Solar PV panels generate electricity from light. They reduce the amount of electricity that you need from the national grid, which is powered by a mix of renewable technologies and fossil fuels. Installing solar panels can therefore cut your carbon footprint meaning that you can make a personal contribution to reducing global warming. Also, it can save money in the long term and shield against dramatic energy price rises.

Whilst a battery does not save carbon in itself, it does mean that the carbon and cost savings from the solar PV are maximised. Renewable energy generation is not constant – it fluctuates depending on the weather. Similarly, there are peaks and troughs in demand for electricity. If we can store excess green electricity and use it later, the UK electricity grid does not need to rely so heavily on electricity generated by fossil fuels to meet peak demand. As well as storing excess electricity that your solar panels generate during the day, you can store electricity at night from the grid, when demand is lower, and the electricity mix is greener. 

Adding a battery to a solar PV system has become very common. 

Please note, if you install a battery as part of your solar PV system, the whole thing is exempt from VAT. However, as batteries are not classed as energy saving measures in their own right, they are subject to VAT if installed separately i.e. at a later date. Therefore, you may lose out financially if you postpone the decision to get a battery, plus the job may be less attractive to installers. 

This depends on the size of the system, the manufacturer and spec of the equipment, how easy the panels are to install and whether you need any work to your roof or electrical system. It also depends on whether you add a battery.  

A typical solar PV system for a family home, consisting of about 12 panels with a battery would cost around £11,000, of which the battery would be about £3,000. 

The amount of time it takes for you to recoup the initial cost of the solar panel system (the payback time) depends on: 

• The amount you paid for your system 
• The amount of electricity that you generate – see more below 
• The amount of generated electricity that you use – see more below 
• How much you pay for your electricity from the national grid via your electricity supplier 
• How much you get paid for electricity that you export (the Smart Export Guarantee, which varies from supplier to supplier) – see more below  

If you can optimise these variables (i.e. a reasonably priced system, good generation, good self-consumption, low rate for buying electricity and high rate for exporting (selling) electricity), your payback could be around 10 years. Once an installer has designed your specific system, payback can be estimated, but will remain difficult to pin down exactly due to the factors that are outside of the installers’ control. 

The amount of electricity that you will be able to generate from your panels depends on: 

• The size of the system (number of panels, and the power rating of the panels) 
• The amount of light that falls on your panels, which is determined by their orientation and any overshadowing and your location in the UK. 

Electricity generation is not constant – it varies dramatically both across the day and across the year, to reflect the changing levels of light. 

This depends on where you live and the orientation of your roof. There is standard data table for the UK that provides one single factor for Cumbria.  

The power of typical solar panels is currently around 400Wp (the p stands for ‘peak’ and 400W is the power of the panel in standardised laboratory tests). For a 12 panel system, the total power is therefore 4.8kWp. Using the standard Cumbrian factor, this will result in an estimate that the system on a south-facing roof, will generate around 4,000 kWh per year. 

However, there is a variance across Cumbria since some places are sunnier or cloudier than average. So be mindful that the quote you receive might be an over- or under-estimate of what your system will produce. You can explore the differences across Cumbria on this map. 

Yes. For the same total number of panels you will get about 15% less energy over the year from an east-west facing roof, compared to a south-facing one. For other orientations you will get a different percentage, e.g. for a south-west facing roof you will get about 5% less. 

However, in summer you will get more electricity from an east-west facing roof early in the morning or late in the evening and you could well find this an advantage. Also, east-west oriented houses (assuming they have a simple pitched roof) have twice the viable roof space of a comparable north-south oriented house.

Solar panels produce most of their electricity in summer and much less in winter, whereas most homes use more electricity in winter and less in summer. On a sunny day in summer your panels could produce 30kWh and not many houses use this amount in a single day. On a dull winter’s day they may produce less than 1kWh.

Typically, for solar panel systems without a battery, you will use about 30% of the electricity that you generate, and the rest will be exported back to the national grid.

If you add a battery, your self-consumption can increase to around 60% as you can store excess electricity generated during the day to use at other times.

Aside from adding a battery, the best approach is to try to match your electricity usage with your electricity generation. For example, run appliances when the sun is shining, but spread them out to avoid demand spikes.

You can also looking into storing energy as heat, or switch more of your systems, equipment and appliance to electric (see ‘Complementary technologies below’).

