Green home solar energy

Solar Energy in 2023:
All Your Questions Answered

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There are many benefits to solar energy. From tackling climate change, to saving you money on your electric bill and raising the value of your home, there are many things that make it an attractive choice.

If you’re a homeowner and you’re thinking about transitioning from grid electricity to a solar power system, the available options can be confusing and overwhelming.

In this article we’ll attempt to explain what the three main types of solar panel are, outline the positives and negatives of each one and explain how they’re installed on different roof types.

What Is Solar Energy?

Solar energy refers to the radiation emitted from the sun that hits the earth. This solar energy comes in the form of light waves, and can be harnessed with solar panels to produce electricity.

how solar energy works


How Do Solar Panels Work?

Solar panels, also known as photovoltaic modules, absorb light energy from the sun and convert it into direct current (DC). As we don’t use DC in our homes and businesses, this current has to pass through a solar inverter.


What is in a Solar Panel System?

A solar panel system will consist of the following equipment:

  • Solar panels
  • A solar inverter
  • DC and AC wiring
  • A Solar battery (optional)


What is a Solar Inverter?

Solar inverters convert DC electricity to alternating current (AC). Alternating current is the usable form of electricity that runs our homes and businesses. 


There are four different types of solar inverters typically used in residential installations. They are:


  1. The on-grid solar inverter

    , also known as the grid-tie inverter. This type of solar inverter is tied to the grid, and feeds excess electricity into it.
  2. The off-grid solar inverter

    , also known as the stand-alone inverter, which is not connected to the utility grid and instead charges solar batteries with AC voltage.
  3. The special battery backup solar inverter

    , which recharges a solar battery from backup AC supply, and feeds excess generated electricity into the utility grid.
  4. The hybrid solar inverter

    , which can manage the functions of the on-grid inverter, the off-grid inverter and the special battery backup inverter.


How Much Power Does A Solar Panel Produce?

The amount of power that a solar panel produces are dependent on numerous factors, including:

  • The type of solar panel
  • The efficiency rating of the panel
  • The tilt and orientation of its placement
  • The temperature
  • The amount of cloud cover

We will outline the efficiency ratings and solar power output range in peak conditions for each type of solar panel later in the article.


What Types Of Solar Panels Are There?

There are three main categories of solar panels. They are:

  • Monocrystalline solar panels
  • Polycrystalline solar panels 
  • Thin Film

Types Of Solar Panels

How Are Solar Panels Made?

There are different manufacturing processes involved in the production of each type of solar panel. We will explore each one below.


  • Monocrystalline Solar Panels

Monocrystalline solar panels are made of a single silicon crystal that is dipped in a vat of molten silicon to form an ingot. Once cooled, the ingot is sliced into thin wafers and the edges are cut.


  • Polycrystalline Solar Panels

In the manufacturing of polycrystalline solar panels, molten silicon is poured into square molds and then cut into wafers when cooled. Unlike monocrystalline panels, the edges are not cut.


  • Thin Film

Thin film solar panels are made of layers of semiconducting materials that are placed between transparent conducting layers, such as glass. 


Which Type Of Solar Panel is Best?

Listed below are the stats for each type of solar panel.


Monocrystalline Solar Panel Specifications

  • Efficiency

    : The efficiency rating of monocrystalline solar cells ranges between 17 to 22%.
  • Power Output

    : The solar power output of monocrystalline solar cells ranges between 327 to 425 watts.
  • Lifespan

    : Between 25 and 40 years.
  • Appearance

    : Monocrystalline solar panels have a uniform black finish.
  • Temperature coefficient

    : 0.3 – 0.4%.


Polycrystalline Solar Panel Specifications

  • Efficiency

    : The efficiency rating of polycrystalline solar cells ranges between 15 to 17%.
  • Power Output

    : The lower efficiency rating of polycrystalline solar panels means that their solar power output ranges between 240 to 300 watts.
  • Lifespan

    : Polycrystalline solar cells have a higher degradation rate than monocrystalline cells, so their lifespan ranges between 20 to 35 years.
  • Appearance

    : Polycrystalline Solar Panels have a marbled finish with a blue hue. No two panels look the same.
  • Temperature coefficient

    : 0.45 – 0.5%.


