Get more from the solar and battery you already own.
For homes that already have solar, a battery, or both.
Suntide reads your system every five minutes. It plans each night around your tariff. It checks your bills. Every month it sends a statement that proves what your system earned. No engineer. No new box. About ten minutes to set up.
Start 30 days free 30 days free. No card. In beta, with a direct line to the people building it.
- Connects to the inverter you already have
- Octopus Energy, E.ON Next and EDF accounts, or any tariff
- UK company. Data held in London. No trackers
Green band: the cheap window, 00:30 to 04:30. Red band: the peak. The line is the battery. Gold is the sun.
Suntide is a UK service for homes that already have solar panels, a battery, or both. It reads your system every five minutes. It plans battery charging around your electricity tariff. It checks your bills and sends a monthly statement of what your system earned. If you have an electric car, it stops the car draining your battery. It costs £3.99 a month to monitor, or £7.99 a month to optimise, after a 30-day free trial with no card. It connects to your inverter with a key from your own manufacturer account, and adds new makes as owners ask for them. It works with Octopus, E.ON Next and EDF accounts, or any tariff you describe.
Proof, monthly
Every month, a statement your household can read. What the system earned. What the same month would have cost without it. Whether a better tariff exists for the way you use power. It is built to be printed.
£11.82 earned
6 events in 13 days. 11.8 kWh exported, measured at the inverter. Between £1.62 and £1.88 each after the cost of refilling the battery.
One household, one fortnight. Yours will differ. Suntide refuses an event that would lose you money, and shows the arithmetic.
The small print is the best part: “This statement covers 97% of the month's five-minute intervals. Figures describe the data we have, and nothing is estimated to fill gaps.”
| Your electricity cost this month | -£47.82 |
| Same month with no solar or battery | £70.32 |
| Your system earned | £118.20 |
| Solar generated | 732 kWh |
| Exported to the grid | 554 kWh |
| Tariff benchmark | Agile: £129.20 |
| Battery health trend | steady |
| Configuration score | 86 / 100 |
The benchmark line reads: on Octopus Agile, this household's battery would have earned £11.00 more than on its current tariff. Statements say so plainly, and say nothing when a switch isn't worth it.
How it works
Most solar and battery owners cannot tell whether their system is set up well. Suntide is a loop, not a dashboard.
Measure
Suntide reads your inverter every five minutes. It scores your settings against what matters to you: lower bills, export income, self-use, battery life or backup.
Fix and verify
Each finding is a plain problem with its cost in pounds and the exact fix. Apply it and press verify. Suntide checks the next days of data and shows the before and after.
Plan and report
Tomorrow's plan is drawn tonight, priced. A monthly statement shows what your system earned against a home without one. Alerts arrive when something is wrong, not at month end.
The day, in words
The app writes your day from your own readings. If the data cannot support a sentence, the sentence is not written.
The sun is covering the house and filling the battery, and the spare half kilowatt is being sold. Width is power; the drift is direction. When a link goes quiet it fades to a dotted line, so a glance tells you everything.
27 checks, priced at your rates
The health check runs every night against your settings, your readings and your bills. Here are ten of them. Each is priced at your own tariff where a price is honest.
- Charge window misses your cheap rate often £10–20/mo
- Battery empties before the evening peak ends often £10–25/mo
- Solar export clipped at the limit while export pays seasonal, up to £5–15/mo
- Battery reserve fighting your goal locked-away capacity
- Full-to-empty cycling against a longevity goal battery years
- Battery full hours before the cheap window closes gentler charging, free
- Not selling from the battery on a strong export rate a considered suggestion
- Inverter clock drift shifting every schedule checked daily
- Inverter missed the clock change an hour off until someone notices
- A bill that does not match your own readings worth querying
Your battery is emptying before the expensive peak period finishes, so the house falls back to peak-price grid power.
Those final peak hours are the most expensive electricity of the day, exactly what the battery exists to avoid.
- Widen the overnight charge window in Settings → Battery → Charge/Discharge schedule, or raise the charge current so the battery starts the day fuller.
