You should have had a backup supply.
Now, it seems that Saudi Arabia wants to keep the price at current levels by using its stored oil as a backup supply.
It may be necessary to increase backup supplies.
The backup supply immediately takes over in the event of a failure by the primary supply.
Arranging for backup supplies is an obvious solution.
It also supplies water to three towns west of the reservoir and acts as backup supply for three others.
On the International Space Station, chemical oxygen generators are used as a backup supply.
"I've got a backup supply of tree sap, prepared for just such an emergency."
A fierce run on milk stores led the city to resort to its backup supplies of powdered milk.
Inside was our transmitter receiver and through it the California sent backup supplies and equipment to us.