Energy Storage Alternatives for Household and Utility-scale - PowerPoint PPT Presentation

Energy Storage Alternatives for Household and Utility-scale Applications Marc Secanell Energy Systems Design Laboratory, http://www.esdlab.mece.ualberta.ca Department of Mechanical Engineering, University of Alberta, Edmonton, Canada Solar Energy Society February 25, 2015

Overview 2  About the presenter  Introduction  Why do we need energy storage?  How much energy storage do we need?  Choosing among options  Small scale/Residential energy storage  Electrochemical batteries  Flywheels  Large scale/Grid scale energy storage  Pumped-hydro  Synthetic fuels, e.g., solar hydrogen  Conclusions

About the presenter 3  Experience  2013-Present, Associate Professor, University of Alberta, Department of Mechanical Engineering o Teaching: Energy conversion, Thermo-fluid systems design, Electrochemical systems o Research: Director of Energy systems design laboratory  2009-2013, Assistant Professor, University of Alberta, Department of Mechanical Engineering  2008-2009, Assistant Research Officer, National Research Council, Institute for Fuel Cell Innovation  Education  Ph.D. Mechanical Engineering, University of Victoria, Canada, 2008  M.A.Sc. Mechanical Engineering, University of Victoria, Canada, 2004  B.Eng., Universitat Politècnica de Catalunya, Barcelona, 2002

Energy systems design laboratory: 4 Overview • Mandate: "To design energy systems that can meet society’s needs while minimizing their cost, environmental and socio-political impact." • 10 researchers • 1 Post-doctoral fellow • 3 Ph.D. students • 5 M.Sc. students • 1 undergraduate students • Open for collaboration with local industry • Website: http://www.esdlab.mece.ualberta.ca/

Energy systems design laboratory: 5 Expertise Computational Design and Optimization of Energy Systems • Polymer electrolyte fuel cell design • Flywheel design Computational Analysis of Experimental Testing of Energy Energy Systems Systems • Developing energy system • Fuel cell fabrication and models and simulation testing • Hydrogen electrolyzer software, e.g., openFCST • Clean hydrogen fabrication and testing • Flywheel fabrication an testing production processes

Overview 6  About the presenter  Introduction  Why do we need energy storage?  How much energy storage do we need?  Choosing among options  Small scale/Residential energy storage  Electrochemical batteries  Flywheels  Large scale/Grid scale energy storage  Pumped-hydro  Synthetic fuels, e.g., solar hydrogen  Conclusions

Why do we need energy storage? 7  Our current energy infrastructure can be simplified to:

Why do we need energy storage? 8  Energy supply: ***Includes geothermal, solar, wind, heat, etc. Source: International Energy Agency, Key World Energy 2014.

Why do we need energy storage? 9  Our energy storage are our coal, oil and natural gas reserves  Heating: Natural gas pipeline  Transportation: Gas stations, refineries  Electricity: Electrical grid  The electrical grid is the largest just-in-time supply system in the world  Electricity demand matched by turning on/shutting down power plants o Power plants with largest inertia, e.g., nuclear and coal, are not usually shut down  Current storage in U.S. can provide 2.3% of the grid power capacity, i.e. 23.6 GW  Energy vs. power  Energy = Joules or kWh = “how much water is in the bathtub”  Power = Energy / Time = MW = “how fast is the water draining”

Why do we need energy storage? 10  Increased use of renewable energy in households  Solar PV to produce electricity Source: Mill Creek NetZero  Solar thermal for DHW greenedmonton.ca  Global goal to increase renewable energy production worldwide  Reduce GHG emissions  Distributed and large-scale solar PV, wind farms, … Source: International Energy Agency, Key World Energy 2014.

Why do we need energy storage? 11  Renewable energy resources are intermittent  They cannot be switched on/off on demand o Reduce our current ability to match supply and demand  Resource is intermittent and hard to predict  High energy demand hours/months do not match with high energy production hours o Solar: Highest production hours from solar would be 10-16h but highest demand hours would be 18-22h Source: Fraunhofer Institute for Solar energy systems (ISE) Electricity production from solar and wind in Germany in 2011

Why do we need energy storage? 12  Wind production in Alberta, first week of January 2010  Data from Alberta Electric System Operator  Variability leads to curtailment  At very high production times, AESO cannot accept all wind power due to oversupply and transmission limitations (2-10% not used) Wind power production from Jan 01 to 07, 2010 (MW) 600 Power produced (MW) 500 400 300 200 100 0 0 2000 4000 6000 8000 10000 12000 Time in minutes