Thin Film Solar Panel Specifications

  • Efficiency

    : Thin film solar panels have the lowest efficiency rating of the three types, with efficiency typically ranging between 10 and 13%.
  • Power Output

    : The much lower efficiency rating of thin film means that their solar power output peaks at 250 watts.
  • Lifespan

    : Thin film have the shortest lifespan, lasting between 10 to 20 years.
  • Appearance

    : Thin film solar panels have a uniform black finish, and they’re 350 times thinner than their crystalline counterparts.
  • Temperature coefficient

    : -0.2%


What Does Temperature Coefficient Mean?

The term temperature coefficient refers to the decrease in solar panel power output for every 1°C (1.8°F) that the temperature rises over 25°C (77°F).

 Byju's Temperature Coefficient Of Resistance

How Much Does It Cost To Install Solar Panels?

When it comes to calculating the cost of installing solar panels, you have to first calculate the cost of the panels and then add the cost of installing that particular type of solar panel.


Nationally, the average price tag of a solar installation is $20,498 in 2022 after federal solar tax credits have been factored in. The overall national average cost per watt in 2022 is $2.77.


How much does it cost to install solar panels in Illinois?

The average cost of a solar panel installation in Illinois ranges from $13,048 to $17,652, with a mean average of $16,740. The average 6kW system costs $17,880, and the average 10kW system costs $29,800.


On a cost per watt basis, a solar panel installation in Illinois has a price range of $2.61 to $3.53, with an overall average cost of $2.98 per watt.

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What is the average payback period for a solar panel system?

The solar panel payback period is a calculation that provides an estimate of how long it should take you to ‘break even’ with your solar panel installation. 


The payback period is calculated by dividing the cost of your solar panel system by the amount that you will save annually from the investment. The average solar payback period is around 8.7 years.


What impacts the cost of a solar panel system?

  1. Panel Type:

    – Monocrystalline solar panels

    have an average cost of $3.00 to $3.50 per watt, meaning that an average 6kW system would cost around $19,000.

    – Polycrystalline solar panels

    on average cost between $2.80 to $3.00 per watt, so the average 6kW system would cost around $17,400.

    – Thin film panels

    cost on average $2.00 to $3.00, so the average for a 6kW system is $17,000.
  2. System size:

    the larger the size of your system, the more expensive it will be. The price per unit decreases however, the larger the system is.
  3. Panel brand and quality:

    As with most products, solar panel brands are of variable quality and the prices reflect this.
  4. Roof characteristics:

    the cost of installing the system will vary, based on your roof type and level the difficulty for the installation.


What Are The Advantages and Disadvantages of Solar Panels?

  • They have the highest efficiency rating and solar power output, so you require less of them to meet your energy needs.
  • They have the longest lifespan of the three types of solar panels.

What are the disadvantages of monocrystalline solar panels?

  • They’re the most expensive type of solar panel.
  • They’re more difficult to install than thin film solar panels.

What are the advantages of polycrystalline solar panels?

  • They’re less expensive than monocrystalline solar panels.
  • They have a higher efficiency rating and solar power output than thin film solar panels.

What are the disadvantages of polycrystalline solar panels?

  • They have a shorter lifespan and lower efficiency rating and solar power output than monocrystalline.
  • They’re generally considered to be the least aesthetically pleasing, due to their inconsistent appearance.

What are the advantages of thin film solar panels?

  • They have the lowest temperature coefficient of all three types of solar panel, so they lose the least amount of efficiency in hot weather.
  • They’re generally considered to be the most aesthetically pleasing type of solar panel, due to being so thin and having a uniform appearance.

What are the disadvantages of thin film solar panels?

  • They have a significantly shorter lifespan than the other types of solar panel, which contributes to them being less cost-effective in the long run.
  • They are much less efficient than other types of solar panel, so you require a lot more of them to meet your energy needs.


Can I Install Solar Panels Myself?

Installing solar panels on a roof is a complex job, with many steps. If you’ve decided to install solar panels on your roof, the following steps offer an outline of how to get it right.  


