@thirstforwine this is a fascinating issue. Wind turbines produce power when the wind blows. Energy production from wind can fall off quickly if the wind gets gentler. When this happens, other sources of electricity need to come online. Right now, those other sources are mostly gas power plants.
Conversely, when the wind blows fierce, some of these gas power plants need to be turned off. What’s weird about it all, though, is that the National Grid can’t let them be too unprofitable (at least not yet). If they had to shut down entirely, there might be power shortages when the wind dies down. This is the reason for the payments to balance electricity generation. Even if the gas plants are not needed during a season, they are paid to be kept online just in case.
There are tons of exciting ideas for balancing electricity generation that don’t involve fossil fuels, One is the plethora of awesome battery technologies – pumped-storage hydro is, in a sense, one such technology. A second is demand-response technology – smart appliances like dishwashers that only turn on when electricity is plentiful. This second idea can even be combined with the first; an electric car that only charges up when electricity is plentiful, yet also gives some of its stored power to the grid when electricity is scarce. Non-intermittent renewable energy sources, such as anaerobic digestion and hydropower, are another piece of the green solution. (Read more about these ideas here: http://www.vox.com/2016/2/12/10970858/flattening-duck-curve-renewable-energy – the article relates to solar in California, but most of the ideas also apply to wind in the UK.)
In summary, this is the next frontier of the quest for green energy – finding a way to manage wind and solar’s intermittency. There is no dearth of solutions if we find the will to implement them.