the article and source mis-represent how it arises, working back from bills to say this amount is attributable to this issue. its built in to the cost of wind power, into the contract structure, as it's inevitable this will occur. you accept storage isnt cheap, it's the same problem, paying for...
we dont pay directly for that sneaky bonus, we'll pay the same kWh/p. it's absorbed with all the other inefficencies and subsidies, someone else int he system got a little less revenue. the storage is another cost and the incentives aren't there - why store when you can switch off? so another...
i believe it's becaue they are contracted to produce, so they get paid when the production is available. when the wind is too strong there is excess supply, combined with insufficent demand, they get paid anyway. and they turn off the turbines. there's nothing new about this, no secret...