Storage Heater Cost/Benefit Calculation Check

ch_152

Hello all.

Been in this flat for nearly 3 years now. It's a maisonette and the top floor bedrooms get very cold (poorly insulated roof)

The previous owner removed the two storage heaters from the upstairs bedrooms, replaced with simple plug-in heaters which I set timers to run using Tapo switches.

I was looking to possibly reinstate storage heaters in these rooms as the plug in heaters are costly to run (of course), but it seems it would not be that sensible a move, financially, but was hoping to get a sanity check on my calculations, and to make sure there's nothing else I'm missing...

Taking the main bedroom as an example:

• I've assumed that I run the plug in heater for 3 hours in the morning and 3 hours in the evening
• This has a rating of 2kW
• I'm on agile, and have averaged the unit cost for last winter (Nov-Apr inclusive) during the morning and evening periods at 22p and 19p, respectively.
• This results in a cost of ~£2.45 per day, or £445 per year (for the 6 months when it's below 10 degrees outside).
  

• I will control the Quantums so that they are supplied with electricity for around 6 hours per night (let's say 00:00 - 06:00)
• Looking at a 2.2kW rated unit in the bedroom (although should probably should go bigger)
• The average rate for agile between 00:00 and 06:00 last winter was ~16p/kWh
• This results in a cost of ~£2.13 per day, or £387 over the year.
  

So the saving by installing the storage heater in that room would only be ~£57. New, the Quantum QM100RF is over £800, and even second hand are upwards of £400. Plus electrician bills to wire up.

So it seems like it's definitely not worth the investment (while I do like this flat, I won't be living here forever)? Or have I missed something?



Worth noting that on a standard E7 day/night tariff of approx 30p daytime and 12p night-time the calculated saving comes out at over £350 - somewhat more appealing.

QrizB

If the bedrooms only require a few hours of heat each day, storage heaters are unlikely to make sense financially.

I'd also suggest that you're hugely overestimating the heat demand of your bedroom; 12kWh (2kw for six hours total) is roughly a quarter of the total daily heating demand of my 3-bed semi.