Just Bought Plug-In Solar Panels? Download This First.

Congratulations. You've done the sensible thing. Your plug-in solar panels are up, connected, and quietly generating electricity from sunshine that was previously doing absolutely nothing for you.

Now comes the question everyone asks about three days after installation:

Am I actually getting anything out of these things?

And then, slightly later:

Why does every app I try want to know what my azimuth is?

Good news on both fronts.

Your panels can't talk to you. This app can.

Plug-in solar panels — sometimes called plug-and-play solar, sometimes balcony solar, sometimes "that thing I saw on Instagram and ordered impulsively" — are brilliant in their simplicity. Two panels, a microinverter, a plug. Done.

The slightly frustrating part is that once they're in, most people have no idea what they're doing from one hour to the next. Your inverter display shows a number. Your electricity bill will eventually be smaller. But right now, on this slightly grey Tuesday morning — are your panels generating enough to justify putting the dishwasher on?

That's the question Sun Hours answers. Every day. In about three seconds.

It works exactly like checking the weather

Open the app. See your forecast.

No login screen. No setup wizard. No fields asking for your inverter model, your roof pitch, or your system capacity in kWp.

Sun Hours asks two things when you first open it:

Your postcode. So it looks at the actual weather conditions for your specific area — not a broad regional average, your street.

Your best solar day. The highest kWh number you've ever seen on your inverter on a clear sunny day. That one number tells the app everything it needs to calibrate to your panels — their size, how you've positioned them, any local shading — all pulled from real-world output rather than theoretical specs.

Type those in. Takes eight seconds. You'll never be asked again.

From then on, every morning you open Sun Hours and see:

• Today's kWh forecast — how much your panels are expected to generate today
• An hourly chart — exactly when they'll be working hard and when they'll be coasting
• A 7-day view — so you can plan the big stuff ahead of time
• A 30-day outlook — based on historical sunshine for your postcode

It's your weather app, but for electricity you're generating for free.

Here's where most people leave money on the table

Here's the thing about plug-in solar that the sales pages don't make obvious enough:

You only benefit when you use electricity at the same time your panels are producing it.

If your panels generate 2 kWh on a sunny Wednesday and you're at work, out shopping, or just not running anything — you export that energy to the grid for around 4–5p per unit. Great for the grid. Less great for your payback period.

But if you know — because Sun Hours told you — that 10am to 1pm on Wednesday is your peak window, and you put the washing machine on at 9:55am? You just used roughly £0.30–£0.40 of electricity you generated yourself rather than buying from the grid at 25p a unit.

Do that consistently and plug-in solar stops being a vague "probably saving something" and starts being a predictable, plannable part of how your household runs.

The notification that does the thinking for you

If you work shifts, odd hours, or just don't want to remember to check an app every morning — Sun Hours has you covered.

Switch on the Sun Hours peak alert and your phone buzzes the moment your best two-hour generation window opens. No checking. No guessing. Just a tap on your screen that essentially says: now's the time — switch something on.

There's also an optional daily morning briefing that lands first thing and gives you a one-line summary: great day, decent day, or don't hold your breath. Takes two seconds to read and sets your expectations for the whole day.

That's it. That's the whole system. Your panels generate. Your app tells you when. You act accordingly.

Can it really be as accurate as complicated paid setups?

Honestly? More often than not, yes.

The reason isn't magic — it's that the single biggest variable in your generation forecast isn't your panel specs or your tilt angle. It's the weather. Specifically, cloud cover. A technically perfect setup with a £200/year monitoring subscription and an API-connected inverter still can't generate electricity through clouds.

Sun Hours uses real-time cloud cover data for your postcode. That's the number that matters most. And because the app calibrates to your actual real-world best day rather than theoretical panel specs, it naturally accounts for your specific positioning, any shading, any losses — without you ever having to think about them.

It won't match a professional inverter-connected monitoring platform on every data point. But for the practical daily question — is it worth running the dishwasher now? — it's accurate where accuracy counts.

Completely free. No account. Nothing to sign up for.

Sun Hours is free. You don't create an account. You don't hand over an email address. Your postcode stays on your device.

It's not a freemium app with the useful bits locked behind a subscription. The forecast, the notifications, the 7-day view, the hourly curve — all free.

Because the app that's simplest to open is the one you'll actually open every day. And an app you open every day is the one that makes your solar panels pay for themselves faster.

⬇ Download Sun Hours — free on Android

Get Sun Hours on Google Play →

Your panels are ready. Sol's ready. ☀️