Solar farming reaches new heights in the Swiss Alps
1,810 metres above sea level lies a man-made reservoir that freezes over in the winter and sustains wind speeds of up to 140 km/hr. Despite these harsh conditions, it’s the perfect place to capture solar energy.
Bourg-Saint-Pierre is the last village before the Great St. Bernard Pass and the tunnel that leads to Italy. It’s a popular destination for hiking and mountain-biking, but lately it’s become more famous for an impressive engineering feat that’s giving the passing tourists a glimpse of what a greener future could look like.
Set against a background of the majestic mountains, 2,200 square metres of photovoltaic panels float on the Lac des Toules, making it the highest altitude solar farm on the planet.
Floating solar farms are costly to build, but when compared to ‘dry’ farms, the benefits make it worth the expense. Not only do they avoid taking up land area that’s needed for other things, they’re also up to 16% more efficient due to the cooling function naturally provided by the water.
One might imagine that the concept would work most effectively in a warmer, lower-lying climate. Surely a village in the Swiss Alps that plunges to -30 °C wouldn’t be the best place to capture solar energy?
Yet it turns out that alpine conditions are remarkably well suited to solar power. UV rays are more intense at a higher altitude because the air is thinner, and the surrounding mountains act as reflective surfaces, sending more radiation onto the surface of the panels.
All this translates to a solar farm that generates twice as much energy when compared to a similar plant in a warmer, lower lying location.
Current production at the Lac des Toules plant exceeds 800,000 kilowatt hours (kWh) per year, which is enough to satisfy the energy requirements of about 220 households. Plans are already underway to expand the farm for it to eventually cover the needs of more than 6,000 households.
As it stands, Switzerland is one of the lowest carbon intensive countries in the world, thanks to our extensive use of nuclear energy and hydropower. However, in 2017 we voted to phase out nuclear power in a national referendum. As we move to an even greener future, is it possible that floating solar farms could fill the gap left behind?