What? They got paid by their energy supplier to keep warm…?

During our ongoing household trials, we have been testing our ability to charge our ZEBs using variable tariffs like Octopus Energy’s Agile tariff. One of our trial houses has had a ZEB installed since early December and we’ve been charging the ZEB using this tariff. 

On the 27th of December 2020, this trial house used enough negatively-priced electricity that the electricity provider owed money to the consumer for the ZEB’s electricity usage over the 24 hour period. Yes, that’s right… they got paid to keep their house warm and heat their hot water even though it was only 5C outside!

In the graph above, the red line is the price of a unit of electricity per half-hour and the blue line is the electricity used per half-hour.

Key points:

  1. The ZEB took advantage of the negative pricing (where the red line dipped below zero) by charging (blue line) with more energy than was delivered to heat the homeThe ZEB avoided charging during the most expensive periodsThe house was owed around £2 at 8:30am, before using positively priced electricity during the next necessary charge which still meant it ended the day at 20p in the positive.

  2. Shifting electricity demand to times when renewable energy is plentiful seems like the obvious thing to do and would be a much less wasteful answer for balancing the grid than wind farm curtailment. Our ZEB is exactly the type of technology that will enable this.If we could move electricity demand away from peak times and towards times with plentiful renewable energy, the nation would use the electricity grid more efficiently by smoothing the demand peaks while also reducing carbon emissions. If you would like to be kept informed of our progress towards the launch of the ZEB later this year, please sign up here: Future Customer Sign-Up