Electricity storage systems
Goal:
- Saving on the electricity bill
- Backup solution in case of a power blackout
- prevent grid pollution as caused by intermitting electricity sources
How:
- Prevent injection or feed-in of electricity coming from renewable energy sources to be fed into the public grid at low prices that afterwards need to be bought at higher prices.
- Charge batteries at low prices during off peak periods (Time of Use).
- Switch loads in order to maximize the availability of battery power (Demand Side Mgt)
What:
- There are DC or AC connected storage systems. In a DC connected system the PV panels are directly connected to the storage system, this is the most efficient system and is mainly done for installations where there was not yet a PV system installed or there was a PV system installed but the installed inverters need to be replaced.
An AC connected system is a system that is connected to an existing PV system. This is also called a retrofit.

- There are grid connected or off-grid installations. Off-grid installations are mainly used when there is no grid available or for rural electrification. For Off-grid installations, the battery sizes are usually bigger and different inverters need to be used. On-grid installations are in general the most economical and most efficient.
- A full system consists out of batteries, chargers, inverters, power switches, a communication module and finally our so called ‘EFM system’ (EneRa propriatery name) or ‘electricity flow management system’ which also includes the battery management system. The EFM system controls and drives: the load, the charging, de-charging and maintenance of the battery and finally the electricity production.