edge of the building when you’re installing the solar array. You may place the PV modules in landscape or portrait orientations considering your convenience and efficiency in the installation area. 
  • You need to estimate how many solar PV panels can fit in your planned installation area (on your roof). Match with how much money you want to spend to produce your required power.

Let’s continue with the following approach.

Measure the width and length of 

  • the area where you plan to set the solar PV panels 
  • the solar PV panels you will be using 

Let’s consider, the measurements of your solar modules are:

Width = 35 inches 

Length = 60 inches 

If any number comes in fraction, round them up to the next integer. 

Set the PV panels equidistant from other panels but not too close to each other.

For this example, we’ll be placing the panels horizontally (in landscape orientation) beside each other. 

Let, the width of the installation area (east-west) be 

= 15 ft 

= 15×12 inches

= 180 inches

And the length (north-south) be 

= 300 inches

Then the maximum number of solar PV panels in a column (landscape orientation) can be 

= 300 / 35 

= 8.57 ~ 8

And, the number of solar PV panels in a row will be 

= 180 / 60 

= 3

You’ll need two rails of a minimum of 180 inches installed at the top and bottom of a row of modules to attach 3 PV panels. One of the rails requires grounding clips for their mid & end clamps. 

Grounding clips construct a grounding path for panels through the rail. For 8 panels in a column, there’ll be 8 rows and for that, you’ll require = 8 x 2 = 16 rails, of the 8 rails require grounding clips. 

Each rail needs 2 mid-clamps and 2 end clamps. 

Thus, 8 rails require = 4×8 = 32 grounding clips

Estimation of rail size 

Portrait orientation Landscape orientation
PV Module width x the number of PV modules in a rowPV Module length x the number of PV modules in a row

Installation of Clamps: Evaluating the thickness of your PV modules from the specification sheet, pick the compatible clumps. Screw the clamps into the rail to put pressure at the edges of PV panels. 

  • The End clamps hold the PV modules down at the end of each rail to keep the PV panels in place. 

Leave a gap 2 inches at each end of the PV module’s end clamps.

The number of end clamps = 2, for each rail

In a row the required gap = 2 x 2 = 4 inches 

In a row of modules for two rails you’ll need 4 (2×2) ends clamps. 

For 8 rows (16 rails), you’ll need 32 (16×2) ends clamps.

  • The Mid clamps secure the PV modules to the frame in between every module. Leave a gap of 1 inch between the PV modules for the mid-clamps. For 3 panels, the required gap between them = 1 x 2 = 2 inches

The number of mid clamps = PV modules in a row – 1

                = 3 – 1 = 2 for each rail.

For 8 rows (16 rails), the number of mid clamps = 2 x 16 = 32

In the scenario above, installing 3 60-inch modules in a row, you’ll require at least 180 (3×60) inches of rail. 

Adding 2 (1×2) inches for mid-clamps and 4 (2×2) inches for end clamps, the required length of the rail becomes 

= 180 + 2 + 4 

= 186 inches 

However, you can add multiple rails of different sizes with splices to get your required length of the rails.  

b) First glance at how do you hook up solar panels to your house?

You must know how the solar panels are hooked up in the system before you start following the necessary steps. 

The more information you gather the more you’ll be prepared to qualify yourself to install a solar panel at home.  

How To Install Solar Panels on Roof? How It's Crucial To Understand!!
How To Install Solar Panels on Roof? How It's Crucial To Understand!!

Solar panel installation process

a) What is the best direction for solar panels to face?

It is one of the crucial factors you should take into account before installing a solar PV system.  As a thumb rule, you need to lay the PV panels facing towards the equator. 

HemisphereNorthern Southern 
Panels facingSouthNorth

b) How many solar panels does it take to run a house?

It depends on the following factors

  • The size (watts) of each panel
  • Manufacture and type (efficiency) of solar panels
  • Your required kW, location (weather)
  • Capacity of battery and inverter and 
  • How long does it take to charge your battery? 

How much power a solar PV panel can provide depends on the charge controller type as well. 

