Photo Credit: YouTube
Winter changes the equation for homes that combine rooftop solar, battery storage, EV charging, and a heat pump.
That is why one U.K. homeowner is comparing Octopus Energy’s winter options, trying to decide whether staying on Flux or moving to Intelligent Go or Cosy offers the best chance of ending 2026 with a net $0 energy bill.
Here’s what to know
A YouTube video laid out the problem using a real household with solar panels, battery storage, a heat pump, and two EVs. The main point was that a tariff setup that works extremely well in summer may need rethinking once seasonal solar production falls.
January 2026 shows why. Jonathan Tracey (@JonathanTracey) said the home imported about 1.5 megawatt-hours that month, largely because two electric cars needed charging and the heat pump was running through a cold spell. In that kind of winter pattern, Flux’s strong evening export payments are less valuable because less spare solar energy is available to send back to the grid.
The sunnier months, however, appear to have gone well under Flux. By the end of September 2026, the account had moved from roughly £222.70 (about $295 at current exchange rates) owed in early April 2026 to about £248.21 ($328.65) in credit. At the end of September 2025, the balance was only around £127 ($168) in credit, so 2026 was more than £100 ($132) ahead.
He described the goal this way: “My aim is to finish the year with a net £0 energy bill, with export earnings covering what I spend.”
Any switch also has to be judged against its downside. He said some tariffs include exit fees, and leaving a plan early could mean paying £50 ($66), which could erase much of the gain from a short-term tariff tweak.
More background
Each tariff solves a different problem, which is what makes the decision difficult. Cosy provides three cheaper charging windows that may better match heat pump use, Intelligent Go can lower the cost of overnight EV and battery charging, and Flux is most attractive when exports can be timed well.
Export choice adds another complication. Outgoing Agile offers variable export pricing, but getting value from it can require either close hands-on tracking of prices and battery levels or software that automates the setup.
One commenter said, “Getting the most out of Agile Outgoing needs a lot of spare battery capacity,” plus “a lot of manual daily work or automation via Home Assistant or a third-party tool.”
A separate Thunder Energy plug-in solar system on the property saved the equivalent of £46.04 ($61) over 88 days, which worked out to roughly 7% of its retail value recovered in about three months.