Thermal power plants generate both electricity and heat, and with the continuous updating of thermal power plant technology, coal is burned more fully than in traditional thermal power plants． In orde

Q put =mq=4000×10 3 kg×3×10 7 J/kg=1.2×10 14 J;

(2) the electricity generated in 20h:

W=Pt= 5×10 5 kW×20h=10 7 kW?h=3.6×10 13 J;

(3) the energy utilization of the thermal power plant:

η=

So the answer is:

(1) 1.2 × 10 14 ; ?

(2) 10 7 ; ?

(3) 60%.