ZEB has an internet connection, drawing real-time information about the grid and live weather data and combines the information with the historical use of the house to take advantage of the best electricity prices throughout the day and night. Typically, it will draw most of the energy it needs during the night when electricity is cheaper and less carbon-intensive and only top up when necessary during the day.

 

PROS: The ZEB is compatible with a normal boiler installation. If you are refurbishing, you can run your existing gas boiler for the last couple of years to save money (windows, floor and loft insulation), but remember to reinforce the floor and verify all other compatibility aspects. 

What do you need to check:

• Weight: the ZEB weighs 375kgs, so it can’t just sit anywhere. Its ideal location is on the ground floor, or if you are refurbishing the property, you can reinforce the floor where you plan on installing the ZEB for peace of mind.

• Access: the weight and size also create a few problems for the installation. Very tight stairs could prove impossible to conquer. 

• Cost: The ZEB, including VAT and installation, is £6000. It will pay itself in the long run but it is still an investment. The government doesn’t consider energy batteries worthy of incentives; we disagree and think there should be tax breaks similar to the ones benefitting heat pumps.

• Maximum power: at a maximum of 12000 kWh per year, the ZEB is suitable for properties up to 120-130 square metres (unless super insulated).

• Electric power load: the ZEB draws 40 amps. The typical home fuse is 80Amp, giving ample load for other items. Nonetheless, if you have a lot of other electric loads, you should consider upgrading the fuse to 100 Amp.  

• You’ll need to switch your energy provider to one that gives discounts at night. Octopus energy, for example.