In a six-part blog series, InEExS spotlights solutions to help accelerate Europe’s transition to a smart, resilient, competitive and more efficient energy system. Each blog will explore the solutions, technologies and approaches, from energy communities to the role of blockchain in energy management, that can make our homes and buildings smarter and more energy-efficient. The first blog in the series investigates how to help citizens maximise the use of homegrown solar energy.
Lessons from the InEExS Project demonstrators in Spain and Germany
European policy has significantly evolved in recent years to empower “prosumers” – consumers who also generate renewable energy. The EU’s Renewable Energy Directive guarantees citizens the right to produce, consume and share their own renewable energy individually or collectively without undue barriers. Spain, once known for the so-called “sun tax” (referring to the controversial law that taxed self-consumption), reversed its approach with a 2019 self-consumption law. This new framework allows for collective self-consumption, enabling neighbours to share a solar installation’s output. Germany, a long-time leader in solar energy, moved from feed-in tariffs towards encouraging on-site use through schemes like Mieterstrom (tenant electricity), offering modest bonuses for solar power used directly by tenants or encouraging them to install solar panels on their balconies.
Across Europe, solar panels are becoming an increasingly common sight. With the support of the EU-funded InEExS project under the LIFE Clean Energy Transition programme, initiatives in Spain and Germany are helping citizens use more of their homegrown solar energy on-site. This approach, known as solar self-consumption, is helping communities and tenants to cut energy bills, strengthen grid resilience and support Europe’s renewable energy goals.
Policy shifts in favour of prosumers
These policies have shifted the emphasis from selling surplus electricity back to the grid to using it locally. Doing so not only reduces household bills but also enhances energy system efficiency and resilience by lowering demand on the central grid.
Collective action in Crevillent, Spain
In the town of Crevillent, Alicante, the local cooperative Enercoop is demonstrating how a community-centric approach can maximise solar self-consumption. With support from InEExS, Enercoop provides its members with real-time data on solar generation, local demand and electricity prices through a smartphone application and public information displays.
When solar production peaks around midday, members receive prompts suggesting optimal times to use appliances. This behavioural guidance is supported by a token-based incentive system. Using a blockchain platform and smart contracts, users are rewarded with digital tokens when they improve their alignment between consumption and local solar production. The system provides transparent tracking and rewards users for actions such as shifting water heating to solar hours.
The approach is already delivering results. Participants report lower energy bills, higher solar self-consumption rates and increased awareness of their energy habits. The wider community benefits from more efficient use of local renewable resources and reduced pressure on the grid. Spain’s regulatory environment, which now supports collective self-consumption and simplifies net billing, makes models like Crevillent’s easier to replicate across other sunny towns and cities.
Solar self-consumption for tenants in Berlin
In Germany, InEExS is demonstrating how tenants, who often lack direct access to rooftop solar panels, can still benefit from self-consumption. In Berlin, five apartment buildings owned by a public housing company have been equipped with 99 kW of solar PV on their green roofs.
Traditionally, tenants have little incentive to directly use the solar power generated on-site. In this pilot project, however, recommendations for contract models are being developed that encourage the direct use of PV power. Tenants have access to an application called “Zählerfreunde” (“Meter Friends”), which provides real-time insights into their electricity use, the share covered by solar, and CO₂ emissions avoided. Smart meters and a Measurement, Reporting and Verification (MRV) system enable detailed tracking.
The model encourages tenants to shift their consumption patterns: for example, running appliances or loading their EV when solar production is high. It also creates a financial incentive for the ESCO to support and optimise tenants’ solar usage. This contrasts with traditional EPCs focused solely on energy efficiency measures like insulation. By combining efficiency improvements with renewable generation, the Berlin pilot shows how buildings can be treated as integrated energy ecosystems.
Technology and behaviour: two sides of the same coin
The Spanish and German pilots underscore that technology alone is not enough to maximise solar self-consumption. Behavioural change, enabled by smart tools and incentives, is equally important.
In Crevillent, every household smart meter feeds data into a central system, while Berlin required the addition of sensors to standard, legacy meters. Cloud-based analytics integrate these data streams. The blockchain platform in Berlin verifies ESCO performance for settlement purposes, while in Spain it underpins the community token reward system. These technologies facilitate transparency and trust among participants.
With the support of these tools, behavioural change is encouraged, not enforced. Families are nudged, not mandated, to run appliances during solar hours. By aligning incentives and making information readily accessible, InEExS helps households participate actively in the energy transition.
Enabling Policies
The success of the InEExS pilots also reflects the importance of supportive policy environments. Simplified net billing for surplus solar in Spain and tenant solar support schemes in Germany have been crucial. Both countries also have Energy Efficiency Obligation schemes (EEOS) that encourage innovative projects linking efficiency and renewables.
InEExS also contributes directly to the goals of the EU Energy Efficiency Directive by developing ways to measure, verify and incentivise real energy savings, including tokenising these savings via blockchain. This creates the potential for utilities and obligated parties to meet part of their efficiency targets by supporting community-led solar self-consumption initiatives.
Broader impacts
The experiences in Crevillent and Berlin show that solar self-consumption can deliver benefits across different contexts – from a Spanish town to a dense German city. Households enjoy lower bills and greater energy independence, while local grids benefit from reduced peak loads and lower transmission losses.
Environmentally, every kilowatt-hour of solar energy consumed locally reduces reliance on fossil fuels and CO2emissions, but also costs related to energy transportation. Empowering citizens to become active participants in the energy transition can also increase public acceptance of wider renewable energy infrastructure.
Importantly, the pilots demonstrate that successful solar self-consumption requires the alignment of technology, behaviour and policy. Apps and blockchain ledgers alone are not sufficient; residents must be motivated and enabled to use them. Similarly, policy incentives are most effective when paired with accessible, user-friendly technology.
A blueprint for Europe
The InEExS pilots provide a replicable model for other regions. Sunny housing blocks in Athens or cooperatives in Italy could adapt similar models of tenant engagement and community data-sharing.
The underlying message is clear: by combining smart technology, behavioural incentives and supportive policies, it is possible to maximise the benefits of rooftop solar energy. Spain and Germany, through the InEExS project, are demonstrating how to make every hour of sunlight count – offering practical lessons for the energy transition across Europe.
You can find out more about these cases by exploring our business case factsheets:
Improved self-consumption of DER in Energy Cooperatives (Crevillent, Spain)
Recommendations for innovative energy contracts with Pay4Performance guarantees (Berlin, Germany)
