They are not paying for someone to take the power - that's poor journalism.
It works like this: Every energy producer bids a price for their power, the lower your price the higher you are on the order book.
Then energy consumers will meet the demand by buying from the producers in the order of their price.
Once they have filled their power demand they pay everyone the price of the last price they needed to fill their needs.
So by setting a negative price they ensure they are always on top of the order book - but they don't actually have to pay for their power since other power sources have positive prices, and that's the price that is actually paid.
It works like this: Every energy producer bids a price for their power, the lower your price the higher you are on the order book.
Then energy consumers will meet the demand by buying from the producers in the order of their price.
Once they have filled their power demand they pay everyone the price of the last price they needed to fill their needs.
So by setting a negative price they ensure they are always on top of the order book - but they don't actually have to pay for their power since other power sources have positive prices, and that's the price that is actually paid.