In May 2019, Britain was powered by energy sources other than coal for a continuous record-breaking period of over 100 hours. While that may now be a while ago, this was the first monumental landmark that emphasised just how far renewable energy sources have developed. The National Grid also confirmed that the country is becoming increasingly less dependent on coal as renewable energy sources have become more viable. As the general public are opting in to install more solar panels into their home than ever before, reliance on renewables is becoming “a regular occurrence”.

Fast forward five or so years and it’s safe to say things have moved on, a lot.

This development built upon the success of 2018, which was a landmark year for renewable energy, with renewable capacity having overtaken fossil fuels in the UK for the first time in history.

Over the past five years (2019–2024), the UK’s renewable energy capacity has significantly increased. Total renewable capacity rose from approximately 45 GW in 2019 to over 59 GW by early 2024, representing a growth of more than 30%. This growth was driven by the expansion of offshore wind farms, solar power installations, and increased biomass energy generation. Offshore wind, in particular, now contributes nearly half of the UK’s renewable electricity, with installed capacity exceeding 14 GW (Statista / GOV.UK / IRENA)

The continued government support through initiatives like the Contracts for Difference scheme and advances in technologies, such as floating wind farms and green hydrogen production, have played a critical role in this growth (Gallagher Global).

Why Consider a Solar Battery?

With the rise of Solar power’s popularity as a renewable energy source, Solar Batteries have also been gaining recognition. Companies, such as Tesla, are designing these batteries to store the energy produced through Solar Panels for later use, further increasing the renewable energy efficiency levels.

Alongside the current Smart Export Guarantee (SEG) at an average rate for 2023-24 of 12.9p per kWh (depending on the provider), many solar PV owners, and even first-time buyers are choosing to purchase solar batteries alongside their panel set-up.

Homeowners and small business owners, in particular, should be considering ways to optimise energy-consumption through much more lucrative methods than simply feeding solar energy into the National Grid. With this market opening up more and more, homeowners are requesting Solar-plus Storage to take charge of their electricity usage. Solar Batteries provide the option for around the clock energy usage, even throughout the night, utilising the energy stored during the daylight hours. Having this piece of technology present in a premises, whether residential or industrial, can improve self-consumption efficiency by up to 85%.

Another key feature which is highly desirable is having peace of mind that should a power cut occur then the Solar Battery will act as an emergency storage system preventing any electronic downtime which would otherwise be experienced. It is important to note that not all battery systems provide this ability, with some Emergency Power Supplies (EPS) operating in a restricted manner during a power outage.

Having a comprehensive power supply should be very significant for any business owner who operates predominantly with electronic technology; preventing any technical issues which may arise from having work cut off mid-session. When looking at Solar Batteries which may double as an EPS it is vital to look at both the capabilities and discharge rate limit.

All Solar Batteries can be used as reserve energy units, but many units are sold under the perception that they are Uninterrupted Power Supply (UPS) units. This unit would provide instantaneous power replacement to connected devices in the event of a power cut. This is a prime concern for business owners and can cause problems should an owner buy any solar battery assuming there would be no electrical down time.

When you are looking to purchase a Solar Battery, it is wise to envisage what electrical output you would require, how fast the charge could restore power, and whether the energy storage units you are contemplating have the capabilities to match your needs.

Alongside business owners, homeowners will also appreciate the saved costs from preventing food spoilage due to refrigeration units with can afford a small period of downtime receiving no power amongst.

How does Solar Battery Storage Work?

During daylight hours Solar Power will be converted through the photovoltaic cells present on Solar Panels (Solar PV), which allow photons (light particles) to knock electrons free from atoms, which in turn generate a flow of electricity. This energy will then be streamed to all appliances and units which require electrical input to function, with the remaining energy being diverted into the Solar Battery. Each type of battery will have its own maximum energy capacity, and when this level is reached the excess power will be diverted to the grid as is the standard practice when no battery is present.

During night-time, a Solar Battery can provide its owner with free and renewable energy which has been stored in previous light periods. Should this reserve energy be used before it can be recharged, then a user will be seamlessly reconnected to the power grid. This instance is more likely to occur during the Winter season; however, efficient storage systems are able to store 100% of the energy requirements in the Summer, and upwards off 75% in the Winter.

All batteries have different discharge rates, from 5 kW to 2 kW, however, a common misconception is that a battery’s discharge rate alone will decide how much electricity it can output to your house at any one time. Whenever a solar battery unit is installed it will come with a charge controller which is designed to limit the power output of an energy storage unit. This charge controller unit acts as the brains for a storage unit and will regulate the power output of a battery.

For example, if a Solar Battery’s max power specification was 4 kW’s, but the adjoining charge controller was set to 2kW’s, then the peak amount of energy output which a residence could receive would be 2 kW’s. This discharge limitation must be taken into account if you are concerned with shorter, but more demanding, periods of energy consumption.

There are Solar Batteries available with numerous differing capacities able to meet various needs. The following chemical compositions form the basis for most Solar Batteries: