An intelligent hybrid inverter or smart grid inverter is a new generation of inverter for dedicated solar applications using renewable energy for home consumption, especially for solar photovoltaic installations. Electricity from solar panels is generated only during the day, with a peak production around midday. This electricity is fluctuating and not synchronized with the electric consumption of the household. To overcome this gap between what is produced and what is required during the evening when there is no solar electricity production, it is necessary to store energy for later use and manage energy storage and consumption in an intelligent (smart grid).
With the development of systems using renewable energy and rising prices of electricity, private companies and research laboratories have developed smart inverters to enable correlation between energy production and consumption.[1]
Principle
The function of a (smart-grid) is enabling selection and orientation of renewable energy, energy from the grid and energy storage based on consumption.
Unlike conventional inverters, rather than systematically storing energy in batteries (with significant loss of yield >20%),[2] hybrid inverters store energy only when necessary, e.g. when there is more production than consumption.
This system also allows choosing whether electricity from photovoltaic panels should be stored or consumed through an internal intelligent apparatus control unit.
This is possible through a technique that adds different energy sources (phase coupling: on-grid or grid-tie techniques) and the management of stored electricity in the battery (off grid technology). Hybrid inverters therefore operate on grid (grid-tie) as well as off-grid, hybrid (both on-grid and off-grid at the same time) and Backup (in case of a black out).
According to the E.R.D.F. (French Electric Network) smart inverters are the future of photovoltaic solar panel installations dedicated to energy self-use, or auto-consumption of energy.
Usage
Use in off grid mode (without network) with the possibility of linking to a generator. The inverter must be connected to a battery bank.
Use in on-grid or grid-tie (connected to the network) with the possibility of selling energy or excess energy. There is a need to have the norm compliance of protection and decoupling (DIN VDE 0126.1).
Use in hybrid mode the inverter functions with a battery bank, but also connected to the grid. This dual functionality is the highlight of hybrid inverters that hence enable energy management (smart grid).
Use in Back-up mode, or storage mode prevents blackouts by switching from on-grid mode to off-grid mode at the moment of electric outage, thereby eliminates network cuts.
