A rooftop solar power system is a photovoltaic (PV) system whose solar panels are mounted on the roof of a residence to generate electricity for use in a house. The different components of such a system include panels, mounting systems, cables, solar inverters, and other electrical accessories.
For the most part, rooftop solar panels are a great way to generate green energy for your home.
They’re also one of the cheapest ways to get started on solar power, but there are some things you should know before investing in them.
What are rooftop solar panels?
Solar panels that are mounted on the roofs of residential buildings are known as rooftop solar panels. Since home roofs receive the maximum amount of sunlight, these are often the bese places to install a solar panel.
These are like any other type of home appliance—they convert sunlight into electricity with an inverter that converts direct current (DC) into alternating current (AC). In fact, they do so at a higher voltage than other types of DC-to-AC converters.
This is because they need more power in order to run at full capacity while generating power from the sun’s rays.
The result is a device that can produce up to 5 kilowatts per day (kWPD), which comes out as about three times more than what it would take for just one house’s worth!
Types of rooftop solar panels
There are three core types of solar panels commonly available for deployment onto a residential house. Monocrystalline, polycrystalline, and thin-film. Each of these has its pros and cons and will suit specific homes better.
The pros and cons of each panel can be pictorially compared in the table below.
| Type of panel | Efficiency | Cost | Appearance | Lifespan |
| Monocrystalline | ★★★★☆ | ★☆☆☆☆ | ★★★★☆ | ★★★★★ |
| Polycrystalline | ★★★☆☆ | ★★★☆☆ | ★★★☆☆ | ★★★★★ |
| Thinfilm | ★★☆☆☆ | ★★★☆☆ | ★★★★☆ | ★★☆☆☆ |
Monocrystalline solar panels
These panels are the most popular type of solar panel, and for good reason. They are the most efficient and have the most extended lifespan. They are called monocrystalline because they are made from single-crystal silicon.
And because of this, the electrons have more room to flow, generating more electricity per panel, also known as efficiency. Their average efficiency ranges between 15% and 20% and even goes up to 24% in some cases.
Monocrystalline solar panels are also more aesthetically pleasing and provide a high weight-to-capacity ratio than their polycrystalline counterparts, and so are often preferred for residential applications. The only downside with these panels is the cost. They cost more than polycrystalline and thin-film solar panels.
Polycrystalline solar panels
These panels are a good balance between cost and efficiency. They are not as efficient as monocrystalline panels but aren’t as costly either.
If cost is a major factor, these are definitely your best option. However, you will require more space to get the same amount of electricity generated as monocrystalline panels.
The disadvantages of polycrystalline panels are; low efficiency (13% to 16%), lower weight-to-capacity ratio, and they aren’t as aesthetically pleasing as monocrystalline and thin film panels.
Read: Monocrystalline vs Polycrystalline solar panels
Thin film solar panels
Thin film solar panels offer a different take on solar panels. Several thin layers of photovoltaic materia – either amorphous silicon, cadmium telluride, copper indium gallium selenide, or organic PV cells– are layered on top of each other to create these flexible solar sheets.
The main draw of these panels is the fact that they can easily blend in with the background on the roof of a house. In addition, they won’t stick out like a sore thumb since they are much thinner. Nonetheless, they are also great for homes with limited roof space because they can be wrapped around objects.
The downside with these panels is low efficiency and a shorter life span than monocrystalline and polycrystalline panels.
Read more on “Thin film photovoltaic cells (TFPV)” here!
How do rooftop solar panels work?
A solar panel generates electricity by knocking electrons from atoms with photons or light particles.
Rooftop solar panels consist of two or more layers of semi-conducting material. The first layer is usually made of silicon wafers, which absorb light and convert it into electricity by creating an electric current when they’re hit by electrons flowing through them.
The second layer consists of photovoltaic cells that produce current when sunlight strikes them; these “solar cells” produce direct current (DC), rather than alternating current (AC).
More specifically, the top silicon layer is seeded with phosphorus which adds extra electrons with a negative charge, and the bottom layer is dosed with boron which results in fewer electrons, or a positive charge.
This then adds up into an electric field at the junction between the silicon layers. When sunlight photons hit these electrons free, the electric field pushes the electrons out of the silicon junction.
Benefits of rooftop solar panels
Reduce your carbon footprint
The amount of CO2 you emit when using electricity is directly related to the amount of power generated at home. For example, if you have a 20kW system installed and generate 100kWh per month, then each day, this will reduce your total annual CO2 emissions by 130kg/year.
