I’ve got a fire suppression system. An agricultural sprinkler on each of the two roof peaks, fed by a pump from storage tanks. We’re off-grid (no mains) and already have the storage tanks - 2 x 22500litre/5000 gallons. With full tanks, the sprinklers should operate for ~7 hours, which is way more than necessary - three to four hours would be enough. The sprinklers “throw” interlocking circles of water, they intersect over the roof and saturate all the ground and foliage out to about 15 metres/50 feet. Water falling on the roof goes back into the tanks. The pump is electric, but being off-grd, we’ve got big batteries and a backup generator, so I’m confident the pump would run long enough for the fire to pass.