5. Solar panel installation guide

a) Installation diagram / Electrical wiring

So how will you wire the solar PV panels-series or parallel?

If any shade hits slightly at any part of your solar array of parallel connection, a considerable power decrease occurs from just the particular PV panel.

However, it decreases power considerably from all of the panels of a series connection. Even after that, a series connection gets all the recommendations as it produces sufficient voltages throughout the day to charge your battery.  

Series connection: Connect one panel’s positive terminal to the negative terminal of the other. 

How To Install Solar Panels on Roof? How It's Crucial To Understand!!

Total voltage = 18 x 3 = 54 Volts 

Total current = 5 Amperes

Total power = 54 x 5 = 270 Watts

Parallel connection: Connect one panel’s positive terminal to the negative terminal of the other. 

How To Install Solar Panels on Roof? How It's Crucial To Understand!!

Total voltage = 18 Volts 

Total current = 5 x 3 = 15 Amperes

Total power = 18 x 15 = 270 Watts

Make the connections above with branch connectors.

b) The racking and mounting system installation

You can mount the PV panels on the roof, ground, or pivoting stand

If your roof is not convenient for installing PV panels considering the size, stability, and efficiency, you can go for ground mounting or a pivoting stand. The PV panels can track the sun throughout the day with a pivoting stand.    

  • Choosing the solar panel racking is critical as it is related to orientation, shading phenomenon and conditions of the roof or soil, etc. depending on where you plan on mounting your solar energy system.
  • Evaluate whether the roof can sustain the extra weight of the PV panels. 
  • All the solar PV panels must be of equal size in every array you make. 

For proper distribution of wind, snow and other loads rafter-attached system are more convenient and safer. 

Rafter attachment is a widely acknowledged method that supports the load of solar PV panels. 

To waterproof the penetrations and prevent any leakage, use high-grade flashing and sealing materials such as butyl tape and components of stainless steel.

  • You’ll be needing stanchions or roof hooks to provide support to the solar PV panels. Set the stanchions equidistant from the others in an appropriate area on the roof (evenly distanced). They must have a flat mount underneath the shingle.
  • With a hand tool mildly hit the positions where you intended to set the stanchions till you find hard materials to attach the stanchions to the rafters. Put the tiles / shingles back down after that to cover part of the hook.
  • To lay a concrete tile flat, create a groove grinding its back.  
  • For preventing the clay tiles to crack, replace the clay tiles with Eric tiles or corresponding ones. And for slate tiles in the roof, you can attach Solar Limpets by drilling through the tiles. 

The solar PV installations are roof-mounted for the most part and most steep-slope roofs use tiles and asphalt shingles.

You may require to penetrate the roof to mount a solar array. To secure the PV panels in place you may mount brackets into the roof rafters.

You must employ flashing techniques to decrease the possibility of water infiltration through the holes. 

Asphalt Shingle Roofs

Drill holes to the roof stud and attach lag bolts to the frames/roof rafters. The bolts hold the solar PV panels and the racking firmly. 

Flashing: Slip the flashing underneath the shingle/wood pieces.

With a piece of metal plate seal and enclose the brackets to prevent leakage of water. 

Tile roofs 

Tile roofs of metal, concrete, composite, etc. are well-suited with solar PV panels. 

Evaluate and inspect your tile roof for cracks, holes, and protective layers before you start installing solar PV panels. 

Remove the clay, concrete, or slate tiles from the locations in your roof where you plan to attach mounting foot and flashing. Buy metal hooks and flashing according to the shape and size of your tiles so you can suitably drill them into your roof to hold the solar PV panels. Put the tiles at their position above the feet of racking. 

Metal Roofs

The standing metal roofs are most suitable for solar PV panels. 

You don’t require any penetrations into your roof as you can clamp your solar PV panel racks to the raised seams. 

Use a U-clamp to secure the standing seam and then attach solar PV panel mounting to the clamp.

A raised seam allows circulating air underneath the solar PV panels to keep the panels cool.

But if you have a corrugated metal roof, you require to make penetrations into your roof. With a specified bracket attach solar PV panels and mounting to corrugated metal roofs. 

