Unexplained half-hourly usage pattern

Unfortunately heaters are heaters and they are all about the same. It's actually the easiest thing to do to turn electric power into heat but it's inefficient. What to do?

Economy 7 and storage heaters used to be a way of heating for less but unless you have E7 now you won't get anyone (as far as I know) to install you a meter. The night and day rates have been converging anyway so there is precious little saving these days anyway. ​@Firedog may be able to pad that out with words wiser than mine but we had a discussion recently about the official/unofficial phasing out of E7.

People usually heat with gas but I'm assuming that is not installed / not possible so not an option. That is how most people keep their heating bills low.

Assuming that you are electric only the other form of cost efficient heat is a heat pump. ​@juliamc is good with the ASHP type and I have an air to air heat pump (A2AHP) or just A2A which is both cheap and effective but not a complete solution. Having tagged Julia I hope she will offer words of wisdom on that.

As a comparison ASHP is quite an installation process but gives very good efficiency although I'm now thinking you don't have any water radiators. A2A is an easier installation and a multi split unit will distribute warm air around the house. The heat pumps cost about a third of the cost of simple heaters to run.

Peter 

Err, not sure how wise my words would be !!
If there were already radiators and the associated pipework all ready to go then maybe a heat pump installation to run them wouldn’t be massively disruptive. However if your mother doesn’t have gas I doubt there’s ‘wet’ central heating? Maybe she had storage heaters in the past… in which case economy 7 might be a possible available tariff?

Efficiency wise I’d be tempted to look into the Air to Air units that ​@Peter E has. I think you can get a grant for A2A heat pumps now  - but it won’t be a BUS grant as that’s the Boiler Upgrade Scheme. 

Another thought (which could be a bit of a gamble) is changing your mother’s tariff to something like Octopus Agile which is invariably much cheaper at night - though can be prohibitive during the early evening so probably a daft idea. 
 

Thanks so much for going to the trouble to get Bright up and running. The data you see there are taken direct from mother’s meter, so they’re not mangled by OVO’s slightly dodgy billing system. As you remarked, they give an accurate representation of mother’s slightly eccentric usage pattern.

The ⠇menu to the top right of the app screen gives the option to show usage in kWh instead of cost in £. This should be helpful when trying to compare equipment and tariffs, for example. You can use screenshots like the one you shared here to persuade OVO’s support staff to mend mother’s account.

You asked for “recommendations for more energy efficient heaters.” As ​@Peter E pointed out, all electric heaters are 100% efficient - all of the electricity they consume is turned into usable heat. For comparison, a modern gas boiler only manages to turn 90% of the energy it consumes into usable heat - the rest goes up the chimney 

A heat pump isn’t an ‘electric heater’ in the normal understanding of the term. It works just like a fridge, using electricity to cool one body of air in order to warm up another. This gives an apparent efficiency of greater than 100%, but that isn’t in fact the case. Nevertheless, each kWh of electricity can pump three or four kWh of heat from outside to inside the home. You might want to investigate this possibility, but please seek advice from trusted sources. There are lots of snake-oil merchants out there eager to sell ‘more efficient heaters’ - don’t be taken in. This forum may be a good starting place.