The lines company asked businesses affected by the nine-hour blackout on June 14 to email it, detailing losses, and most received a reply last week.
The email closed with: "If you are a business for whom a continuous supply of electricity is essential, then you might like to consider the option of a back-up generator.
"Our team are happy to advise on the solutions available to you if you believe your business needs this additional contingency."
The Old Clyde Bank cafe owner Wendy Hecht-Wendt said on Friday most businesses got the same "bog standard" email.
Affected businesses would be credited line charges via their energy retailer for an unplanned outage of more than four hours, she said.
Her credit amounted to $318 — well short of the cost of a day’s lost trade.
Eade Gallery owner Melanie Eade said the noise created by generators would be disruptive and Aurora was taking a "sorry, not sorry" approach.
Retired Delta engineer Steve Tilleyshort said generators were expensive.
"This is a return to old technology with noise, fuel handling and storage, and a safety and environmental disaster."
For Aurora to advise clients to install generators was admitting to inept asset management.
"This is an admission of fault."
The cost for a simple retailer to install an 8000W generator, not including fuel and regular servicing costs, was about $7000, he said.
For a small dairy or cafe with refrigeration, a 14 kilo-volt-ampere generator could cost $11,000 and for a restaurant with electric cooking and heating, a 22kVA generator would set it back about $16,000.
"I have not allowed for compliance with fuel storage," Mr Tilleyshort said.
