What's to be done with 'spent' wind turbine blades?

Given that there are already an estimated 345,000 utility scale wind turbines installed around the world (based on Global Wind Energy Council statistics) and that most are designed for service lives of 20-25 years, there is a looming issue; what should happen to large fibre reinforced plastic blades when their service lives have expired? Another statistic, that some 10-15 tonnes of FRPs are associated with each megawatt of rated wind turbine power, further illustrates the scale of the emerging challenge.