26 September 2026

 

There comes a point every autumn when closing the curtains no longer feels sufficient. You turn on the heating, listen to the boiler start and wonder how much that small moment will cost by spring.

This year, the question feels particularly uncomfortable. In mid-September, Europe’s gas stores were around 69% full, compared with a five-year seasonal average of approximately 85%. Gas prices had risen sharply, while diesel and heating-oil costs were also putting pressure on households.

Petrol may dominate the headlines, but for most European homes the largest controllable winter energy cost is heating. Around 80% of the energy used in EU homes goes towards heating, cooling and hot water.

The most useful home energy technology generally does one of four things: sensors reveal where energy goes, algorithms learn how a home behaves, controls stop unnecessary consumption and software moves flexible demand to cheaper hours.

The first step is discovering which problem you actually have.

 

Find where your home is losing heat

 

Heat is invisible. A room may feel draughty, but that does not reveal whether warmth is escaping through a window frame, an uninsulated wall or the loft hatch.

A thermal camera turns temperature differences into a coloured image, revealing cold surfaces and possible thermal bridges. Professional energy surveys remain the gold standard, but compact thermal cameras that connect to a smartphone can provide a useful first look.

They work best on cold days when there is a substantial temperature difference between indoors and outdoors. Sunlight, rain and reflective surfaces can distort the image, so a bright blue patch is a clue rather than a diagnosis.

For electricity, a simple plug-in energy meter shows what individual appliances consume.

More advanced whole-home monitors use non-intrusive load monitoring. Instead of attaching a sensor to every appliance, they analyse changes in a home’s electrical waveform and use signal processing or machine learning to recognise different devices.

A kettle creates a strong, distinctive signature. Separating several low-power electronics is much harder, so the results are not always perfect. Still, the technology can expose an ageing freezer or dehumidifier quietly consuming far more electricity than expected.

 

How smart thermostats reduce heating costs

 

Buildings warm and cool slowly. Each room loses heat at a different rate, while sunshine, wind, cooking and human bodies continuously alter the calculation.

A  programmable thermostat follows a schedule. A smart thermostat can combine temperature sensors, weather forecasts, occupancy information and previous heating patterns to predict when the boiler needs to start.

The International Energy Agency estimates that lowering a thermostat by 1°C can reduce heating-energy consumption by around 7%. Programmable reductions while people sleep or leave the house may cut heating bills by as much as 10%.

These are estimates, not guarantees. Actual smart thermostat savings depend on climate, insulation, the heating system and how carefully the household already manages it.

Turning the temperature down also affects humidity. Cold air holds less water vapour, so moisture can condense when warm indoor air touches a cold wall or window. Persistent condensation may eventually contribute to mould.

An inexpensive temperature and humidity sensor can help track both. Saving energy should not mean allowing rooms to become permanently cold and damp. Ventilate after showering and cooking, and investigate recurring condensation rather than simply wiping it away.

 

Smart radiator valves control heat room by room

 

Traditional central heating treats a home rather democratically. If the thermostat says it is cold, every radiator receives heat, even if nobody has entered the guest room since Easter.

Smart radiator valves allow different rooms to follow different heating schedules. Bedrooms can remain cooler during the day, while a home office is heated only when someone uses it.

Note that a smart valve can close an individual radiator, but it does not necessarily tell the boiler to stop heating. The best systems coordinate radiator controls with the boiler rather than leaving it cycling unnecessarily. Some heating systems also require sufficient water flow when several valves close.

Check whether important functions require a subscription or permanent cloud connection. A radiator valve should not become considerably less intelligent because its manufacturer loses interest in the app.

 

Can smart plugs save electricity?

 

A smart plug only saves electricity if it measures or stops consumption that would otherwise continue.

A smart plug with energy monitoring might reveal an inefficient appliance or switch equipment off according to a schedule. Placing one on a modern lamp that is already turned off when not needed will achieve very little.

Never connect a high-power electric heater to a smart plug unless both manufacturers permit it and the plug is rated for the load. Saving a few euros is not worth overheating an underrated socket.

The same scepticism applies to plug-in “electricity-saving boxes” promising dramatic reductions without explaining what they control. Consumer gadgets cannot magically prevent an appliance from using the energy required to do its job.

An energy dashboard can also produce attractive graphs without reducing consumption. Data only lowers a bill when a person or an automated system acts on it.

 

How dynamic electricity tariffs can lower bills

 

Dynamic electricity tariffs turn time into another source of savings. Prices vary with market conditions, often falling when wind and solar generation are abundant and rising during the evening peak.

Households can schedule dishwashers, water heaters, home batteries and electric vehicles for cheaper periods. The deeper technology appears when software combines smart-meter data, electricity-price forecasts and connected devices to do this automatically.

Dynamic tariffs do not suit everyone. A household that must cook, heat the home and charge a car during expensive hours could pay more. Examine your existing consumption pattern before switching.

Nor should cheap electricity override safety. Running washing machines or dishwashers unattended overnight is not worth the small saving if a leak or electrical fault goes unnoticed.

 

Can a heat pump reduce heating costs?

 

The largest potential saving requires more than a gadget.

A gas boiler creates heat by burning fuel. A heat pump uses electricity to move existing heat from outdoor air, water or the ground into a building.

A heat pump delivering three units of heat for every unit of electricity has a coefficient of performance of three. Whether that beats a gas boiler financially still depends on the relative prices of electricity and gas.

The European Commission says replacing a gas boiler with a heat pump could cut the average EU household’s heating bill by up to 60%. The words “up to” are important.

Insulation, climate, radiator size and installation quality all affect heat-pump efficiency. Heat pumps work best at lower water temperatures. A draughty home with undersized radiators may need upgrades before the technology delivers impressive savings.

Replacing a functioning heating system also requires a much larger investment than installing sensors or controls. Compare the expected annual saving with the complete cost of installation and any necessary building improvements.

 

The best order for home energy upgrades

 

A sensible energy-saving plan begins with inexpensive diagnosis, not an expensive shopping basket.

Starting point	Technology	Main purpose
Under €30	Plug-in meter or humidity sensor	Find wasted electricity and damp
€50–€200	Thermal-camera hire or basic heating controls	Locate heat loss and improve scheduling
€100–€500+	Smart thermostat and radiator system	Automate room-by-room heating
Contract-dependent	Dynamic tariff and energy software	Shift consumption to cheaper hours
Major investment	Insulation, heat pump, solar or battery	Improve the home’s underlying performance

Prices are approximate and vary across European markets.

The smartest home is not necessarily the one with the most connected devices. It is the one that can see where energy is going, learn when it is needed and quietly stop wasting it, preferably before anyone has to think about it.

 

 

Some product links in this article may be affiliate links. MTN may receive a small commission from qualifying purchases, at no additional cost to the reader.