Heat Pumps

Octopus Energy Tariffs for Heat Pumps, EVs & Solar: Complete Guide

By James Crawford | 2025-10-10 | 10 min read
Octopus Energy Tariffs for Heat Pumps, EVs & Solar: Complete Guide

TLDR: Octopus Energy offers smart tariffs that dramatically reduce costs for heat pump, EV, and solar owners. Cosy Octopus provides 10p/kWh heat pump hours. Go/Intelligent Go offers 7-9p overnight EV charging. Flux pays premium export rates for solar batteries. Choosing the right tariff can save £300-£800/year compared to standard flat-rate tariffs. This comprehensive guide helps you choose the right option for your home.

Why Smart Tariffs Matter for Clean Energy Homes

If you've invested in a heat pump, electric vehicle, or solar panels, you're probably using significantly more electricity than the average household. That's completely normal—you're running your heating and transport on electricity rather than fossil fuels.

But here's the thing: not all electricity costs the same to produce or deliver. At 3am, when demand is low and wind turbines are spinning, wholesale electricity prices often drop below 5p per kWh. During the 4-7pm evening peak, when everyone's cooking dinner and watching telly, prices can hit 30p or more.

Traditional flat-rate tariffs charge you the same whether you use power at midnight or during Coronation Street. Smart tariffs pass on those wholesale price variations—giving you cheap electricity when it's genuinely cheap, and charging more when demand is high.

For homes with flexible loads like heat pumps (which can pre-heat your home), EVs (which can charge overnight), and batteries (which can store cheap energy for later), this creates massive savings opportunities.

Real Homeowner Experiences

Before diving into the details, here's what actual British households are experiencing with Octopus smart tariffs.

Rachel and Simon, Nottingham (EV + heat pump): "We've got a Tesla Model 3 and a Samsung heat pump. Before switching to Intelligent Go, we were paying about £280 a month on electricity. Now we're at £165. The car charges overnight automatically—we just plug it in and the Octopus app figures out the cheapest times. The heat pump pre-heats the house before the peak rate kicks in. We didn't change our behaviour at all, really. Just switched tariff and let the automation do its thing."

Marcus, Bristol (Solar + battery): "Octopus Flux has been brilliant for us. We've got a 6kW solar system and a 9.5kWh GivEnergy battery. The system charges from solar during the day, exports to the grid during the 4-7pm peak window when Flux pays 25p/kWh, then recharges overnight at 15p. We're actually making money most months between April and September. Our annual electricity cost went from £1,400 to about £400 net—and that includes running a home office."

Janet and David, Sheffield (Heat pump only): "We were nervous about heat pump running costs after switching from gas. Our bills in the first winter were higher than expected—about £170 a month. Then we switched to Cosy Octopus and set the heat pump to run during the cheap windows. Same comfort, bills dropped to £110. The house is well-insulated, so it holds the heat through the expensive periods. Wish we'd done it from the start."

Tom, Cambridge (Agile tariff): "Agile isn't for everyone, but I love it. I'm a bit of a tech nerd and I've got everything automated—dishwasher, washing machine, hot water cylinder, EV charger. The app shows me tomorrow's prices and my home automation shifts all the flexible loads to the cheapest slots. Some days electricity goes negative and I literally get paid to use power. My average unit rate over the last year was 8.2p. The price cap is what, 24p? It takes some setup but the savings are real."

Understanding Each Octopus Tariff

Octopus Cosy

Designed specifically for heat pump owners. The tariff provides extended cheap windows that align with how heat pumps work best.

Rate structure (typical, rates may vary):

How to maximise savings:

Set your heat pump to pre-heat your home during the cheap windows. A well-insulated home will retain that warmth through the expensive peak period. Most modern heat pumps have built-in scheduling, or you can use a smart thermostat like Hive or tado to automate this.

Best for:

Potential savings: £200-£400 per year compared to standard flat-rate tariffs.

Octopus Go / Intelligent Go

The EV owner's tariff. Provides ultra-cheap overnight electricity for charging.

Octopus Go rates:

Intelligent Octopus Go rates:

How Intelligent Go works:

You tell the app when you need your car charged by (say, 7am), and Octopus's algorithm figures out the cheapest times overnight to charge. The car might charge 1am-3am one night and 4am-6am the next, depending on wholesale prices. You don't notice any difference—the car's always ready when you need it.

Compatible chargers for Intelligent Go:

Best for:

Potential savings: £300-£600 per year compared to charging on a standard tariff.

Octopus Flux

The solar and battery owner's tariff. Designed for households that can export electricity during peak demand periods.

Rate structure:

The arbitrage opportunity:

Charge your battery overnight at 15p/kWh, use that stored energy during the day, then export to the grid during the 4-7pm peak at 25p/kWh. You're earning 10p profit on every kWh you shift. With a 10kWh battery cycling daily, that's £1 per day in arbitrage value alone—before considering solar generation.

Compatible battery systems:

Best for:

Potential savings: £300-£500 per year, or more with larger systems.

Octopus Agile

The dynamic tariff for tech-savvy households. Prices change every 30 minutes based on wholesale electricity costs.