How to Install Solar Panels

solar panels installation

  1. Before anything else, familiarize yourself with the rafter layout in your attic. Take a measurement as a point of reference. This will be needed later.
  2. Once you’re up on the roof, mark the location of where you plan to mount the solar array. You should also mark the locations of where you intend to install the rails. 
  3. Using a point of reference on your roof, locate your first rafter. Verify the locations with a stud finder. If you miss them when drilling, the holes can easily be filled in with silicon. 
  4. Mark the general location of each rafter using their spacing measurement, so you know where they will cross your rails, then drill the holes, completing one rail at a time.
  5. Use a roofing pry bar to lift the shingles located where the mounting bosses will be placed. Install the mounting boss’s flashing under the shingle and align the boss with the hole that you have drilled.
  6. Repeat step 5 until you have fitted the flashing under each of the holes.
  7. Remove the bosses that you have just installed, flip them over so that the bottom side of the flashing is facing up and place them over the holes.
  8. Completely fill each of the holes with caulking and caulk a line on the flashing, then proceed to reinstall the flashing and secure the bosses and L-brackets.
  9. Assemble the rail to the length specified by your plans, and secure it loosely to your L-brackets. Attach the optimizers and connect the wires, then install the junction box.
  10. Finally, you can mount your solar panels. Make sure that they are secure, and connect the wires as directed in your wire diagram both to the panels and the junction box.

Once your solar panels are in place, you’ll need to install your inverter. To learn more about inverters and how to install them, check out our blog post “The Ultimate Guide to Solar Inverters”.


Can You Install Solar Panels on a Flat Roof?

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Solar panels can be installed on a flat roof, but there are different ways to do this. Two factors to consider when designing a solar panel system for a flat roof are:

  1. Solar panel orientation
  2. Solar panel tilt angle.

These aspects will affect the efficiency of your panels. If you’re concerned about drilling into your roof, a solar ballast system is a common way to get around this. 


A solar ballast system uses gravity to keep the panels in place, with concrete blocks being typically used to weigh the panels down.


Can You Install Solar Panels on a Metal Roof?


Solar panel installation is absolutely possible on metal roofs, but the method of installation depends on the type of metal roof that you have.


How To Install Solar Panels On A Metal Tiled Roof

This requires no drilling holes or penetrating the metal. The mounting rail that’s used has metal tiles already attached, which will match those on your roof for consistency.


Installation involves swapping them out and aligning them with the remaining tiles. The panels provide additional protection for the roof, extending its lifespan in many cases.


How To Install Solar Panels On A Standing Seam Metal Roof

A series of high strength aluminum clamps is attached to the vertical legs with a single bolt. The mounting rail can then be secured with no drilling into the roof.


How To Install Solar Panels On A Corrugated Metal Roof

To install solar panels on a corrugated metal roof, you require a specialized mounting system that uses brackets known as straddle blocks.


Unfortunately, installation of solar panels on a corrugated metal roof requires drilling holes, but the holes are plugged with thick rubber gasket seals that are attached to the brackets.


How Do You Install Ground Mounted Solar Panels?

ground mount panels, installation

The process of installing ground mounted solar panels is a little different to fitting them to a roof. Ground mounted solar arrays offer many benefits though, and can be more efficient.


The following steps offer a guideline of what is involved in installing a ground mounted solar panel system.


How to Install Ground Mounted Solar Panels

  1. Select the perfect location. It shouldn’t be obscured by shade. Determine the right orientation for your installation.
  2. Build the concrete foundations on which your mounts will be placed.
  3. Install the mounting frames.
  4. Attach your solar panels to the frames.
  5. Connect the wiring.


Weather Suitability For Solar In Illinois

Solar panel power output can be affected by weather conditions. Panels operate at maximum efficiency during peak sunlight hours, and power output gradually decreases outside of these times.


Solar Suitability Summary For Illinois

  • Average Annual Sunlight Hours:

    2500 hours.
  • Average Number of Clear Days:

    95 days per year.
  • Summer Peak Sunlight Hours:

    4.08 hours per day.
  • Winter Peak Sunlight Hours:

    1.47 hours per day
  • Average Peak Sunlight Hours:

    3.14 hours per day.

