Battery Storage for Solar Panels

Why install battery storage?

• Grid independence: meet 70% or 80% of your annual electricity load with solar + storage.
• Solar PV battery storage stores excess solar for later use.
• Buy electricity cheap, use it peak: reduce your bill - there are savings of up to 20p per kWh to be made with Green Energy TIDE tariff or with Economy 7. Read more on our recent blog.
• Back-up in a power cut: emergency lighting / power (optional).
• Protect against rising electricity prices.
• Reduce your carbon footprint.
• Get paid to provide grid balancing services (> 50kW).
• Off-grid solutions.

The best solar power storage systems

The best all round residential solar storage product on the market is the Tesla Powerwall 2, a single unit system with a 5kW charger (7kW peak) and 13.5kWh of storage capacity. We are Tesla Powerwall Certified Installers.

We recommend the Powerwall 2 for several reasons:

• Design and efficiency.
• High capacity (13.5kWh) and high power output (5kW) - the best on the market, ideal for back-up, buying electricity cheap (e.g. Economy 7) and using peak, and storing surplus solar.
• Quality control and safety.
• 10 year warranty.
• Lowest lifetime cost per kWh.
• Beautiful design, wall hung or ground-mounted, and weather-proof.
• Offers off-peak charging (buy cheap, use peak) as well as storage of excess solar.
• Offers back-up from Q2 2019.

Is the Powerwall 2 for you?  Download our guide to find  out:

Sometimes our customers are looking for solar PV battery storage with less capacity, or bespoke, with increased UPS capability. As well as Tesla, we offer customised Victron based systems (ideal for off-grid), with a range of batteries including BYD, Simpli-Phi, and LG Chem.

If you would like to learn more about back-up functionality, click here or download our Guide to Residential Battery Back-Up:

Guide to Residential Battery Back-Up - is back-up worth paying for and how much will it cost?

SolarEdge also provides a product called StorEdge, directly compatible with SolarEdge solar systems and indirectly with any solar PV system using an additional inverter.

The economic case for solar power storage

In economic terms, with the correctly sized system, the lifetime cost per kWh of stored electricity is below the average domestic grid cost of around 16p per kWh, and well below the average expected cost over the life of a typical system of around 25p – 30p per kWh. Storage now makes sense.

How much will battery storage for solar panels cost?

The installed cost of Tesla Powerwall 2 is around £7,000 + VAT.  Storage capacity is around 13.5kWh and so this gives a cost of around £520 + VAT per kWh. 

This is about as competitive as it gets … on a cost per kWh basis, pretty much every other system will be a similar cost or more expensive. Note that in general  lithium ferro phosphate (LFP) – in other words Sonnenbatterie and Simpli-Phi – is more expensive than lithium manganese cobalt (NCM) – in other words Tesla and LG Chem.  But the LFP batteries offer 10,000 life cycles (25 – 30 years on most usage cycles) as opposed to 15 years.

Why choose Spirit?

We’re experts in battery storage systems. We’re also passionate about the technology and excited by the tremendous potential it offers to transform the way in which electricity is generated and distributed. We are technology agnostic; we continuously analyse the batteries and chargers available on the market to ensure we are offering our customers best-in-class technology.

It is very important that residential solar storage systems are sized to the time analysed loads of the property. Solar PV battery storage needs to be sized to take account of variability in solar output. We use in-house software to model both the electrical load and the charging and discharging behaviour of a battery system working in combination with solar PV. We will design a battery storage system, with or without PV, to minimise the lifetime cost per kWh of stored electricity. We recommend a home energy monitor / smart meter is installed to monitor the loads prior to sizing the system – click here for more information.

We have designed systems for back-up and off-grid applications and we are well aware of and compliant with the standards applying to power systems for essential services.

We don’t employ pushy salesmen – just technical people, passionate about energy efficiency - who will provide you with a system combining technical excellence and value for money. With systems typically lasting 15 - 20 years, we are here to support you and your system over the long term.

All projects are managed in house and installed by our solar panel installers. 

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Call us on 0118 951 4490, request a quote online, or email your requirements to residential@spiritenergy.co.uk.  We would love to talk about your project; there is no charge for an initial consultation or quote.