How it works:

When prices go negative:

On windy nights when demand is low, wholesale prices sometimes go negative. Agile passes this on—you literally earn money by using electricity during these periods. Charging an EV, running a hot water boost, or doing laundry during negative pricing is free money.

Best for:

Not recommended for:

Potential savings: £400-£800 per year for highly engaged users; can backfire for inflexible households.

Which Tariff Should You Choose?

Here's a decision matrix based on your home setup:

Your SetupBest TariffPotential Annual Savings
Heat pump onlyCosy Octopus£200-£400
EV only (smart charger)Intelligent Go£350-£600
EV only (any charger)Octopus Go£300-£500
Solar panels (no battery)Standard + SEG£50-£150 (export)
Solar + batteryFlux£300-£500
Heat pump + EVCosy or Go (compare both)£400-£700
Solar + battery + EVFlux or Intelligent£500-£800
All-electric home, tech-savvyAgile£400-£800

When two tariffs might work:

If you have both an EV and a heat pump, you'll need to decide which matters more. Cosy's heat pump hours don't align perfectly with Go's EV hours. Run the numbers for your specific usage—the Octopus app has a tariff comparison tool that shows estimated costs based on your actual consumption data.

How to Set Up Smart Tariffs

Step 1: Get a Smart Meter

All smart tariffs require a smart meter for half-hourly billing. If you don't have one, Octopus installs them free. The process takes 2-4 weeks from request to installation.

SMETS2 meters (the current standard) work with any supplier, so you're not locked in. If you have an older SMETS1 meter that went "dumb" after a previous supplier switch, ask Octopus to re-enrol it—this often works.

Step 2: Sign Up with Octopus

You can switch to Octopus from any supplier in minutes online. There are no exit fees from most suppliers (check your current contract). Octopus is consistently rated the UK's best energy supplier for customer service, so you're in good hands.

Step 3: Choose Your Tariff

Start on the standard flexible tariff. Once you've had the smart meter for a few weeks, Octopus can analyse your usage patterns and recommend the best smart tariff. You can also use their in-app comparison tool.

Step 4: Connect Your Devices

For Intelligent Go, you'll need to connect your EV charger to the Octopus app. For Flux, connect your battery system. The app guides you through the process for each compatible device.

Step 5: Automate and Optimise

Most smart tariffs work best with automation. Set your heat pump schedule, configure your EV charger to use Octopus smart charging, and let your battery system optimise charge/discharge cycles. The more you automate, the less you need to think about it.

Frequently Asked Questions

Q: Can I switch between tariffs easily?

A: Yes. Octopus has no exit fees and switching between tariffs takes effect within a day or two. As your setup changes (adding solar, getting an EV), you can switch to a more suitable tariff. Many households switch seasonally—using Cosy in winter for heat pump savings, then Flux in summer to maximise solar export value.

Q: What if I don't have a smart meter yet?

A: You'll need one for any smart tariff. Octopus arranges installation for free. Book online and an engineer visits your property—usually takes 30-60 minutes. The meter starts transmitting data immediately, and you can switch to smart tariffs within days.

Q: Do these tariffs work with non-Octopus equipment?

A: Mostly yes. Flux works with GivEnergy, Tesla, SolarEdge, Fox ESS, and others. Intelligent Go supports most major smart charger brands. The main limitation is the specific integration required—check the Octopus app for your equipment's compatibility.

Q: Are daytime rates higher than standard tariffs?

A: Often yes. Smart tariffs trade cheap off-peak rates for higher peak rates. If you can't shift at least 30-40% of your consumption to cheap periods, you might not save money. For inflexible households, a standard flat-rate tariff might actually be cheaper. Run the comparison before switching.

Q: What happens during a power cut or internet outage?

A: Your electricity supply isn't affected. Smart meters store data locally and upload when connectivity returns. Automated charging might not work during internet outages, but you can always override and charge manually. Your tariff rates don't change during outages.

Q: Can I have solar export AND a smart import tariff?

A: Yes. Flux specifically handles both—it's designed for solar homes. For other tariffs, you can combine them with Octopus's export tariff (Outgoing Fixed or Outgoing Agile). The app handles both sides of the billing.

Tips for Maximising Savings

For Heat Pump Owners

For EV Owners

For Solar and Battery Owners

The Bottom Line

Octopus smart tariffs can save £300-£800 per year for homes with heat pumps, EVs, or solar—sometimes more. The key is matching the right tariff to your equipment and being willing to shift some electricity use to cheaper periods.

Start with your main energy user: EV owners typically save most with Go or Intelligent Go, heat pump owners with Cosy, and solar/battery owners with Flux. If you've got multiple clean energy technologies, you'll need to decide which matters most or experiment to find the best fit.

The beauty of Octopus is flexibility. No exit fees mean you can try a tariff, see how it works for your household, and switch if something else suits you better. The app shows exactly what you're paying and saving, so there are no surprises.

For most households investing in heat pumps, EVs, and solar, smart tariffs aren't optional—they're essential to making the economics work. A heat pump on a standard tariff might cost more than gas. The same heat pump on Cosy or Agile often costs less. The tariff choice can be as important as the technology choice.