My Whole House Energy Bill Was £633 in 2025

Whole House Energy Bill 2025

My 1930 semi detached house in Sheffield along with our two electric vehicles used over 10,000 kWh in 2025… but the total cost was only £633.

That’s everything.

• heating and hot water
• cooking and appliances
• and around 9,000 miles of driving
• full electric home, no gas

These are the actual numbers from our house.

TL;DR

• Imported Electricity Cost: £965 (electricity bought)
• Export Income: +£545 (electricity sent back to the grid)
• Standing Charge: £213 (electricity only as we have no gas supply)
• Total Annual Cost: £633

Table of Contents

Use the Table of Contents below to jump straight to the section that matters most or scroll through at your own pace.

Introduction

In my recent Energy Unwrapped podcast episode with Nigel Banks we talked through the announcement of the recent future homes standard, Octopus zero bills offering and then towards the end we spoke about how retrofit homes could try and get towards ‘zero bills homes’.

You can watch that episode here: Future Home Standard with Nigel Banks.

In essence, the future homes standard puts a heat pump and solar panels into new homes.

Zero bills homes requires more panels, battery storage and uses smart time of use tariffs to

• a) make more use of the generated solar within the home becoming more self sufficient and then
• b) trading energy at the right time to maximise profit on the investment. By buying energy at cheap times and selling back to the grid when the grid needs and it’s more profitable to do so.

In a way, this is what I’ve been doing in my house for a number of years. 

Here’s a reminder of what our house is, the equipment I have and the installation timeline.

Property Information

• 1930’s 3 bedroom semi detached house in Sheffield
• 2 adults and 2 teenagers (14 + 16)
• 98 square metres floor space
• 3 floors (ground, first and loft extension)
• 20 year old ground floor single storey extension to rear
• 15 year old rockwool cavity wall insulation
• 10 – 20 year old mix of double glazing
• 10 year old loft extension (with terribly installed PIR insulation)
• EPC Rated D (EPC assessment prior to solar install)

Although i have made changes over the years, as per the details in this Fabric Retrofit article.

A combination of the older improvements like double glazing, cavity wall insulation alongside the newer work I completed, the full house heat loss is less than 4kW as detailed in this article; Air Changes Per Hour Heat Loss.

Kit Installation Timeline

• Sep 2018 – 5.1kW of Solar Installed on a 3.68kW Solaredge inverter
• Feb 2020 – Installed 4.8kWh Pylontech battery system (2 batteries) on a Lux AC coupled inverter
• Aug 2020 – Took delivery of EV and installed Myenergi Zappi Charger
• Oct 2020 – Installed a third battery taking total capacity to 7.2kWh
• Feb 2021 – Installed a further two batteries taking total capacity to 12kWh
• Feb 2022 – 250L Mixergy hot water cylinder installed and myenergi Eddi PV diverter
• Oct 2022 – Vaillant Arotherm 5kW heat pump installed
• Nov 2022 – Upgraded from Pylontech batteries to Hanchu
• Aug 2023 – Expanded battery system to 16kWh usable capacity
• Feb 2024 – Induction cooker installed and gas supply removed
• Mar 2025 – Added a second EV to the household

Tariffs and Control

For all of 2025 I was on the following import and export tariffs.

• Import: Octopus Intelligent Go
• Export: Octopus Fixed 15p export tariff

Which had the following pricing and structure:

• ~7p/kWh overnight (6 hours)
• ~30p/kWh peak

Beyond EV charging, most of the optimisation is handled by Predbat.

Predbat runs inside Home Assistant and automatically:

• schedules battery charge/discharge
• uses solar forecasts
• reacts to tariff pricing
• adjusts to household demand

Once it’s set up, it just runs in the background and schedules all charging and discharging of the battery with cost savings (and profit) in mind.

Yearly Solar Performance

I have been tracking performance of my 5.1kW solar array each month right back to 2018.  You can find all the data here: Solar Performance History.

Historical Solar Generation Stats (kWh per month)

Note: One panel was offline for most of 2024, hence the lower generation numbers across many months in that year.

Electricity Usage and Cost Breakdown

For billed electricity, the table below shows total imports of 10,051kWh in 2025, at an average import rate of 9.44p/kWh.

That led to £964.97 of import cost.

Exports totalled 3,634kWh at 15.00p/kWh, earning £545.10 back.

Standing charges added £213.95, leaving a final net annual electricity cost of £633.82.

That monthly billing breakdown looks like this:

The standout bit here is that three months came out negative overall: May, June and July.