That’s almost double what it would be if you weren’t generating any renewable energy from solar (70kg/year).
Save money on your electricity bill.
Even though installing rooftop solar panels may cost money upfront (depending on where you live), they’ll pay back over time because they save money through lower bills every month or year after installation.
You might also make money from your installation by sending your excess generated electricity to the grid. If this option is available in your home area, we advise that you take it.
Low maintenance costs
Solar systems generally require little to no maintenance. Often, all that is needed is cleaning the panels to maximise efficiency by allowing the maximum amount of sunshine in.
Increased home value
You don’t only benefit from having a home solar system installed if you also invest in it. Your property value can also be enhanced if you sell it later on. Considering how important it is to plan ahead, you might want to consider installing a home solar system.
Not only will it save you on your energy expenses, but it will also increase the value of your home significantly. You can also get many benefits from a home solar system if you’re looking for an energy-efficient home.
How much power do rooftop solar panels generate?
The majority of residential solar panels on the market today produce 250 to 400 watts of power. A 4 kW solar PV system on an average-sized house in England can generate approximately 2,850 kWh of electricity in a year (within ideal conditions).
The output of a solar panel depends on a myriad of factors;
- Size of the panel
- Type of solar panel
- Capacity of the panel
- Location of the house
- Weather conditions
- How clean the panel is
How to clean rooftop solar panels?
Cleaning your rooftop solar panels is important to maintain the life of your equipment. The following steps will help you clean your solar system:
Use a soft cloth and water to clean the surface of the solar panel. Do not use chemicals or abrasives, as this can damage it.
Do not use high-pressure water jets or acid-based cleaners on your own; these types of products can cause damage if misused. Instead, choose something like vinegar for cleaning purposes (it’s safe for people and pets).
If you do decide to use vinegar, though, make sure it has been diluted with some water first before applying it directly onto any type of material that might be sensitive such as glass surfaces—and also try not to overdo it!
If there’s too much liquid coming out when using an applicator brush, then simply dip another cloth into some plain old tapwater instead; this will help remove any excess residue without risking damaging anything either way.”
For more details, read “How to clean your solar panels?”
How much do rooftop solar panels cost?
The cost of rooftop PV panels depends on the type of panel, size of the panel and brand. The total cost will also depend on how much electricity you would like to generate, as this will inform how many panels you require.
Average cost of rooftop solar panels
In the UK, the average price of a monocrystalline panel is £250–£375, the average for a polycrystalline panel is £225–£250, and that of a thin film solar panel is £200–£250.
The solar panel cost is only part of the total cost, though, as you will also need inverters, batteries, charge controllers, cables and installation fees.
Cost to install rooftop solar panels
Solar panel installation costs will vary depending on your energy needs. In the UK, the costs will vary between £6,000 – £10,000.
The cost will depend on a few factors. These are:
- The type of panels you want
- The amount of electricity you want to generate
- The size and type of your property
- The direction in which your roof faces
- The quality of components you require
- Whether or not you want a battery
Rooftop solar panels FAQ
1. Are rooftop solar panels a fire risk?
Fires from rooftop solar panels are quite rare. If there’s any risk from a PV system, it would probably be from the batteries or the electrical connections and not the solar panels.
For more information, read “Solar panel fires.”
2. How heavy are rooftop solar panels?
Most solar panels weigh about 40 pounds (18 kilograms). The total weight of all the panels on your roof will depend on your energy needs. Most roofs are built to handle significant weight, and so the panels shouldn’t be a problem.
3. Do solar panels cause roof leaks?
If the company doing the installation is good, there will be no incidences of leaks. Leaks from solar panels are extremely rare.
4. Which solar panel is best for rooftops?
This really depends on your needs and budget. Overall monocrystalline panels are best because of their efficiency. They are more costly than others though.
5. Are rooftop solar panels worth it?
Their impact on the environment, coupled with the energy savings, low maintenance and impact on the house value, we’d say that it is a resounding yes!
6. How long do rooftop solar panels last?
The lifespan of solar panels largely depends on the type of solar panel.
- Monocrystalline panels 30–50 years
- Polycrystalline panels 30–40 years
- Thin film panels 10–20 years
Conclusion
Rooftop solar panels are a great way to generate your own clean energy and take control of your own power supply.
There are many options out there, but we hope our guide helped you make an informed decision about whether they’re right for you.
If so, then congratulations! You’ve made an important step toward becoming more environmentally responsible—and saving money in the process.
