Do we need a Night Rate meter?
Usually it will pay, unless you are in a very small property (there may be a slightly higher standing charge). The night rate is around half the price of day rate, and a heat pump which is linked to the weather takes natural advantage of what is usually the coldest period in the 24hr cycle. You can also schedule the heatpump to work a little harder during the off peak period and store the energy in the concrete floors if you are using floor heating.