One restaurant says the 60 pence hike means they are reducing their opening hours.
The unit price of electricity went up overnight by 60 pence to £1.14, some 88 pence a unit more than it is in Guernsey.
The price hike was imposed in two stages by the owner of Sark Electricity, Alan Witney-Price, to pay for a predicted legal battle against compulsory purchase by Chief Pleas.
Time and Tide restaurant in the Avenue has used social media to say that its power bill is effectively trebling and it is restricting its opening times to two hours at lunch and two hours at dinner.
It says it will keep this under review.
Meanwhile, Chief Pleas has condemned the price hike, which it describes as 'unjustified.'
It says the Sark Electricity Price Commissioner is expected to publish an initial review next week, with a final report by the end of the month.
Sark's government says if anyone is threatened with disconnection because they cannot pay their electricity bill, then they will use Civil Contingency Authority powers to ensure no-one is at risk.
It says it is in the process of trying to appoint a valuer for the company.
Earlier this summer the States of Guernsey agreed to loan Sark's government £1.5M specifically to take Sark Electricity into public ownership.
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