Solar Panels Guide

The popularity of solar energy has been rapidly rising in the UK over the years. In fact, in 2020 alone, the energy derived from solar technology went up by 4.4%, pointing towards a significant increase in capacity.

If you have not jumped on the bandwagon already, what are you waiting for?

Solar energy is one of the cleanest sources of energy and is never going to run out. So, why not make the most of it?

This solar panels guide will walk you through everything you need to know about solar panels and solar power generation systems. We have also covered the different types of systems available along with their cost in this article.

Advantages of Solar Panels

If you’re on the fence about installing a solar panel system for your property, check out these advantages.

1. Save on Electricity Bills

With the large number of electrical appliances that we use today, electricity bills can burn a sizeable hole in our pockets. By using solar energy, you can reduce your utility bills to a large extent.

You don’t just get free energy; you can also sell the surplus energy produced to the national grid and earn some returns on your investment.

2. Reduce your Carbon Footprint

Traditional sources of energy, such as coal, oil, and fossil fuels, release harmful substances like oxides of carbon, nitrogen and Sulphur. These are highly potent gases and lead to air pollution and global warming.

You can offset this environmental impact by switching to solar energy for your domestic electricity consumption. Solar energy generation does not release any toxic gases, and domestic solar panels can potentially offset about 25 tons of carbon dioxide over their lifetime.

3. Round-the-year Energy

It is a misconception that solar panels need heat to be effective and are not valuable during winters.

Solar panels harness sunlight, not heat. Although they function best during the summer months, they do work well during the winter months and even cloudy days.

4. Minimal Maintenance Required

Solar panels require very little maintenance. On average, they last for about 25 to 30 years without any technical hassle.

However, for their efficient working, it would be best to clean your solar panels regularly. You should also ensure that they do not collect dirt, branches, etc. For this, schedule regular inspections for your system, and you should be good to go for months at a stretch.

5. Independence From the Grid

You can integrate solar batteries into your solar panel system to store energy for nighttime, rainy days, or during a power outage. This way, you can be completely independent of the National Grid.

Installing a battery is especially helpful if you live in areas where extending power lines is not feasible.

6. Renewable Source of Energy

Since the sun’s energy is not going to run out any time soon, it can be considered a renewable source of energy. Moreover, you can even store this energy to get free electricity even when the sun is not around.

7. No Permit Required

You do not need prior permission to install solar panels. While they are some rules and regulations in place, they are pretty minor.

8. Increases Your Property Value

Solar panels are an excellent investment if you want to increase the market value of any real estate. A property with a solar panel system can command a higher price than one without it in the current market conditions.

Disadvantages of Solar Panels

There are a few downsides to installing solar panels on your property. Some of them are listed below.

1. Dependent on Weather

Although solar panels work on dark or rainy days, they do lose quite a bit of their efficiency. If you are not connected to the grid, you’ll have to store energy in a battery backup for such situations.

2. High Initial Investment

Upfront, solar panels can be a little expensive. However, you earn your money back over time, but it can take a few years.

3. Dependence on Surrounding Structures

Incorrect placement of solar panels can seriously hamper their effectiveness. Typically, panels with large buildings or tall trees around them do function very well. In case you live in such an area, solar panels might not be the best option for you.

These are the most common downsides of installing a solar power generation system on your property. However, its pros greatly outweigh the cons, making it a worthwhile investment.

Types of Solar Panels

A solar panel is a device that absorbs the sun’s energy and converts it into electricity. These panels are made of photovoltaic (PV) cells that use semiconductor technology to convert the sun’s energy into usable electricity.

Over time, there have been countless improvements to solar cells and panels. Let us explore the different types of solar panels available in the market today.

1. Monocrystalline Solar Panels

Monocrystalline solar panels are the earliest form of solar panels and the most developed ones so far.

The term “mono” means single, and “crystalline” refers to the crystal, indicating that these panels are made of single-crystal silicon solar cells. Because of their composition, these cells offer higher output.

Pure silicon is formed into bars and then sliced into wafers to make monocrystalline solar cells. During this process, the edges of the cells are cut, smoothened, and rounded to increase efficiency of the cells.

Monocrystalline cells appear black as a result of light interacting with the pure silicon crystal. However, their back sheets and frames can be found in various colours. Typically, their back is black, white, or silver, and the metal frame is silver or black.

These panels generally offer the best efficiency and power capacity among other solar panels available in the market.

Advantages of Monocrystalline Solar Panels

• They perform well even in low levels of sunlight.
• They are space-efficient.
• They are made with pure, high-quality silicon.
• They are long-lasting.
• They have a higher power output.

Disadvantages of Monocrystalline Solar Panels

• They are the most expensive kind of solar cells.
• Plenty of waste is produced during their production.
• The performance of these panels suffers when the temperature goes up.

