Switching electricity supplier in the summer

xyzperson

My flat only has electricity. My storage heaters use a lot of electricity. My use of electricity in the winter is huge. At night my use is, say, 88 kWh in winter but only 11 kWh in the summer. My day time use has an average of 10 kWh and remains constant throughout the year - only visitors or going away seem to really change it. The cheapest rates for night-time use have a high daytime cost. Does anyone swop supplier for the summer and winter?