In other words, export income more than covered import costs plus standing charges in those months.

Peak vs Off-Peak Usage

Roughly:

• 88% off-peak
• 12% peak

This is probably the primary reason my average unit rate across the whole year is so low.  Shifting usage into the cheap rate, filling the batteries and  then using the solar and batteries to avoid peak rate usage really helps.

Heat Pump vs Solar (Monthly)

Across the whole year the solar array generated 4442 kWh and our heat pump used 2789 kWh of electricity.

Here is a month by month breakdown.

Solar alone covers the full annual heating demand (in pure total numbers), but obviously not 1:1 match each month.

Annual Heat Pump Usage and Performance

Here is a month by month breakdown of the heat pump usage and performance taken from my Heat Pump Performance History page, where I have details going back to installation in October 2022.

Headline usage figures

• Electrical Input: 2789 kWh
• Heat Output: 10,728 kWh

Annual Performance Numbers

• Combined SCOP: 3.8
• Heating SCOP: 4.2
• Hot Water SCOP: 3.4

If you want to monitor my heat pump directly you can via my Open Energy Monitor Feed.

EV Charging Usage

EV charging has been tracked since August 2020 using the Zappi.

You can see the full appliance-level breakdown here:
https://energy-stats.uk/appliance-usage-history/

For 2025, the monthly usage looked like this:

Across the year, that’s 2,271 kWh of electricity going into the cars.

Using a conservative 3.9 miles per kWh (the Renault Zoe is closer to 3.7, the Hyundai Kona closer to 4.0), that works out at:

• 2,271 × 3.9 = ~8,800 to 9,000 miles

Almost all of that charging happened on Intelligent Octopus Go during the off-peak window, at around 7p per kWh.

So as a simple estimate:

• 2,271 kWh × 7p ≈ £159 for the year

That works out at roughly:

• ~1.8p per mile

Around a quarter of the £633 annual electricity cost is actually EV charging, covering roughly 9,000 miles of driving at around 2p per mile.

EV Savings Calculator

I have created this to help you compare the annual cost of driving a petrol or diesel car with the cost of driving an electric car.

EV Savings Calculator

Appliance Electricity Usage (2025)

These are the actual measured kWh figures for 2025, taken from individual device monitoring.

Full breakdown and historical data:

https://energy-stats.uk/appliance-usage-history/

Monthly Appliance Usage (kWh)

* Fridge freezer data available from June onwards.

I find it useful to see the breakdown of each device.  The obvious biggest swing is how the tumble dryer usage drops during the spring and summer when we can get the washing out on the line to dry.

What About the Upfront Cost?

This is always the pushback when those of us that have been lucky enough to have made this sort of investment, and it’s a fair pushback.

Yes, there is a capital cost:

• solar
• batteries
• heat pump
• EV

As an early adopter I have probably spent more and got less capacity than I could for the same money now.

My 300 watt panels and those original 2.4kWh batteries I had look very old specs now.

Costs have come down significantly, especially for solar and batteries.

And as proved in my experience here, the savings are now large enough that they offset a meaningful portion of running costs and in some cases can cover financing costs.

Hopefully with the release of the UK government warm homes plan, the hardware can make it’s way into the hands and homes of more people.

Looking ahead and forecasting 2026

As of April 2026, there have already been some meaningful changes to tariffs.

The off-peak rate on Intelligent Octopus Go dropped to around 5.2p/kWh (down from ~7p), although a few weeks later, after wider wholesale price volatility, it moved back up towards 7p.

With such a high proportion of usage already off-peak (around 88% in 2025), that off-peak rate is key. It directly affects EV charging, battery charging and most of the overnight load in the house, so even small changes here have a noticeable impact on the overall bill.

At the same time, export rates have moved the other way. The fixed export tariff dropped from 15p to 12p per kWh, which reduces the value of simply exporting everything at a flat rate. I covered this in more detail in Solar Export Rates Cut.

Because of that change, I’ve moved over to Agile Outgoing export. Instead of a fixed rate, export is now linked to wholesale electricity prices, so it’s higher when the grid needs energy and lower (or very low) when there’s excess generation. That shifts the approach slightly. Rather than exporting whenever there’s surplus, the focus is now on exporting at the right time and holding energy back when prices are low.

This was something we discussed in the podcast with Alex Schoch from Octopus Energy: Why Intelligent Octopus Go Had to Change.

The direction of travel is pretty clear. More flexibility, more automation, and more value for households that can respond to price signals.

