Stationary Battery Storage Systems Dirk Magnor Chair for Electrochemical Energy Conversion and Storage Systems (Univ.-Prof. Dirk Uwe Sauer) Institute for Power Electronics and Electrical Drives RWTH Aachen University Stationary Battery Storage Systems - Technology Overview, Cost Calculation and Application Examples -

Definition of a Storage System Stationary Battery Storage Systems

Definition of a Storage System – Pumped Hydro Storage Stationary Battery Storage Systems

What Size do Storage Systems Have? Pumped Hydro Storage: 1 m3 at a hight of 360 m for 1 kWh Source: http://www.goldisthal.de Stationary Battery Storage Systems

Definition of a Storage System – Battery Storage Stationary Battery Storage Systems

What Size do Storage Systems Have? Battery Storage: 20 ft container can house 1 MWh / 1 MW lithium ion batteries Approx. 4 times the size for same amount of lead-acid or redox-flow batteries PV battery systems have approx. the size of a fridge Stationary Battery Storage Systems

Example for Storage Dimensions Most modern class of container ships can carry approx. 15,000 containers (400 m x 56 m base area) Stationary Battery Storage Systems

≡ Example for Storage Dimensions Most modern class of container ships can carry approx. 15,000 containers (400 m x 56 m base area) Completely loaded with battery containers, this equals a capacity of 15 GWh / 15 GW (all German pumped hydro plants: 60 GWh / 6 GW) ≡ Energy Stationary Battery Storage Systems

≡ Example for Storage Dimensions Most modern class of container ships can carry approx. 15,000 containers (400 m x 56 m base area) Completely loaded with battery containers, this equals a capacity of 15 GWh / 15 GW (all German pumped hydro plants: 60 GWh / 6 GW) ≡ Power Stationary Battery Storage Systems

Outline Battery Technology Overview Aspects of Battery Cost Calculation Application Examples Stationary Battery Storage Systems

Lead Acid Batteries Stationary Battery Storage Systems Parameter Efficiency 80 % – 85 % Calendar Life 5 – 15 years Cycle Life 500 – 2.000 Specific Energy Cost 80 – 200 €/kWh Specific Power Cost 100 – 200 €/kW SWOT Strengths High availability Experience with large systems Weaknesses Low cycle life Space ventilation mandatory Oportunities Many manufacturers worldwide Cost reduction potentials Threads Limited reservoirs of lead Competing with lithium ion batteries Sources: Varta, Hoppecke Baterrien Stationary Battery Storage Systems

Lithium Ion Batteries Stationary Battery Storage Systems Parameter Efficiency 90 % – 95 % Calendar Life 5 – 20 years Cycle Life 1.000 – 5.000 Specific Energy Cost 200 – 500 €/kWh Specific Power Cost 100 – 200 €/kW SWOT Strengths Long lifetimes, high efficiencies, High energy density Weaknesses High cost Intrinsic safety Oportunities High cost reduction potentials Threads Lithium reservoirs limited to few countries Sources: Saft, Kokam, GS YUASA Stationary Battery Storage Systems

High Temperature Batteries Parameter Efficiency 82 % – 91 % Calendar Life 15 – 20 years Cycle Life 5.000 – 10.000 Specific Energy Cost 250 – 500 €/kWh Specific Power Cost 100 – 200 €/kW SWOT Strengths Long lifetimes, existing systems Cheap raw materials (NaS) Weaknesses Thermal losses High operation temperatures Oportunities Expiring patents Availability of raw materials Threads Few manufacturers Quelle: NGK, MES-DEA Stationary Battery Storage Systems

Redox Flow Batteries (Vanadium) Parameter Efficiency 60 % – 74 % Calendar Life 10 – 15 years Cycle Life > 10.000 Specific Energy Cost 150 – 400 €/kWh Specific Power Cost 100 – 200 €/kW SWOT Strengths Power and energy capacities independently scalable, high cycle life Weaknesses System complexity High maintenance cost Oportunities Expiring patents Threads Vanadium is rare material Quelle: www.vrbpower.com Stationary Battery Storage Systems

Redox Flow Batteries (Vanadium) – Functional Principle Stationary Battery Storage Systems

Definition of a Storage System - Redox Flow Battery Stationary Battery Storage Systems

Redox Flow Batteries (Vanadium) Parameter Efficiency 60 % – 74 % Calendar Life 10 – 15 years Cycle Life > 10.000 Specific Energy Cost 150 – 400 €/kWh Specific Power Cost 100 – 200 €/kW SWOT Strengths Power and energy capacities independently scalable, high cycle life Weaknesses System complexity High maintenance cost Oportunities Expiring patents Threads Vanadium is rare material Source: www.vrbpower.com Stationary Battery Storage Systems