Any excess, over and above what you are using at any time gets automatically exported to the national electricity grid. Conversely, if your panels are not producing enough electricity to power your home the extra needed comes automatically from the grid. You only have to pay for what you take from the grid. 

Solar panels can be fitted on a variety of different roof coverings. Newer systems can actually replace your tiles or slates and be in-line with the rest of your roof.  

It’s important to think about your roof condition before you install solar. It needs to be able to take the weight of the panels, and you need to be confident that you won’t have to remove the panels after a few years to maintain or replace your roof covering. You can seek an independent roof survey or ask your installer for advice. 

Also do consider whether you have a sufficiently clear space on your roof. If you have lots of dormer windows or chimneys or other features, they can cast shadows and reduce the amount of space available for the panels. An average panel is approximately 1.7m long by 1m wide (although a variety of different sized panels is emerging) and you need to be able install enough in one area to make it worth the cost of scaffolding. 

Yes, and you should shop around for the best electricity tariff. The things to look out for are: 

• Who is charging the lowest unit cost for the electricity that you need to buy from the grid; 
• Who is offering the highest rate for the electricity that you export into the grid? This payment is known as the Smart Export Guarantee (SEG) payment. As of September 2023 best rate is around 15p per kWh. You do not have to sign up for SEG from your current supplier. You can find SEG rates for different electricity suppliers here; and 
• If you have a battery, are they offering a ‘time of use’ or ‘agile’ tariff? These offer cheaper rates at off-peak times. If you have one of these tariffs, you can charge your battery overnight with cheaper grid electricity and use it during the day to avoid higher day time rates.   

At present, Octopus energy seem to be offering the best tariffs, but keep on the look out for others who might catch up. 

You may well have to replace the inverter (the box that converts direct current from the panels mains alternating current) after 10 – 15 years at a cost of perhaps £800 at 2022 prices. The panels themselves should still produce at least 80% of initial power after 25 years.  

For batteries, many manufacturers provide a warranty of perhaps 10 years or some number of cycles (filling and emptying the battery), whichever is the smaller, with some level of degradation, for example 20%. However, it’s too early to know what the lifetime of batteries will be in practice. 

Solar PV systems are generally very low maintenance. 

There seems to be a difference of opinion on whether it is necessary to clean panels and you can find advocates for annual cleaning (this could cost £100 – £200) while others say that this isn’t needed in UK conditions (but check more carefully if pigeons roost nearby!). Investigate further before getting this done or trying to do it yourself. 

They should be covered by your buildings insurance, but we recommend that you contact your insurer to confirm this. 

The other consideration is whether you have any birds nesting in your walls or eaves. It is illegal to disturb them, so you should ensure that there aren’t any before installing panels or erecting scaffolding. Whilst house martins and house sparrows are usually obvious, swifts may not be. If they are present, the work should not be carried out – or scaffolding erected – between mid-April and mid-August. 

If bats are discovered before or during a planned installation, extra consideration must be taken. A licence may need to be obtained from you Statutory Nature Conservation Organisation. Further details can be found at: Solar panels – Things to consider when planning works – Bat Conservation Trust (bats.org.uk)

Generally speaking, no. Installing solar panels is considered to be permitted development (as long as the installation doesn’t extend beyond certain limits). However, for domestic properties, you will need planning permission if “in the case of land within a conservation area or which is a World Heritage Site, the solar PV or solar thermal equipment would be installed on a wall which fronts a highway”, or if “the solar PV or solar thermal equipment would be installed on a building within the curtilage of the dwellinghouse or block of flats if the dwellinghouse or block of flats is a listed building”.

For non-domestic properties you will need planning permission if “in the case of a building on article 2(3) land (i.e. land within a conservation area or which is a World Heritage Site), the solar PV or solar thermal equipment would be installed on a roof slope which fronts a highway”, or if “the solar PV or solar thermal equipment would be installed on a listed building or on a building within the curtilage of a listed building”. 

See here for more details. See class A for domestic and class J for non-domestic.

There has been a recent government consultation about these rules, so keep an eye out for updates.

There are numerous conservation areas in Cumbria and the Lake District National Park is a World Heritage Site. If you are in doubt, please check the planning advice page on your local planning authority’s website, for Cumbria that is either Cumberland Council or Westmorland & Furness Council. 

