December 14, 2021

Energy-Self-Sufficient Living - Solution for the Future

In the fight against climate change, building technology is assuming its responsibility with innovative concepts

The future-oriented development "Am Aawasser" in Buochs ​​consists of 26 apartments and commercial space on the ground floor, forming a small residential area with three buildings. With the various apartment sizes from 2.5 to 5.5 rooms, these form beautiful and contemporary living space for families, singles and couples. But what is future-oriented about this development? The development is characterized by a sustainable energy concept and a particularly innovative rental price concept, in which an annual energy budget is available to the tenant.


The aim of the "Am Aawasser" development in Buochs ​​is to be energy self-sufficient. This means that no electricity is fed into the development by the Nidwalden Energy Works (EWN). The conditions for an energy self-sufficient supply of the three residential and commercial buildings are optimal, because the property includes a hydroelectric power station that is powered by the Engelberger Aa. This means that a basic supply is almost constantly guaranteed. In addition to the hydroelectric power station, various other energy-generating and energy-saving components have been installed. A photovoltaic system with around 626 m2 has been installed on and around the three buildings, which corresponds to 371 installed modules to generate electricity using sunlight. Heat-recovering shower channels from Joulia have been installed in all showers in the entire development, which leads to an energy reduction of around 20% per shower.
The excess energy is stored in batteries and is therefore available to the user at a later time. A fuel cell is also planned to take over the power supply when the hydroelectric power and the photovoltaic system do not produce enough electricity and there is a shortfall.

Installed photovoltaic system (Image: Sämi Zgraggen)

The greatest potential for energy savings lies with the user themselves. For this very reason, it is important that the building technology components in the apartment can be easily controlled by the user. To make this possible, it is possible to operate the building technology components with an app. Now the user knows at any time how much energy he has used in the current month. This is divided into electrical energy, heating energy, hot water and cold water consumption. The owner and operator is breaking new ground in the rental of apartments. He rents the apartments "all inclusive" with a certain energy budget per month / year. If the user does not use up the energy budget, the surplus is credited to him; if he exceeds it, however, he has to pay extra.
The "all inclusive" offer is not limited to energy, but also covers internet usage, use of the parcel box and in-house e-mobility for tenants, with one day per month included in the rental price for the latter.

Visualization of consumption data on the app (Image: Sämi Zgraggen)

W&P Engineering was responsible for the overall planning of the heating, ventilation, air conditioning and sanitary installations. The energy concept was meticulously developed and refined in close cooperation with the client and the other specialist planners involved. The Minergie certification of the development, the entire energy monitoring and the simple maintenance of all building technology components played a central role. As part of the normal coordination process, specialists for energy self-sufficiency were involved in the early planning phase. They were responsible for the control system, the intelligent energy management system and the storage of electricity. The challenge of the project was that all the specialist planners involved and, in a later phase, the implementing contractors had to view the development as a complete system. It was important to think and act in an integral and interdisciplinary manner. This was already evident in the planning phase and extended to the commissioning, where the complex systems had to be coordinated with one another.