FARMERS have breathed a sigh of relief after the Geelong Shell Refinery started diesel production again yesterday.

Victoria's diesel supply was halved after an electrical fault caused production to cease at the Geelong plant.

Diesel shortages across Victoria over the last week, which saw the fuel run out at numerous petrol stations across the state, will now ease according to Shell spokesperson Paul Zennaro.

"The good news is the refinery is up and running again,'' Mr Zennaro said.

"Over the next 24 hours we will ramp up production.

"Shell is working with its customers . . . with farmers and those in regional areas to make sure the diesel gets delivered.''

The Shell shut down caused much angst across regional Victoria with farmers in the midst of harvesting season.

Diesel supplies at petrol stations ran out in several places including Colac.

Victorian Farmers Federation grains president Andrew Weidemann said he was confident things would return to normal within the week.

"Some obviously couldn't source their full allocation of fuel,'' Mr Weidemann said.

"Within four to five days, everything should be back on track.''

According to Mr Weidmann more dialogue between fuel companies and farmers needs to occur, to ensure "fuel security'' in peak harvesting season.

Reports of one million litres of diesel to be delivered from Sydney to help alleviate the pressure are still awaiting confirmation.

Murray Goulburn spokesperson Kim Lovely said as food services were considered a priority, the company and others like it received the deisel necessary for deliveries.

"We have received our necessary supplies as we are considered an essential service,'' Ms Lovely said.

"We've been in direct contact with our fuel suppliers and we will be getting the fuel necessary for all our deliveries to arrive on time.''

A CFA spokesperson said emergency supplies ensured the trucks could continue to run in an emergency.

"Measures are in place to make sure there's plenty of fuel,'' she said.