Gandhinagar: Power minister Saurabh Patel today said Gujarat has sold surplus power available in the State to 10 States. In reply to a question in the assembly, Patel said Gujarat generates lot of power, supply of which depends on situation on demand side. Power can’t be stored. Demand and supply of power go up and down depending on monsoon, holidays,temperature and availability of wind and solar energy and other factors. When power demand is low, the State supplies power to other states.