ECOBATTEM – Eco-friendly and Ageing-Aware Energy Management software for Li-ions Battery

• Research unit: SFOE
• Project number: SI/501689

Short description (English)

The main goal of the project ECOBATTEM is to experimentally proof that the large installation of battery storage systems (BSS) equipped with an ageing-aware energy management software is the best way to satisfy the 2050 Swiss Energy Strategy. The main reasons behind this goal are :

The BSS will allow to increase the energy self-consumption and consequently reduce the global C02 emissions;

An ageing-aware strategy for BSS deployment allows for maximizing the lifetime of the BSS itself with a consequent large renewable energy self-consumption and C02 reduction ;

A BSS with a minimum state of ageing can be deployed by utility/DSO in order to provide ancillary services to the power grid (such as peak-shaving and frequency/voltage control)

Short description (French)

L'objectif principal du projet ECOBATTEM est de démontrer expérimentalement que l'installation à grande échelle de batteries de stockage électrochimique (BSE) équipées d'un logiciel de gestion de l'énergie intégrant la notion de vieillissement est la meilleure solution pour satisfaire la Stratégie Energétique 2050. Les éléments clés derrière cet objectif sont:

• Les BSE permettent d'augmenter l'autoconsommation énergétique et de ce fait réduire l'émission de CO2;

• Une stratégie de déploiement des BSE intégrant le vieillissement permet de maximiser la durée de vie de la batterie, tout en augmentant l'autoconsommation d'énergies renouvelables et la réduction de CO2;

• Un système BSE avec un vieillissement minimal pourra être utilisée par des distributeurs d'énergie  électrique dans le but de fournir des services auxiliaires au réseau électrique (coupage de pics de puissance et contrôle de fréquence/tension).

Final report (English)

The ECOBATTEM project has proved that:

1. Low C-rate (below 1C-Rate) and low SoC during micro-cycling have a large impact on ageing mitigation of Li-ion Battery Energy System (BES);

2. A rational management of BES for building application is needed in order to maximize the benefit and extend the lifetime of the BES;

3. Extending the lifetime of BES is essential from a C02 footprint point of view;

4. New business models, such as the leasing one, can involve large deployment of distributed BES and give clear indications to stakeholder in order to define rational subvention of BES;

5. Ageing mitigation via dedicated non-conventional ageing stress test, as well as, ageing-aware energy management seem essential for vehicle to the grid application and second-life battery applications.

Main findings:

1. Reducing charging and discharging C-rate in Li-ion cells can mitigate the ageing of the targeted battery up to 95%, while reducing the SoC from 90% down to 50% during micro cycling application (such as primary frequency control) can reduce the ageing of a factor 12.6 (from 300 thousand cycles up to 3.8 million of cycles, experimental findings);

2. The energy management software, integrating dedicated Li-ions ageing model, developed model free and sensor free PV and load consumption forecast, is able to reduce, when it is possible, the C-rate up to 87 %(experimental findings, during 72 days of measurement in the three targeted sites). The associated average ageing reduction and consequent extended lifetime is up to 38.5%.

3. From a C02 foot print point of view, extending the lifetime of the BES up to 38.5%, thanks to an ageing-aware energy management allows for 24% reduction of C02 emission (compared to the same system equipped with a BES without any ageing-aware strategy);

4. The ageing-aware business models showed that adding economic concepts like time value of money (trough leasing) increases the internal rate of returns (IRR) up to 6.14%. The computation for a pooled system enabling multiple revenue streams showed 62.81% of profitable cases with a maximum IRR of 4.91%. Finally, the principle of wealth redistribution leads to IRR bigger than 0% in 29.75% of the scenarios.

Related documents

• ECOBATTEM - Final Report [PDF] 2'305 kB