How Battery Storage Works: A Step-by-Step Guide to Solar Energy Storage

Solar battery storage is driving the renewable energy revolution, enabling homeowners to capture and store clean energy for a more sustainable future. Storing excess energy generated by solar panels allows homeowners to use solar power even when the sun isn’t shining. These battery systems reduce reliance on the grid, lower electricity costs, and ensure backup power during outages.

Power your home with Upvolt’s smart solar solutions.

In this guide, we will explain how solar battery storage works, from capturing sunlight to using stored energy efficiently. We’ll also explore key benefits and different battery types to help you understand whether a solar battery system is right for your home.

In Brief: Why Solar Battery Storage Matters

• Solar battery storage enables homeowners to store excess solar energy for use when the sun isn't shining, reducing reliance on the grid.
• Storing excess solar energy allows homeowners to reduce reliance on grid power, particularly during peak demand times when electricity costs are higher.
• Solar battery storage provides homeowners with energy independence and ensures backup power during outages.
• Smart monitoring allows homeowners to track energy production, storage levels, and optimise energy usage in real time.

What is Solar Battery Storage?

Solar battery storage is a system that stores excess electricity generated by solar panels for later use. Instead of sending unused solar energy back to the grid, a battery system captures and saves it, allowing homeowners to access stored power in the evening or on cloudy days.

Battery storage is rapidly growing in popularity as more homeowners and businesses seek energy security and sustainability. According to the latest analysis from SolarPower Europe, Europe installed 17.2 GWh of new battery energy storage systems in 2023—an increase of 94% compared to 2022. This marks the third consecutive year of doubling the annual market, highlighting the rising demand for battery storage solutions.

Is Solar Battery Storage Really Worth The Investment?

Solar battery storage is becoming an increasingly popular solution for homeowners and businesses seeking energy independence and sustainability. It offers several advantages, especially when combined with solar panels. Here are some of the main benefits of battery storage:

Maximising Energy Efficiency

With solar battery storage, excess solar energy produced during the day can be stored for use at night or during periods of low sunlight. This maximises the efficiency of solar power systems, ensuring that energy is not wasted. According to a report by National Energy Action, energy storage can increase the self-consumption rate of solar systems from around 20 to 30% to over 70% with a 6kWh battery.

Reducing Electricity Bills

One of the primary benefits of solar battery storage is the potential for significant savings on electricity bills. By storing excess solar energy, homeowners can rely less on the grid, which often involves high utility rates that continue to rise. Homeowners could save up to £796 per year on their energy bills by installing a battery storage system in their homes.

Energy Independence and Resilience

Solar battery storage allows for greater energy independence, offering significant benefits during power outages or emergencies. In situations where the grid fails due to storms or other disruptions, homeowners with solar battery systems can continue to power essential appliances. This energy storage solution ensures that, even during times of grid instability, homeowners have a reliable backup power supply, providing peace of mind and enhanced resilience.

Lower Environmental Impact

Storing solar energy helps homeowners reduce their carbon footprint and support environmental sustainability. According to the Energy Savings Trust, even the average residential solar project can save over a tonne of carbon emissions every year. That's the equivalent of driving 3,600 miles, or from London to Bristol 30 times. 

Types of Solar Battery Storage Systems

There are two main types of solar batteries commonly used for home solar systems: lead-acid and lithium-ion. Each of these battery types has distinct advantages and drawbacks, depending on factors like cost, lifespan, and energy storage capacity.

Lead-acid batteries

Lead-acid batteries are one of the oldest and most affordable options for solar energy storage. They come in two types: flooded (wet) and sealed (AGM or GEL). While they are less efficient and have a shorter lifespan compared to other batteries, they are still used by some homeowners due to their lower initial cost.

Key Features:

• Lower upfront cost
• Shorter lifespan (3-7 years)
• Lower efficiency (around 80%)
• Requires more maintenance for flooded types

Lithium-Ion Batteries

Lithium-ion batteries are the most popular choice for home solar installations, known for their high energy density, long lifespan, and fast charging times. These batteries, used by Upvolt, offer superior efficiency, lasting 10-15 years with minimal maintenance.

Key Features:

• High efficiency (up to 95%)
• Long lifespan (10-15 years)
• Low maintenance
• Fast charging and discharging

How Can Battery Storage Supercharge Your Solar Savings?

Battery storage systems play an important role in maximising the efficiency of solar energy systems. Here’s a breakdown of how battery storage works in a solar panel system:

Energy Generation from Solar Panels

When sunlight hits the solar panels, the photovoltaic (PV) cells within the panels convert the sunlight into direct current (DC) electricity. This electricity is then sent to an inverter, which converts it into alternating current (AC) electricity, the type of power typically used in homes. While solar generation in the UK may not be as intense as in sunnier climates, modern panels are highly efficient even in cloudy conditions.

Storing Excess Energy

During the day, solar panels often generate more energy than a household needs, especially when the sun is at its peak. Instead of sending this excess energy back to the grid, a battery storage system captures and stores the surplus electricity. The energy is stored as DC power within the battery, waiting to be used later. 

