As UK homes adopt more low-carbon technologies – electric vehicles (EVs), heat pumps, batteries, and solar panels – these devices increasingly need to coordinate with each other. Without this important coordination between devices, they can potentially work at cross-purposes. For example, importing expensive peak power for heating while simultaneously exporting battery power, misses an opportunity for self-consumption and bill savings.
Home energy management systems (HEMS) exist to solve this. They monitor and optimise how home energy devices work together to help reduce bills, maximise renewable self-consumption, maintain comfort and provide valuable flexibility services to the grid. This might be delivered through a central hub device in the home, software in the cloud, or via smart devices coordinating directly with each other.
Making this work in a simple way, for mainstream consumers, is harder than it might seem. Drawing on insights from our Living Lab of more than 5,000 UK homes trialling new technologies, we’re seeing multiple layers of challenges: technical interoperability, control coordination, user experience and market structures. Let’s delve into each and how we might solve them.
Interoperability – the ability for different devices and systems to connect and exchange information – is foundational. Energy management systems may connect to devices within the home, and/or via APIs to the device manufacturer’s cloud services. API, or application programming interface, is a set of rules that enables different software applications to communicate with each other.
Within the home, devices need common protocols (shared languages) to communicate. Matter is emerging as a standard that enables device-to-device communication, for instance allowing a heating controller to talk to a HEMS. Matter is a universal, open-source, and secure connectivity standard for smart home devices, allowing products from different brands (like Apple, Google, Amazon, and Samsung) to communicate seamlessly. It simplifies setup, enhances local control, and ensures interoperability using Wi-Fi, Ethernet, and Thread, rather than relying on lots of separate control hubs. But adoption takes time and many existing devices predate newer standards.
Beyond the home, devices connect to manufacturer cloud platforms via APIs, which are proprietary and often inconsistent – even between manufacturers of the same device type. A home’s EV charger, car, heat pump, battery and solar inverter may each connect back to their manufacturers’ cloud services, requiring a HEMS to support a wide range of manufacturers.
At the market level, flexibility services need a way to request demand response from homes. OpenADR is emerging as a standard here. It enables grid signals to be sent to a HEMS or device manufacturer platform, which then translates those requests into instructions for devices.
Poor interoperability creates purchase anxiety for consumers. Which brands work together? Which HEMS supports my devices? One manufacturer’s devices may work together beautifully as a proprietary ecosystem, but not integrate third-party equipment. Lock-in fears add friction to expensive purchase decisions.
Even with perfect interoperability, coordination requires clear control authority. But it’s possible for multiple systems to try to control the same device simultaneously.
EV charging is the prime example. Instructions can come from the car’s app, the charger’s app, a smart charging service, a flex service, or the energy supplier, resulting in potentially conflicting commands. To participate in smart charging services like Octopus Intelligent Go or ev.energy, users must disable all other control sources to prevent conflicts. But understanding which services and settings to disable can be complicated.
The PAS1878 standard for energy mandates that only one ‘energy manager’ should control a device at one time, but this isn’t currently the situation. We need to see these standards adopted to clarify the control hierarchy.
Managing multiple smart home devices takes continuous effort. And the ‘best’ way to optimise might vary by season.
In summer, if you have solar PV and a battery, then prioritising self-consumption may make most sense. But in winter, when you’re generating less of your own energy, some tariffs make it economically attractive to import cheap energy at night and export during higher-price periods. This might not align with grid needs. My colleague Will Rowe has discussed how we’ve seen indications of this arbitrage behaviour in the Living Lab.
Early adopters love tinkering with their devices to get the best outcomes. But mainstream consumers don’t want a part-time job managing their energy.
Mass market adoption will require automated, set-and-forget systems that consumers can easily understand and trust to optimise on their behalf, eliminating frequent manual intervention.
Solutions must also address the needs of consumers in vulnerable circumstances – something we’ve explored through the Department for Energy Security and Net Zero’s (DESNZ’s) Inclusive Smart Solutions programme and our ongoing work with Northern Powergrid on Inclusive Flexibility.