- If it already reaches 100%, the battery may simply be undersized for your evening usage; consider trimming peak-time loads.
Each finding comes with the fix steps for your inverter's own app. Then Suntide checks from the data that the change worked: “Verified 28 Aug: your change worked.”
The plan, shown before it runs
Suntide takes tomorrow's real half-hourly prices, the solar forecast for your roof and how your house draws power on days like tomorrow. It works out the cheapest plan for the day. Then it shows you, each block priced, before anything changes.
Tomorrow's prices are published tonight, so the plan is drawn tonight: the battery fills at the cheapest hours, the solar band is the forecast's honest range for your roof, and the battery line fans into the range your evenings actually vary by. Dashed means predicted.
It earns your trust first
For as long as you like, the plan runs in shadow. Every morning Suntide publishes what it would have done and what that would have saved, measured against what happened. You decide when the numbers have earned it.
You hold the switch
Suntide plans each night. After 7 nights in shadow you can let it steer: it applies its plan to your inverter itself, tells you what it changed, and you can pause it at any time. Grid events, the inverter clock and car protection run on their own once you switch them on. Where an inverter does not take changes from outside, you make them in its own app with Suntide's steps. One pause switch stops every change.
Every change read back
Each change is sent, then read back from the inverter until the schedule on the device matches. It is written to your timeline with the reason. A change that did not take says so.
Steering needs your agreement in the app. Until then Suntide watches and changes nothing. In Steer it applies its plan itself, within the bounds it shows, and tells you what it changed. One pause switch stops it.
The car charges. The battery stays full.
A charging car is a big load, and a battery empties itself into it. On a cheap smart-charging slot you then buy that power back at the day rate. Suntide reads the slots your supplier plans and the battery charges through them instead. With the battery guard on, the battery is held whenever the car draws. Suntide never controls the charger.
Works with the kit you own
Suntide connects with a key from your own manufacturer account, and adds makes as owners ask for them.
| Inverter | Reads it | Checks and fix steps | Changes from Suntide | How it connects |
|---|---|---|---|---|
| Solis | Yes | Yes | Yes, when you confirm | A key from your own account. Never your password |
| GivEnergy | Yes | Yes | In the maker’s app, with our steps | A key from your own account. Never your password |
| Fox ESSBeta | Yes | Yes | Yes, when you confirm | A key from your own account. Never your password |
| SigenergyBeta | Yes | Yes | In the maker’s app, with our steps | A key from your own account. Never your password |
| SolarEdgeComing soon | With the Link | With the Link | No | Suntide Link, in development |
| Anker SOLIXComing soon | With the Link | With the Link | No | Suntide Link, in development |
Tariffs
Octopus tariffs including Agile sync from your account.E.ON Next and EDF connect in beta. Agile, Flux, Go, Intelligent Octopus Go, Cosy, Tracker and two-rate tariffs are all priced half hour by half hour. Any other tariff is described in a minute, or read straight off a forwarded bill.
Guides: Octopus Flux with a battery · Octopus Agile battery charging
Every brand, meter and charger
Another inverter brand? Name it when you sign up. What people say they have decides what Suntide supports next.
Pricing
Watch
£3.99/month
See it and check it.
- Your system read every five minutes, whoever made it
- An alert when something is wrong: an offline inverter, a missed cheap window
- A monthly statement of what your system earned
- Every electricity bill checked against your own readings
Pick Watch if you want to know it is working.
Start free trialOptimise
£7.99/month · £79/year
Fix it and run it.
- Everything in Watch
- 27 checks, priced at your rates. Each with the fix. Each fix verified
- Tomorrow’s plan, priced, on your phone tonight
- Suntide plans each night. After 7 nights in shadow you can let it steer: it applies its plan to your inverter itself, tells you what it changed, and you can pause it at any time. Grid events, the inverter clock and car protection run on their own once you switch them on. Where an inverter does not take changes from outside, you make them in its own app with Suntide's steps.
- Paid grid events, accepted only when they pay
- The battery guard: an electric car never drains your battery
Pick Optimise if you want the bill to go down. £79 a year is two months free.
