How much can you save with solar?
Save up to 95% on your electricity bill on the Octopus Flux tariff, or even get paid to use energy on Intelligent Octopus Flux. We dig into how saving with solar really works and what makes a solar installation worth it.
How can solar power save you money?
Curious about the potential savings with solar energy? You're not alone. Following years of unpredictable energy costs and with environmental concerns growing, more people are choosing to generate their own green power at home with solar. But when you take up-front costs into consideration, how do the savings actually work? We’ve simplified the jargon and provided just the answers - so you can decide if solar is the right fit for you.
What is export?
Simply put, ‘exported’ energy is electricity that has been generated by your solar panels, but has not been used at home (or stored in your battery). These excess electrons are instead diverted to the National Grid, and you will get paid for every unit (kWh) of energy you export. Ka-ching! 🤑
Whether you opt for a solar and battery installation with Octopus or with another installer, we have a selection of solar tariffs available that will allow you either just sell your energy back to the grid at a standard fixed rate, or use smart technology to offer dynamic pricing based on energy demand, for greater savings.
Smart tariffs and how they work
Solar smart tariffs can help you to save money on imported and exported electricity by offering cheaper electricity when demand is low, and paying more for exported energy when demand is high. Broken down further, this means that if you're able to utilise a battery to sell your energy back to the grid at a time when the UK is using a lot of energy (dinner time, for example), you may get paid more per kWh, whilst helping to reduce strain on the grid by supporting it with clean energy at times when there’s generally a lot of fossil fuels in the mix.
Equally if you use electricity or charge your battery when demand is low (and energy is more likely to come from renewable sources), that energy will be cheaper to buy. Our latest solar smart tariff, Intelligent Octopus Flux, offers you amazing export rates for your solar energy, and automatically charges and discharges your battery at the best times so you don’t need to worry about programming your system - easy peasy. We’ve gone into more detail about our tariff options below - skip to smart tariffs.
We've found that an average customer on Intelligent Octopus Flux can reduce their annual bill to almost zero, or even make a small profit. Whereas customers on our standard Octopus Flux tariff, save up to 95% on their electricity bills.
What is a payback period?
After several years of saving on your electricity bills, and making money on export payments, your solar system will begin to pay for itself; however, how long it takes will depend on the number of solar panels you have and the amount of energy you use. We compared the typical installation cost and annual bill savings for our most common solar system (10 x 435W panels and with or without s 5.2kWh battery) in different scenarios and found that the payback period varied from 8 - 11 years, depending on the energy tariff. To see the variables, check out the table below.
What will the costs and savings look like for you?
There isn’t a one-size-fits-all answer to this one. Solar savings are dependent on many variables, such as your tariff, how many solar panels you have or how much electricity you use and when you use it. At Octopus, we’ve found that our most popular system has 10 PV panels with a battery, so we’ve chosen this example to display what savings could look like, depending on whether you have a battery, and your tariff. Savings are based on the Ofgem average usage of a medium sized household.
If you’d like to find out what costs and savings would look like for your home specifically, our Solar Design Specialists will put together a full breakdown for you, when you get a quote.
Find your solar tariff
TL;DR - if you’re looking for quick answers, check out our smart tariff quiz to find out which tariff is right for you. Keep in mind that you will need a smart meter to take advantage of any Octopus smart tariffs.
The future is Flux
The original Octopus Flux, and the more recent Intelligent Octopus Flux are gaining a lot of traction as the leading tariffs for homes with solar and a battery – and for good reason. Both take care of your import and export electricity usage, and offer great savings.
On Octopus Flux you can get super cheap rates between 2am-5am every day to top up your battery, plus a peak export rate from 4pm-7pm when you can discharge your battery. All of which can be scheduled in your solar generation app.
On Intelligent Octopus Flux, you don’t need to lift a finger to get the best export rates on the market. Octopus Energy pairs with your battery to optimise charging and discharging; filling up your battery when energy is cheapest and greenest (often overnight), and then exporting the electricity when demand is high on the grid and electricity is more expensive. With the Intelligent version, customers save £97 a year on average compared to Octopus Flux, and get paid to use energy.
To check the rates for Intelligent Octopus Flux in your area, enter your postcode here. For Octopus Flux, you can find your rates here.
Intelligent Octopus Flux
Best for:
- UK’s highest export rates
- Takes care of import and export usage
- Easy to manage: Octopus do all the work
- If you have a GivEnergy battery
- You’re able to shift your energy usage to off-peak times of day
Octopus Flux
Best for:
- If you’d prefer to schedule your own import and export.
