Solar Panels FAQ's
Here you can find the answers to the most commonly asked questions about Solar Panels. In the UK solar panels for homes are becoming increasingly popular and we aim to keep you up to date with all the latest information and news.
Most Common Questions about Photovoltaic Solar Panels
What are PV Solar Panels?
PV Solar panels are made up of photovoltaic cells arranged in a grid-like pattern on a panel. The photovoltaic cells convert photons of light from the sun into electrical energy for use in the home or workplace.
A solar panel consists of an aluminium frame, a panel of PV cells and a sheet of glass, which is on the side facing the sun. The glass is there to protect the cells but allows the light to easily pass through.
The Solar PV cells are made up of a semi-conducting material, most commonly silicon. When light reaches the Solar PV cell a field of electricity is created across the cell, the more powerful the sunlight the more electricity is created. An inverter converts the energy from a direct current (DC) into an alternating current (AC) to either be used by the property or sent back to the grid.
PV Solar panels are usually attached to the roof of a building, but can also be attached to a wall facing within 90 degrees of south. In some cases are installed at ground level, where a property has enough land.
How do PV Solar Panels Work?
PV Solar Panels work in daylight, so it does not need to be sunny; in simple terms the photons of light that are collected by the solar panel are converted into electrical energy. PV Solar panels are most efficient when tilted towards the south, where there is direct sunlight and the exposure time is at it greatest throughout the day.
Solar energy begins its journey at the heart of the sun. The sun is constantly enduring thermonuclear explosions, which reach the earth as light radiation. The PV cells on the solar panel are able to convert this radiation into electrical energy, which the solar panel is then able to make available for us to use.
PV solar panels all contain PV cells, they may differ in their make-up but they all experience the same 'photovoltaic effect'. The semiconducting material (usually silicon) that is present in a solar cell absorbs the photons of light. As the energy is transferred the electrons are loosened in the cell. Electric fields are present in PV solar cells and force the electrons to flow in a particular direction, the flow is otherwise known as a current and when combined with the voltage of the cell it determines the wattage a cell can produce. The current created is a direct current (DC) and is converted into an alternating current (AC) by an inverter for use in the property.
How much do PV Solar Panels Cost?
PV Solar panels typically cost anywhere between £8,000 and £15,000, it depends on the type of system and the size that you are installing. Over time it is possible to get a greater return back from the energy your solar panels produce. The Energy Saving Trust estimates that you can save approximately £200 a year on your electricity bill and cover 40% of your electricity needs using a 2kWp-sized system.
There are many schemes in place that are backed by the government to try and make PV solar panels more affordable. For example the Feed-in Tariff scheme (FITs) pays out for every kW of energy produced by a renewable source and also pays for any energy exported back to the grid. Over time PV solar panels should become a profitable investment.
What is Photovoltaic Energy?
Photovoltaic energy is the energy produced by solar cells reacting with photons of light. PV Solar cells are made up of a semiconducting material, most commonly silicon and react to light by producing energy. The PV cells do not contain any moving parts or corrosive materials; so do not require ongoing maintenance. The amount of energy produced from one cell is directly related to the amount of sunlight it is exposed to and which semiconducting material that cell is made of, as some are more efficient than others, which has an impact on cost.
The term Photovoltaic is made up of two parts, photo is a Greek word meaning light and voltaic is a reference to Alessandro Volta, who was an electrical energy innovator.
What is a solar module?
A solar module is another word for a solar panel. It is a string of solar cells wired together enclosed in a glass unit for protection. Modules are connected together via cables and are linked to the inverter, which converts the direct current (DC) into an alternating current (AC) that can be used in the home.
What is a solar array?
A solar array is an inter-connected system of photovoltaic modules, panels. The size of an array will vary depending on the space available, the larger the solar array the more energy will be produced.
How does electricity get from a solar panel to my sockets?
The solar panel system is connected to a property's fuse board for use within the home. The current produced by the panel is converted into an AC current by the inverter and is then made available within the property or exported to the grid.
What is different about PV solar systems to other solar systems?
The term photovoltaic refers to generating electricity from light, other systems such as solar thermal systems use light to heat water.
What happens if I move house from a property with a PV Solar System?
The Solar installation is part of the home, so the benefits that come with the system will be passed on to the new owners. This means that when selling a property with PV solar panels there are additional unique selling points that the estate agent will need to make potential buyers aware of. For example, energy bills will be lower than a typical property of that size and if the system is eligible the new owner will be able to receive payments from the feed-in tariff.
If I move in to a house with PV Solar Panels will I be eligible for the feed-in tariff?
The PV Solar installation will be part of the property, so providing the system meets the eligibility criteria whether it has previously been registered or not, as the new owner you should be able to benefit.
Why should I install a Solar PV System?
Solar PV Panels generate clean, green electricity, as solar power is a renewable energy source it does not rely on fossil fuels. This means that by having a solar PV system you will be reducing your carbon footprint. There are also financial benefits, the energy produced is free to use, so in the daytime you will be able to make use of this electricity therefore reducing the cost of your bills.