Start free trialSuntide Link
£29 · estimated, one-off
Your inverter, read at home.
- A small device that reads your inverter over your own network
- Monitoring that keeps working whatever happens to a manufacturer's cloud, or its pricing
- Some inverters need an adapter or cable as well; we tell you which before you order
In development. Account holders hear first when it ships. More about the Link
The trial is the full Optimise plan for 30 days, with no card. You pick a plan on day 30, or do nothing and it stops. Prices include VAT.
Every statement prints what Suntide cost beside what it earned. If the second number is not bigger, cancel from Settings. No call, no form.
Before you pay anyone anything
You have spent thousands on the kit. These are the questions worth asking.
My inverter app already does this for free. Why pay?
Your inverter app shows what happened. It does not price it. Suntide runs checks against your own tariff and puts a cost on each problem it finds. It checks every bill against your own readings. It draws tomorrow’s plan tonight, priced. Then it sends a monthly statement you can check against your meter. Your app keeps working alongside.
Will this affect my warranty or my installer’s settings?
Suntide changes only what you could change in the maker’s own app. It uses the manufacturer’s platform, with a key you issue and can revoke. Where an inverter accepts changes, Suntide can set the charge and discharge schedule and the charge current, and keep the clock correct. It never touches grid protection or safety settings. Every change is shown to you first, read back from the inverter, and recorded. When you leave, Suntide puts your own settings back. Some manufacturers restrict third-party control, so check your warranty terms. On an inverter that does not accept changes, Suntide only reads.
How much will I actually save?
It depends on your tariff and your current set-up. A well-tuned home may gain little from scheduling and still gain from bill checks, alerts and grid events. That is why the trial is free and the statement prints what Suntide cost beside what it earned. If the second number is not bigger, cancel.
What happens to my system if Suntide goes down, or the company folds?
Nothing changes at home. The schedule lives on your inverter, so your system carries on with its last plan. There is no box to remove. You hold a pause switch that stops every change. Your data exports in one step, and deleting your account puts your own settings back first.
What data do you hold, and who can see it?
Suntide holds your readings, your tariff, your bills’ figures and your home’s location for weather. Inverter keys are encrypted and never shown again. Suntide never asks for your inverter password. The main database is in London. There are no trackers and no advertising. The privacy policy names every provider.
Why pay £79 a year when Octopus does it in the tariff?
On a supplier-controlled tariff the supplier decides when your battery charges and sells. You take the result. With Suntide you keep any tariff from any supplier. You see the plan before it runs. You hold the switch. And your bills are checked by someone who is not the one sending them.
I already run Home Assistant. Why would I hand this over?
You do not have to. Keep Home Assistant. Suntide adds what it does not do. A statement checked against your meter. Bill checks. A record of what each plan would have saved, before you trust it. The Suntide Link has an open Home Assistant integration that reads your inverter locally every second. The Link is in development.
In your pocket
The phone app carries the day, the plan and the statements, on Android and iPhone. A nudge arrives before the cheap rate, not after the missed one. On an iPhone the charge window sits on your lock screen.
Google Play and the Google Play logo are trademarks of Google LLC.
There is more
Insights
What your battery really holds. Tomorrow’s sun for your roof. What the big things cost to run.
Bills and rates
Rates synced from your supplier or read off a forwarded bill. Every bill checked.
Grid events
Paid to export for an hour when the grid needs it. Refused when it would lose you money.
The phone app
The day, the plan and the statements in your pocket, on Android and iPhone. On Google Play now.
How Suntide compares
Against inverter apps, supplier control and home-built set-ups, row by row.
Electric car
The battery held through smart-charging slots, and guarded whenever the car draws.
Home Assistant
Keep Home Assistant. Add the statement, the bill checks and the shadow record.
No battery yet?
Your own year, replayed with batteries you do not own yet, on every tariff we price.
Find out what your set-up is costing you
Create your account and tell Suntide about your home. It starts reading your prices tonight. About ten minutes, and you can stop and come back to any of it.
Start 30 days free 30 days free. No card. In beta, with a direct line to the people building it.