Solar panels battery storage system

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Solar Panels Battery Storage System

With the increase in government incentives and a decrease in solar panel costs, the UK has seen an upward trend in the adoption of generating renewable energy off-grid.

This has many benefits in terms of cost savings and an environment-friendly alternative to commercially produced electricity that leaves a massive carbon footprint and is a huge contributor to greenhouse gases.

Solar battery storage systems work well with solar panels and let you capture the electricity produced by them for later use. What this means is that you can store the electricity generated during the day and use it at night to power your property.

It is a relatively new technology but is worth considering if you generate your own electricity and could use more of it.

Read on to find out how solar panel battery storage systems work, what types of solar batteries there are, their pros and cons, and much more:


A solar system is made up of several components that use the sun’s energy and converts it into electricity to be used around the property.

The panels feed energy into an inverter that then travels through a switchboard where it makes its way to the appliances and electrical systems in your home or office.

The system generates energy till the sun is shining, after which you have to rely on the grid to keep your property running. If you are generating more energy than you need, it will automatically go back to the grid and you’ll receive a tariff as a credit on your bill.

However, if you’ve installed a solar battery storage system, instead of sending the excess electricity to the grid, it is directed to the battery that gets charged up for later use.

This is especially beneficial after the sun goes down and if you require more energy than your panels produce during the day.

The system stores energy in the battery which is then used to power your property and appliances. If, for instance, your battery goes empty, the grid will step in to lend a helping hand.

Here’s an example of how a solar system works coupled with an AC-powered solar battery:

  • The solar panels use the sunlight and convert it into energy, which travels through the inverter as direct current (DC) so that it can be converted into alternating current (AC) to be used by the appliances and machines in the home or office.
  • The switchboard directs the energy first to power the appliances and the excess into the battery inverter.
  • The battery inverter converts the energy into storable energy to be used later when the sun goes down.
  • After the sun goes down, the solar panels stop generating energy and the property shifts to the stored battery energy.
  • The battery sends energy to power the property through the battery inverter that converts the energy into electricity that the appliances can safely use.
  • After the battery’s charge runs out, the grid will provide electricity to keep your property running.


Batteries are by far the most important part of a battery storage system and they come in two categories: lead-acid batteries and lithium-ion batteries.

Compared to newer technologies, lead-acid batteries are inexpensive and more widely used in many applications from cars to backup storage devices for infrastructure.

While their alternatives can provide more storage in a given volume and can be charged much faster, lead-acid batteries are relatively cheaper, reliable and, not to mention, easily recyclable.

These batteries are commonly used for domestic battery storage systems and, like modern car batteries, do not produce harmful or toxic gases.

They have a finite lifespan and can be charged and discharged about 4000 times before their efficiency drops to a critical level and they have to be replaced. They can be easily recycled since there is a huge market for recycling lead-acid batteries with minimal waste.

Lithium-ion batteries, on the other hand, are a modern alternative to lead-acid batteries and use similar electrochemistry to the batteries used in mobile phones and laptops.

They are, however, optimised for high-power usage to drive electric vehicles and power complete households and offices, and deliver a considerably better performance than their counterparts in terms of a higher energy density and charging rate.

Like lead-acid batteries, lithium-ion batteries also degrade over time and have a lifespan of about 8000 charge and discharge cycles, after which their storage capacity will have reduced to around 80% of its original value – this is twice the lifespan of lead-acid batteries.

Although lithium-ion batteries contain fewer toxic materials than other technologies, since they are relatively new, their recycling methods are still under development.

When it comes to battery storage system types, there are two main types: DC and AC battery systems.

DC battery systems

DC (Direct Current) battery systems are directly connected to the solar panels and do not require an additional inverter since they are connected before the electricity meter.

While this makes the system more efficient, it makes charging and discharging less efficient and could affect your feed-in tariffs.

AC battery systems

Instead of being connected directly to the solar panels, AC (Alternating Current) battery systems are connected after the electricity meter and require an AC-to-DC inverter to convert the electricity being generated into AC so that it can be used by the appliances in your property.

AC systems are costlier than DC systems but they won’t affect your feed-in tariffs since the electricity meter registers the total output of the system.

Hybrid battery systems

Hybrid batteries are DC and AC coupled solutions providing the best of both worlds where you can store power in the battery before it is converted into AC, do so during cheaper times, and also use them as a backup power source during power outages.

Hybrid battery systems are a great fit for both residential and commercial properties and are becoming more popular as people are becoming more aware of the technology.


The type of solar battery storage system you choose for your property depends purely on your energy needs. What might be perfect for one may be completely wrong for the other.

Here are the few things you need to consider when looking for the best solar battery storage system for yourself:


The storage capacity refers to the amount of energy that can be stored within the solar battery at a time, and the usable capacity refers to the amount that can actually be used, which is calculated by the depth of discharge (DoD).

On average, a typical house in the UK uses around 8 to 10 kWh of electricity each day. You need to choose the battery’s capacity depending on your use and if you wish to be completely independent of the grid or not.

The maximum capacity of some of the best solar batteries is 20 kWh, which is more than enough for a house and its everyday use.

Some solar batteries are also stackable, which means that you can increase their capacity by adding more units to them over time.


This refers to whether you wish to opt for lead-acid or lithium-ion batteries for your solar battery system.

Although lead-acid batteries are the cheaper option and there is still a strong and pretty well-established market for them, lithium-ion batteries are the more advanced type with a higher efficiency level and lower lifetime costs.


