Switzerland recently unveiled an engineering marvel that promises to accelerate the country‘s renewable energy transition – a gigantic "water battery" stored high in the picturesque Swiss Alps near the Vieux Emosson and Emosson reservoirs. Costing over $2 billion and 14 years to construct, the Nant de Drance pumped storage hydroelectric plant is one of the world‘s largest batteries by storage capacity. Equivalent to 400,000 Tesla electric vehicles fully charged, this facility acts like a massive storage bank – using water and gravity to stockpile huge amounts of energy and generate additional power on demand.
Why Nant de Drance Matters for Switzerland
Switzerland is ramping up efforts to meet ambitious sustainability goals, targeting net zero emissions by 2050. But the massive shift towards solar, wind and other renewables poses challenges in balancing electricity supply on the grid. These renewable sources fluctuate based on weather patterns and time of day. So Switzerland needs a way to effectively stockpile excess clean energy and dispatch it during times of scarcity to keep the lights on. And that‘s exactly why Nant de Drance exists.
Nestled in the heart of Europe adjacent to hydropower-reliant neighbors like Italy and France, Nant de Drance will help smooth electricity supply and demand swings across the entire region. By using cheap surplus power to pump water uphill into storage reservoirs, then releasing it to activate turbines at times of peak consumption, Nant de Drance functions essentially like a giant rechargeable battery. It‘s a closed renewable loop that will enable Switzerland to keep expanding clean energy.
| Specification | Nant de Drance |
|---|---|
| Total storage capacity | 20 GWh |
| Max generating capacity | 900 MW |
| Round-trip efficiency | ~80% |
| Equivalent new Tesla EVs | 400,000 |
Nant de Drance‘s storage capacity dwarfs all rivals in Europe
At 900 MW max output, Nant de Drance alone can power nearly 1 million households. Its 20 GWh capacity exceeds the next largest facility in Europe, Spain‘s La Muela (7 GWh) fivefold. With countries across Europe racing towards carbon neutrality while phasing out nuclear plants, balancing electricity supply and demand will make or break their success. Nant de Drance sits poised to lead that charge.
Inside Nant de Drance: A Technical Marvel
The rediscovered natural potential of mountain water batteries is what makes Nant de Drance remarkable from an engineering perspective. Built on a grand scale unseen since the 1950s, it revives the fundamental pumped storage concept using cutting-edge 21st century technology. Here‘s an inside look at what powers this mechanical marvel:
- Two giant reservoirs – Upper lake (Vieux Emosson) 6.6 billion gallon capacity. Lower lake (Lac d‘Emosson) over 5 times larger. Almost 1000 feet of elevation difference to drive water flow.
- Water conduits – 2 parallel pipelines 23ft in diameter, running over 0.8 miles from upper to lower reservoirs. Gravity pulls water down through penstocks.
- Reversible pump-turbines – Each of 6 pump-turbine units can generate 150MW. Water flow spins Francis turbines, driving generators to produce electricity.
- Rapid switchover – In just 5-10 minutes, the pump-turbines transition between pumping water uphill and driving downhill electricity generation.
- Control software – The Plant Management Optimization Tool allows precise control over operation of the 6 individual pumping/generating units in response to supply and demand.
This interconnected symphony of water, machine, and code gives Nant de Drance astounding 1.8 gigawatt hours per minute responsiveness – able to summon massive bursts of green power on demand or absorb huge amounts of excess electricity within minutes.
Economic and Environmental Impact
Constructing an energy megaproject of such proportions required enormous capital investment – over $2 billion from a consortium of Swiss utility companies, banks and private investors. But with superb 80% roundtrip efficiency, Nant de Drance is already profitable after only a few months of operation by selling stored energy at premium peak rates.
Nant de Drance went to great lengths during its 14 year construction timeline to conserve the spectacular mountain landscape. Local environmental regulations strictly governed construction processes, materials usage, and biodiversity protection – such as safeguarding habitats for eagles, foxes and endangered butterflies near the reservoirs. In fact, most of the mammoth underground powerhouse was excavated directly out of solid Alpine granite. The minimal surface footprint preserves majestic vistas so tourists can continue flocking to the region‘s scenic hiking trails and ski slopes.
The Future is Battery-Powered
As solar, wind and electric vehicles transform global energy over this decade, industrial-scale batteries like Nant de Drance emerge as the makes-or-breaks supporting their growth. Stabilizing electricity supply grids has become big business – by 2030 over $20 billion annually will get invested into new energy storage.
With countries around Europe racing to scale their renewable energy, Nant de Drance provides a blueprint. Its strategic Swiss location, advanced engineering, and vast capacity can facilitate further regional expansion of solar and wind to drive deep decarbonization. Battery-boosted flexibility is the new key ingredient enabling affordable clean energy for the masses. Watch for giant mountain water batteries to play a soaring role in this upcoming revolution.
