Case study · Domestic · Scottish Borders

Scottish Borders: 10kWh libbi battery retrofit & zappi EV integration.

A 2013 3kWp solar PV system brought into a modern connected energy setup — myenergi libbi storage plus existing zappi EV charging, controlled through a single app. No grid electricity use for the property during summer.

Sector: Domestic
Solar PV: 3kWp
Storage: 10kWh
DNO: G98

Overview

Eastern Electric upgraded an existing domestic solar PV system in the Scottish Borders by adding battery storage and smart EV charging integration.

The original 3kWp system — 12 × Sanyo 250W panels with an SMA Sunny Boy 3kW inverter — had been installed in 2013 and had performed reliably for over a decade. More recently the client had introduced an electric vehicle and installed a myenergi zappi EV charger to make better use of solar generation.

The aim of the project was to modernise the existing setup by adding battery storage, improving self-consumption, reducing grid reliance, and bringing the solar PV, battery storage and EV charging into one connected energy system.

myenergi libbi 10kWh battery installed in the garage — 10kWh myenergi libbi battery installed in the garage adjacent to the property.

The challenge

The existing solar PV system was still performing well, but the way the household used energy had changed since the original installation. The introduction of an electric vehicle created a new opportunity to use more solar electricity on site. Without battery storage, surplus daytime generation could still be exported at times when the home or vehicle was not using it — leaving value on the table for a system that had already been performing for over ten years.

• Maximise use of the existing solar PV generation
• Reduce reliance on grid electricity, particularly at peak
• Integrate EV charging with solar generation
• Extend the value of a 2013 solar PV system

The solution

Eastern Electric designed and installed a 10kWh myenergi libbi battery storage system to complement the existing solar PV and EV charging setup. The battery was installed in the garage adjacent to the property — a clean and practical location. The system was configured to work alongside the existing myenergi zappi EV charger, allowing the client to manage solar generation, battery storage and EV charging through a single myenergi ecosystem.

• Captures excess daytime solar for use later in the day
• Reduces evening and peak-rate grid import
• Enables off-peak charging for lower winter costs
• One platform for PV, battery and EV

Original SMA Sunny Boy 3kW inverter in the loft space — The original 2013 SMA Sunny Boy 3kW inverter — still going strong and retained in the retrofit.

Technical specification

Existing solar PV capacity	3kWp
Solar panels	12 × Sanyo 250W
Solar inverter	SMA Sunny Boy 3kW
Battery system	myenergi libbi
Battery capacity	10kWh
EV charger	myenergi zappi
Mounting type	Roof-mounted solar PV
Battery location	Garage adjacent to the property
Supply type	Single-phase
DNO application	G98
Immersion diverter	Not included
Monitoring platform	myenergi app / ecosystem

The result

Summer

No grid use

for the property

Winter

Off-peak

charging cuts cost

System age

12+ yrs

original PV extended

During summer, the client has achieved no grid electricity usage for the property, with the solar PV, battery storage and smart controls working together to maximise self-consumption. In winter, off-peak charging keeps costs down when solar generation is naturally lower.

Why this matters

This project demonstrates how older solar PV systems can be upgraded with modern battery storage and smart EV charging technology. For many homeowners with early solar PV installations, a battery retrofit can significantly improve the value of the original system — increasing self-consumption, cutting grid import, and pulling PV, battery and EV into a single connected setup.

Key benefits

2013 solar PV system upgraded with modern battery storage
10kWh myenergi libbi battery installed
Existing myenergi zappi EV charger integrated
Improved self-consumption of solar generation
Reduced reliance on grid electricity
Off-peak charging available for winter cost reduction
Single-app control through the myenergi platform
Practical retrofit solution with minimal disruption

Got an older solar PV system? We'll retrofit it.

Battery storage, EV charging and myenergi integration to modernise an existing solar install — designed and fitted by our own engineers across Scotland.

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