Store excess power
Offset peak usage
Less carbon contribution

If your solar system generates more than you consume, the surplus is normally given to the grid. Store the extra power in a battery system, and use it when you would normally draw it from your supplier - just like how a water butt works. 

Use a smart battery system with Octopus Energy to use the batteries power during peak times. This technology gives functionality all year round, regardless of weather conditions and reduces electricity bills even more!

Further reduce your reliance on the grid, consume less carbon contributed power and make the most from your PV system. Batteries can be wired to function as an emergency power supply so power cuts are a thing of the past. 


K Cahill Renewables and Octopus Energy are working together to provide homes and businesses across the UK with fairly priced energy storage options, and cutting edge technology. Our battery systems work perfectly with the Octopus Agile tariff. 

Whenever more electricity is generated than consumed, energy prices fall – sometimes below zero. Agile Octopus introduces Plunge Pricing – a world first that lets you take advantage of these negative price events, and get paid for the electricity you use.

With Octopus Agile, you get access to half-hourly energy prices, tied to wholesale prices and updated daily. So when wholesale prices drop, so do your bills – and if you can shift your daily electricity use outside of peak times, you can save even more.

It's easy! Simply shift your usage, or use a battery between 4PM to 7PM. Then nearly always pay below the national average for power. 




If you can supply a quote for the same equipment, being fitted by a fully MCS accredited engineer, we will match the price.

Battery FAQs

How long do the batteries last?

This is dependant on your usage. The battery systems are modular, so you can customise the size of the system to your needs. You can also add in more cells at a later date. Feel free to book in a no obligation survey so your property can be assessed in greater detail

Do battery systems require maintenance?

In short, no. A battery storage system is typically made up of two main components, the battery cells and the battery management unit. The battery cells are consumable, designed to wear out and need replacing, just like the battery in your phone. We use lithium-ion cells now which are the industry standard. Both the cells and management unit are covered by a 10 year guarantee supplied by the manufacturer. We also provide an insurance backed guarantee as standard for added peace of mind.

What is the Octopus Agile tariff?

Octopus is a supplier that offer a tariff suited best to properties with batteries installed. Instead of charging customers one rate 24/7, you are charged a different rate every half an hour. It's expensive when demand is big (4pm-7pm), but cheaper the other 21 hours of the day. If you use a battery system to offset that period of 'expensive' usage, you're almost always paying under what the big 6 suppliers would charge. It also gives batteries a functionality all year round. For more information see

Will the battery work with Octopus Agile?

Yes, all battery systems we install are compatible with the Octopus Agile tariff. Our fitters and company are MCS accredited, meaning we can provide all necessary paperwork.

What is a hybrid battery system?

In simple terms, it's an inverter and battery management system, merged into one. We often see batteries retrofitted to systems with existing functional inverters, in most instances it's more cost effective to leave this in place and add a standalone battery management system. In new installations, it is often the contrary. We can install both hybrid and retrofitted battery systems to new and existing PV installations. For more information and a quote, book a survey using the form below.


Arrange a free-of-charge, no obligation consultation with one of our trained engineers. From health checks to new install surveys, you have experts at your disposal. Use the form and we'll be in touch. Or if you prefer to speak to someone, drop us a call on 01206 646664


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