Monitored consumptionElectric heatingBattery storage

Detached house, Kalvodova, Jeseník

Even an older house can be heated cost-effectively using radiant heating once it has been insulated, ideally in combination with solar panels and a battery.

heating matsheating filmsradiant panelsHES battery storage

An older family home in Jeseník was insulated and subsequently fitted with a 9.9 kWp photovoltaic system, a 41 kWh battery storage unit and electric radiant heating. The four-person household has an annual electricity consumption of around 12 MWh and annual costs of approximately 28,000 CZK. Thanks to its rapid regulation, maintenance-free operation and low investment costs, the owners opted for radiant heating rather than a heat pump.

Electric radiant heating allows for precise regulation via thermostats and smart control systems. It responds quickly to changes in temperature and to so-called heat gains caused by the sun, cooking or the presence of more people. The heating can be switched on or off immediately, thereby efficiently heating only the rooms in use, which brings further energy savings.

Annual electricity consumption is approximately 12 MWh. Heating is provided by a FENIX electric direct heating system; consequently, electricity consumption peaks during the heating season. Domestic hot water is heated using an electric boiler with an integrated heat pump. A wood-burning fireplace is also used as a supplementary heat source.

In autumn 2022, a 9.9 kWp photovoltaic power plant was installed on the south-facing roof and the adjacent canopy. The PV system was supplemented with a HES home battery storage system with a total battery capacity of 41.1 kWh.

Since June 2023, the supply and sale of electricity have been carried out under the spot price regime. Detailed monthly statements have therefore been available since that month. As part of the HES home battery storage system, a control algorithm has been activated which, based on predictions of sunlight levels, consumption and spot electricity prices for the following day, creates a behaviour plan for the photovoltaic system and subsequently controls the system with the aim of achieving the best possible economic outcome.

An example of the system’s behaviour on a sunny day: PV generation is stored in the batteries throughout the day, with targeted feed-in to the grid taking place only in the evening when spot electricity prices are at their highest.

During the period under review (June 2023 – December 2023), an average price of 0.85 Kč/kWh, including all charges, was achieved.

Detailed monthly operating results

Period	Total consumption (kWh)	Off-take from the grid (kWh)	Generation from PV system (kWh)	Feed-in to the grid (kWh)	Consumption from the grid (CZK)	Feed-in to the grid (CZK)	Electricity costs (CZK)	Achieved price (CZK/kWh)
06/2023	435	215	1,084	864	1,560	2,219	-659	-1.5
07/2023	287	252	1,144	1,109	1,345	2,425	- 1,080	-3.7
08/2023	359	348	919	908	1,531	2,342	-811	-2.2
09/2023	425	352	1,018	945	1,515	3,121	-1,606	-3.7
10/2023	642	570	581	509	2,126	1,565	561	0.87
11/2023	1,226	1,097	280	151	3,865	435	3,429	2.8
12/2023	1,739	1,622	230	113	4,662	181	4,481	2.6
Total	5,113	4,456	5,256	4,599	16,604	12,288	4,316	0.85

The monthly results for 2024 confirm that the entire system is functioning very well. The best results are achieved during the summer months, whilst the worst results are seen in months when PV production is at its lowest. However, in the overall annual balance, the resulting price per kWh consumed is significantly more favourable than that achieved through conventional electricity procurement.

Period	Total consumption (kWh)	Off-take from the grid (kWh)	PV system generation (kWh)	Feed-in to the grid (kWh)	Consumption from the grid (CZK)	Feed-in to the grid (CZK)	Electricity costs (CZK)	Achieved price (CZK/kWh)
01/2024	2,111	1,816	328	33	8,493	47	8,446	4.0
02/2024	1,157	794	402	39	3,638	67	3,571	3.1
03/2024	1,134	493	763	122	2,574	131	2,443	2.1
04/2024	706	190	914	398	1,303	722	581	0.8
May 2024	498	169	1,051	722	1,168	1,529	-361	-0.7
June 2024	439	155	1,022	738	1,297	1,955	-658	-1.5
July 2024	371	155	1,092	876	1,232	2,159	-927	-2.5
08/2024	386	176	1,060	850	1,407	2,674	-1,267	-3.28
09/2024	485	252	830	597	1,630	1,742	-112	-0.23
10/2024	850	408	669	227	2,342	770	1,572	1.85
11/2024	1,782	1,398	459	77	8,411	634	7,777	4.36
12/2024	1,974	1,727	300	53	8,047	378	7,669	3.89
Total	11,893	7,733	8,890	4,655	41,542	12,808	28,734	2.42

Detailed monthly operating results for 2025

Period	Total consumption (kWh)	Grid consumption (kWh)	Generation from PV system (kWh)	Feed-in to the grid (kWh)	Consumption from the grid (CZK)	Feed-in to the grid (CZK)	Energy costs (CZK)	Achieved price (CZK/kWh)
01/2025	1,771	1,513	327	69	7,986	488	7,498	4.23
02/2025	1,488	951	587	50	5,848	154	5,694	3.82
03/2025	1,367	673	897	203	3,458	645	2,813	2.05
04/2025	1,049	445	920	316	1,916	888	1,028	0.98
May 2025	843	290	933	380	1,473	1,108	364	0.43
06/2025	494	187	994	687	1,341	2,101	-760	-1.54
07/2025	365	74	962	671	1,207	1,794	-587	-1.60
08/2025	368	89	1,082	803	1,180	2,093	-913	-2.48
09/2025	480	276	699	495	1,815	1,827	-12	-0.03
10/2025	1,069	733	539	203	3,704	901	2,803	2.62
11/2025	1,557	1,376	445	264	7,180	69	7,111	4.57
12/2025	2,130	1,839	324	33	9,109	69	9,040	4.24
Total	12,981	8,446	8,709	4,174	46,217	12,137	34,080	2.63

Detailed monthly operating results for 2026

Period	Total consumption (kWh)	Grid consumption (kWh)	Generation from PV system (kWh)	Feed-in to the grid (kWh)	Consumption from the grid (CZK)	Feed-in to the grid (CZK)	Energy costs (CZK)	Achieved price (CZK/kWh)
01/2026	2 578	2 289	315	26	10 638	109	10 529	4,08
02/2026	2 067	1 785	307	25	7 676	67	7 609	3,68
03/2026	1 653	1 110	854	311	4 555	1 113	3 442	2,08
04/2026	1 447	761	1017	331	2 412	930	1 482	1,02
05/2026	830	490	975	635	1 714	2 152	-438	-0,53
06/2026	448	265	1 034	851	1 697	3 320	-1 623	-3,62
07/2026	428	308	1 060	940	1 770	3 147	-1 377	-3,22
08/2026	387	226	1 090	929	1 785	3 702	-1 917	-4,95
09/2026
10/2026
11/2026
12/2026
Total	9 838	7 234	6 652	4 048	32 247	14 540	17 707	1,80

Prices include VAT.

Reference video

Homeowner's Testimonial

As the owner of an energy-efficient house, I can say that choosing electric radiant heating has proved to be the right decision for us and our family. We were looking for a solution that would make sense in the long term, and we particularly appreciate the significantly lower upfront costs compared to a heat pump, the minimal maintenance requirements and a lifespan that is comparable to that of the house itself. Thanks to flexible regulation, operation is highly efficient, and in our energy-efficient home, energy consumption is on a par with that of a heat pump.