I am currently successfully experimenting with very small solar panels that when linked to my system create control voltages dependent on the amount of light hitting them. These panels seem to work fine but am I risking my gear ? I guess I should have asked this question earlier, here are the details of the type of solar panels I am using-

"Seeed Studio Solar Panel
The Seeed studio 0.5W is a monocrystalline silicon solar panel. This solar panel performs a higher conversion rate that up to 17% as compared to polycrystalline silicon solar panel and thin-film solar panel. This kit has a length of 70mm, a width of 55mm and a height of 3mm. It can be used for power supply.

Features and Benefits
• Maximum load voltage 6.4V
• Open circuit voltage 8.2V
• Typical current 100mA
• Typical voltage 5.5V"

Thanks for any input!

Those voltages all seem quite safe in the Eurorack environment. Be very careful, however, not to patch these into outputs by mistake!

Thanks Lugia, thats what I thought but I needed to double check!