La Chaux-de-Fonds Plant Restart After Alternator Damage

Key Takeaways

• Vadec restarted its La Chaux-de-Fonds plant on 9–10 November 2026 after a shutdown from 2 November.
• Lightning on 24 August 2026 damaged the alternator and abruptly stopped the turbo-generator.
• Shaft vibrations prompted an inspection, which revealed alternator damage needing major repairs.
• District heating stayed guaranteed without fossil-fuelled backup boilers.
• The plant will run in heat-only mode until the alternator is repaired; no completion date was given.

Vadec brought its plant in La Chaux-de-Fonds back into operation during the day and night of Monday 9 to Tuesday 10 November 2026. The restart followed a shutdown for maintenance on 2 November. The operator had warned that the work might cause occasional noise in the neighbourhood, both by day and at night.

Lightning Strike Damaged the Alternator

On 24 August 2026, lightning struck the electricity network. The strike damaged the alternator and abruptly stopped the turbo-generator, the turbine and alternator unit that produces electricity.

After an initial phase of analysis and repair, the installation was returned to service. Vibrations were subsequently detected on the turbo-generator shaft. To identify the cause and ensure safe operation, Vadec shut the plant down again for an inspection on 2 November. The inspection revealed damage to the alternator section that requires major repair work.

District Heating Supply Remained Guaranteed

Vadec sought solutions to keep the plant running and to continue supplying heat to the district heating network. The aim was to heat the many homes in La Chaux-de-Fonds through the autumn without having to use the backup boilers, which run on fossil fuels. According to the company, heat supply was guaranteed for all district heating customers.

The restart included several technical tests to confirm that the plant functions correctly and can operate safely. During this phase, steam produced by the boiler had to be released via the roof at times. Vadec stated that this had no environmental impact but could be clearly audible to neighbours, day or night.

Heat-Only Operation Until Alternator Repair

According to Vadec, if the tests are successful, the plant will initially resume operation solely to produce energy for the district heating network. In this interim configuration, steam releases from the roof could continue for several weeks, until the alternator is back in service. The operator did not give a date for the completion of the alternator repairs.

Read More

• La Chaux-de-Fonds
• Enfinium Fund Aids 15 Repair Cafés to Reduce Waste
• Alkmaar Waste-to-Energy Plant Line 3 Reopens After Upgrade
• New Nitrous Oxide Regulation in Germany: What You Need to Know
• The Sale of Nitrous Oxide Is Now Banned In Germany