Virtual Power Plants and Missed Opportunity

One area that’s becoming more interesting in 2026 is virtual power plants (VPPs). These platforms connect home batteries to the grid and pay you to export during periods of high demand, rather than just on a fixed tariff.

One example is Axle Energy. They offer a guaranteed minimum payment each month, and during grid events they can pay around £1 per kWh exported, along with a £25 joining bonus.

At the moment my battery system isn’t compatible, which is a bit frustrating. Based on how I already run things, storing energy cheaply and exporting when it makes sense, it’s exactly the kind of setup that would benefit from this.

If you want to explore it yourself and take advantage of the £25 joining bonus, you can check out the Axle Energy Referral page.

Feed-in Tariff (FIT) Payments

One small extra worth mentioning is Feed-in Tariff (FIT) payments. Because my solar was installed before March 2019, it still qualifies for the legacy scheme. That means I’m paid 5.54p per kWh on everything the system generates, not just what’s exported, and that rate is index linked so it increases slightly each year.

In 2025, with around 4,400 kWh generated, that comes out at roughly £240 for the year.

I moved away from the old 50% deemed export so I could use Octopus export tariffs, take part in flexibility events and optimise when I export. So the export side is now fully market-based, but the generation payment remains in the background.

For most people this isn’t something to focus on. FIT is a legacy scheme, new installations can’t access it, and it really only applies to early adopters. It’s not something you can build into a modern system.

That said, it does make a difference here. If you take the £633 total cost and knock off around £240 of FIT income, the effective cost drops closer to about £390 for the year.

It’s not part of the modern setup, but for those of us that got in early, it’s still a nice bonus on top of everything else.

Smarter Heat Pump Control with Havenwise

Alongside tariffs and battery optimisation, I’m also using Havenwise to control the heating side of the system.

I’ve covered this in more detail in my Havenwise Review and in this podcast episode with co-creator Alex Nelson: Smart Heat Pump Control with Havenwise.

Havenwise sits on top of the heat pump controls and gives more precise control over flow temperatures, heating schedules and hot water timing. In practice, that means you can better align heating with off-peak electricity periods, warmer outdoor temperatures and how the house is actually used day to day.

Heat pumps are already efficient, but timing still matters, and being able to shift heating and hot water into cheaper periods adds another layer of optimisation on top of everything else.

If you want to try it yourself, Havenwise offer a free month via this Havenwise referral link.

Future Home Standard, Zero Bills and Retrofit Reality

There’s a lot of discussion right now around Future Homes Standard, Zero Bills homes and electrification.

Nigel Banks and I have a great episode on the Energy Unwrapped podcast all about this.

But at a practical level, most of it comes down to one core idea.

The “Holy Trinity” of a Modern Home

I’ve described this before as the:

The Holy Trinity and Renewable Quintessentials

At its simplest, the “Holy Trinity” is solar, batteries and a heat pump

Three technologies that each solve a different problem, but work best together.

• Solar generates energy
• Batteries control when you use it
• Heat pump turns it into heating and hot water

Individually useful. Together, they completely change how a home uses energy.

From Trinity to “Quintessentials”

Once you add:

• EVs
• time-of-use tariffs

…it becomes what I’ve called the “Renewable Quintessentials”.

That’s the amazing combination I have.

Introducing the Holy Half Dozen (name to decided!)

In fact, you could even build upon the Quintessentials even further adding a sixth element; Control

• Solar
• Batteries
• Heat Pump
• EV
• Time of Use Tariffs
• Control and Automation

As of April 2026, I crown this the “Holy Half Dozen of Renewables”.

Summary and Round-Up

This isn’t a low energy home. It used just under 11,000 kWh in 2025, runs a heat pump for all heating and hot water, and covers around 9,000 miles of driving across two EVs. On paper, that should be an expensive house to run. But the total cost came in at £633 for the year.

That only really makes sense when you look at how the energy is being used. Most of it is bought off-peak, a good chunk is offset by solar, and the rest is either stored or exported at the right time. It’s not about using less energy, it’s about using it differently. And once you factor in that a quarter of that £633 is actually charging the cars, the “household” cost looks even lower.

There is, of course, an upfront cost to all of this. Solar, batteries, heat pumps and EVs aren’t cheap, and as an early adopter I’ve probably spent more for less capacity than someone installing today. But the direction of travel is clear. Hardware costs have come down, tariffs have become more flexible, and the ability to shift and trade energy is now a real part of the equation. This is essentially the Holy Trinity and Renewable Quintessentials in action, layered onto a fairly typical 1930s semi, and it shows what’s possible when everything is working together.