The Impact of Temperature on Solar Panels

The efficiency of solar panels is greater in cooler temperatures, due to there being less friction for the electrons within the panels. 


The temperature coefficient indicates how much the efficiency will decrease for every 1°C the panel gets over 25°C (77°F).

  • The average high temperatures in Illinois in July are between 82°F and 89°F.
  • The average temperatures in Illinois in January are between  11°F and 43°F.


The Impact of Wind on Solar

Wind can exert a cooling effect on solar panels, thereby increasing their efficiency. According to a study by Lancaster University, wind direction can also boost solar panel efficiency. A southerly wind was found to increase output by up to 43%.


Wind Summary In Illinois

  • State Wind Rank:

  • Average Annual Wind Speed:

    0.3 miles per hour.


Frequently Asked Questions


What Happens After The Sale?

After you’ve signed the contract and all the necessary paperwork is in place, the following steps happen:

  1. Installation:

    Your chosen provider will come and install the solar panel system.
  2. Inspection:

    After installation is complete, a final inspection needs to take place before your solar system can be connected to the grid.
  3. System activation:

    Following the approval of the inspector, the utility company will come and install a bi directional meter to track how much energy you’re producing.


What Type of Maintenance is Required in the Solar System?

Cleaning your solar panels can improve their output by up to 12%, as removing the dirt that accumulates on the panels allows more light energy to reach the photovoltaic cells.


How Often Should I Clean Off My Solar Panels?

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Generally speaking, you should clean your solar panels every 6 months to a year in order to maintain maximum efficiency. If you live in an area with a lot of pollution, however, you may need to clean them more frequently.


How Often Should I Have My Solar Panel System Inspected?

A properly installed solar panel system should be inspected every five years, to make sure that the connections remain tight and that the wiring is in good condition.


If you have flat solar panels, or you’re not confident that the installation was done correctly, it would be wise to have the system inspected more frequently.


Solar Panel System Technical Issues

Although technical issues of solar panel systems are uncommon if installation is carried out by a skilled professional, they can sometimes occur further down the line. Potential technical issues may include:


Inverter Problems

Inverters are a common cause of technical issues in solar panel systems. 

  • Overheating

    : If installed in an unsuitable location, they can overheat. 
  • Isolation Faults

    : Excess moisture and damage to the sleeve of the cabling, or faulty installation, could cause a short circuit.
  • No Restart

    : Following a grid fault, the inverter has to restart itself. If it doesn’t, a service team will have to come to restart the system.
  • MPPT issues

    : the Maximum Power Point Tracking on which inverters operate can run into problems if there is a difference in output between solar panels in your system.


Solar Panel Damage

Solar panels are exposed to the elements, and in the event of moderate to extreme weather events they can sustain damage. High winds or hail can cause cracks in the panels.


Following extreme weather, it is important to inspect your solar panels to ensure they remain safe for operation, so that you avoid any risks that might come with a damaged system.


Hot Spots

Hot spots may occur in the event of an electrical problem with the panels. This can be caused by incorrect installation, or if there is a break in the wiring. This could lead to power loss, or even a fire.


To prevent hot spots, you should have your system inspected regularly to ensure that all of the connections are tight and there are no loose or damaged components.



Solar panel systems can be susceptible to damage from lightning strikes. If a panel is struck by lighting, it can be damaged beyond repair.


To avoid this kind of damage, you should have your system inspected periodically to make sure that the panels are properly grounded.



If you’ve made it to the end of this article, you’re probably thinking about installing a solar panel system for your home. 


As this article has outlined, installing solar panels is a complex process – and it’s one that you need to get right, so that you don’t face problems further down the line.


That’s why Green Home Makeover are here to help. We are able to manage every aspect of your solar installation for you, covering things such as:

  • Design of your solar power system, to ensure it’s suitable for your needs.
  • Application for permits.
  • Financing applications, and advice to ensure that you get the best deal from a financial perspective.
  • Application for solar tax credits and rebates.
  • Finding the right installer for your project.
  • Ensuring the installation runs on schedule and that follow up inspections are on time.
  • After care, including advice on how to get the most out of your solar power system, and how to maintain it.

If you are interested in a free, no-obligation consultation and quote, contact us today.