LONDON (Reuters) - National Grid, which runs Britain’s energy systems, said on Tuesday that electricity and gas flows from continental Europe would continue as normal even under a no-deal Brexit as it has made preparations for all scenarios.

“We anticipate no additional operability challenges for this summer as a result of the UK’s planned exit from the EU,” National Grid said in its Summer Outlook, covering the period from April to October.

Britain imports around 5-6 percent of its electricity via interconnectors with continental Europe.

“Should the UK leave the EU with no deal, cross-border trading of energy would take place outside of the (EU) single market framework, i.e. under World Trade Organisation rules for the majority of countries,” National Grid said.

There are no tariffs on electricity or gas shipments between the EU and other WTO members.

Nearly three years after Britain voted to leave the EU, and three days before it was supposed to leave the bloc, it remains unclear how, when or even if Brexit will take place.

Britain also imports more than half of its gas via pipelines from continental Europe and Norway and through shipments of liquefied natural gas (LNG) from countries such as Russia, the United States and Qatar.

LNG is more widely available on the world market as Russia and the United States have been ramping up deliveries. National Grid said it expects higher deliveries of LNG than last summer and that it expects there will be sufficient gas supply to meet demand. It also said it would be able to meet electricity demand.

It forecast gas demand during the summer period will total 36.1 billion cubic meters, almost 6 percent higher than summer gas demand in 2018, once weather related adjustments were made.

Electricity demand in Britain is expected to peak at 33.7 gigawatts (GW) this summer while the minimum summer electricity demand is forecast at 17.9 GW.