An advantage of a temporary provision is that it can continue to work independently of the network as long as it is robust against water.
Examples include solar panels, biomass, a CHP plant, wind power and a sealed drinking water tank.

Generators

Generators make it possible for buildings to temporarily create their own energy supply.
In combination with batteries, it is possible to ensure a continual supply, starting before the power outage.
In case of a regional or national energy supply failure, essential amenities remain functional, perhaps in combination with CHP and decentralised energy generation.

Energy from renewable sources

During a flood a building can generate the energy it requires, independently of the network. Energy is generated from renewable sources, such as solar cells.