The story of added value to storage in distribution systems
The growing need for clean and inexhaustible sources of energy is becoming a global priority. Yet, increasing the share of renewable energy sources entails many challenges, the main one being the temporal mismatch between energy demand and renewable energy availability, which has an intermittent nature. Energy storage enables decoupling demand and supply and adds flexibility to the system. The EU-funded STORY project investigated six demonstration cases with different local or small-scale storage concepts and technologies, ranging from neighbourhood residential storage to multi energy grid in industrial areas. “The case studies had indeed very different goals, but some common goals can be mentioned: increased use of local renewable energy, reduction of CO2 emissions and limiting the negative effects on the grid,” says project coordinator Mia Ala-Juusela.
An ambitious and demanding approach
The focus of the project was on electricity storage, but thermal storage was also included in some of the demos. One essential aspect was the control strategies developed for the different cases to reach their goals, contributing to the formulation of policy recommendations based on the experiences from the demos. During the project, acquiring the storage systems was not always an easy endeavour. Despite the tenders received during the preparation phase, some systems were not available at all, while in other demos, the suppliers withdrew their offers. Moreover, maintenance proved to be a key aspect, as very few of the systems worked reliably from beginning to end. “One thing that was also not anticipated was the low level of interoperability,” notes Ala-Juusela. “We knew that there are challenges in this field, and we developed solutions to mitigate this, such as the digital twins and the interoperability platform. Still, it was surprising for us to discover how little interest there seemed to be among the component developers to make the products compatible with other parts of the system, or even inside their own system.”
Valuable conclusions for future storage applications
Among other issues, STORY investigated the interrelations between technologies and stakeholders as well as the impact of policy and regulations on the business opportunities of the storage-related industry. “The small- and medium-sized energy storages studied in STORY can indeed give valuable support to the grid, but a careful cost-benefit analysis needs to be carried out, with analysis of sensitivity to different changes,” explains Ala-Juusela. “The constant changes in regulations may undermine the assumptions in these analyses.” One surprising result of the large-scale analyses was that, to reach the level where the environmental effects of storage installation are on the positive side, high penetration of renewables is imperative. The storage reduces the need to curtail the renewable energy and increases the share of CO₂-free energy in the system. The renewable energy and the energy grid/market branches are the sectors that will benefit the most from the project’s findings. The STORY consortium continues the development of the solutions, both in public-funded and commercial projects. “The new projects are related to positive energy buildings, energy communities, digital twins, data platform, flexibility market, life-cycle assessments and simulation models, to mention a few,” adds Ala-Juusela.
Keywords
STORY, energy storage, renewable energy, energy grid, distribution systems
