Retrofitting Gains Momentum Across Europe

Across Europe, households already equipped with solar panels, heat pumps, EV chargers, or batteries are increasingly turning to retrofits instead of full equipment replacements. gridX’s 2025 Retrofit Report positions these incremental upgrades as one of the fastest ways to expand grid-responsive demand while helping families lower their bills. The company estimates that about 15 million households across Germany, Spain, the Netherlands, and the UK are strong candidates for retrofit integration.

What’s shifting is not just technology adoption, but how people expect their energy systems to behave. “Analog” homes—those with equipment operating independently—are giving way to setups that coordinate generation, heating, mobility, and storage in real time.

Households Are Ready to Add More Technology—If It Works Together

gridX surveyed 265 homeowners who already have at least one major energy asset in place. Their responses show a market that is no longer experimenting, but actively planning its next steps:

• 66% expect to buy another energy asset in the next two years.
• 81% want those assets integrated into a home energy management system (HEMS).
• 88% view compatibility as essential, not optional.
• 78% want to see the investment in a HEMS pay for itself within five years.

This appetite reflects a broader reality: as devices proliferate, homeowners are no longer satisfied with individual components. They want systems that communicate and optimize automatically, especially as more countries shift toward dynamic electricity pricing and time-dependent tariffs.

Savings Grow Once Devices Start Working in Sync

The strongest economic gains appear when households combine solar generation, storage, and smart control. gridX’s modelling shows the cumulative benefits clearly:

• In Spain, adding a battery, HEMS, and a dynamic tariff to an existing solar array cuts annual costs by roughly $505 (converted from €467).
• In the Netherlands, EV-owning households that add solar, a battery, a HEMS, and a dynamic tariff see around $1,048 in annual savings (from €970).
• In the United Kingdom, a home starting with a heat pump can save about $1,895 a year by adding solar, a 10 kWh battery, a HEMS, and a dynamic tariff (from £1,492).

Rather than full overhauls, gridX distinguishes between two approaches: retro-connect, which simply links existing assets to a HEMS, and retro-expand, which adds new hardware. Both push households toward higher self-consumption and lower reliance on peak-time grid power.

A Growing Installed Base—and a Growing Grid Challenge

Europe now has more than 63 million installed rooftop solar systems, heat pumps, and wallboxes. Yet the majority—70% to 85%—still operate without any form of intelligent coordination. This disconnect is becoming more visible as adoption accelerates. In the UK, for example, the number of wallboxes is projected to climb nearly 16-fold by 2030, and heat pumps are following a similar growth trajectory.

Without better control, these trends strain local networks. Retrofitting offers a middle path: it gives grid operators the flexibility they need without requiring households to replace equipment that still has decades of useful life.

Industry Alignment Will Determine the Pace of Adoption

A retrofit-friendly environment depends heavily on cooperation among manufacturers, installers, and utilities. 

CEO Anne Bicking notes that households want clarity and simplicity—and that the energy sector needs shared standards and partnerships to deliver “plug-and-play” retrofit experiences at scale.

The Retrofit Report points to a market in transition. Europe’s installed base of energy equipment is growing quickly, but much of it remains digitally unmanaged. Retrofitting, rather than replacing, gives households a path to meaningful savings and gives grid operators the flexibility they increasingly need.