German clay core heaters save you money
German Clay Core Heaters vs Storage Heaters: Running Costs
Our German electric heating clay-core heaters can, in some homes, use less electricity for heating than previous storage-heater arrangements. The amount you could save is difficult to predict because every home is different. Here we explain some of the ways savings may arise and show the assumptions behind our examples.
Some years ago we had a customer who had storage heating , was a retired chartered engineer and kept meticulous records of his energy consumption and was concerned about the high running costs of his storage heaters. He changed to our German Clay core heaters and we happened to bump into him a few years later. We asked him how he had found our heating in comparison to his storage heaters. He said they found the rooms much more comfortable than before and (as he was still keeping records) , was saving about a third in his heating costs.
We have had many other customers over the years who have told us they were delighted with their heaters. Others have not commented on running costs, so we cannot assume a particular result for them. The example above is one customer’s experience, not a guarantee of the saving another household will achieve.
We will now look at a worked example using published tariff figures. It illustrates how the potential running-cost difference can change when electricity tariffs change, but it is not a prediction of what any particular household will save.
The example above describes one customer’s experience. The worked figures below are separate theoretical calculations, based on stated assumptions. They should not be taken as evidence that every household will achieve a similar percentage saving.A word of warning, remember your electricity bills also include not just your heating but lights, cooking television etc, which will not have changed so you may not get the overall reduction in your electricity bill you might be expecting. Also many people will take advantage of the potential savings using our heaters in other ways and maybe opt for warmer rooms than they had before. Everyone is different .
Back in February 2019 we updated one of our factsheets to include the then current electricity prices. At the time we were comparing SSE rates (Scottish and Southern Energy or Scottish Hydro ) prices for “cheap” overnight rates with their standard single tariff. Since then OVO energy have taken over their customer base . This can be seen (on page 2) here
For this historical comparison, we reviewed the April 2025 prices shown by the OVO Energy website for THTC (Total Heating Total Control), which has two rates, and the simple energy tariff with one rate. These figures are included as a worked example and should not be treated as current tariffs.
Here are the results
| Ovo Energy Tariffs 1/4/25 | £ Unit Price | Ovo Energy Tariffs 1/4/25 | £ unit Price | Saving £ using THTC | Saving % using THTC |
|---|---|---|---|---|---|
| Simpler Energy THTC | Simpler Energy | ||||
| Paid by direct debit | Paid by direct debit | ||||
| Multi Rate Meter | Standard meter | ||||
| Anytime | £0.2844 | Anytime | £0.2570 | – £ 0.0274 | -10.66% |
| Heating | £0.2271 | Heating | £0.2570 | £0.0299 | 11.63% |
| Standing Charge | £0.5873 | Standing charge | £0.5797 | -£0.0076 | -1.31% |
These April 2025 figures show a roughly 11% reduction in the heating unit rate using THTC compared with the single-meter tariff shown, alongside a higher rate for other consumption. It is possible to better these standard meter tariffs shown above even more by shopping around See here
The spreadsheet we used for the above table can be downloaded here If you want to put in your own rates to analyse, then please do.
The table below shows these figures applied to storage heater and German heater performance
| Type | Power (KW) | Total Time On | Time on per working hour | Unit rate £ per hour 2019 | Unit rate £ per hour 2025 | Running costs per day 2019 | Running Cost per day 2025 |
| Storage Heater | 3.4 | 8 | 100% | 0.1294 | 0.2271 | 3.52 | 6.18 |
| German Clay Core | 2 | 16 | 33% | 0.1774 | 0.2570 | 1.87 | 2.73 |
| Saving per day German heater | £1.65 | £3.46 | |||||
| % saving per day German heater | 46.78% | 56.06% |
On the assumptions used in the worked example above, the calculated saving rises from over 40% to over 50%. This is a theoretical comparison rather than a prediction of what an individual household will save. Actual results depend on heat demand, heater sizing, thermostat settings, occupancy, insulation, tariff and how the heating is used.
Why does the result change? In this particular comparison, the difference between the two tariff rates had changed over time. The night-time heating rate had increased relative to the day rate, which reduced the tariff advantage that storage heating previously had in this example. Tariffs change, however, so the calculation should be revisited when comparing current prices.
Please browse our website to see the other benefits of using our heating solutions
For a broader comparison of electric heating costs in Scotland, see our Elsco Heating guide to electric heating costs. If you want an initial indication of the cost of new heaters for your home, you can also use the free heating calculator on the Elsco Heating website. It is intended as a useful guide to heater sizes and likely costs, rather than a substitute for a full heating assessment.
Useful info in this Press & Journal article about the benefits of our heating compared to storage. Click here
If you are concerned about older storage heaters, see our storage heater problems and alternatives page.
