The capital reviewed potential savings with the companies operating Budapest’s public transportation system, seeking measures that would have the smallest possible impact on passengers.

Metro and tram services will adopt timetables under which vehicles accelerate less intensively, Karácsony said.

“This will increase journey times by a few minutes, but it can achieve daily energy savings of 15 MWh. In addition, on certain routes, modern diesel buses equipped with efficient air conditioning will operate on working days instead of electrically powered trolleybuses,” the mayor wrote in a post on social media.

Paks May Shut Down Earlier Than Expected, Magyar Says

The announcement came as Prime Minister Péter Magyar said the Paks nuclear power plant may need to shut down fully earlier than expected, potentially as soon as this weekend.

In a video posted on Facebook on Saturday, Magyar said Danube water levels had continued to fall, prompting engineers to carry out another shutdown at the plant overnight and during the early morning.

Paks is now operating at just 480 MW, compared with its normal capacity of about 2,000 MW, he said. The facility is Hungary’s only nuclear power plant and normally accounts for around half of domestic electricity generation.

Magyar said transmission system operator Mavir had activated its protocol for major system disruptions because of the significant reduction in power plant capacity across Hungary’s electricity system.

“The emergency situation demands immediate decisions and coordinated government action,” Magyar said. “Our task is clear: to protect people’s safety, maintain the country’s energy and drinking water supply, and implement all necessary measures in time.”

Largest Industrial Energy Users Asked to Reduce Consumption

The government has also asked Hungary’s largest industrial energy users to reduce consumption voluntarily. Those measures have so far lowered the load on the grid by around 240 MW, Magyar said in a separate video.

“This shows that Hungarian companies understand the seriousness of the situation and are willing to contribute to maintaining the country’s security,” he said. “However, in the event of a further outage at the Paks nuclear power plant, voluntary commitments may no longer be sufficient.”

A new government decree taking effect Saturday will change the previous system of restrictions, Magyar said.

Under the new rules, large consumers will first be asked to reduce electricity use voluntarily. Compliance will be monitored continuously, and failure to meet commitments may be sanctioned.

Should developments in domestic production and electricity imports require stronger action, MAVIR will be able to order mandatory consumption reductions after prior warning and temporarily disconnect selected large consumers from the grid.

“Households are at the end of the restriction chain,” Magyar said. “The state, major companies, industrial plants and institutions with deferrable energy consumption will bear the burden first. The system operator will only resort to cutting off power to Hungarian homes when all other options are exhausted. This is the practical change in the system.”

The latest measures follow several days of falling output at Paks as record-low Danube levels restrict the water available for cooling. The prolonged heat wave and extreme drought have also pushed electricity demand higher, particularly because of air-conditioning use.

Budapest had already ordered decorative lighting to be switched off at more than 300 city-managed buildings during the outage. The new transport measures extend the capital’s energy-saving effort to public transportation while seeking to preserve normal service as far as possible.