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WESTERN WASHINGTON CLEAN CITIES COALITION

The economics of providing workplace charging

Scott DeWees

Clean Cities Co-CoordinatorScottD@pscleanair.org

October 17th 2014

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What makes up the cost of providing charging?

Electrical

Electricity use

Monthly demand charges

Equipment and

installation

EV charger (EVSE)

Installation labor / site

work

Permit

Electrical service

upgrades

EV Charger management

EV charger networking

Maintenance budget

Data fees

EVSE or parking

enforcement

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Rate of electricity consumption impacts your demand charge

Billed as: Peak 15-min interval of consumption rate X utility demand charge

6 KW X $7.0/KW = $42 monthly demand charge

Amount of electricity consumption impacts your electricity charge

Billed as: Total monthly electricity X the electricity rate

600 kWh X $0.06/kWh = $36 electricity charge

EV charging impacts electricity cost in in two ways

Rate Price

Amount Price

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But, demand charges are not applicable to facilities under “small general service” rates (e.g., less than 50 KW aggregate demand)

Demand charge rates depend on: • Your utility (TPU, SCL, PSE) • The utility rate-schedule the facility is under• Time of year

Typically range from $2.00 -$9.00 / KW

EV demand charges

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Rocky Mountain Institute: • EV charger: ~$2,000- $6,000 • Installation is the major contributor to public station cost (60–80 percent of total)• Parking garage installations are the easiest and most economical public charging

stations and typically cost about $6,000

Installation costs: It depends

Data and graphs sourced from: http://blog.rmi.org/blog_2014_04_29_pulling_back_the_veil_on_ev_charging_station_costs

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• Locate chargers close to electrical service

• Avoid trenching

• “Rough in” capacity for future chargers

• Locate chargers between parking stalls

• Bundle installation with other site upgrades (e.g., lighting retrofits)

Strategies to reduce installation costs

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Marginal costs Per charge event

EV charger 5 year period?

Infrastructure + installation

5-10 year period?

How to treat EVSE + installation costs?

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Scenario A: Level 1 charging without revenue recovery

Electricity cost per charge $0.72

Monthly energy-demand charge $10.50 (or $1.18/ charge)

Annual total (electricity+ demand)

$307

Vehicles supported 1

Marginal cost per charge $1.65

Marginal cost including EV charger

$2.60

Marginal cost + total install $2.84

• Charger used once per day, five days per week (~42 miles of range provided)

• PSE midsize commercial service tariff• $100/ yr. maintenance budget

Not included: charger management, or revenue recovery

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• Charger used twice per day, five days per week (~52 miles of range provided)

• PSE midsize commercial service tariff• $100/ yr. maintenance budget

Scenario B: Level 2 charging without revenue recovery

Not included: charger management, or revenue recovery

Electricity cost per charge $0.90

Monthly energy-demand charge $49.50 (or $1.18/ charge)

Annual total (electricity+ demand)

$1,048 ($524 per employee)

Vehicles supported 2

Marginal cost per charge $2.29 OR $1.01/ Hr.

Marginal cost including EV charger

$3.48 OR $1.53/ Hr.

Marginal cost + total install $5.27 OR $2.32/Hr.

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• Charger used twice per day, five days per week (~52 miles of range provided)

• PSE midsize commercial service tariff• $100/ yr. maintenance budget

Scenario C: Level 2 charging with revenue recovery

Electricity cost per charge $0.90

Monthly energy-demand charge $49.50 (or $1.18/ charge)

Annual total (electricity+ demand)

$1,048 ($524 per employee)

Vehicles supported 2

Marginal cost per charge $2.77 OR $1.22/ Hr.

Marginal cost including EV charger

$4.16 OR $1.83/ Hr.

Marginal cost + total install $5.94 OR $2.62/Hr.

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Ensure chargers will be used regularly

Fixed costs: Demand chargesMaintenance recoveryNetworking/revenue recovery

2 3 4 5 6 7 8$0.00

$2.00

$4.00

$6.00

$8.00

$10.00

$12.00

Cost declines sharply with regular charger use

level 2 smart charger

Exponential (level 2 smart charger)

level 2 simple charger

level 1

Charges per week

$ per charge

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Charger type Level 1 charger Level 2 (low power)

Level 2 (high Power)

Level 2 (high power & smart)

Range per hour 4.9 miles per charge-hour

11.55 miles per charge-hour

23 miles per charge-hour

12-23 miles per charge-hour

Cost $600-$1,500 $600-$2,000 $1,000-3,000 $3,000-$5,000*

Charger networking and revenue recovery

- - - ~$20 per month

Demand charge incurred

$4-11 per month $9-25 per month $18-50 per month

$9-50 per month

Charger management

no no no yes

EVSE costs and benefits

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On Charger Revenue• Via charger membership • Credit card

Restrict Access• Charging “sticker pass”• Gated parking• Keypad, key fob

Indirect• Payroll deduction• Permit parking

How can you charge for charging?

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How to estimate cost of charging