It’ll be the heating.
This month, our gas is providing hot water only - around 110 kWh used. In January, with the central heating on, it was over 1,800 kWh.
An extra 1,700 kWh at 7.5p (current SVR for gas) = £127.50 extra.
At 12p/kWh (guesstimate SVR from October) = £204 extra
That’s on my usage. We are also 2 people in a biggish 4-bed, but it’s new build and energy efficient. I don’t scrimp, but I have taken steps to reduce usage. So my prediction is that your actual cost next January will be a lot more than £145 + £204.
With a level DD all year round, you build up credit in the summer and use it up over the winter. If your DD now was only just covering your usage, you would be storing up trouble. Whether your £300 DD will be enough to see you over the winter - bearing in mind you will receive £400 credit from the Government between October and March - I can’t be sure, but I’m inclined to think not.
£300/month = £3,600/year, and that is now the price cap prediction for the mythical TYPICAL household usage of 12,000 kWh gas and 2,900 kWh electricity. I rather suspect yours will be higher than that.
So you might need to pay £400/month, or £500/month, who knows. If you can do that, and are happy to do that, fair enough. If that would be an issue, or if, you know, you have grasped that the severe heat we had last week was a result of climate change, and that reducing CO2 emissions is urgent, then there are lots of things you can do to reduce your usage (without skimping on comfort.)
Make sure all your light bulbs are LED.
Only boil the water you need, not a full kettle
Wash at lower temperatures, making sure it’s a full load.
Turn down flow temperature and hot water temperature on boiler.
Fit aerators to taps and shower head
Etc etc etc - lots of things which individually may only save half a percent or one percent (though the boiler things could save 5-10%), but taken together make a big difference.
The steps I’ve taken include driving an EV, installing solar panels and battery and getting on an EV tariff. I’ve just fixed that for the next 12 months (7.5p/kWh for 4 hours a night, 40.9p the rest of the time and 51.36p standing charge) and our estimated electricity cost for the next year is less than £600, including charging the EV. If I didn’t have the solar and battery it would be nearly £1,500 on this tariff, about the same on the standard variable tariff as it currently is, and therefore more on the SVR from October.
On gas, I got us on to Octopus Tracker when that was capped at 6p, that puts our annual gas costs at around £700. But Tracker has since increased its cap to 11p, and then to 16p. SVR for gas is now 7.5p, could be 12p from October - so if we were on that, our gas costs would be £1,800.
All of which adds up to saying - if we were on standard variable tariffs and had not done the solar/battery thing, we would be looking at close to £4,000 pa for energy for 2 people in a new, fairly energy efficient 4-bed - although that does include charging an EV, so no petrol bill to budget for.