2. Polycrystalline Solar Panels

Polycrystalline solar panels, or multi-crystalline solar panels, are mid-range solar panels. They are not as effective as monocrystalline panels but are more affordable.

These panels consist of several fragments of silicon crystals melted together. This process of creating such panels lower their efficiency and reduced lifespan. This is because the electrons get lesser freedom to move around since there are many crystals in each cell.

To make these panels, raw silicon is melted and poured into square moulds to create wafers. Unlike monocrystalline cells, these edges do not have to be cut, resulting in reduced wastage. The wafers are then assembled to create polycrystalline solar panels.

These panels have a blue hue to them because of how light reflects off the silicon fragments of the cell. Popular back sheet colours for polycrystalline panels are white and silver, while the frames are typically silver.

The efficiency of these cells is typically between 15% to 17%, and their wattage is lower than that of monocrystalline cells.

Advantages of Polycrystalline Solar Panels

• The manufacturing process is faster.
• There is not a lot of wastage during production.
• They are more affordable compared to monocrystalline solar panels.

Disadvantages of Polycrystalline Solar Panels

• They have a lower efficiency rate and shorter life span.
• They are not very space-efficient.
• They are not tolerant of high temperatures.

3. Thin-Film Solar Panels

As the name suggests, these panels consist of extremely thin cells. Its cells are about 350 times thinner than the wafers used in monocrystalline and polycrystalline solar panels.

These panels are manufactured using layers of semiconducting materials, like silicon, copper indium gallium selenide, and cadmium telluride. The layer of semiconductors is placed between the conducting and transparent layers and topped with thin glass, which helps in trapping sunlight.

These non-crystalline panels generally have lower efficiency (close to 11%) and lower power capacity as compared to crystalline variants. They require plenty of roof space to generate larger amounts of energy.

Although thin-film solar panels are quite flexible, they tend to degrade faster than crystalline panels. However, because of their flexibility, they can be moulded into different shapes, like shingles or tiles, to suit a variety of applications.

The colour of thin-film panels could be blue or black, depending on their manufacturing material. Since they are tolerant of high temperatures, they are an excellent choice for tropical countries.

Advantages of Thin-Film Solar Panels

• They are the most affordable kind of solar panels.
• They can tolerate very high temperatures.
• They are highly flexible.

Disadvantages of Thin-Film Solar Panels

• They are not very efficient.
• They have a short life span.
• They take up a lot of space.

Other Types of Solar Cells

Besides the three main kinds of solar panels listed above, there are two other less-common solar cell options. They are:

1. Amorphous Silicon Solar Cells

Amorphous silicon cells are the most recent development in the solar cell industry. They are made of amorphous silicon, and the atoms are not ordered in a crystal lattice pattern.

To produce these cells, silicon is deposited in an extremely thin layer on a backing substrate. At times, numerous layers of silicon are deposited in slightly different ways to respond to varying wavelengths of light and are laid on each other to enhance efficiency.

Advantages of Amorphous Silicon Solar Cells

• They are mass-produced and lead to cost efficiency.
• They can be flexible.
• They can perform well even with lower light levels.

Disadvantages of Amorphous Silicon Solar Cells

• They are not as space-efficient as crystalline panels.

2. Bio-hybrid Solar Cells

A bio-hybrid solar cell is formed by combining organic and inorganic matter. These cells were first created when a team recreated photosynthesis using Photosystem I to get better solar energy conversion efficiency than regular PV cells.

When several layers of Photosystem I are put together, they convert the energy collected into chemical energy, resulting in current passing through the cell.

Advantages of Bio-hybrid Solar Cells

• They are far more efficient than any other kind of cell.
• The production process is relatively cheap.
• No power is lost during the conversion of chemical energy to electrical power.

Disadvantages of Bio-hybrid Solar Cells

• They have a shorter lifespan.

How Do Solar PV Panels Work?

Solar PV panels consist of numerous tiny photovoltaic cells that convert sunlight into electricity. These cells are made of semi-conductive materials, typically silicon, that enable them to conduct electricity while simultaneously maintaining the electrical imbalance required to create an electric field.

As sunlight comes in contact with the semiconductor in PV cells, solar energy is absorbed in the form of photons. It knocks electrons loose, allowing them to drift freely within the cell.

Solar PV cells are carefully designed with negatively and positively charged semiconductors packed together to form an electric field. The field compels the freely moving electrons to flow towards the conductive metal plates lining the cell.

This is referred to as an energy current, and its strength determines the amount of electricity each cell can produce. As soon as the loose electrons strike the metal plates, the current is directed into the wires, enabling electrons to flow as they would in any other mode of electricity generation.

The Flow of Energy

When the solar panels generate electric current, energy passes through a series of wires into an inverter. The energy generated by solar panels is DC electricity, while most of us need AC electricity to power our buildings.

An inverter is thus required to transform the electricity from DC to AC and make it useable.