Poor user experience compounds the problem. Each manufacturer’s app works differently with different designs and settings. Right now, many are designed to be data and feature dense, which suits early adopters but can be overwhelming for everyone else. Designs need to be tested with a wide range of consumers to ensure they work for as many as possible.
Complex systems can produce emergent behaviours that are hard to predict and debug.
We’ve seen EVs needing battery replacements because a charging service glitch sent excessive status queries. The cars’ telematics responded so frequently it drained the 12-volt batteries beyond recovery. Owners thought their cars were faulty.
Overvoltage is another example. When neighbouring homes all export solar energy simultaneously, local network voltage rises. Some EV chargers respond by shutting down. Consumers think their charger is broken when it’s actually a network effect.
These problems arise from system interactions, are difficult to diagnose and can permanently damage trust. Real-world testing, with real households, in a safe, controlled environment, such as our Living Lab, can help identify these interactions before mass deployment, reducing the risk of serious issues.
Current market structures don’t always align individual benefit with system benefit. Many tariffs target single technologies, such as your EV or your heat pump. But what if you have both, plus solar panels and a battery?
Financial incentives can pit consumers against the system. One Living Lab participant charges his EV and battery overnight at cheap rates, then exports all his solar at premium rates. This is economically rational for him, but self-consumption would be better for the network.
Dynamic tariffs offer more flexibility but at the cost of uncertainty, and many consumers fear bill shock. Better-designed tariffs and flex mechanisms that reward system-beneficial behaviour would help align incentives.
Beyond tariff design, consumers now face complexity in who provides their energy management. They can opt into services from their supplier, or from a flexibility service provider, who may (or may not) be the manufacturer of some of their energy devices.
Propositions vary from service models that promise lower pricing in exchange for handing over control (like Intelligent Octopus Go for EVs), to dynamic tariffs (like Agile Octopus) that keep users in control but require more engagement.
This competition is good for the market but creates friction for consumers comparing complex arrangements across multiple organisations. Changing supplier requires authorising device access, disconnecting previous services, and reconfiguring multiple apps – with no standard for transferring permissions. DESNZ’s Smart Energy Systems and Services (SSES) programme aims to mandate standards that should reduce this switching friction once implemented.
‘Energy as a service’ models promise one path to simplicity. Rather than consumers managing devices themselves, a service provider takes on the complexity in exchange for delivering outcomes like warmth or mobility at agreed prices. We’ve explored a variety of ways models like heat as a service could work for consumers through our Living Lab trials.
But who will consumers trust to optimise their home? What if it behaves unexpectedly? Would an energy supplier’s customer service team be equipped to debug problems stemming from hardware, settings, control conflicts or system interactions? Early adopters may tolerate these problems, but mass-market consumers won’t. Building trust will require service providers to invest in technically capable customer support that can troubleshoot complex system interactions.
Solving these challenges requires coordinated action across multiple layers.
At the technical layer, widespread adoption of emerging standards like Matter, PAS 1878, and OpenADR will create the foundation for reliable interoperability.
At the experience layer, the industry needs automated, set-and-forget systems that work without constant user intervention. These need careful user experience (UX) design, tested with diverse users, not just early adopters, to ensure the consumer experience is not overwhelming.
At the market layer, tariff structures and flexibility mechanisms must better align individual benefit with system benefit, rewarding behaviours like self-consumption rather than enabling perverse incentives.
At the institutional layer, SSES-mandated standards for device permission transfer will reduce switching friction, once implemented. Service providers will need to invest in technical support, providing customer service staff equipped to diagnose multi-system problems and communicate transparently when systems behave unexpectedly.
Underpinning all of this is the need for real-world testing to identify edge cases, unexpected interactions and trust-breaking failures before mass market deployment.
We offer a realistic environment to test home energy coordination. Our diverse panel of households has low-carbon technology adoption rates several years ahead of the UK market.
The Living Lab can help you:
To discuss how the Living Lab can help you test and derisk home energy coordination challenges, click on the ‘get in touch’ button below to start a conversation and take the next step.
Find out more about how Energy Systems Catapult can help you and your teams
Find out more about how Energy Systems Catapult can help you and your teams