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’).
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.
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)
They should be covered by your buildings insurance, but we recommend that you contact your insurer to confirm this.
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.
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.
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 :
Check their quote includes:
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.
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.
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. 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.