Are Batteries Worth It Without Solar?

Full Installation Walkthrough

This tutorial video tackles one of the most frequently asked questions in the home energy space: can you save money with a battery storage system even if you do not have solar panels? The answer, as we demonstrate in this video featuring a Fox Cube 11.52kWh battery-only installation, is a resounding yes, provided you are on the right electricity tariff and the system is configured correctly.

The concept behind battery-only storage is elegantly simple. Time-of-use electricity tariffs such as Octopus Go, Intelligent Octopus Go and Octopus Cosy offer significantly cheaper electricity during overnight off-peak periods, typically from midnight to five or six in the morning. During these hours, electricity can cost as little as seven pence per kilowatt-hour, compared to the standard daytime rate of thirty pence or more. A home battery charges during the cheap overnight window and then discharges during the day and evening when you would otherwise be paying the full rate.

The financial calculation is straightforward. If you charge 11.52kWh overnight at seven pence per kilowatt-hour, the electricity costs approximately eighty pence. If you then use that 11.52kWh during the day and evening instead of importing at thirty pence per kilowatt-hour, you avoid spending approximately three pounds forty-five pence on grid electricity. The daily saving is approximately two pounds sixty-five pence, which over a full year amounts to savings of nearly one thousand pounds.

For this particular installation, the homeowner did not have suitable roof space for solar panels but was determined to reduce their electricity bills. After discussing the battery-only option and running through the financial projections using their actual consumption data, they decided to proceed with a Fox Cube 11.52kWh battery paired with a Fox hybrid inverter configured in battery-only mode without any solar input.

The installation was straightforward compared to a full solar and battery project. Without the need for roof work, scaffolding or DC solar wiring, the entire installation was completed in a single day. The Fox hybrid inverter was mounted on the garage wall alongside the two Fox Cube battery modules that together provide the 11.52kWh total storage capacity. The inverter was connected to the consumer unit through a dedicated circuit, and the CT clamp was installed on the main supply cable to monitor the household energy flow.

The key to making a battery-only system work financially is the inverter configuration. We programmed the Fox inverter with a charging window from midnight to five in the morning during which it draws cheap grid electricity to charge the battery to one hundred percent. During the rest of the day, the inverter discharges the battery to supply the household loads, only allowing grid import when the battery reaches its minimum reserve level. The discharge schedule is aligned with the tariff peak rate period to maximise the financial benefit of every stored kilowatt-hour.

We also configured the system to hold a small reserve of approximately ten percent at all times, ensuring the battery is never fully depleted. This reserve protects the battery cells from deep discharge stress and provides a small buffer for unexpected consumption spikes during the discharge period.

The Fox Cloud monitoring platform provides the homeowner with complete visibility of the system operation, showing the overnight charging cycles, daytime discharge, and the cumulative savings calculated from the difference between the cheap import rate and the standard rate that would otherwise have been paid. After the first month of operation, the monitoring data confirmed that the actual savings closely matched our pre-installation projections.

There are some important caveats that we always discuss with customers considering a battery-only installation. First, you must be on a time-of-use tariff for the savings to materialise. If you are on a flat-rate tariff with the same price all day, a battery-only system will not save you any money because there is no price differential to exploit. Second, the savings are dependent on the differential between the cheap and peak rates, which can change when the tariff provider adjusts their pricing. Third, battery systems have a finite lifespan measured in charge-discharge cycles, so the economics need to account for eventual battery replacement.

Despite these caveats, the financial case for battery-only storage is strong under current tariff conditions. The Fox Cube battery is rated for over six thousand charge-discharge cycles, which at one cycle per day equates to over sixteen years of operation. With annual savings approaching one thousand pounds, the payback period on the battery investment is typically four to five years, leaving over a decade of pure savings before any consideration of battery replacement.

This installation also future-proofs the property for solar panels. If the homeowner later decides to add solar, the existing Fox hybrid inverter and battery system can simply have solar panels connected to the DC input, transforming the battery-only setup into a full solar and battery system with no wasted investment. We always mention this to battery-only customers because it means they are not locking themselves into a solar-free future by starting with battery alone.

Whether you are unable to install solar due to roof constraints, planning restrictions or budget considerations, or you simply want to start saving immediately while you plan a solar installation for later, a battery-only system is a proven, effective way to reduce your electricity bills today. Contact ALPS Electrical for a free assessment of your suitability for a battery-only installation.