Battery Technologies – Interim Conclusion Lead acid batteries Lithium ion batteries NiCd batteries High temperature batteries (NaS, NaNiCl2) Redox flow batteries Currently dominating technologies for decentralized PV battery systems Technologically viable, but not to be expected to large extent Application especially for larger systems feasible; market not stimulated through small systems‘ sales Stationary Battery Storage Systems

Cost Calculation Application parameters power [kW] Technology specific power cost [€/kW] efficiency [%] self discharge [%/d] energy [kWh] cycles [#/d] energy storage cost [€ct/kWh] annuity method specific energy cost [€/kWh] maximum depth of discharge (DOD) [%] electricity cost [€ct/kWh] system lifetime [a] maintenance & repair [%/a] cycle life @ DOD [#] capital cost [%] Stationary Battery Storage Systems

Project Example – M5Bat Goal: Construction and operation of a 5 MW / 5 MWh hybrid BESS in the reserve market with 2 x Li: NMC/LMO and LFP/LTO 2 x Pb: OSCM and VRLA NaNiCl Budget: 12.5 Mio. € total 6.5 Mio. € public funding

Applications – Primary Control Reserve (PCR) Frequency [Hz] Stationary Battery Storage Systems

Primary Control Reserve (PCR) – Load Profile 72 % of the time no load (dead band) Activation nearly symmetrical pos. and neg. reserve – not quite Maximum demand in 3 months 70 % of nominal power rating Activation of > 25 % of nominal power in 0,36 % of the time  15,4 hours per year Activation of > 50 % of nominal power in 0,0036 % of the time  8,5 minutes per year Data 3,5 months cleaned data > 25 % 25 % < > 50 % 50 % < Stationary Battery Storage Systems

Applications - Secondary Control Reserve (SCR) Market volume in Germany: Positive SCR 2.470 MW Negative SCR 2.420 MW 267 M€ in 2012 (BNetzA) Period of supply min. 4 h (4 MWh per MW) Potential earnings (ideal) 200 k€ / MW = 50 k€ / MWh Invest MW-battery system 2015 ca. 550 k€ / MWh Annuity (550 k€; 12 years, 8 %) = 68 k€ / MWh Plus operation cost and electricity purchase  Currently, batteries can not provide SCR economically  Viable approx. 2020 - 2025 Traded seperately Stationary Battery Storage Systems

Prospective Storage Markets Control Reserve EV / PHEV PV home storage Stationary Battery Storage Systems

Why Decentrelized Storage? Data: BMU, EEG 2013 und BMWi Energiedaten B.Burger, Fraunhofer ISE, Stand 28.01.2014 PV reimbursement German EEG Households Industry Increasing electricity cost + PV cost Increasing margin for storage operation Dependent on cost for generation, electricity purchase, storage Storage Storage Stationary Battery Storage Systems

Conclusion – Take Home Messages Different applications need different storage solutions Batteries support short to medium term storage For each application load profiles need to be evaluated to select the right battery Large battery capacities will be available in the electricity grid from: Increasing numbers of electrified vehicles PV battery systems Multiple use of storage systems can open markets earlier and improve economics of battery storage Stationary Battery Storage Systems

Thank you very much for your attention. Contact Details: www.isea.rwth-aachen.de Dirk Magnor dma@isea.rwth-aachen.de Stationary Battery Storage Systems

Primary Control Reserve (PCR) – SOC Profile Operational strategy for compensation of losses necessary (slow and low power) Time share at given SOC depends on size of battery – influence on aging Smaller capacity results in larger variation of SOC i.e. increased aging String influence on invest (capex) Prequalification requires 2 x 15 min full load, ENTSOE pushing towards 2 x 30 min Technically 0.5 MWh / MW sufficient Dwell time at respective SoC [h] State of Charge (SoC) of the battery [%] Stationary Battery Storage Systems

Battery Aging – Example: Lithium Ion Batteries Cycle Life Calendar Life Impact Factors: ∆SoC and SoCavg Shallow Cycles long lifetime Deep Cycles short lifetime Impact Factors: Temp. and SoCavg Full LiB are aging faster Cool LiB are aging slower Stationary Battery Storage Systems

Lithium Ion Batteries – Functional Principle Stationary Battery Storage Systems

High Temperature Batteries – Functional Principle Stationary Battery Storage Systems