A common question for homeowners who are considering investing in a solar photovoltaic (PV) system is:“What happens to all of the solar energy captured by solar panels in the daytime, but that doesn’t get used?”
The answer to this is two-fold…it will either be fed back into the UK national grid or if you have a solar battery storage system that can be saved for later use.
A solar battery storage system can be a very useful piece of equipment, but before going into whether it would be right for you, let’s first break down some of the key points surrounding them.
What is a solar battery storage system?
Solar battery storage is a type of energy storage technology that homeowners can use in conjunction with their solar panels to store electricity gathered during the daytime. This energy can then be used when needed, for example, at night when the sun isn’t shining.
Battery storage solutions will be included in any personal recommendation produced by Solar Together and can include different capacity bands.
These batteries are often made of lead-acid or lithium-ion. They have the ability to store the electricity generated by your solar panels while you are away from home during the day.
Lithium-ion batteries are the most efficient batteries available on the market, delivering fast-charging and large capacity.
Why combine solar panels with battery storage?
If you have your own solar panels, your energy bills will be reduced due to your energy self-consumption.
This is because it is cheaper to use the electricity your solar PV has generated directly at your home rather than purchasing it through an energy company.
If you have a solar PV system and are not at home during the day to use the energy produced by the panels, then a battery will help you use that energy later on, cutting your electricity bills.
A battery is the right decision for many people, but you don’t need to take our word for it, as Which? Conducted a survey by 119 solar battery owners in May 2019, with almost 75% of those asked stating that battery storage has helped them save money on electricity to a great extent or some extent.
What is self-consumption?
Self-consumption is intrinsically tied to the concept and functionality of solar panels. One of the main aims of solar panels is to help homeowners become self-sufficient in electricity production.
When the sun is shining during the daytime, you can meet your consumption needs by using your household appliances. Without a battery storage system, when nighttime comes, and your solar panels have clocked off for the day, you will return to being dependent on energy suppliers for all of your needs.
Batteries solve this issue by storing excess energy for use when your panels cannot generate any green energy.
What are the benefits of investing in solar battery storage?
As is becoming evident, solar battery storage systems are a key component in truly becoming independent from grid energy and carry with them many attractive advantages, including:
You optimise the usage of your self-generated green electricity
Solar panels are environmentally friendly as they generate 100% renewable energy; however, this energy source is completely reliant on what time of the day it is.
Solar battery storage solves this by holding the additional energy generated – allowing you to use less of the UK national grid’s power supply…reducing your carbon footprint even further.
In fact, a recent study has found that battery storage increases self-consumption above 50% and could be the cornerstone for unsubsidised residential PV systems moving forward thanks to their efficiency.
Microgeneration Certification Scheme (MSC) provided further details with an average household utilising 35 - 50% of the generated system without a battery. However, they stated that battery storage could raise this level to as high as 80%! Increased rates are dependent on if you are in the house for much of the day.
You save on your energy bill
Whilst a standard solar PV system will help you cut down energy consumption during the day; it is during the evening when solar battery storage can discharge the stored electricity, providing you with renewable-generated electricity at no additional cost.
According to E.ON, in central England, a 9.6 kWh solar battery storage system (with 12 x 315W panels) might allow you to utilise up to 30% more of the energy generated by your solar panels and save up to £560 on your annual energy bills.
This helps you make further cuts to your energy bill.
Read our blog post on how to save money on your energy bills with a solar PV system.
You are more energy independent
Generating your own electricity with your solar panels and storing your surplus on your home battery makes you more independent from the electricity grid.
Companies that provide energy are constantly raising their prices to get more money from their clients.
Purchasing a solar battery will be a significant step toward off-grid self-sufficiency as you are keeping your costs to the energy suppliers and the grid operator lower.
You are well prepared for later
Being more independent from the UK electricity grid can help protect you from price changes that may occur throughout the year.
If you make more use of your own generated electricity and therefore have to take less from the grid, the impact of rising energy prices will be lessened to an extent.
You can retrofit existing solar PV systems with a battery storage system
It's not a problem if you already have solar panels at home; you can easily add a solar battery to an existing solar PV system.
The solar battery must be either AC-coupled or DC-coupled when installed, depending on the type of inverter used by your solar panels.
The solar battery must be AC-coupled if your PV system includes a microinverter. This is the less expensive of the two solutions (because you won't have to replace the inverter), and the installation is simple.
Are there any downsides to investing in home batteries?
Solar battery storage systems can be expensive.
Solar battery prices can range from £3,000 to well over £10,000 before installation, which is likely to cost around £500-£2,000.
This is a significant investment, and looking at more exclusive and powerful models like the Tesla Powerwall 2.0, which has a 13.5 kWh capacity, can emphasise this cost.
Indeed, the current price for a fully installed Tesla Powerwall 2 system will be between £8,600 and £10,500 depending on the complexity of the installation needed and the VAT rate you are eligible for.
Fortunately, the average family would not require such a model and can look to something more proportionate to their needs. Solar Together helps recommend the ideal battery storage systems for your own needs.
It is best to choose a storage capacity that is tailored to your situation. This way, you achieve the best results, and your investment returns are optimal!
How much does the “average” home battery cost?
Meanwhile, in the UK, there are now almost 10,000 homes with solar batteries.
The cost of a solar battery generally ranges between £1,200 and £6,000, depending on the battery's quality, capacity, and lifespan.
Of course, the larger your solar battery, the more electricity you’ll be able to store, and the more money you’ll be able to save.
You can be completely independent of the grid, but your investment will then be substantial
Do you want your energy footprint to be completely off the grid? It is certainly viable to reach this state of self-sufficiency; however, your investment costs will reflect this.
Financially, your investment will then be 5 to 10 times larger, just like your battery. Our climate is not favourable to go completely off-grid.
During the winter months, your solar panels do not produce enough power to compensate for the heating costs, and accordingly, you will have to get extra power from the grid.
Storage systems can be space demanding
Some high-capacity solar batteries are about the size of a small kitchen fridge, so be ready to give over some room for one of these things – especially if the model can only be located indoors.
You need to pay extra to have backup functionality included
Many more economical and low-cost batteries will not be fitted with a backup power function if you experience a power outage. However, when accepting the Solar Together personal recommendation, this can be discussed with the installer and can be added to your package at the best cost possible.
You could also provide your inverter with a separate circuit to which you can connect devices with low consumption so that you still have lighting, for example, in the event of a power failure.
Battery storage retrofits cost more
Batteries added to existing solar PV systems are subject to 20% VAT.
Batteries installed at the same time as solar panels are subject to 5% VAT.
Is investing in a solar battery storage system a good idea?
Having covered all of the points, if you already have a solar PV system or consider having one installed, it may make sense for you to get a solar battery storage system. Read more about a battery storage installation.
Using Solar Together makes it possible to have these systems installed or retrofitted at the best price possible to maximise your energy savings and gain higher levels of autonomy.