Octopus Energy launched their Agile Octopus tariff in February 2018. It’s still a very novel concept; rather than paying a set rate for your electricity regardless of the time of day, Octopus track the wholesale price of electricity which means that the rate you pay changes every half an hour. There’s a premium time between 4pm and 7pm where the rate is highest, so you really don’t want to be using much, if any, electricity during that period.
There are even times when the price of electricity drops so much that it goes negative, which means Octopus are paying its customers to use electricity!
Agile Octopus therefore suits those with a battery storage system in their home, and particularly those who also have solar panels (or any other form of renewable electricity generating equipment) which can feed the battery to keep it topped up prior to the premium evening period.
We were already with Octopus on an economy 7 tariff but we switched over to the Agile tariff on 7 December 2018. It was an easy process as we already had a smart meter fitted from a previous supplier. It’s a SMETS1 type which according to the tabloids won’t work when you change suppliers, but Octopus adopted our meter with no issues.
We have 6kW of solar panels which is large for a domestic system, but the house doesn’t have a gas supply and therefore is electrically heated by a 9kW air source heat pump. We also have an electric car which we mainly charge using surplus solar in the summer and on cheap rate in the winter, and the odd top-up from Chorley’s public chargers.
A Tesla Powerwall 2 gives us 13.5kWh of storage capacity for any surplus electricity from our solar panels, and also charges on cheap rate electricity in the winter when solar yields aren’t as good. The Powerwall 2 was installed on 15 May 2019, replacing a Powerwall 1 which we had been using for around 3 years and which is now saving my brother money on his electricity bills.
Finally, we have an Eddi immersion heater controller that uses surplus electricity to heat our water once the Powerwall 2 is fully charged.
Octopus are a tech-led company and a great feature is that their systems work with the IFTTT service. As we have Heatmiser Neo heating controls in our home which are also IFTTT compatible, I’ve set up and IFTTT rule that automatically switches on the heat pump to heat the hot water cylinder if the Agile electricity price drops below 5p per kWh. This triggers quite often on a Sunday morning but the cylinder is usually hot in the summer from the day before so we only tend to get the benefit in winter.
Our electricity bills
Below is a summary of the bills we’ve had so far from Octopus. Note that the bill amounts and average price per day include VAT and the 20p per day standing charge. The weighted average unit cost is what a standard tariff would have to be set at for the bill to come to the same total.
unit cost (p/kWh)
|7 Dec 18 – 27 Jan 19||£ 91.24||51||£ 1.79||13.81 p/kWh|
|28 Jan 19 – 27 Feb 19||£ 38.07||30||£ 1.27||11.86 p/kWh|
|28 Feb 19 – 27 Mar 19||£ 29.69||27||£ 1.10||9.55 p/kWh|
|28 Mar 19 – 6 May 19||£ 18.03||39||£ 0.46||8.70 p/kWh|
|7 May 19 – 15 May 19||£ 6.04||9||£ 0.67||8.46 p/kWh|
|16 May 19 – 27 Jul 19||£ 22.67||43||£ 0.53||9.89 p/kWh|
|28 Jul 19 – 27 Aug 19||£ 12.68||31||£ 0.41||7.71 p/kWh|
|29 Aug 19 – 28 Sep 19||£ 18.54||31||£ 0.60||7.55 p/kWh|
|29 Sep 19 – 28 Oct 19||£ 28.16||30||£ 0.94||7.50 p/kWh|
|29 Oct 19 – 28 Nov 19||£ 57.59||31||£ 1.86||8.47 p/kWh|
You’ll notice that the price reduces significantly once we’re out of the heating season and our electricity usage becomes more comparable with a gas-heated house. Our bill for 12 months has amounted to less than £350!
Switching to Agile Octopus
If you have a battery storage system and you’re already with Octopus Energy, contact them and ask to switch to the Agile tariff. If you’re not with Octopus Energy then you can use the following link to switch your electricity supplier. There’s a £50 opening credit from them for you, and £50 applied to my account too.
Battery storage systems
We install battery storage systems to all types of solar PV system in the North West of England, including adding batteries to existing systems. We only use excellent quality products that actually work, and include full monitoring so that you can see it in action. Give us a call for a chat.