How Helena gets her electricity for free
Helena from Hampshire no longer pays for electricity. With a battery and solar system managed by Capture AI, she has brought her energy bills down to zero. In this article, we explain the system installed, how it's used, and how she's unlocked free electricity - even getting paid in some months.
The topic in a nutshell
Helena used to pay over £500 annually for electricity, with costs peaking at £700 during the energy crisis.
After charging her EV on off-peak rates, she realised they could do the same for the home with a battery.
With [Capture AI] and their system, their electricity bill has hit £0 - and in some months, they’re even paid to use electricity.
Helena (29) lives with her partner Paul in Fleet, Hampshire and has been a Capture Energy customer since August last year. Their household consumes an estimated 2,000 kWh of electricity per year, in addition to the electricity their EV draws when charging at home. At the peak of the energy crisis, their bills went up to almost £700 per year – an equivalent of approximately 35p/kWh. Since then, they’ve been looking for ways to save on electricity costs.
The idea of using a battery to save on electricity costs first came up, when they charged their EV on off-peak rates with the Octopus Go tariff. They purchased the EV at the start of 2024 and needed a suitable electricity tariff: Octopus Go offers electricity at 8.5p/kWh between 11:30pm and 5:30am - enough time to charge their car. That’s when Helena thought: “Why not power the home on these lower rates too?” She confirmed with Octopus that they could charge a battery on off-peak rates and decided that they were going to install battery storage.
How a 10 kWh battery system on [Capture AI] powers their home
Their system consists of a 10 kWh InstaGen battery with a 5 kW inverter, as well as 8x 435 W InstaGen solar panels - 3.48 kWp in total. An electrician completed the straightforward garage installation in just one day.
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Since then [Capture AI] has been managing their system to reduce Helena and Paul’s electricity costs to an absolute minimum. Our artificial intelligence:
- Forecasts household consumption as well as solar production to charge the battery with just the right amount of energy at off-peak tariff rates, while leaving enough capacity for solar generation during the day
- Maximises export revenues by discharging the battery to the grid at the times with the highest export rates
- Helps earn extra payments from grid services such as the local flexibility markets - where Capture continuously monitors for any opportunities their battery can participate in.
More than 50% saved on electricity costs since switching to Capture
Before installing the battery, Helena and Paul consumed more than 90% of their electricity at the peak times of the Octopus Go tariff, where they were charged 26 p/kWh rather than the 8.5 p/kWh off-peak rate. This added up to a total electricity costs of £520 per year.
Savings from charging at Octopus Go off-peak rates
Since adding the battery system, their import patterns have completely flipped. The battery charged electricity with Capture at off-peak rates of 8.5 p/kWh - storing cheap energy for use at a later time.
Once stored, this electricity can either be discharged for household consumption or exported at a later time when prices are higher. However, for Helena and Paul the benefit of exporting was limited, as their Outgoing Lite tariff offered a flat export rate of just 8p/kWh.
Switching to Agile for lower import and higher export rates
That’s why they switched to Octopus Agile a few months ago. On Agile, both import and export rates follow the wholesale electricity prices. Sometimes, import rates go negative when there is an oversupply of electricity from renewable power production, while export rates can reach multiples of the 8p/kWh they were getting paid before.
However, using Octopus Agile requires even more accurate forecasts and management of the system. “That’s where [Capture AI] comes in”, comments Helena. Their charging schedule now changes daily, depending on import/export rates and forecasts of their usage and solar production. By moving from a fixed charging schedule, Capture AI was able to collect data from Octopus Go and reduce Helena’s electricity bills by £350.
Figure 3 illustrates how [Capture AI] imported electricity to Helena's battery at the lowest (negative) prices - paying her to store electricity.
Figure 4 illustrates how [Capture AI] exported Helena's excess stored electricity back to the grid at the highest prices - maximising her export revenues.
Helena’s Capture Price
This resulted in an overall Capture Price of -9p/kWh. The Capture Price shows the real cost of the electricity used - in pence per kilowatt-hour (p/kWh). Think of it as the actual cost per kilowatt-hour of electricity you consumed, after factoring in the benefits of charging from the grid at low prices, using solar, and exporting energy back to the grid. In their case, they got paid 9p/kWh for every kWh of electricity consumed.
Helena is quite excited for summer, when periods of low or even negative electricity prices on the Octopus Agile import tariff occur more frequently. “I always get excited when I see that we’ve been paid to import electricity to our battery. Looking the electricity prices from last year, we’ll get a lot more of these periods in summer,” Helena explains.
Outlook
Helena’s journey shows just how much more [Capture AI] increases the value of your battery. While a standard battery might save you money, it’s the intelligent scheduling, forecasting, and access to extra income through grid services that make it possible to turn energy costs into revenues. This is what [Capture AI] is built for: powering your home for free. If you would like to learn more about Capture Energy and how we help our customers get free electricity, please get in touch using the form below.