- You have any brand of home battery
- Save up to 95% on your electricity bills
Outgoing Octopus
If you don’t have a battery, or if you’d prefer to pair your export tariff with a different import tariff, Outgoing Octopus may be the option for you. Also a smart tariff, Outgoing comes in two flavours: Agile and Fixed.
Outgoing Fixed offers a standard rate of 15p kWh for every unit you export - great if you prefer a predictable income or if you don’t have energy storage.
Alternatively, Outgoing Agile offers changing rates every half-hour, depending on the price of energy at the time. Which means that if you’re on the ball, you can take advantage of amazing rates and programme your battery to import energy or discharge accordingly.
Another popular reason for choosing Outgoing is if you have particularly high electricity usage - like if you have an electric vehicle or heat pump. In this case, there are import tariffs, like Cosy Octopus or Intelligent Octopus Go which will give you better bang for your buck on purchased energy than Intelligent Octopus Flux might, making it a more suitable combination for your home. Find out more about which tariffs work together here.
On Octopus Go? You get a Lite version of Outgoing Fixed with export at 8p per kWh. Why?
Outgoing Agile
Best for:
- Dynamic, half-hourly pricing
- If you’re on the ball with importing and exporting energy
- You have a battery
Outgoing Fixed
Best for:
- Predictability: get 15p per kWh for every unit you export.
- You don’t have a battery
- You want a different import tariff to your export
- You’re not able to shift your usage outside of peak times (such as 4pm-7pm
Smart Export Guarantee (SEG)
If you’d prefer to go with another supplier for your import energy, you can still join our standard Smart Export Guarantee tariff. With the SEG, you will earn a flat rate of 4.1p per kWh for every unit of electricity you export.
If you still need a hand to decide whether solar is the right fit for your home, we’re here to help. Give our solar experts a call on 0808 196 6842 or email solar@octopus.energy for a personalised quote, and tailored advice. Or check out our FAQs page for further information.
How we calculated the total savings
How we calculated total annual electricity cost for a property with no solar panels
We started by using a total annual consumption figure of 3,500kWh. This is an example figure used, based on standard MCS calculations (with the customer at home half the day) and is also the mean, non-population weighted British electricity consumption according to UK Government statistics
To calculate how much it costs to consume 3,500kWh of electricity, we took the April 2024 regional average price cap figures from Ofgem, which are:
Average Unit Rate - 24.50p/kWh
Average Standing Charge - 60.10p/day
The total cost of electricity, for a property with no solar panels, with the above assumptions works out to be:
Cost of Imported Electricity + Standing Charge (3,500kWh x 24.50p) + (60.10p x 365) = £1,077
How we calculated total annual electricity cost and savings for a property with a 10 solar panel system, no battery storage. On Flexible Octopus for import, and Fixed Outgoing for export
We took the same total annual consumption figure as above, and assume the 10 x 435W panels generate, annually, 4,350kWh of electricity.
Based on MCS standardised calculations and guidance, a property with total annual consumption between 3,500 - 3,999 kWh, and a total annual generation between 4,200 - 4,499kWh, with a panel only system, self consumes 22% of the energy generated. This works out to be: 4,350kWh x 22% = 957kWh
This means the remainder (4,350kWh - 957kWh) of 3,393kWh is assumed to be exported back to the grid.
We assume the exported energy is paid for at a rate of 15p/kWh. This is our April 2024 Fixed Outgoing Tariff export rate.
Since total annual consumption is assumed to be 3,500kWh, of which 957kWh is consumed from electricity generated by the solar panels, the remainder (2,543kWh) needs to be imported from the grid.
To calculate the total annual electricity cost of this property, we will again use the April 2024 average Ofgem price cap figures. To recap, these are 24.50p/kWh unit rate, and a 60.10p/day standing charge, and the mentioned Fixed Outgoing tariff rate of 15p/kWh.
The total annual electricity cost works out to be:
Cost of imported electricity + standing charge - (Export Savings)
(2,453kWh x 24.50p) + (60.10p x 365) - (3,393kWh x 15p) = £333
Versus a property with no solar panel system installed, the total savings are:
Total Annual Elec bill of property with no solar - Total Annual Elec bill of property with solar
£1,077 - £333 = £744 (69% saved)
How we calculated total annual electricity cost and savings for a property with a 10 panel system, 5kWh battery storage. On Flexible Octopus for import, and Fixed Outgoing for export
Based on MCS standardised calculations and guidance, a property with total annual consumption between 3,500 - 3,999 kWh, and a total annual generation between 4,200 - 4,499kWh, with a 10 solar panel system AND a battery storage with 4.1 - 5.1kWh usable capacity is expected to self consume 54% of the energy generated.