Alternatively, homeowners can choose to export excess energy back to the grid via the Smart Export Guarantee (SEG) for compensation, though many prefer storing energy to use later during peak hours.

Energy Use from Battery Storage

When the sun goes down or when there is not enough sunlight, the stored energy in the battery is converted back to AC electricity by an inverter. This stored electricity can then be used to power the home’s electrical devices, reducing reliance on grid electricity, especially during times of peak demand when utility rates are higher.

Grid Interaction (Optional)

In many solar battery storage systems, the battery is integrated with the grid. This means that if the battery runs out of stored energy, the system can automatically switch to grid power. Conversely, if the battery is fully charged and there’s still excess solar power being generated, it can feed this excess back into the grid, with compensation from the SEG. This option offers flexibility for homeowners to earn from surplus solar energy. 

SEG rates can range from 3p to over 20p per kilowatt-hour (kWh). For instance, E.ON's Next Export Exclusive tariff offers 16.5p per kWh, while British Gas provides 15.1p per kWh. 

A typical 3.5kW solar panel system in the UK generates approximately 3,000 to 3,500 kWh annually. Depending on household consumption, you might export around 1,000 to 1,500 kWh of this energy. At a rate of 15p per kWh, this equates to an additional income of £150 to £225 per year. 

Smart Monitoring and Management

Modern battery storage systems often include smart technology that allows homeowners to monitor energy production, storage levels, and usage patterns in real-time. With UpVolt's Skygate™ platform, homeowners gain full digital oversight of their system's performance. Through the Skygate™ app, users can monitor and control their entire energy setup from anywhere, providing live insights into energy flows within the home. 

While Skygate™ gives users complete control, it also works automatically in the background to optimise energy consumption. It prioritises solar energy, storing excess power in the battery or charging an electric vehicle when solar production is at its peak. 

It allows homeowners to instruct their battery to charge from the grid during off-peak hours when electricity prices are lower. This stored energy can then be used the next morning to power the home, helping to minimise costs and reliance on grid power during peak demand times.

Ready to Maximise Your Solar Savings?

Solar battery storage helps homeowners make the most of the solar energy they generate, reducing reliance on the grid and lowering energy bills. By storing excess energy, homeowners can ensure they have power available during periods of low sunlight or peak demand, all while minimising costs. 

With smart monitoring systems like UpVolt’s Skygate™, users can track their energy production, optimise consumption, and make informed decisions about when to store or use energy. The platform allows for charging during off-peak hours when electricity prices are lower and ensures efficient use of stored solar energy. This system enhances energy independence and provides reliable backup power during outages, offering peace of mind and greater control over your home’s energy usage.

About Upvolt

At Upvolt, we offer high-performance lithium iron phosphate (LFP) batteries that are designed to provide reliable and long-lasting energy storage. Our LFP batteries are scalable, with sizes ranging from 5kWh to suit the specific needs of your home. These batteries come with up to a 15-year performance warranty, ensuring peace of mind for years to come.

We pride ourselves on using the highest quality batteries sourced from leading global manufacturers, ensuring that you benefit from the latest technological standards and the best charge and discharge rates available. Our expert team handles every step of the process, from planning and installation to commissioning and ongoing maintenance, ensuring your battery storage system is set up to perform at its best.

By integrating these advanced battery storage solutions with our innovative Skygateâ„¢ platform, you can further optimise energy usage, all while monitoring and managing your system through a single intuitive app.

Ready to maximise your energy efficiency? Contact us today for a free quote and let Upvolt’s experts design the perfect battery storage solution for your home.

FAQs

How do solar batteries work?

Solar batteries store the excess energy produced by your solar panels during the day, so you can use it at night or during times when the sun isn’t shining. When the solar panels generate more power than your home needs, the surplus energy is stored in the battery. When your solar panels aren't generating power, such as at night or on cloudy days, the battery supplies energy to power your home.

What happens when my solar battery is full?

When your solar battery reaches full charge, excess energy is typically sent back to the grid (if you’re connected to one) or is redirected to the home’s consumption, depending on your system setup and local regulations. Some systems allow you to store only a certain amount of energy, so after reaching full charge, no further energy will be stored until it’s used.

How much battery storage do I need to run my home entirely on solar power? 

The amount of battery storage needed depends on your home’s energy consumption and the size of your solar panel system. On average, a home may need anywhere from 10 kWh to 20 kWh of battery storage to meet daily energy needs. You should have a professional assess your energy usage and recommend the proper battery size.

How much does a solar battery storage system cost?

The cost of a solar battery storage system in the UK can vary based on factors such as the brand, capacity, size of the system, and installation requirements. On average, solar battery storage systems in the UK range from £4,000 to £10,000 or more, including installation. The price typically covers the cost of the battery itself, electrical components, and labour. 

Alex Lomax

CEO & Co-Founder

Share article

• 
• 
•