When talking about the future of power distribution everyone uses the buzzword smart grid. It will solve the problems of the grid on the higher levels but why not also use it in the low distribution grid?
This contribution will focus on the possibility of increasing the stability and efficiency by connecting household appliances into a smart grid.
With more renewable energy sources the grid is more and more decentralized. The structure of the grid and its stability control became very complex. For that reason coal plants are still used to stabilize the grid.
The focus here is on cooling appliances because it is very energy consuming. But it has also more flexibility when it needs to run. A fridge or a air conditioning rarely runs the full time. Normally it cools down to a threshold temperature, switches off and starts cooling again when it became too warm again. These timings are not precise at all and could give possibilities.
For air conditioning the dimension of the energy consumption can be seen. Especially countries with unstable grids have a high usage of electricity for it.
Looking at statistics the dimension of the energy consumption for air conditioning can be seen. Especially countries with unstable grids have a high usage of electricity for it.
The problem is the power production and the consumption are hard to match. Right now the strategy is to adjust the production to the demand. For that conventional plants, coal or nuclear have additional capacities the whole time. To reduce that the consuming hardware has to be more intelligent: Devices with high energy demand as cooling appliances should regulate their consumption smarter to make the grid more stable and with that more efficient.
The typical grid looks like in illustration #1 (very simplified): The producers of renewable energies and consumers are together in a low voltage distribution grid. It is connected to the bigger grid that is managed by the grid provider. Between all participants of the low grid is no communication.
To communicate between devices normally an other network is needed. As we already have a common grid between them that should be used. Power-line communication is a already developed technology that uses high frequencies (>2MHz) to communicate in live power lines. The same could be implemented in the producers to send and in appliance to receive messages from the grid.
The idea is that all data of the producers is send into the grid and the consumer devices use the energy when available. So cooling appliances decide to cool earlier when the supply is high and wait if the supply is low. The at the transformer the data is forwarded to the higher provider and back over an online service. The provider can also control the higher grid easier as they have more data of the status of the local grid. See illustration#2
An emergency detection can also be implemented. When the grid gets unstable a message could call the consumers to stop and prevent a collapse.
What it means for the people:
The consumer would not even notice the freezer or air conditioner varying a few degrees more. The only thing the consumer would notice is better air quality and less blackouts.