Rennovates project

European project transforms outdated houses into intelligent ‘zero on the meter’ homes

The objective behind the ‘Rennovates’ project – which is part of the Horizon 2020 programme of the European Commission – is to examine the extent to which older rented houses can be converted in a cost-efficient manner, in such a way that they meet today’s efficiency and comfort standards.

Zero on the meter

The aim is to significantly extend the life of such homes and to improve the energy efficiency in such a way that a ‘zero on the meter’ scenario can be realised. This scenario makes it possible to work out a scheme whereby the tenants pay the same amount for their energy as before, while the amount paid in practice is divided between the actual energy cost – which is drastically reduced – and the costs of the renovation, which the construction company can recuperate this way.

Benefits for all parties

The result is that the tenant can immediately enjoy the increased living comfort, without having to pay extra for it. And since the value of the home is increased considerably, the owner of the house – the Dutch Social Housing Company – also benefits from the upgrade. Finally, Rennovates also offers benefits for the local distribution grid operators, in this case, Stedin and Alliander, because it allows them to handle their congestion problems1.

249 homes

In concrete numbers, the Rennovates project involves 249 homes. They are located in the Dutch municipalities of Heerhugowaard, Soest, Soesterberg and Woerden. The construction company (BAM) equipped each of these homes with an insulating shell, consisting of secondary façades and an extra roof layer with solar panels. This drastically improves the insulation values and generates energy for free. In addition, a compact energy module is installed near the house which includes a heat pump, a hot water boiler and the Enervalis gateway. Finally, the comfort inside is upgraded by means of a new kitchen, bathroom and sanitary facilities.

The added value of Enervalis

Using the gateway and the underlying software and smart machine learning algorithms, Enervalis analyses the energy and hot water consumption in each of the homes. This allows the system to ensure sufficient hot water is available at the right times. This takes place in such a manner that the sense of comfort of the residents remains unaffected while preventing the production of excess hot water. This results in considerable energy savings. The system also provides a ‘safety buffer’ for hot water. This allows the residents to always have sufficient quantities of hot water available, even when unexpected situations arise.

Additional income thanks to energy trading

The application of the gateway also adds a second important value. The reason is that the machine learning data described above are compared with the data from the local distribution grid operator in terms of possible congestion problems. Based on that comparison, the production of domestic hot water in the various homes is planned at specific times, taking account of both the usage requirements of the residents and the congestion problems of the distribution grid operators. The latter is based on the USEF (Universal Smart Energy Framework) market model, which provides the necessary architecture and regulations for the flexible trading of energy. The distribution grid operator pays a fee in exchange for this flexibility.

Battery systems

The Rennovates project also includes eight home batteries (the capacity varies from 3.6 to 7.8 kWh) and a large district battery – in the municipality of Woerden – of 200 kWh. These batteries allow Rennovates to offer additional energy flexibility to the distribution grid operator, which of course also allows the compensation to be increased further.

Technical challenges

The technical partners in the project who integrate the Enervalis gateway into the energy module and subsequently install it at the construction site are actively supported by an advanced New Product Integration (NPI) tool. It was especially developed for this purpose by Enervalis and allows automatic testing programs to verify that the gateway is functioning properly and is correctly connected to the other components of the energy module. This way, any problems or connection errors can immediately be detected and corrected, so they do not cause unnecessary delays and complications later in the flow.


Although there are currently insufficient statistical data available to draw definitive conclusions, it is assumed that the total energy consumption of the homes in the Rennovates project will decrease by more than 60%. In addition, the solar panels will generate approximately 4 to 7 MWh per year. Consequently, the houses will effectively meet the zero on the meter scenario, exactly as intended.

Based on the experiences and results of the Rennovates project, BAM has decided to start up more similar projects in collaboration with Enervalis. Initially, this will involve some 300 homes, but in the longer term, this number will probably continue to rise…

1Congestion problems arise when users, within a certain period of time, want to use more energy from the grid than the capacity of the cables and/or the transformer at the point of congestion can process. Conversely, congestion problems can also arise when users want to inject too much energy into the grid.

Facts & Figures

Product(s) involved: Enervalis SBEM (Smart Energy Management Module) gateway
Locations: Heerhugowaard (NL), Soesterberg (NL), Soest (NL) and Woerden (NL, location of district battery)
Client: European Commission, BAM
Realised benefits: The 249 homes are 100% energy-neutral (zero on the meter)
Potential added value of € 300 per property per year through smart control
Direct consequences: Project has led to new, similar projects in collaboration with BAM
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