We are currently working with five local installers, who between them, cover the whole of Cumbria. We can support anyone who wants a quote – please visit Solar Made Easy – CAfS.

If you wish to proceed independently, we would recommend that you look out for the following when you seek quotes : 

• Are they MCS (Microgeneration Certification Scheme) accredited? You can search for installers in Cumbria here. 
• Are they a member of the Renewable Energy Consumer Code? 
• Do they have good reviews? 

Check their quote includes: 

• A realistic estimation of electricity generation and percentage of electricity that is likely to be used. 
• A financial assessment of savings over time and estimated payback period. 
• Technical information on the system they are proposing for you. 
• Warranty information. 

Installers may not visit your home initially and may not provide complete information until they are more confident that the job might go ahead. If this is the case, check that this will be done at the next stage before you place the order with them.

If you are installing a large system (your inverter has an output greater than 3.6kW), you need to apply to connect to the national grid (via Electricity North West). This is to ensure that if you are exporting 100% of your electricity at any particular time, the network in your local area can cope with the additional electricity. Your installer should be able to apply on your behalf. Unfortunately, there is often a wait of several weeks before permissions are granted.

There is a possibility that you may be charged for any upgrade works to the grid that are required to enable your electricity to be exported. If this is the case, you can avoid this by asking your installer to set a restriction on the amount of electricity that can be exported, so that it is below the threshold where permission (and the associated network upgrades) are required.

If you have a small system with an inverter with output 3.6kW or less, you do not need permission in advance, but you should notify Electricity North West once the installation is complete. Again, your installer should do this on your behalf.

Generally speaking, no. This is to protect anyone repairing the line from electricity coming from your panels.

Solar PV systems are not really designed to be back up power systems. This is because the generation is intermittent. Even if you had a battery, it may not be full at the time of the power cut, and the electricity held within it might not last very long.

That said, certain systems can be adapted to work in a power cut. If this is something that is of particular interest to you, make sure you discuss this with your installers at the outset.

The major components of panels that are mined and processed are quartz, copper and aluminium. Various attempts to calculate how much greenhouse gas is produced in the mining of these materials and the manufacture of panels suggest that this is recovered by production of carbon-free electricity in about two years. This is regarded as a good return on investment, particularly as panels are expected to be used for well over 25 years. So from a global warming perspective they have a positive environmental impact.

However, there can be negative social and environmental impacts from the mining process, which depend upon where the minerals are sourced and how well the mines are managed. Panels made from ethically sourced materials do exist, so it is worth asking your supplier about this (even if just to get them thinking about it). Ethical Consumer rank different panel manufacturers, but you do need to subscribe to them to access the rationale behind their scoring. Recycling at the end of their lifetime is yet to be fully solved, but once well-established, this should reduce the need for new raw materials.

There are more serious social and environmental issues around the mining of the materials used in electrical batteries, which are mainly lithium, cobalt, nickel and manganese. Again, there is significant work to be done to up systems and facilities for recycling these batteries, as well as research and development of alternative battery technology that avoids lithium in particular.

If you have an electric car, or are planning to get one, you may want to consider installing an electric vehicle charge point. Technology is evolving to allow “bi-directional charging” which means that you can store electricity in your vehicle battery in the same way as a stand-alone battery and then use it in your house. That does however depend on when your vehicle is at home and plugged in. If plugged in during the day, it could store electricity generated by your solar panels.  If plugged in at night, it could store lower carbon and potentially lower cost night-time grid .

There are technological developments around water heaters that have smart controls and can be directly connected to your solar PV electricity supply, as well as your other energy sources. Have a look at Mixergy and iBoost as examples, but note that we have no experience of actually using these products. Storing excess electricity as hot water is another way of maximising the electricity output from your panels. An example of a homeowner who has adopted lots of complementary technologies is presented in this video presentation. 

There are also heat batteries. As explained by the Energy Saving Trust, these store either spare heat or electricity, often generated by renewable energy systems. Heat can be stored in a material when it changes phase from a solid to a liquid. These materials are called phase change materials (PCM). Spare heat or electricity is used to charge the PCM inside the heat battery. When the heat is needed, the phase change material changes back into a solid with a release of heat, which is used to provide hot water.