Finally and probably the most substantial benefit, is that if your system is eligible for the government-backed feed-in tariff you will be able to generate an income from the panels. This is a scheme where the energy suppliers pay an amount per kWh of energy produced and then an additional bonus payment for any electricity that is sent back to the national grid. Over the 25 years that the feed-in tariff runs for it should be possible to see a return on the initial investment of installing the solar panels.
Most Common Questions about Thermal Solar Panels
What are Thermal Solar Panels?
Thermal Solar Panels are panels that are fitted to the roof of a building and are used to heat water for use in the home or workplace. There are two types of thermal solar panels, flat plate and evacuated tubes – these names refer to how the water interacts with the panel. Both will generate equal amounts of hot water, but evacuated tubes are often smaller in size as they are more efficient. As a rough guide, one square metre of thermal solar panel will need 30 to 60 litres of water tank volume and should be enough for one person in a household.
How do Thermal Solar Panels Work?
Thermal solar panels concentrate the light from the sun to create heat energy, the solar panel collects this heat energy and then transfers it to a heat transfer fluid.
This heat transfer fluid is circulated through the solar panel using an electrically powered pump. The heat transfer fluid then passes through the heat exchange coil at the bottom of the hot water tank, here the heat is transferred through the coil heating the water.
The heated water then rises to the top of the cylinder and is made available to the taps within the property. The process then continues on with more fluid being pumped to the roof for heating. When solar energy is not available a boiler will be used to provide back up.
How much do Thermal Solar Panels Cost?
Thermal solar panels will cost between £3,000 and £5,000 and have the potential to save you between £60 and £90 per year on water heating costs, based on a three bedroom semi-detached property. The savings will be increased if you currently have an electric heating system.
There are government-backed schemes in place to help encourage households and businesses to move towards thermal solar energy. The Renewable Heat Incentive (RHI) is a scheme where a fixed payment is made based on the output of system that has been installed. Over time this makes a thermal solar panel system more cost effective, it is possible for it to become profitable after a period of time.
Will I use my Solar Thermal system in place of my current water heating system?
Thermal Solar Panels work best when used in conjunction with a traditional system such as gas or electric water heating. This means that the traditional system can act as a back up when the solar system is not able to provide enough heated water to meet the households needs.
Will my Thermal Solar Panels work in winter?
Yes, the systems will produce hot water in the winter, but the system may require anti-freeze protection depending on the type of system. The amount of hot water produced is likely to be reduced in the winter months.
Will my Thermal Solar Panels work on a cloudy day?
Yes, the thermal solar panels will generate hot water on cloudy days, as the system requires daylight as opposed to direct sunlight. The amount of hot water generated is likely to be less than a very bright summers day.
Will a Thermal Solar System be able to work with my current hot water system?
This really will depend on your hot water system, but in many cases a simple solar conversion valve can be connected to the existing hot water tank.
How long will my Thermal Solar System last?
In most cases the manufacturer warranty will be for 10 years and the system is expected to last in excess of 20 years.
Will my Thermal Solar System require a lot of maintenance?
The amount of maintenance required is very low, it is advisable for the system to have a yearly service to help maintain efficiency levels and to avoid any problems developing.
General Solar Panels Questions
How do Solar Panels work in the UK – we don’t get that much sun?
It may not feel like the UK gets that much sun, but we receive per square meter between 900 and 1,300 kWh of solar radiation each year, about 60% of the amount the equator receives.
So solar power works just fine, obviously on the equator more energy will be produced, but solar power is still efficient and worth having in the UK. It is important to remember that solar panels do not require direct sunlight; daylight is enough.
Is my home suitable for Solar Panels?
The ideal position for solar panels is on a south-facing roof. It is possible to do an installation on an east or west-facing roof providing the roof is within 90 degrees of south, but the return will not be as great.
In some cases panels will be installed on both sides of a roof to take advantage of the east and west if the position of the roof allows for this.
Do I need Planning Permission?
Since 2008 planning permission is not usually necessary, but it is always worth checking with your local authority to be sure.
If you live in a conservation area or in a listed building then you will almost definitely require planning permission.
Can Solar Panels be installed on flat roofs?
An A Frame would be used so that the panels can be tilted at the correct angle to maximise the light exposure.
Will my roof need to be strengthened before installing solar panels?
Generally most roofs are built to withstand additional weight, for example the weight of snow in winter.
Therefore most roofs that are in good condition will not require strengthening, but this is something only a solar panel surveyor will be able to tell when they visit a property for assessment.
How long will my Solar System last for?
Many solar panels will come with up to a 25 year warranty, giving a very good indication that the manufacturers are confident they will last up to and beyond this point. The majority of manufacturers suggest a lifetime of up to 40 years; the inverter that converts the solar energy into electricity tends to need replacing every 10 years.