The home energy transition usually starts small: first solar panels, then an EV or a heat pump, perhaps a battery later on. Each purchase feels like a smart move at the time. But sooner or later, many homeowners find themselves with a basement full of devices that do not communicate with each other, and nothing to tie them together into a single, integrated system.
Hager: in-building energy supply with storage and EV integration
For installers and energy providers, this changes the sales conversation, because the equipment chosen today will shape what a customer can add tomorrow. We believe compatibility should become a defining measure of quality in Europe’s home energy market. A successful installation should leave the household free to choose its next investment, whatever hardware that involves.
What customers actually want
There is clear evidence that customers care about compatibility. In a 2025 survey by energy management provider gridX, 88 percent of 265 asset owners in Germany, the Netherlands and the UK said compatibility between existing and new devices was important. Their answers point to a practical concern: how easily can the next purchase be integrated into what is already installed at home?
But it is worth being precise about what technological openness actually means. Can an energy management system integrate equipment from different manufacturers? Can it actively control those devices, with the functions the household needs? Can the customer change their electricity supplier or optimisation service while keeping useful equipment? These are all different questions, and a list of compatible brands answers only part of them.
An open interface that provides meter readings does not necessarily allow another service to control a battery. At the same time, proprietary software can integrate equipment from many manufacturers. An all-in-one package may leave plenty of room to expand, while a multi-brand platform may still tie its optimisation to a single tariff. Customers need to know exactly which functions and options their purchase includes.
The trade-off between convenience and choice
Integrated systems have considerable strengths. A defined set of components can simplify design, commissioning and customer service, households value having one app and a clear point of contact, and installers benefit from standardised processes and familiar equipment. But that convenience comes at a cost. When all components depend on a single vendor, the household’s options for future purchases narrow: replacing one device may mean replacing several, and switching providers may not be practical. Any case for greater openness must preserve the simplicity customers value, without the dependency they did not choose. Customers should not have to become systems engineers to turn their homes into smart homes.
For installation businesses, broader compatibility also opens up business in the many homes that already have equipment installed. A customer with a working PV system may want storage or smarter charging without replacing what already works. Meeting that demand can build a lasting customer relationship, but it also requires investment in training, integration testing and clear responsibility when something goes wrong.
Europe's uneven foundations
Countries across Europe are starting from different places. The Netherlands has a standardised P1 interface for access to metering data, while Spain and Italy achieved almost complete smart meter coverage in 2024, according to figures from the EU energy regulator ACER. These are useful foundations for digital energy services, but they do not tell us how freely households can combine devices. That depends on the home energy management system (HEMS).
Solax Power: new systems for residential and commercial buildings
For providers with tightly integrated HEMS, opening their platforms to compatible equipment from other manufacturers may seem counterintuitive, but it works in their favour too. Above all, it creates a way into the retrofit market, giving households more ways to use existing equipment, while providers can reach customers beyond their initial installations. That commercial incentive can bring integrated systems and broader compatibility closer together.
Shared technical standards can help here. In 2026, the EU’s voluntary code of conduct for energy-smart appliances expanded to cover additional product categories such as energy management systems, PV inverters, batteries and private charging points. But the value of such frameworks ultimately depends on how they are put into practice: the specific device, software version and control function must work together reliably.
Building for what comes next
This places a new responsibility on suppliers and installers. Compatibility should be documented at the level of individual models and functions, and customers should know what happens if their internet connection fails, a subscription ends or they want to change provider. They also need to understand the full cost, including installation and ongoing services. Transparency is most useful when it leads to dependable, affordable choices.
SAJ Electric: innovative storage solutions for residential & C&I
At SpotmyEnergy, our approach is to connect compatible equipment from different manufacturers and optimise its use in line with dynamic electricity prices, without tying the optimisation service to a specific hardware package. Our installation partners can give reliable advice on compatibility, while we are open about any linked services and give customers full control over equipment they already have. Building trust in those capabilities matters as much as adding another brand to a compatibility list.
Future-proofing belongs in the standard package of every home energy system. Whether you are an installer or a manufacturer, the key question is not only what a system does today, but also whether it can easily adapt to developments in the energy market. A home energy system should grow with the household, and that means no more closed boxes. (hcn)
