Does anybody have any experience of pond pumps, or of solar powered devices?

As I've finished most of the things I wanted to do on the house, I'm starting the garden from scratch this year.
The garden includes a small pond, with a raised bed behind it. The raised bed has a waterfall feature built into it, but no working equipment.

The pond is approx. 2.5m by 1.5m, and the top of the waterfall feature is 50-60cm above the pond water level.

The pond is on the shady side of the garden, but there's a shed right next to it. The roof of this shed would get a lot of light.

The shed does have power - there's a RCD on the outside of the house with a length of armoured cable running down the garden to the shed. But the shed is fairly old and not in top condition, so I'm happier with the RCD switched off when the shed is unattended.

So I'm looking at a solar pump. The shed roof means that I could have as many panels as necessary.

Specific questions I have...

- In reduced light levels, does the voltage or current from a solar panel get reduced? It'd make a difference to how I wire multiple panels together.

- Can you suggest a suitable pump and panels?

- Maybe a battery charging mechanism to store extra charge in better light conditions?

- Recommendations for connecting it all up? I have some electronics and soldering equipment and skills.

If it makes any difference, the pond gets frogs in it, so nothing that'll harm them please.

Is it possible in a budget of, say, £50?

With the shed nearby, I can obviously house anything like the battery indoors.