Flat roof

You’ll require slanted metal mounting for flat roofs. Make small penetrations and seal the holes properly.

You may utilize a ballast setup, a weighted mounting system that secures the solar PV panels. This setup doesn’t require drilling holes and allows the proper orientation of solar PV panels for optimal production. 

Standoffs are posts attached to the structural support of the roof. 

The standoff provides a gap between the solar PV panels and the roof. 

The air gets to circulate beneath the PV panels and restrain the panels from overheating. 

L-feet or Standoffs hold the rails and on top of the rails, we’ll mount the solar PV panels.  

The number of Standoffs / rails = the number of PV panels + 1

The solar panel mount or rack secures the solar PV panels. It is the hardware under the solar PV module. 

Typically, the space between the roof-rafters can be 12, 16, 24 inches, etc.

Typical space between the standoffs can be 48 – 60 inches.

For 186 inches of rail, you’ll need 4 (186/48 = 3.775 ~ 4) standoffs, if external load due to snow or wind is insignificant. Otherwise, you’ll require more standoffs.

 If the roof space is non-conventional, you must consult with a specialist.

Lastly, we’ll need grounding lugs for creating space for grounding wire.  You’ll require one grounding lug for each rail. For 16 rails, you’ll need 16 grounding lugs.

c) Install solar inverter and battery

Once you’ve opted for the wattage and number of solar panels, you’ll need to pick an off-grid solar inverter that can handle what the installed PV panels generate. 

A solar inverter transforms direct current (DC) from the solar PV panels into alternating current (AC) that powers the electrical devices.

With a backup battery bank, you can power required electrical appliances or critical electrical loads when the grid is down. A battery backup necessitates specific wiring from the battery to these loads.

An Off grid solar PV system transforms the solar energy into electricity to run loads and with the in-built solar charge controller, you can charge the battery bank. 

Connecting a Solar Charge Controller to Solar PV Panels

Typically, a deep cycle leisure battery requires 12.6 – 14.6 volts to recharge. The batteries won’t charge for voltages below 12.6 and voltages beyond 14.6 will cause the batteries to harm drastically. A solar charge controller monitors the voltage and regulates the recharging of the battery.

String inverter: Install on a wall to connect a string of solar PV panels into an inverter. Unless you have a huge solar system then you’ll require multiple inverters. 

For a 150-kW solar system, you’ll need 10 inverters of 15 kW each. 

If you want to expand your system, you can consider another type of inverter-

Micro-Inverter: Install behind each solar PV panel.

Buy single or multiple MPPT expandable inverters according to your estimated roof capacity with a warranty of a minimum of 10 years, digital display, and best AC power rating. 

Conclusion: What are the steps to installing solar panels?

Bring the DC cables from the roof into the house and connect them to an isolator (DC). With a DC isolator, you can switch off power flow from PV panels.  

Now, connect the DC cables from the isolator to the inverter input.

Connect the inverter’s output cable (AC) to an isolator (AC). 

If you put the inverter far from the house or easy reach, connect the cable from the isolator to another one adjacent to the fuse box. So, you can turn off your PV system at any urgency.

Connect the AC cable from the isolator to a generation meter that goes behind the fuse box which then is connected to a fresh MCB (16 Amp, etc.). 

Turn off the power of the house and insert the MCB into a gap of your fuse box to regulate the circuit of your PV system. 

7. Summary

Solar PV global capacity (on- and off-grid) has increased to 627 GW whereas in just a decade ago it was not more than 23 GW. The future of solar PV development does look even brighter!

Solar PV panels allow you to have an independent lifestyle without relying too much on the power grid. Solar PV panels are one of the best off-grid solutions whether you want to power an air-conditioner or charge up your cell phones. 

From the layout of a PV system covered in this article, you can pick the right components for your desired solar array. “How to install solar panels step by step” guide will let you make proper decisions for precise considerations.

With this DIY you’ll be able to continue solar construction on your own without any assistance from the installer companies. Disruption in installation and maintenance of solar PV panels won’t occur anymore. 

LEAVE A REPLY

Please enter your comment!
Please enter your name here