[cinntaile]

Regular consumers don't offer their production on the energy markets so they don't set the price. Maybe your panels can be counted as part of the energy company's solar production, in that case I guess they could indirectly have an influence? I'm not sure if this is done though. A negative price can just be a result of tax subventions (in case you still make a profit even if the price goes negative) or when it's simply cheaper to bid a negative price so that you can keep producing instead of having to turn off production and then reboot it at a later time.