Assuming the same total annual generation as above, the new self consumed electricity is:
4,350kWh x 54% = 2,349kWh
This means that the remainder (2,001kWh) is exported to the grid.
Assuming the same total annual consumption as above, the new imported electricity is:
Total Annual Consumption - Self Consumption: 3.500kWh - 2,349kWh = 1,151kWh
Assuming the same unit rate, standing charge and export rate as above, the total annual electricity cost works out to be:
Imported electricity + standing charge - (Export Savings)
(1,151kWh x 24.50p) + (60.10p x 365) - (2,001kWh x 15p) = £201
Versus a property with no solar panel system installed, the total savings here are:
Total Annual Elec bill of property with no solar - Total Annual Elec bill of property with solar.
£1,077 - £201 = £876 (81% saved)
How we calculated total annual electricity cost and savings for a property with a 10 panel system, 5kWh battery storage. On Flexible Octopus for import, and Fixed Outgoing for export
All assumptions remain the same as above, except for the import rate, export rate and standing charge, as the tariff has changed here.
We have used a weighted average import rate of 22.54p/kWh, a weighted average export rate of 20.93p/kWh, and a standing charge of 58.03p/day
The standing charge is our April 2024 rate for the Octopus Flux tariff.
The weighted import and export rates were obtained by looking at the average expected usage patterns for customers on the Octopus Flux tariff. This found that, on average, we expect our customers to import 25% of their total import at the night rate, 70% of their total import at the day rate and 5% of their total import at the peak rate.
While on average, of the total exported electricity, our customers export 0% at the night rate, 40% at the day rate and 60% at the higher paying peak rate.
We then took our April 2024 Octopus Flux rates (in p/kWh) which are:
Import / Export
Night 14.70p / 5.28p
Day 24.60p / 15p
Peak 34.30p / 24.88p
And used this to calculate the weighted average import and export rate.
With all other assumptions remaining the same, the total annual electricity bill for this property works out to be:
Cost of Imported electricity + standing charge - (export savings)
(1,151kWh x 22.54p) + (58.03p x 365) - (2,001kWh x 20.93p) = £52
Versus a property with no solar panel system installed, the total savings here are:
Total Annual Elec bill of property with no solar - Total Annual Elec bill of property with solar
£1,077 - £52 = £1,025 (95% saved)
How we calculated total annual electricity cost and savings for a property with a 10 panel system, 5kWh battery storage. On our Intelligent Octopus Flux import and export tariff
All assumptions remain the same as above, except for the import rate, export rate and standing charge, as the tariff has changed here again.
We have used a weighted average import rate of 22.42p/kWh, a weighted average export rate of 26.46p/kWh and a standing charge of 58.03p/day
The weighted import and export rates were obtained by looking at the average expected usage patterns for customers on the Intelligent Octopus Flux tariff. This found that, on average, we expect our customers to import only 5% of their total import at the day rate and 95% of their total import at the cheaper off peak rate.
And on average, of the total exported electricity, our customers export 60% at the higher paying peak rate and 40% at the off peak rate.
We then took our April 2024 Intelligent Octopus Flux rates (in p/kWh) which are:
Import / Export
Peak 29.40p / 29.40p
Off Peak 22.05p / 22.05p
And used this to calculate the weighted average import and export rate.
With all other assumptions remaining the same, the total annual electricity bill for this property works out to be:
Cost of Imported electricity + standing charge - (export savings)
(1,151kWh x 22.42p) + (58.03p x 365) - (2,001kWh x 26.46p) = -£60
The above shows a total annual electricity bill of -£60. This means that the combination of the self consumption of electricity generated with the solar PV system, and credits for the electricity exported, covered the entire cost of any imported electricity and the account was credited £60.
Versus a property with no solar panel system installed, the total savings here are:
Total Annual Elec bill of property with no solar - Total Annual Elec bill of property with solar
£1,077 - (-£60) = £1,136 (105% saved)
Published on 26th April 2024 by:
Hey I'm Constantine, welcome to Octopus Energy!
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