Mayens de Sur-le-Scex, a real-scale mini-grid

Goal

To conduct a practical, real-scale trial of a mini-grid isolated from the network and lay the foundations for a larger “smart grid” project

Partners

Studer Innotec , HES-SO Valais, The Ark Foundation

The island mini-grid system set up by Studer Innotec, a Sion-based SME, allows energy to be produced, stored and exchanged with neighbours. The pilot project, established in the Sanetsch region and supported by The Ark Foundation, is producing excellent results. Sharing energy provides a greater security of supply.

Content of the project

Market demand and the competitive environment in which Studer Innotec operates are both evolving very quickly. New challenges and new opportunities are arising in the provision of independent energy supplies for isolated sites (mini-grids) and handling communications between the public supply network and private electricity producers (smart grids).

This is the context in which the pilot project at Mayens de Sur-le-Scex was set up. The site is at a high altitude, is inaccessible in winter and comprises about 20 chalets. The chalets are fairly close together and have been connected to one another. Each one has a small photovoltaic solar power system with battery storage. As soon as a battery is fully charged, excess energy is made available to other users. Each chalet is therefore no longer just a producer, it is also a storage facility that stabilises the supply for all the participants. The site will be ready for connection to the public supply network, which would enable excess electricity from Mayens to be injected into the public supply network. This project demonstrates that distributed production and storage contribute not only to the energy independence of the whole site, but also to the reliability, robustness and stability of the network.

Practical outcomes

The system has been in operation since summer 2011. The results have been rated as excellent, because the owners of the chalets have not needed any additional supply of energy from outside the mini-grid.  In the past, petrol-powered generators were required several times each week. One further observation is that the exchange of energy works well, because of the quotas that have been established. Greater use is made of the batteries, which should therefore have a longer lifespan.

In general, Studer Innotec is able to establish the foundations required in order to seize the opportunities offered by the market (particularly in emerging countries), to develop its competitive advantages and to grow. This project is enabling the company to advance even further in the field of “intelligent” inverters, which interact with other items of equipment. In addition, with the Mayens de Sur-le-Scex mini-grid, Studer Innotec has a real-scale demonstration site, which it can test and show to its clients.

This project fits perfectly into The Ark Foundation’s strategy for the energy sector and the results can be used in other companies and projects.