Energy storage options: All-electric 13  Option 1: All-electric energy storage/transportation

Energy storage options: All-at-once 14  Option 2: Electric and fuel energy storage system e -

Choosing among options 15  Questions you should ask (yourself) when selecting an energy storage option  How much energy do we want to store? o Specific energy and energy density (in kWh/kg or kWh/m 3 ) o Discharge depth limit  How much power do you need the system to provide? o Specific power and power density (in W/kg and W/m 3 )  How much of the energy stored do you expect to recover, and after how long? o Turnover efficiency o Losses during charge, no-load (self-discharge) and discharge  How long do you want your system to last? o Durability (cycling capacity)  What type of energy do we want to store? What do we want to use the stored energy for?  How much are you willing to pay up-front (capital cost)? Overall?

How much do we want to store? 16  Household storage:  In 2011, the average Canadian household consumed 105 GJ/yr o ~ 40% (actually 38%) electricity o 45% natural gas o Rest wood, oil and propane  NG used for heating  Electricity used for heating (in some provinces), appliances, etc.  If we want to store only necessary electrical power we would need: 32 kWh/day Source: Statistics Canada, Households and the Environment: Energy Use, 2011

How much do we want to store? 17  Grid level storage  Wind power in Alberta  Total capacity: 1,434 MW (9% total capacity)  Provided 5.1% of the energy in Alberta  In Jan 01-07, 2010, average power 126.06 MW, peak 500 MW  Curtailment of wind power generation due to oversupply and transmission constraints Wind power production from Jan 01 to 07, 2010 (MW) 600 Power produced (MW) 500 400 300 ~20 TJ = 5,555,556 kWh = 5.56 GWh 200 100 0 0 2000 4000 6000 8000 10000 12000 Time in minutes

How much do we want to store? 18  If I produce electricity using renewable energy, then I can be “energy independent” and “zero - emissions”  Not so quickly…  What about transportation, heating and industrial applications? Source: Statistics Canada, Households and the Environment: Energy Use, 2011

Choosing among options 19  The answer to these questions leads to different energy storage options Source: Fraunhofer institute

Choosing among options 20  Cost is different per unit energy and per unit power Source: H. Ibrahim, Renewable and Sustainable Energy Reviews, 12:1221-1250, 2008

Choosing among options 21  Capital cost are not the full story  Cost also depends on the durability of your technology Source: H. Ibrahim, Renewable and Sustainable Energy Reviews, 12:1221-1250, 2008

Energy storage options 22  Electricity must be stored in some other energy form, e.g., chemical, kinetic, potential and thermal  In this presentation we will focus on one of the most mature and one of the most “risky” for residential and grid -scale storage  Flywheel energy storage (residential scale)  Chemical energy storage (residential and grid-scale) o Batteries o Hydrogen  Pumped hydro (grid scale)  Many other available  Compressed air energy storage (grid scale)  Thermal energy storage (TES) (grid and residential scale)  Ultra-capacitors (residential scale)

Overview 23  About the presenter  Introduction  Why do we need energy storage?  How much energy storage do we need?  Choosing among options  Small scale/Residential energy storage  Electrochemical batteries  Flywheels  Large scale/Grid scale energy storage  Pumped-hydro  Synthetic fuels, e.g., solar hydrogen  Conclusions

Electrochemical batteries: How they work 24  Energy is stored in the form of chemicals inside the battery  During discharging the positive electrode is reduced and the negative electrode oxidized  During charging the positive electrode is oxidized and the negative electrode is reduced  Example: Lead-acid battery 𝑂𝑓𝑕𝑏𝑢𝑗𝑤𝑓 𝑓𝑚𝑓𝑑𝑢𝑠𝑝𝑒𝑓 (𝑒𝑗𝑡𝑑ℎ𝑏𝑠𝑕𝑓): 2− → 𝑄𝑐𝑇𝑃 4(𝑡) + 2𝑓 − 𝑄𝑐 𝑡 + 𝑇𝑃 4 𝑄𝑝𝑡𝑗𝑢𝑤𝑓 𝑓𝑚𝑓𝑑𝑢𝑠𝑝𝑒𝑓 (𝑒𝑗𝑡𝑑ℎ𝑏𝑠𝑕𝑓): 2− + 2𝑓 − → 𝑄𝑐𝑇𝑃 4(𝑡) + 2𝐼 2 𝑃 𝑄𝑐𝑃 2 (𝑡) + 4𝐼 + + 𝑇𝑃 4 Source: http://chemwiki.ucdavis.edu