When electricity is changed into AC form, it is sent from the inverter to the breaker box, also known as an electrical panel. From there, it gets distributed throughout the building and can be used to power appliances, lights, etc.

Where Does The Unused Electricity Go?

The electricity consumed through the electrical panel is then directed to the utility grid via the utility meter. It is a device that measures the flow of electricity from the grid to your house and vice versa.

If your solar energy system produces more electricity than you consume, the meter runs backwards, and you get credited for the excess electricity you generate via net metering.

Unless you are entirely off-grid with an energy storage solution, you will have to take electricity from the utility grid when your solar panels are not producing energy, for instance, during the night.

Factors Affecting Solar Panel Efficiency

To make the most of your investment in your solar electricity generation system and get the best returns, there are a few things you must keep in mind. Maximize your solar panel efficiency with these tips and tricks.

1. Location, Angle, and Direction

You must install the PV system at an angle such that the solar cells can capture as much sunlight as possible. In the United Kingdom, we receive excellent sunlight from 9 AM to 3 PM.

The panels should be well exposed to sunlight during this period. Moreover, the angle of your roof will also play a role in sun exposure. Ideally, solar panels should be south facing so that they are exposed to sunlight for the longest time.

A study published by Stanford University suggests that a tilt angle of 34 degrees is the best placement position for solar panels in the United Kingdom.

In case your roof is not oriented according to the angle, you can install brackets. However, this adjustment needs to be assessed by a certified MCS installer.

2. Maintenance

Maintenance is essential for maximizing the lifespan of your solar panels. The panels generally last for about 25 to 30 years and require very little maintenance. You simply need to get the panels checked from time to time by your installer or any other certified service provider.

You can even ensure that your panels are clean at all times by yourself. It will involve removing branches and leaves from your panels and rinsing the panels with a hose.

Be careful not to touch or sponge your panels while cleaning.

3. Roof Suitability

Before you decide to install solar panels, you need to ensure that your roof is strong enough to support the system’s weight.

For instance, a 4 kW system typically consists of 16 panels of 250W, making the total weight close to 280kg.

The material of your roof is also important to consider. While most materials can handle solar panels comfortably, slate and wooden roofs might be too brittle. Moreover, your roof needs to be large enough to fit the solar panels.

You need about 30 cm of space around the panels, so a 4 kW system requires at least 29 sq.m. of roof area.

4. Size of the Solar Panel System

As a rule of thumb, the bigger your solar panel is, the more electricity you will generate. The best way to determine your size requirement is by calculating your electricity needs.

If you’re on a space crunch, monocrystalline panels are the best choice for you. These panels are highly efficient and require comparatively fewer panels to generate energy.

How to Pick the Best Solar Panels

When you’re looking for the best solar panels for your property, you need to take several factors into consideration. These include:

1. Type

The three main types of panels available today are monocrystalline, polycrystalline, and thin-film. Depending on your energy requirements and budget, you can choose the best option.

2. Efficiency

The efficiency of a solar panel measures how much energy from the sun can be converted into usable electricity. It is calculated as a percentage. Domestic solar panel systems usually have an efficiency of around 15% to 20%.

3. Power

Power refers to the energy output of a solar panel system under Standard Test Conditions. You can measure the power of a solar panel in watts (W).

4. Power Tolerance

Power tolerance refers to how much your solar panel system can deviate from its stated power (in watts). The variance can be expressed in watts or percentages.

For instance, if a 200W panel has a power tolerance of +4% / -0%, then its actual power output can vary between 200W to 208W under regular conditions.

5. Size

In case you have limited roof space, you’ll have to be extremely careful with the placement of your panels. Ensure that there is enough space to fit the entire system, and leave some extra room for movement.

6. Temperature Coefficient

The temperature coefficient shows the percentage decrease in power output for every 1 °C increase in temperature after 25°C. It is essential to know how much your solar panels will be affected by a rise in the temperature.

7. Weight

The weight of your solar panels will depend on the strength of your roof. If your roof is not very robust, you will have to look for lightweight panels.

8. Performance Degradation

While the lifespan of a solar panel is typically between 25 to 30 years, the panels will experience some sort of wear and tear over time.

Generally, there is a decline of about 2-3% in the efficiency after the first year, and then 0.2-0.7% every following year.

9. Product Warranty

Try to get your hands on a product that offers a maximum warranty. A warranty shows the manufacturers’ confidence in their products. Warranties for solar panels typically range from between 10 years to 25 years.

10. Wind Tolerance

Since we’re talking about setting up solar panels in the UK, we can’t forget to consider strong winds and hurricanes. You want your solar panels to be able to tolerate such harsh conditions.

Manufacturers typically test tolerance and record it in pascals (Pa). The higher the figure, the more is their tolerance. Most panels can withstand up to 2400 Pa, which is almost equal to 140 mph.

