Salvage your panels

Ask around, watch local listings, and you can frequently pick up replaced panels for free. They are not showroom pretty, but they work, and free beats new every time.

Stack of salvaged monocrystalline solar panels with MC4 cables on grass
A stack of replaced house panels. Not pretty, but they still produce and cost nothing.
Salvaged solar panels beside IBC rainwater tanks in a backyard setup
Salvaged panels in the yard beside the rainwater IBCs. Same frugal instinct: reuse what someone else replaced.

If you want to buy new: flexible panels

Salvaged rigid panels are my first choice, but flexible panels are also worth a look if you are buying new. They are light, easy to mount on a shed roof or caravan, and handy when you do not want the weight and rigidity of a glass panel.

Flexible thin-film solar panel held up to show its bend and MC4 connector
A flexible panel: light, bendable, and easy to fit where a rigid panel will not go.