Fox ESS Solar Installation in Sevenoaks, Kent (TN13)
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What does a modern home energy system look like when solar panels, battery storage, EV charging and backup power are designed to work together?
This recently completed Sunbright Energy installation in Sevenoaks, Kent, TN13 is a great example.
At first glance, the property has a relatively modest 3.72kW solar array comprising eight Aiko solar panels. But solar generation is only one part of the system.
We’ve also installed a Fox ESS KH 10kW hybrid inverter, 7x Fox ESS CQ7 batteries providing 49.14kWh of battery storage, a Fox ESS EV charger and a Fox ESS EPS backup system.
Together, they create a much more complete approach to home energy: generating electricity when the sun is shining, storing energy for later, taking advantage of cheaper electricity periods, charging an EV and providing backup capability if the grid goes down.
Let’s dive into this full project:
System Size
Solar Generation
Total Savings
The Sevenoaks Installation at a Glance
Location: Sevenoaks, Kent, TN13
Solar Array Size: 3.72kW
Solar panels: 8 × Aiko Neostar 2S 465W
Inverter: Fox ESS KH 10kW Hybrid
Expected Annual Generation: 3,431kkWh
Annual Electricity Consumption: 8,000kWh
Estimated Payback: 7 years
This installation in Sevenoaks is one we already installed solar panels on a few years ago. But having been thrilled with their previous results, the homeowner asked us to return to install more solar panels, batteries, and more at their property, so they could cut even more off of their energy bill.
This case study focuses on the additional system components we installed in 2026.
The System in Sevenoaks
8 Aiko Solar Panels Generating an Estimated 3,431kWh a Year
The solar side of the installation consists of eight Aiko Neostar 2S 465W All Black ABC N-Type Mono panels, giving the property a total array size of:
3.72kW
Based on the detailed modelling carried out for the property, the system is expected to generate approximately:
3,431kWh of electricity per year.
That projection isn’t simply based on multiplying the output of the panels. Factors including the property’s location, panel orientation and potential shading have all been considered when estimating annual performance.
An important point here is that this isn’t an enormous solar array.
What makes this installation particularly interesting is how the electricity is managed once it has been generated, alongside how the battery system can interact with cheaper grid electricity.
49.14kWh of Fox ESS Battery Storage
Alongside the solar panels, we installed 7x Fox ESS CQ7 batteries, providing approximately:
49.14kWh of total battery storage.
That’s a substantial amount of storage for a residential property.
The basic purpose of a solar battery is straightforward. When the panels generate more electricity than the property needs at that moment, available surplus can be stored in the battery rather than immediately exported.
That electricity can then be used later, such as during the evening when the solar panels are producing little or nothing.
At Sunbright Energy, Fox ESS are always our go to inverter & battery brand thanks to their reliability, high efficiency and fantastic customer service.
Sunbright Energy are also the only Fox ESS Approved Installer in Kent.
Thinking about FOX ESS FOR YOUR PROPERTY?
Sunbright Energy are the only Fox ESS Approved Partner in Kent
Where Will the Home’s Electricity Come From?
The property is expected to consume approximately:
8,000kWh per year.
The detailed annual model predicts that this consumption could be supplied by:
1,827kWh directly from solar
4,796kWh from battery storage
1,377kWh directly from the grid
In other words, around 83% of annual electricity consumption is modelled as being supplied either directly by the solar panels or through the battery, with around 17% coming directly from the grid.
There is an important distinction here.
That doesn’t mean 83% of the home’s electricity originates from its solar panels.
Because the CQ7 batteries can also be charged from the grid during cheaper periods, some of the electricity later supplied by the batteries originally came from the grid.
The goal isn’t necessarily to avoid the grid completely.
It’s to use solar, storage and cheaper grid electricity more intelligently so that the property can reduce its overall energy costs.
A Fox ESS KH 10kW Hybrid Inverter at the Centre of the System
Sitting at the centre of the solar and battery installation is a Fox ESS KH 10kW single-phase hybrid inverter.
The inverter converts the DC electricity generated by the solar panels into AC electricity that can be used around the property while also enabling the integration of the battery system.
The KH range is designed for larger single-phase requirements and works particularly well for installations where substantial battery storage is required.
We’ve previously covered the KH alongside the rest of the Fox range in our Fox ESS inverter guide, where we explain why choosing an inverter isn’t simply about picking the model with the largest power rating.
It’s about designing the inverter, solar array and battery system around what the property actually needs.
Adding a Fox ESS EV Charger
The property also has a Fox ESS EV charger, bringing another major household energy demand into the wider system.
For homeowners with an electric vehicle, charging can represent a significant proportion of household electricity consumption.
The ability to think about EV charging alongside solar generation, battery storage and cheaper tariff periods can therefore make a major difference to the overall energy strategy.
Fox EV chargers offer features including solar-linked charging, scheduled charging and dynamic load management, making them a natural addition for homeowners already using Fox ESS equipment.
It’s one of the reasons we like using Fox across the wider system rather than treating the inverter, batteries and EV charger as completely separate products.
If you’re currently researching EV charging, we’ve also put together a full guide to Fox ESS EV chargers, including the differences between the A Series and L Series and which type of property each may suit.
What Happens During a Power Cut?
This Sevenoaks installation goes another step further with the addition of a Fox ESS EPS backup system.
EPS stands for Emergency Power Supply.
There’s an important misconception around solar and batteries that is worth addressing here.
Having solar panels and a battery doesn’t automatically mean your property will continue operating normally during a power cut. For safety reasons, a conventional grid-connected solar installation will normally stop supplying power when the grid goes down.
Backup power needs to be specifically designed into the system.