How Many Solar Panels do you need?

Each household has its own unique power consumption needs. You will need to look at your electricity bills to figure out your power consumption in kWh.

You could either calculate month by month or take the sum of monthly or quarterly figures to determine an annual estimate. Then, you need to decide what percentage of your bill you would want to cover with a solar panel system.

You also need to calculate the number of panels that can fit on your roof. On average, a solar panel takes almost 1.44 sq.m. roof space. While assessing roof space, you need to leave a minimum of 30 cm from the roof’s edge.

A 4 kW solar panel system would typically require about 16 solar panels with a power output of 250W. Likewise, a 5 kW system will consist of 20 solar panels.

Factors Affecting Solar Panel Requirement

The following factors play a role in determining the number of solar panels you need to power your property.

• Your roof capacity.
• Your electricity consumption.
• The number of sunshine hours.
• How much of your total power consumption do you plan to cover with solar energy.

Solar Panel Installation

Once you have zeroed down on a solar panel installer, the process of actually setting it up will only take a couple of days.

Let us quickly run through the steps.

1. Install the Scaffolding

Scaffolding has to be erected around the house to ensure the safety of the installation team.

2. Set Up Roof Anchors

Roof anchors are required to hold the base of the solar panels. There are different kinds of anchors available, and they are chosen depending upon the type of tiles on your roof.

3. Attach the Frame

The frame is made up of aluminium bars and is required to keep the solar panels in place. All the bars should be fitted in the same direction, parallel to each other.

The structure should be slightly tilted anywhere between 18 to 36 degrees.

4. Erect The Panels

The installation team will clamp the solar panels to the aluminium frame. At first, they are set up loosely in order to leave some room for adjustment. After all the panels are set in their positions, they are tightly secured to the aluminium frame.

5. Wire the Panels

The electrical wiring of the panels depends on the amperage, voltage, and power of the solar panel system. Generally, universal connectors like the MC4 are perfect for wiring because of their versatility. The panels can either be connected in series or parallel connections.

6. Connect to a Solar Inverter

A solar inverter is a part of the solar array that converts the energy captured into AC electricity for use by household appliances. To connect the solar panel system to the inverter, you will need to join the panel’s positive wire to the positive terminal of the inverter and the negative wire to the negative terminal.

7. Connect to a Solar Battery and the National Grid

While connecting the solar inverter to the grid is crucial, you also need a solar battery to store backup electricity for when you don’t wish to be dependent on the grid.

Installers take a standard plug to connect to the main switchboard and an output wire to connect to the electric board.

For connecting the solar inverter to the battery, the battery’s positive terminal and the inverter’s positive terminal are connected, and the same is done for the negatives.

8. Turn on the Inverter

Once everything is set up, you can turn on the inverter to start using clean energy!

How Much do Solar Panels Cost?

On average, a domestic solar panel system costs anywhere between £5,000 to £10,000. This cost varies based on the number of panels, depending upon your energy consumption.

If you go for a more extensive solar panel system, it will be more expensive, but it will also generate more electricity and increase your savings. With the UK government offering financial incentives for domestic solar panel installation, the high installation costs are covered in the long run.

Solar Panel Prices for Different System Sizes

A small house with up to three residents should be able to cover their electricity needs with a 3 kW solar panel system, which will cost about £5,000 to £6,000.

A 4 kW system will be ideal for a household of three to four people and will cost about £6000 to £8,000.

Larger homes with more than four residents would need a 6 kW solar panel system that will cost about £8,000 or higher.

While these are some standard sizes, some providers even allow customization. So, you can get the ideal size for your home’s electricity requirements and pay accordingly.

Grants for Solar Panels in the UK

The UK government encourages offers grants to homeowners to switch to cleaner sources of energy by providing them with the opportunity to earn via their solar panel systems, wind energy systems, etc.

Smart Exchange Guarantee (SEG)

Under the SEG, homeowners can supply their surplus energy to the utility grid. In return, they will receive money for their export.

Everyone receives different tariffs depending on the electricity supplier. The suppliers can offer either fixed rates or flexible options.

Feed-in Tariff (FiT)

Under this incentive, households could export their excess electricity to the grid to receive payments. The tariff consisted of two elements:

• A generation tariff for the total amount of electricity generated, calculated on a per-unit basis.
• An export tariff for the electricity exported to the grid is assumed to be half of the total electricity generated.

The FiT scheme is no longer taking in new applicants.

Finishing Notes

Solar energy is undoubtedly a boon to the environment. However, people have several concerns before installing a solar panel system at home.

We hope this guide answered any questions that you had about solar panels, their types, working, etc.

Setting up solar panels is a good idea if you want to do your bit for the planet. Moreover, with the incentives available in the United Kingdom, its installation will not even burn a hole in your pocket.

Get your solar installation today!