The U.S. Industrial and Building Sectors Industrial energy usage = 35 quads; building energy usage = 40 quads(total = 100 quads) Building energy consumption split roughly 50:50 between commercial and residential buildings These two sectors account for about 70% of total U.S. GHG emissions By 2030, 16% growth in U.S. energy consumption, which will require additional 200 GW of electrical capacity (EIA) Energy efficiency goals of 25% reduction in energy use by 2030(McKinsey and National Academies Press reports) 1

Impacts of proposed US GHG legislation if enacted in

Cap Sets a firm limit of CO 2 emissions Government sets initial cap Cap steadily decreases over time Only effects large emitters Trade Emission permits distributed -Auctioned -Given away Excess permits traded/sold Creates market for emission permits 3 Future GHG Legislation

Other Alternatives Carbon Tax -Price Predictability -Could be Revenue Neutral -Apply to all Carbon Sources Regulated CO 2 -Recent EPA Announcement 4

CO 2 Absorption/Stripping of Power Plant Flue Gas Flue Gas With 90% CO 2 Removal Stripper Flue Gas In Rich Solvent CO2 for Transport & Storage LP Steam Absorber Lean Solvent Use 30% of power plant output 5

IGCC PROCESS 6

7 Theoretical Limit Ceramic Vanes and Blades Ceramic Vanes Precooled Air Conventional Cooling

Increased Generation Efficiency Conventional efficiency: 40-55% Cogeneration efficiencies: 75-85% 8

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What is a Smart Grid? Delivery of electric power using two-way digital technology and automation with a goal to save energy, reduce cost, and increase reliability. Power will be generated and distributed optimally for a wide range of conditions either centrally or at the customer site, with variable energy pricing based on time of day and power supply/demand. Permits increased use of intermittent renewable power sources such as solar or wind energy and increases need for energy storage. 10

Utility of the Future Vision Bio fuels Plug-in H2 Zero Energy Home Distributed Utility Fossil Fuels Solar Nuclear Wind i 11

Electricity Demand Varies throughout the Day Source: ERCOT Reliability/Resource Update

Wind and ERCOT daily load Source: Dispatchable Hybrid Wind/Solar Power Plant, Mark Kapner, P.E 13

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Today’s Grid Smart Grid

Smart Grid 2.0 Tomorrow’s Grid 16

Three Types of Utility Pricing Time-of-use (TOU) – fixed pricing for set periods of time, such as peak period, off peak, and shoulder Critical peak pricing (CPP) – TOU amended to include especially high rates during peak hours on a small number of critical days; alternatively, peak time rebates (PTR) give customers rebates for reducing peak usage on critical days Real time pricing (RTP) – retail energy price tied to the wholesale rate, varying throughout the day 17

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Smart Grid Challenges/Unknowns Design of the grid Power storage Redundancy and reliability for peak/base loads Power flow management Power stability Cybersecurity Automation/decentralized control Distributed power generation (renewables) Power electronics AC vs. DC 19

Electrical Energy Storage (EES) Research Needs Increase energy/power densities, reduce system cost, and improve battery durability and reliability Solve materials challenges and model complex systems Obtain fundamental understanding of atomic and molecular processes that govern performance and durability Reduce the gap between identification, synthesis and characterization of new EES materials vs. manufacturing and design specs for devices 20

Thermal Energy Storage Thermal energy storage (TES) systems heat or cool a storage medium and then use that hot or cold medium for heat transfer at a later point in time. Using thermal storage can reduce the size and initial cost of heating/cooling systems, lower energy costs, and reduce maintenance costs. If electricity costs more during the day than at night, thermal storage systems can reduce utility bills further. Two forms of TES systems are currently used. The first system used a material that changes phase, most commonly steam, water or ice. The second type just changes the temperature of a material, most commonly water. 21

TES Economics Are Attractive for High utility demand costs Utility time-of-use rates (some utilities charge more for energy use during peak periods of day and less during off-peak periods) High daily load variations Short duration loads Infrequent or cyclical loads 22

Methods of Thermal Energy Storage TES for Space Cooling: produce ice or chilled water at night for air conditioning during the day – Shifts cooling demands to off-peak times (less expensive in areas with real-time energy pricing) – May be used take advantage of “free” energy produced at night (like wind energy) TES with Concentrated Solar Power: store energy in thermal fluid to use when sunlight is not available – Gives solar concentrating power plants more control over when electricity is produced Seasonal TES – Long term energy storage – Store heat during the summer for use in the winter Many other methods 23

UT’s Thermal Storage System Acts as chilling station, but with 1/3 of the cost 4 million gallon capacity 30,000 ton-hours of cooling (~105 MWh) – Enough to run A/C for 1500 Austin homes (2500 sq ft) each day 24

TES for Space Cooling: Calmac’s IceBank® Technology Charge Cycle: At night, a chiller is used to cool a water/glycol solution. This runs to the Ice Bank, where water inside the tank is frozen. Discharge Cycle: During the day, the glycol solution is cooled by the ice in the tank and then used to cool the air for the building’s AC needs. 25

An Inside View of the IceBank® Coolant runs through tubes Water in the tank gets frozen by the coolant at night The ice is then used to cool the solution during the day for air conditioning 26

Why Use TES for Space Cooling? Shifts electricity demands to the night to take advantage of lower rates at night Can also be a way to take advantage of wind power, which is more abundant at night 27

TES with Concentrated Solar Power (CSP) CSP technologies concentrate sunlight to heat a fluid and run a generator By coupling CSP with TES, we can better control when the electricity is produced 28

TES with Concentrated Solar Power (CSP) Two-tank direct method – Two tanks, hot and cold – Heat transfer fluid flows from the cold tank and is heated by the solar collectors. – This hot fluid travels to the hot tank, where it is stored. – As needed, the hot fluid passes through a heat exchanger to make steam for electricity generation. Other methods include two- tank indirect (where the heat transfer fluid is different than the storage fluid) and single- tank thermocline (storing heat in a solid material) The two-tank direct method 29

Seasonal Thermal Energy Storage Drake Landing Solar Community (Okotoks, Alberta, Canada) 30

Annual Energy Savings at Drake Landing 31