Sun Hours Is Now on iPhone — Free on the iOS App Store

Sun Hours is on iPhone

It is here. Sun Hours — the UK solar generation forecast app — is now a free download on the iOS App Store.

The same app Android users have been using to time their washing machine cycles, plan their EV charging, and check whether tomorrow is worth leaving the dishwasher for — now on iPhone.

Download free on the App Store →

What it does

Sun Hours answers one question: how much will my solar panels generate today?

Enter your UK postcode. Enter the highest single-day kWh your system has ever produced (find this in your inverter app — 30 seconds). That is the entire setup.

You get:

• A 7-day kWh forecast calibrated to your actual system and postcode
• An hourly generation curve for each day — so you know whether 11am or 1pm is your peak window
• A 30-day view to plan ahead on bigger jobs
• A Smart Appliance Timer that tells you the best hour to run each appliance
• A 100% day notification when forecast conditions match your best-ever output

No account. No login. No inverter API credentials. No wiring diagrams to fill in.

Works with every system

Hoymiles, Deye, Marstek, Envertech, APS, Growatt, Solis — and every unbranded kit from Lidl, Iceland, or City Plumbing. If your inverter has a daily total in its app, Sun Hours can use it.

Find your best-day kWh in your inverter app (Reports → Daily → sort highest), enter it alongside your postcode, and your forecast is live.

Your postcode matters — here's why

The UK's solar resource varies significantly by location. Sun Hours maps every postcode area to measured solar yield data:

• Cornwall / Devon — 1,060–1,080 kWh/kWp/year
• London / South East — 1,010–1,030 kWh/kWp/year
• Bristol / South West — 1,000–1,020 kWh/kWp/year
• Birmingham / Midlands — 965–975 kWh/kWp/year
• Manchester / Leeds / Sheffield — 935–940 kWh/kWp/year
• Edinburgh / Glasgow / Cardiff — 895–905 kWh/kWp/year
• Liverpool / Newcastle / Aberdeen — 880–910 kWh/kWp/year

A forecast using a national average is wrong for most of the UK. Sun Hours uses your postcode specifically.

No account, no tracking, no subscription

Sun Hours does not know who you are and is not trying to find out.

Your postcode and system settings live on your device only. No server stores them. No analytics profile is built. No email required to download tomorrow's forecast.

The free version is ad-supported. A one-time No Ads purchase removes all advertising permanently. A one-time Pro upgrade adds unlimited Saved Locations and Smart Appliance Timer. Both are lifetime unlocks — there is no subscription, no annual fee, no renewal reminder.

The practical use case

Most plug-in solar owners check their forecast the same way: open the app in the morning, see when today's peak window falls, decide whether to run the washing machine now or after lunch.

On a good UK summer day, that peak window is typically 10am–2pm. On a partly cloudy day it might be a two-hour gap in the afternoon. The hourly chart shows you exactly which slot to aim for — not a generic "good day / bad day" rating, but your actual kWh curve for your postcode, updated daily.

Over a year, consistently timing high-draw appliances to your solar peak — washing machine, dishwasher, EV charger, heat pump — can add £30–£80 to the savings your panels generate. The app tells you when that window is. The rest is just habit.

Download Sun Hours free on the iOS App Store →

Also free on Android via Google Play.