Smart Storage Space and Water Heaters

Resources for Grid Management, Renewable Integration, and Conservation

Paul SteffesSteffes Corporation

psteffes@steffes.com888-783-3337

October 4, 2010

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Work with over 200 Electric Utilities across North America (some for over 20 years)

World leader in innovative electric storage

Steffes Corporation“Commitment to Innovation”

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Adjust the target temperature up or down in response to power availability (grid signal) - “Battery” charge level

Adjust the input wattage Provide Comfort Assurance, so

home is always warm and has hot water

“Grid-Interactive Controls” for Electric Storage”

Family of Electric Storage Products

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Grid-Interactive Residential ElectricStorage Furnace

with or without Heat Pump

86 to 240 kWh storage

Stored renewable

and off-peak energy

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Forced Air

Hydronic

480 kWhStorage

960 kWh Storage

Ten Story Office Building

Grid-InteractiveCommercial Size Forced Air and Hydronic Units

“ThermElect”Electric Storage

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Grid-Interactive RenewableWater Heating

Think of a 105 gal. Water Heater as a 26kWh Battery

(nominal two day supply of hot water)

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Grid-Interactive Electric Storage Systems Deliver:

1. Arbitrage Value2. LMP following3. Renewable Integration Value4. Ancillary Value5. Conservation

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Renewable Integration

Wind and Solar ramp up & down quickly. Grid interactive controls can ramp just as fast

Allows a higher percentage of Renewable Energy (RE) to be utilized

Enhances RE value Reduces Carbon footprint Lowers cost for consumers

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NYISO 2008 Data

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Variability of Electric Load

Water Heater Load

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Variability of Renewables Three Year Stable

Annual Wind Output

% of Unusable Wind Energy (Oct-May)Assuming 25% of all KWHs supplied are Wind Energy

and Non-Wind Generated Resources are turned down to 25% of Capacity

0%

5%

10%

15%

20%

25%

30%

35%

40%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour of the Day

% o

f Win

d KW

Hs u

nuse

d pe

r Hou

r

2006

2007

2008

3 Year Avg

When 25% of kWh’s are derived from WindAmount of Potentially Curtailed Wind Energy

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MISO NSP.Buffr Gennode LMP 2007

Real Time Prices

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Variable Real Time Price

Three Year Stable Annual Average Price

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Putting it TogetherOverall Utility Load

Wind Generation

Wholesale Energy Cost

Smart Space & Water Heater Load

Potentially Curtailed Wind Generation

Typical Water Heater Load

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This analysis uses three (3) years of actual load, wind scaled to 25% of load, LMP, and EPRI water heater data.

Energy Storage Method Wholesale Cost ($/y)

Total Energy Used (kW·h/y)

Wind Energy Use (kW·h/y)

Nonwind Energy Use

(kW·h/y)

CO2 Reduction† (lb/y)

55-gal Uncontrolled Storage Water Heater$251 4805 1156 3649 Baseline

0% 0% 24% 76%

85-gal Grid-Interactive Storage Water Heater$133 4940 2726 2214 1436-47% 3% 55% 45% -39%

105-gal Grid-Interactive Storage Water Heater with Smart Signal

$126 4974 2840 2134 1515-50% 4% 57% 43% -42%

Assumes that COP = 2 above 55°F and COP = 1 at or below 55°F

55-gal Heat Pump Water Heater (Zone 1)$126 2407 580 1828 1821-50% -50% 24% 76% -50%

55-gal Heat Pump Water Heater (Zone 3)$153 2936 717 2219 1430-39% -39% 24% 76% -39%

55-gal Heat Pump Water Heater (Zone 5)$187 3566 880 2686 964-25% -26% 25% 75% -26%

55-gal Heat Pump Water Heater (Zone 7)$205 3899 972 2928 721-18% -19% 25% 75% -20%

†Assumes 1 lb of CO2 per kW·h of nonwind energy use.

Renewable Integration and Arbitrage Value

New Dimension of Conservation and Efficiency, charging more when there is renewable energy available and storing more energy to span times without renewable energy

With 25% Wind Energy

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Six days of output from a5MW Solar PV plant

As grid-interactive storage heaters follow solar and wind up and down in realtime, the carbon is

significantly further reduced

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Bonus Economic and Environmental Value

• Note the monetary value of Regulation (Greater then energy at times)

• Regulating with a non fuel consuming resource has a significant carbon reduction (up to 70%)

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Fast regulation, responding to an Automatic Generation Control (AGC), Renewable following or other signals to:• Provide frequency control• Reduce generator fuel consumption• Improve grid reliability• Reduce regulation costs• Reduced system CO2• Yield ancillary value payments

Ancillary Value

Grid-Interactive Renewable Electric Water Heaters

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• Equivalent times and magnitudes above and below nominal

• Requires high-speed two-way communication infrastructure

Ancillary Value

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Ancillary and Other Value

Data from Grid-Interactive Space and Water Heating

(2-way smart communication needed)

3-Step Continuously-Variable

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BPA Balancing Reserves Deployment

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Grid-Interactive Space and Water Heaters are…

“Thermal Batteries”

With smart control, you affect the grid exactly like other electric storage technologies

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Low-Cost Electric Storage To realize the dream of the smart-grid significant storage in needed CALISO says 4000 Megawatts of variable storage need to balance

renewables Grid-interactive Thermal Storage is a small fraction of cost of other

methods Pursue “Low hanging Fruit” Fill low-cost window of opportunity first

Cost

Technology $/kW-h $/kW

Grid-interactive Thermal Storage $30-$60 $100-$200

CAES (above ground) $200-$250 $700-$800

ZnBr Flow Cell $280-$450 $425-$1300

Pb-Acid Battery $330-$480 $420-$660

NaS Battery $350-$400 $450-$550

Flywheel $1340-$1570 $3360-$3920 Source: EPRI 2009 energy storage technology cost estimates Source: Steffes Corporation

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Can Work With Various Interoperable Smart Control Signals

1. One-Way Dual Relay Control2. One-Way Variable Control Signal3. Two-Way High-Speed Signal4. Other…

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Fixed Dual Relay Control

Ramping Dual Relay control

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One-Way Variable Control Signal

Renewable Integration and Arbitrage Value

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Communication Heartbeat1. Hours: to buy low-cost electricity and consume it when

cost are higher (arbitrage value)2. Minutes: to vary charge rate and level based on current

renewable generation output, real-time pricing, and other grid needs or limitations (renewable integration value)

3. Seconds: to provide fast up and down regulation for frequency control and grid reliability (ancillary value)

4. Other…

Arbitrage, Renewable Integration & Ancillary Value

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Grid-Interactive Storage Space & Water Heating Systems are good for…

Environment Consumers Conservation Efficiency The Grid

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“If we want to have a low or zero carbon economy, we must encourage

products or technologies that have the potential of getting us there.”

Paul SteffesSteffes Corporation

psteffes@steffes.com888-783-3337

Questions?