The EPS equipment installed at this Sevenoaks property provides backup capability to the appropriately configured household loads, subject to the system design and the amount of energy available in the batteries at the time.
With 49.14kWh of battery capacity, the homeowner has a substantial energy reserve available, although actual backup duration will always depend on how much charge is available and how much electricity the property is consuming.
This adds something that reducing electricity bills alone cannot provide: greater energy resilience.
How Much Could the System Save?
Before the installation, the financial model assumes the homeowner was paying a flat electricity rate of approximately:
31.5p/kWh
With annual consumption of 8,000kWh, that creates a modelled annual electricity bill of:
£2,520
The new system has been modelled around moving to a variable tariff with electricity rates ranging from approximately 7p to 28p per kWh.
Based on those assumptions, solar generation and battery storage are predicted to reduce the annual electricity bill to approximately:
£1,068
That’s an initial projected saving of:
£1,452 per year
But the modelling doesn’t stop there.
By using the batteries to take advantage of cheaper electricity periods, additional battery-management savings are estimated at up to £767 per year.
That brings the modelled effective electricity cost down to approximately:
£300 in the first year
That’s a significant reduction, but it’s important to treat these figures as projections rather than guaranteed savings.
Actual results will depend on electricity tariffs, future energy prices, household consumption, battery behaviour, solar generation and how the system is operated.
If you want an estimate of how much your home could be saving with solar panels, enter your postcode and get a tailored savings estimate in 60 seconds:
7-Year Estimated Payback and £110,452 Projected Savings
Looking beyond the first year, the financial modelling estimates:
An approximate 7-year payback period
and:
£110,452 in total projected savings over 25 years.
Again, these are long-term projections based on assumptions about factors such as energy prices, generation, consumption and system performance.
What’s particularly interesting about this project is where those savings potentially come from.
It isn’t solar generation alone.
The financial case combines solar self-consumption, battery storage and time-of-use energy management to reduce the cost of powering the home.
Reducing CO₂ Emissions by an Estimated 706kg a Year
Alongside the potential financial savings, the solar installation is expected to reduce carbon emissions by approximately:
706kg of CO₂ every year.
According to the project modelling, that’s equivalent to approximately 2,520 miles travelled by car or the amount of CO₂ absorbed by around 32 trees.
Over the lifetime of the system, generating more electricity from solar can therefore deliver a significant environmental benefit alongside the financial savings.
What This Sevenoaks Installation Demonstrates
This project combines:
- 8 Aiko solar panels
- 3.72kW of solar capacity
- A Fox ESS KH 10kW hybrid inverter
- 7 Fox ESS CQ7 batteries
- 49.14kWh of battery storage
- Fox ESS EV charging
- Fox ESS EPS backup
- Smart tariff and battery optimisation
Rather than looking at solar panels, batteries and EV charging as separate upgrades, this homeowner has taken a much more joined-up approach.
It’s a great example of how a modern, energy-efficient home can generate electricity, store energy, optimise when electricity is purchased, charge an EV and provide additional resilience during power outages.
Considering a Complete Home Energy System in Kent?
Sunbright Energy is the only Fox ESS Approved Partner in Kent, and Fox is our go-to brand for batteries, inverters and EV charging thanks to the combination of reliability, efficiency, flexibility and cost-effectiveness we’ve experienced across our installations.
But that doesn’t mean every home needs four batteries, a 10kW inverter or every piece of equipment used on this Sevenoaks project.
The right system depends on your property.
If you’re a homeowner in Sevenoaks, Kent or the surrounding South East and you’re considering solar panels, battery storage, an EV charger or backup power, our team can design a system around your electricity consumption, property and long-term goals.
Thinking about solar panels FOR YOUR HOME?
Get in contact with Sunbright Energy today
Meet The Owner
Oliver Crouch – Director
“I’m Oliver, the Director of Sunbright Energy. We’re a local, family-run business in the solar industry, which I’ve proudly led since its founding in 2014.
As a family business, we value personal connections and community. We’re driven to treat every customer with the respect and attention they deserve. Don’t hesitate to start your solar journey today – get in touch with Sunbright Energy for a service you can trust.”
FAQs
Can solar panels, battery storage and an EV charger all work together?
Yes. A correctly designed home energy system can integrate solar generation, battery storage and EV charging while continuing to use grid electricity when required. Keeping these technologies within a compatible ecosystem can also make it easier to manage how electricity moves around the home.
How much battery storage does a typical UK home need?
There is no single correct battery size. The right capacity depends on factors including annual electricity consumption, solar generation, electricity tariffs, EV charging and whether backup power is required. The 46.1kWh installed at this Sevenoaks property is substantially larger than many domestic battery systems because it forms part of a wider energy-management and backup strategy.
Can Fox ESS batteries charge from the grid when electricity is cheaper?
With a suitable tariff and correctly configured compatible system, Fox ESS batteries can be scheduled to charge during lower-cost electricity periods. That stored electricity can then be used later, potentially reducing the amount of electricity purchased at higher rates.
Will solar panels and a battery keep my home powered during a power cut?
Not automatically. Standard grid-connected solar installations normally shut down during a grid outage for safety reasons. Backup power requires appropriately designed equipment, such as an EPS solution, with the relevant circuits or loads configured for backup operation. Available backup time also depends on battery charge and household electricity demand.
Is a complete Fox ESS home energy system worth it?
It can be a strong option for homeowners who want solar generation, battery storage, EV charging and energy management to work together. However, the right equipment and battery capacity should be based on the individual property. For this Sevenoaks installation, the complete system has a modelled seven-year payback and projected £110,452 in savings over 25 years, but actual results will depend on future tariffs, consumption, generation and system performance.
