Application: Battery Storage
“Grid-serving customer behavior” in the sense of the 7000-hour rule outlined in the German electricity grid charge regulations (StromNEV § 19) presents an opportunity for many businesses: Industrial companies that use battery storage units and practice smart internal energy management can benefit from considerable savings potential in certain circumstances.
The more uniform their reference curve is, the more favorable the conditions for large industrial companies seeking to obtain electricity. An even reference curve ensures the optimum, most economical utilization of energy supplier or grid operator networks and resources, because the entire infrastructure from generation to distribution to the end consumer connection must always be designed for maximum performance.
The more constant the supply, the better the economic utilization of the infrastructure. The metric used for this is the annual full-load hours (AFLH). It is calculated by dividing the total annual energy output by the full-load power. The theoretical optimum for this figure would be 8760 hours (i.e. the total number of hours annually in terms of energy economy). This would mean full utilization and a constant supply without any downtime.
In practice, the ‘magic’ limit of 7000 annual full load hours is the number from which the supplier considers an electricity consumer to serve the grid so well that it must no longer pay the published grid fees per kW and kWh included in the energy price for this reference year. As a rule, customers can save 80 to 90% of the total grid fees to be paid or agree on these individually with their grid operator. This rule is of particular interest when a storage system is used. In some cases, a storage system can pay for itself in less than a year if it allows customers to apply for these individual grid fees.