Regulation: a key factor for the Storage added value assessment

During the last two to three years important progress in the regulatory framework concerning energy storage systems has taken place. Strong lobby efforts from diverse associations and organizations have culminated in the incorporation of energy storage in many of the Directives and Regulations that comprise the Clean Energy for All Europeans package (link). This gives an idea of the interest and involvement of the European Union in supporting the energy storage deployment and the importance of the regulation for the development of new technologies.

An example of this influence is shown by the Spanish demonstration of the STORY project. The main goal of this plant is to reduce the demand charge of a factory, optimize the use of the onsite PV energy produced and to economize the energy bill. This is achieved by the use of a Li-ion battery for peak shaving and maintaining a balance between the energy generated and used.

The current self-consumption regulation in Spain however, establishes significant restrictions in the operation of energy storage systems in self-consumption plants connected to the grid. Unless one pays the toll “peaje de respaldo” (grid support toll) which reduces considerably the benefits and savings of the plant. However, it is possible to connect these self-consumption plants including storage while precluding energy delivery to the grid and storage charged from the grid. Clearly, this constrained operation mode hinders the capture of the maximum added value of the storage and makes the system cost-ineffective.

Preliminary results obtained in STORY’s Spanish plant (Figure 1) demonstrate that even with the regulatory restrictions applied, the peak power can be reduced by about 20% as well as the energy consumption from the grid during peak hours (17.00-23.00) to amount to overall savings of up to 8%.

Figure 1: Daily operation of the Spanish pilot plant (orange line: loads; blue line: PV energy; green line: in & out battery power; purple line: battery State of Charge, SOC)

Estimates from simulations with an advanced energy management strategy allowing the battery to charge from the grid, reveal that power peak reductions of up to 50% in peak hours and overall savings up to 20% are possible. However the confirmation of these results in real operation will have to wait for the relaxation of the regulations, but there are promising benefits on the horizon…