Cycles are the number of times a solar battery can be fully recharged from empty. The higher the number of cycles, the longer the battery storage can perform efficiently.

On average, a 4kWh lithium-ion battery can reach up to 4000 cycles and, depending on the type of battery you choose, you may have to incur additional charges by replacing them much before your solar panels need replacement, which is a good 25 years.


While the average lifespan of a solar panel system is around 25 years, a solar battery storage system lasts around 5 to 7.5 years for lead-acid batteries and around 11 to 15 years for lithium-ion ones.

This is not a fixed lifespan and is affected by several factors such as how efficiently the battery storage systems are used, if they are over-discharged, or are exposed to extreme weather conditions.

The depth of discharge (DoD) is a crucial factor in how long the battery storage systems will last. It refers to how much you can use the battery before it needs to be recharged.

Similar to how it is harmful to drain your phone’s battery to 2% and keep on using it, the same goes for solar battery storage systems. Using up 100% of the charge and exceeding its DoD before recharging it will significantly shorten its lifespan.

For instance, if you have solar battery storage with a capacity of 5 kWh and 80% DoD, you must always remember to recharge it before using up the entire 4 kWh to extend its battery life.

Compared to lead-acid batteries, lithium-ion batteries are capable of handling extreme temperature changes and have a high tolerance when it comes to discharging.


Solar panel battery storage systems typically cost around £1,200 to £6,000 depending on their type, capacity, and life cycle.

Similar to how solar panels were costlier when they were new in the market but have now become more affordable, solar battery storage systems have also followed the same trend.

Lithium-ion and lead-acid are the two most commonly found chemicals in solar batteries, with the former being more mainstream and cost-effective.

If you compare a 4 kWh lead-acid battery to a 4 kWh lithium-ion battery, a lithium-ion battery will have a higher preliminary cost. But if you look at the long-term cost-effectiveness, it will be much cheaper due to its extended life cycle.

The cost of a solar battery storage system depends on the following factors:

  • Battery material: different materials such as lead-acid and lithium-ion have an impact on the discharge rate and lifespan of the battery, with a higher discharge rate and longer lifespan typically resulting in higher costs.
  • Capacity: measured in kilowatt-hours (kWh), the capacity directly influences how much the system will cost. A larger capacity means it can store more energy, resulting in a higher price.
  • Lifespan: the number of cycles is an important indicator of how long the battery storage system will work efficiently. The more cycles the system can provide, the longer it will be able to perform, and the higher its preliminary cost will be.
  • Installation: solar battery storage systems need to be professionally installed to ensure there are no faults and safety risks, and the cost of installation varies based on the size of the system and how complex the process is.


The market for solar battery storage systems is growing rapidly and many believe them to be the answer to higher energy demands in solar-powered homes. Some of their great advantages include:

  • Cleaner energy

Solar batteries help you use 100% clean energy that is great for the environment and reduces (at times completely eliminates) your dependence on the grid that uses fossil fuels to generate electricity.

By using solar battery systems, you can play your part by reducing the amount of carbon dioxide and other harmful greenhouse gases being released into the environment.

  • Convenience

Solar panel systems are great and produce clean and green energy that is not just beneficial for you but the entire world. The only drawback is that you can enjoy their benefits only while the sun is shining.

To counter this issue, you can install solar battery storage systems and keep the excess energy produced during the day whenever you wish to use it.

Households are unlikely to use up all the energy generated during the day and, depending on the size of your solar panel system and the capacity of your battery storage system, you can easily store excess energy and use it according to your convenience, whether the sun is shining or not.

  • Cost-savings

Generate your own electricity and use it whenever you want – it doesn’t get better than that! With traditional energy methods becoming more expensive every year, solar panels and solar battery storage systems allow you to use clean energy without having to rely on your energy supplier.

Solar batteries are estimated to reduce your energy bills by 35%, with some manufacturers claiming it can go up to 60% with efficient systems.

In addition to that, you can also sell the excess energy that you are not using to the grid and earn an export tariff on the clean energy.


As with everything in life, solar battery storage systems have a few drawbacks. But the good news is that, when you look at the bigger picture, they are negligible and the pros greatly outweigh the cons.

The cost of energy storage can be quite high and can increase the cost of your solar power system substantially. Therefore, it is important to calculate what your return on investment would be if you decide to invest in a solar battery system.

Another factor to consider is that designing and installing a solar battery storage system can increase the complexity of your solar system since it is a little high maintenance and needs the right type of environment and temperature to be installed.

Considering all the above points, the bottom line remains that battery storage systems provide a great number of benefits to property owners, who should consider the costs as long-term investments that won’t just help them save money but will also be great for the environment and the generations to come.


It is detrimental to the health and effectiveness of the solar battery storage system to be installed by a certified professional who knows their job well.

The inability to install it correctly can pose a serious threat to residential and commercial properties in terms of electric shocks, fires, burns, accidents, and explosions.

Calder Electrical services provide a wide range of solutions to help you play your part in making the world a more sustainable place.

If you already have solar panels installed on your residential or commercial premises, installing a battery storage system could help maximise the benefits of making your own energy.

We can assess the amount of energy your solar panels produce and install enough battery storage so that you can minimise any wastage of the energy you create. This will help lower your energy bills and make you more independent from the grid.

Contact us here or call us on 0800 612 3001 to talk to our battery storage system experts right away!

Photo by Riccardo Annandale on Unsplash