You're on the right track. If they generated 380 less than 2012, then in 2013 they generated 9782-380 = 9402.
They used 10472 in 2012, so 10472+390 = 10862 used in 2013. now subtract used from produced to see how much they had to buy...
10862-10472 = 390
They had to buy 390khW from the power company.
