Solar & Battery Storage

Why Solar Panels?

Solar panels harness the power of the sun, allowing you to generate renewable electricity from the comfort of your home. This generated electricity will be free and an average sized system will abate as much CO2 every year as approximately 250 trees.1

Why Batteries?

Adding a battery to your solar panels is a great way to maximise their benefits. As we can’t choose when the sun shines, the majority of people export more than 50% of their generated electricity back to the grid.2 With a battery, you can store this electricity until you need it, allowing you to use more of your solar power.

On most energy tariffs, you’ll pay a fixed price per unit of electricity that you use, no matter the time of day. However, due to fluctuations in electricity demand and the amount of wind or sun, the wholesale price of electricity changes every half hour.

In the future, with smart meters, battery storage and a variable rate tariff, you’ll be able to charge the battery during cheaper periods and discharge during expensive periods. We will then be able to pass these savings on to you, helping reduce your bills and the carbon emissions of the grid.

Our Expertise

As global leaders in renewable generation, we’ve successfully installed over 20GW of solar capacity worldwide, that’s approximately 63 million solar panels. This includes our beautiful new development in Walton, where strategically placed solar panels provide renewable energy to the whole community. We’ve got experience with batteries as well; we’ve been busy retrofitting batteries to homes with existing Solar.

Our Integrity

Just like our Rate Rollover Promise, we like to keep honesty and integrity at the forefront of everything we do. Our calculations will be tailored to you and will provide honest forecasts on your expected savings. Not everyone has a south facing, unshaded roof in Southern England! We know that solar panels and batteries are a big investment and believe that you should have all the facts to inform your decision.

Our personal touch

We always go the extra mile and will base our bespoke solutions using your personal requirements. We know that all of our homes are unique and require an individual solution. We pride ourselves on our customer experience and can’t wait to join you on your journey.

Storage Solutions. Simplified.

There’s a lot of confusion around battery storage, but the concept is rather simple.

It’s very rare that we use items as soon as we’re given them; we store our money in banks, our water in cups and our food in a fridge. Storage is not a new concept, so why do we let our hard earned solar power trickle back to the grid?

With our storage solutions, we will personally handle all the intricacies, ensuring the system is right for you. This means that all you need to focus on is the visible benefits; capitalising on your solar panels and reducing your bills.

That said, if you are interested in a more detailed explanation of this impressive technology, keep reading!

Solar & Storage. Explained.

Even if you don’t have solar panels, you will have been using the sun’s energy your whole life, as it is the primary source of virtually all the energy found on earth. Solar panels just allow us harness this energy directly.

Over the last decade, the popularity of solar photovoltaics has increased exponentially, with UK capacity rising from 0.031GW to 13GW.3 It has transitioned from a niche technology to an established force in electricity production, generating renewable energy in the fight against climate change.

The science behind solar photovoltaic generation is also interesting and is described by the photoelectric effect. This effect was first recorded in 1839 by Edmund Bequerel who discovered that some materials generated a current when exposed to light. Although the technology has improved since then, the premise is still the same, as an electric current is produced when light photons displace electrons in a material.

Modern Solar PV panels consist of a photovoltaic material sandwiched between two semi-conductive materials. When the incident sunlight hits the panels, the semi-conductive materials energise, producing a direct current. This direct current is then passed through an inverter, where it is converted to alternating current, exactly the same as you draw from the grid. This electricity can then be used to power your appliances, or stored in a battery for later use.

Unsurprisingly, the sun also has the ability to heat water, with some research currently focussing on improving hybrid photovoltaic-thermal (PVT) systems. If technological advancements enable PVT systems to heat water to over 60°, they could become an interesting and competitive solution, electrifying and heating our homes of the future.4

However PVT systems aren’t currently capable of high temperature water production and unless you have a swimming pool, they probably aren’t worth considering just yet. Batteries on the other hand are a perfect match for existing solar installations.

A battery works by storing electrical energy in the form of chemical energy, which can then be converted to electricity. They consist of two terminals, an anode and a cathode, separated by an electrolyte. Whilst the battery is charging, the electrons flow from the cathode to the anode, and whilst discharging they flow in the opposite direction. This causes a current, allowing you to use your solar energy when you need it, instead of when it’s generated.

Although batteries can be manufactured from a large range of materials, we are advocates of lithium iron phosphate (LiFePO4) batteries. At ENGIE, we put safety and sustainability at the forefront of everything that we do, and as LiFePO4 batteries are non-toxic, incombustible and don’t contain rare metals, they are a great option. Furthermore, with the ability to charge and discharge quickly, they are well suited for domestic storage. With it’s succinct and subtle design, our batteries are easily integrable to your house and can either be a focal point or tucked out of the way.

As a battery retrofit will not impact your Feed in Tariff or Export Tariff, there’s never been a better time to invest. Our solar and storage solutions are coming soon and we can’t wait to join you on your journey.


1 Grid electricity carbon intensity (2018) = 0.28088kgC02/kWh. [UK Government GHG Conversion Factors for Company Reporting, BEIS,]

Mean PV lifecycle emissions = 0.088kgC02e/kWh [Carbon Footprint of Electricity Generation, Parliament,]

Average rooftop PV size (2010-2018) = 2.87kW [Solar Photovoltaics deployment in the UK, BEIS,]

UK PV load factor (2011-2017) = 10% [FiT Load Factors, BEIS,]

1 tree absorbs 2kg CO2 each year [Mitigation: planting more trees, Forestry Comission,$FILE/6_planting_more_trees.pdf]

Average Rooftop PV generation = 2.87 x 24 x 365 x 0.1 = 2514.14kWh. Abated C02 = 2514.14 x (0.28088 – 0.088) = 484kg. Number of trees = 484/2 = 242

2 [Quantifying self-consumption linked to solar home battery systems: Statistical analysis and economic assessment, Quoilin et al,]

3 [Solar photovoltaics deployment, BEIS,]

4 [Roadmap for the next-generation of hybrid photovoltaic-thermal solar energy collectors, Mellor et al-  Solar Energy, Vol 174, pgs 386-398, 2018,]