To augment my previous reply, a hood is to remove noxious fumes and odors while a fire suppression system is to control, duh, fires.
Regardless of the heat source, gas or electric, cooking produces grease laden vapors as well as other combustible gases and vapors. The hood removes those and dilutes them with air to a safe level. Gas fired appliances produce carbon monoxide which also must be vented.
The fire suppression system, i.e. ANSUL, does just that suppresses any fire that might occur.
There are some electric appliance that incorporate filters and catalytic converters that remove most of the undesirable vapors and trap what little grease might be released from things like ovens but griddles, grills, deep fat fryers, or anything else that might release grease will require a hood.
Again, your fire marshal will know the specific requirements for each appliance you are planning to use. Really, the fire department is your friend, not the enemy!