How Heat Pump Tariffs works: compare every UK tariff against your real usage

Most tariff comparison tools ask you to guess. They want an annual kWh figure, apply a rough profile, and hand you an estimate. The problem is that for a heat pump or EV household, when you use electricity matters as much as how much — and a guessed annual total can't capture that.

Heat Pump Tariffs does it differently. We take your real half-hourly smart meter data and run it against every UK heat pump and EV tariff, in your actual DNO region, to show you precisely what each would have cost you. No estimates, no averages — your numbers. This guide explains how the site works, from signing up to reading your results.

Ready to try it? You can register for a free account in under a minute. If you're still researching tariffs first, our best heat pump tariffs comparison and Cosy Octopus deep-dive are good starting points.

Step 1: Create a free account

Registration is free and takes a minute — email and password, confirm via a verification link, and you're in. There's no payment step and no card required. Once you're registered you land on your dashboard, which is the hub for connecting your data and running comparisons.

If you want to look around before connecting your own meter, there's a sample data mode you can switch on in your profile. It loads a realistic example dataset so you can see exactly what a comparison looks like before committing your own readings.

Step 2: Get your smart meter data in

This is the part that makes the comparison accurate, and there are two ways to do it.

Option A — connect automatically via Bright (recommended). Bright is a free app from Glowmarkt that reads your smart meter's half-hourly data. If you link your Bright account to Heat Pump Tariffs, we pull your readings in automatically and keep them updated — no manual files. The connection is a short wizard: enter your Bright login, pick your property and electricity meter if you have more than one, and you're connected. From then on your data syncs in the background. (Bright data typically lags real time by about 24–48 hours, which is normal for smart meter networks.)

Option B — upload a CSV. If you'd rather not connect an account, you can download your half-hourly data as a CSV from your energy supplier or the Bright app and upload it directly. The uploader checks the file, tells you clearly if anything's wrong with the format, and lets you retry a corrected file. Either route gets the same result: your real 30-minute readings in your account.

Not sure how to get your data? Our smart meter data guide walks through it supplier by supplier. The one requirement either way is a working smart meter sending half-hourly readings — every modern smart tariff already needs this.

Step 3: Run a comparison

With your data in, head to the comparison page. The tool runs your actual consumption — every half-hour slot — against each tariff's rates for your region, and ranks them by what they would have cost you over the period your data covers.

You'll see the best-value tariff highlighted, the estimated annual cost for each option, and how they stack up against each other and against the standard price cap. Because it's built on your real usage pattern, it correctly rewards (or penalises) tariffs based on when you actually use power — so a time-of-use tariff like Cosy or Agile is judged on whether you genuinely shift load, not on an assumption.

Step 4: Let it watch for you with auto-comparisons

Tariffs change. New ones launch, rates move, and the best deal for your usage today might not be the best in three months. Rather than re-checking manually, you can enable auto-comparisons — the site periodically re-runs your data against the current tariff field and lets you know when something changes that's worth your attention. Set it once and it keeps working in the background. If you've connected via Bright, your data stays current automatically, so the auto-comparisons always reflect your latest usage.

How the comparison actually works

It's worth understanding what's happening under the bonnet, because it's the whole reason the results are trustworthy.

Every comparison is built on half-hourly granularity. A day has 48 half-hour slots, and the engine knows what you used in each one. It then applies the correct rate for that exact slot under each tariff — the overnight rate for an overnight slot, the peak rate for a 4–7pm slot, and so on — and sums the whole period. That's fundamentally more accurate than multiplying an annual total by an average rate, because it captures the timing that time-of-use tariffs are built around.

It's also region-aware. There are 14 DNO (Distribution Network Operator) regions across Great Britain, and both unit rates and standing charges vary between them. The engine uses the rates for your region, so you're not comparing against a national average that doesn't apply where you live.

And it's honest about data quality. If a comparison doesn't have enough of your data to be reliable, it says so rather than presenting a confident-but-wrong number. The goal is an answer you can actually act on.

What makes Heat Pump Tariffs different

Beyond the accuracy, a few things set the site apart — and they're deliberate choices.

No ads, ever. The site doesn't show advertising and doesn't let anyone pay to influence your results. The comparison ranks tariffs purely on what they'd cost you.

No third-party tracking. There are no analytics trackers or advertising pixels following you around. Any logging is first-party and internal — we don't sell or share your data, and we don't log your IP address or build a browser fingerprint. You can read exactly what's stored in our privacy policy.

Built for heat pumps and EVs specifically. Generic comparison sites treat all households the same. This one is built around the tariffs and usage patterns that matter for high-electricity, load-shifting homes.

How does the site stay running, then? When you choose to switch to a tariff through one of our referral links, the supplier may pay us a small referral fee — at no cost to you. That's clearly labelled wherever it appears, and it never affects the rankings.

Frequently asked questions

Is it free? Yes. Registration, data upload, and comparisons are all free. There's no paid tier required to get your results.

Do I need a smart meter? Yes — the whole approach depends on half-hourly readings, which need a working smart meter. If yours isn't sending half-hourly data yet, the smart meter guide explains how to enable it.

Is my data safe? Your readings are used only to run your comparisons. We don't sell or share your data, we use no third-party tracking, and we don't log your IP address. Full detail is in the privacy policy.

Which tariffs do you cover? The major heat pump and EV time-of-use tariffs across all 14 DNO regions, including standard, Economy 7, time-of-use, and dynamic tariff types — and the field is kept up to date.

What if I don't want to connect my account? Use the CSV upload route instead. You get the same comparison without linking anything.

Get started

The fastest way to understand what your heat pump or EV is really costing you — and whether a different tariff would cost less — is to see it on your own data. Create a free account, connect your smart meter or upload a CSV, and run your first comparison. It takes a few minutes, and the answer is built on your real usage rather than a guess.