Hydro Ottawa says the damage from Saturday's storm is "simply beyond comprehension", and is "significantly worse" than the 1998 ice storm and the tornadoes that hit the capital three years ago.

Approximately 110,000 Ottawa homes and businesses remain without power two days after a severe storm hit the capital, with wind gusts of up to 120 km/h.

In a letter to Mayor Jim Watson and council Saturday night, Hydro Ottawa said damage is located across the city.

"We are managing this from a whole of city perspective given that no single area of the city was unaffected in some manner," the letter said.

"And to provide some context for you and your residents, this event is significantly worse than both the ice storm of 1998 and the tornadoes of 2018.  The level of damage to our distribution system is simply beyond comprehension."

More than 200 hydro poles have been broken across Ottawa, including dozens along Merivale Road.

Hydro Ottawa says crews will work around the clock until power is restored.

"The widespread nature of this outage persists with no single fix," the utility said.

"Our teams are working as quickly as possible with reinforcement crews coming in from our contractors and utility partners from as far away as the Greater Toronto Area, Kingston and New Brunswick. Crews will work around the clock until all power is restored to our city."

Hydro has been restored to the Queensway Carleton Hospital, the Robert O. Pickard Environmental Centre water treatment plant and the Ottawa International Airport.

Shortly after the storm hit, more than 180,000 customers were without power – which is about half of the Hydro Ottawa customer base.

Hydro Ottawa's director of system operations and grid automation Joseph Muglia told CFRA's The Morning Rush with Bill Carroll the storm hit different parts of Ottawa with different intensities, creating challenges for crews.

"Just the way we were hit with this one, extremely damaging for sure and so widespread across the city which makes it so much more complicated."

More than 150,000 Hydro Ottawa customers lost power when a series of tornadoes hit Ottawa in September 2018.

During the 1998 ice storm, more than 600,000 people lost power across eastern Ontario.