with 321.4 * 10 as the energy consumption by wind, and wind accounts for 21.4%, you can set up an equation such as this:
21.4 / 100 = 3214 / x
This basically says that 21.4 out of the total of 100 is equivalent to 3214 out of the total consumption x. The ratios have to be equal because the problem gives that 3214 of the total energy is 21.4%.
You can cross multiply to get:
21.4x = 321400
and divide by 21.4 to get your answer:
x = 321400 / 21.4
x = 15018.69
This means that your total energy consumption is 15018.69 units. The units here are whatever was originally given in the problem.