WRT the original post, Patullose, the freezer won't use more energy overall if you use this method. Yes it will likely operate for a while after you turn it back on to get back to the set temperature, but the overall amount of energy used will actually be less if you do this. Once the freezer is down to temperature and in steady state, the amount of energy consumed is dependent on how much heat leaks in to the freezer - nothing else. This heat depends on the insulation and temp difference between in and out. So the higher the temp inside the freezer, the less heat leaks in and the less heat the heat pump has to take out. On average your freezer will be operating at a slightly higher temp than when it is constantly on, so the average energy consumed will be slightly less.
Have you considered how much energy your freezer uses to see what the effect will be ? Most freezers use <1kWh/day, so if you turn it off for say 8h/day that will shift about 0.3kWh from daytime to night. What's your FiT and how much is a third of a unit worth to you ?