Solar Power Generation

Photovoltaics is the direct conversion of light into electric power using semiconducting materials. Solar photovoltaic panels are typically made up of silicon (or similar semi-conducting material) which can capture energy from the suns light and convert it into usable electricity.

They work by absorbing sunlight via these photovoltaic cells which generates a direct current (DC) of electricity which is then converted into a usable alternating current (AC) via a device called and inverter. This alternating current can then be used to power your home heating, lighting and electrical appliances.

There’s 5 excellent reasons why you should consider installing solar panels on your property:

1. You will be generating your own totally green and renewable energy which you can use yourself or sell into the grid for others to buy
2. You’ll be saving significantly on your electricity bill as you will be generating at least some of your own electricity
3. Your home will increase in value
4. Your EPC rating will improve
5. Your carbon footprint will decrease and you’ll be “doing your bit” in the Government drive to net zero by 2050

The process for installing solar panels is as follows:

1. Scaffold is erected prior to works commencing.
2. Roof anchors are fitted. These are system specific stainless steel hooks that screw firmly into the rafters of the roof and form a base for the mounting system.
3. Aluminium bars are locked in to the anchors and screwed into place to create the frame for the panels to sit on
4. The solar panels themselves are then carefully positioned and attached to the frame
5. The panels are then wired into your property. t this stage this is direct current (DC) which will need to be converted into Alternating Current (AC) to enable us to use the electricity, Wires are therefor fed into a device called an inverter.
6. The inverter is then ready to be connected to your properties electricity supply – and a consumer unit , isolation switch and generation meter will be installed and connected up.
7. Inverter will be switched on and the system will be powered up 

You’re now producing electricity!

There are several different types of solar panels but the two main types are as follows:

Polycrystalline solar panels

These are made from silicone fragments which have been melted and cooled. These are cheaper but less effective than others – converting between 13% and 18%of sunlight into energy.

Monocrystalline solar panels

These are made from individual silicon crystals and so tend to be a little more expensive but likewise a little more efficient by converting between 15% and 24% of sunlight into electricity.

Yes … but they will be less effective and generate less electricity.

There’s obviously different types and quality of solar panels and some will perform better than others in low light but when light levels fall so does the power output of a solar cell.

Ideally your roof should be south facing and unshaded, that said, whilst east and west facing roofs can lose 10 – 20% of their effectiveness and north facing roofs even more, installing solar panels is still likely to be worthwhile as the panels are designed to work in daylight and not just full sun.

If your roof has a fairly standard slope of somewhere between 30 degrees and 40 degrees the panels can fit flush against your roof. If the angle of slope is different to this then the panels may need to sit on an angled mounting system. They can even be installed on flat roofs or ground mounted.

Size of roof doesn’t matter too much. If you have a small roof area then fewer high performance panels could work just as well as a larger area of standard panels.

There’s always going to be one or two exceptions but most common roof types will be ok to take solar panels but the weight of the panel, including the wind loads, should be taken into account when designing a system. The current roof structure, age, condition etc should also be checked. Under the Building Regulations, if the weight increase is over 15% then a structural survey is required.

You don’t need to live in a big house with a huge roof – solar panels can be highly cost effective even on the smallest roof.

A 3KW system needs just 22 square meters of roof (sun facing) but the bigger the roof the greater the cost but the more you can save!

Planning Permission

When it comes to planning permission, whilst we always suggest checking with your local planning office but the vast majority of residential properties in the UK can have solar panels installed without the need for planning permission as they are usually considered permitted development.

There are two main rules you will need to adhere to however:

1. Panels should not be installed above the highest part of the roof (excluding the chimney).
2. Panels should not protrude more than 200mm from the roof plane.

If you live in a listed building or conservation area you may need planning permission as rules are a different: In these cases the installation should not be on a listed building or within the curtilage of a listed building and the solar panels should not be visible from the highway if the building is in a conservation area or World Heritage Site.

Distribution Network Operator Registration

If you’re planning to install a solar PV system in your home, you must register it with your Distribution Network Operator (DNO). The Distribution Network Operator (DNO) is the company responsible for bringing electricity to your home – .you must register your solar PV system with them but you will normally find that your installer will automatically do this for you.

The domestic solar panels sold in the UK have been specifically designed to work daylight conditions rather than direct sunlight. As a result, anywhere in the UK is suitable for domestic solar panel installations.

Of course, if you live in the south or south west you’re likely to enjoy more sunshine and so solar panels are likely to perform slightly better than those installed further north.

Obviously, every home is different and so is the available roof space but, to give you a bit of a guide:

A single standard solar panel currently (2024) costs between £400 and £500 and will generate 250W of power.

If you’re living in a 2 bedroom house it’s likely that the sort of system you’ll be looking to install is 4KW (4000W) which means you’ll be installing about 16 panels which will take up about 29 square meters of roof area. This will therefore cost you around £6,400.

This will increase to around £8,000 to £9,000 for a typical 3 bed property where some 20 panels spread over 32 square meters will generate 5KW of power

£9,000 to £11,000 for larger 4 or 5 bed houses when the larger roof can house a system of around 6KW comprising of 24 panels over 43 square meters.

Even the smallest roof of a flat or such like can usually house a 3KW system which would need 12 panels over just 22 square meters of roof and cost £5,000 to £6,000.

A 3KW system on the smallest 22sqm roof is likely to save you around £850 per year which means the system will pay for itself in just under 7 years

A 4KW system on a 29sqm roof is likely to save you around £1,000 per year which means the system will pay for itself in around 7 years.

A 5KW system is likely to save you around £1,500 per year which means the system will pay for itself in just 6 years.

A 6KW system is likely to save you more than £1,500 per year which means the system will pay for itself in around 6 years.

At certain times you will generate more electricity than you need in which case you have a couple of choices:

1. Sell the excess electricity to the grid. To do this you will need to find a supplier who offers a Smart Energy Guarantee or SEG Tariff – all licenced energy companies with 150,000 customers or more HAVE to provide such a tariff so it shouldn’t be difficult to find a supplier. This is designed as a support mechanism to ensure small-scale generators are paid for the renewable electricity they export to the grid. When you generate more than you need your controls will automatically feed the excess directly into the grid and the meter will monitor this. Usually every quarter your electricity provider will then provide a statement and a credit against future bills. 
2. Fit a device called a PV Diverter which will add on around £900 to the cost of installation. This device will power can power the immersion heater in your hot water tank enabling you to storing hot water for use later.

At times when you aren’t generating enough you will simply purchase to your additional needs in the usual way.

There are a number of Government grants which can contribute towards the cost of solar panels – if you meet the criteria.

See our section on energy efficiency grants for more information.

For most of us installing solar panels on the roof of our home makes perfect sense but it is possible to mount them on the ground as long as the can face the right way, be angled correctly and are not shaded.

Different planning permission rules apply though – for example, if a ground-mounted solar panel system is larger than nine square metres – it will require planning permission. So, if you have what you think to be appropriate land available check first with your local planning office.