Designer, developer and manufacturer of high-tech batteries for industry, Saft, has supplied specialised Sunica.plus nickel-based batteries to provide off-grid energy storage as part of the modernisation of the Hörnlihütte mountain lodge at a height of 3,260 meters on the Matterhorn in Switzerland.
The Hörnlihütte lodge, popular with hikers and climbers since around 1880, is being modernised by its owner, Hörnlihütte Zermatt Foundation, to provide improved levels of comfort, safety, hygiene and eco-friendliness in readiness for the special 2015 anniversary of the first ascent of the mountain. As part of its contract with system integrator Elektrizitätswerk Zermatt, Saft has provided a Sunica.plus nickel-based battery system. This will be used to store excess energy generated by the lodge’s roof-top solar photovoltaic (PV) panels during the day for reuse in the evening to help ensure a continuous and reliable electricity supply.
“This iconic installation highlights the capabilities of the Sunica.plus battery range to deliver reliable off-grid back-up power,” said Xavier Delacroix, general manager of Saft’s Industrial Battery Group Division. “These nickel-based batteries are able to operate reliably in extremely low temperatures, with erratic charging patterns. This is a particularly important contribution to minimising the total cost of ownership in a remote location where battery maintenance and replacement operations require expensive helicopter transportation.”
The 48 V Saft battery system, comprising three strings of Sunica.plus 1830 cells, will provide a total storage capacity of 5,490 Ah. The Sunica.plus design is optimized for high efficiency at low temperatures. So, even when the winter temperatures in their plant room fall to 0°C, the battery system will still store enough energy to support all the lodge services, including lighting and a 18 kW water pump, for around 24 hours without any sunshine. The 15 kWp solar panel and battery combination forms part of a hybrid power system complemented by a 35 kW canola vegetable oil-fuelled co-generation unit for use during longer periods without sun. The system is fully automated and can be controlled over a GSM cellular link.
The estimated peak consumption of the lodge, when fully occupied by 130 guests, is 45 kW, with a daily energy consumption of 250 kWh. During the high season, from June to October, the Saft batteries will be subjected to a maximum cycle discharge of 50 to 60% capacity. This will reduce to 20% discharge in the off-season, November to May, when the lodge is effectively closed with only reduced operation needed for emergency visits. Based on this specific usage pattern, the Sunica.plus batteries are estimated to have a life time of around 15 years, which is about double the life that could be expected from equivalent lead-acid batteries.
