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Demand Optimization with Lighting

Scott Ziegenfus, LEED APSenior Applications Engineer Lutron Electronics Co., Inc

ASHRAE SPC 201P Facility Smart Grid Information Model Committee MemberASHRAE SSPC 135 BACnet Committee Member

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Demand Response - what is it?

Demand Response (DR)– Manage customer electricity consumption in response to supply conditions,

critical times or market prices. – A different concept from energy efficiency.– The goal is a STABLE Electric Supply with minimal transients (peaks and

valleys).

Source: NIST Smart Grid Framework 1.0 Sept 2009

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Demand Response - what is it?

• Emergency DR vs. Economic DR– Emergency demand response is primarily needed to avoid outages and

peak charges. – Some facilities, corporations, and institutions have initiated internal Demand

Response initiatives to avoid peak charges, emphasize onsite generation, move demand to non peak hours (night time)

– Economic demand response is because Electricity is a tradable commodity.

Source: NIST Smart Grid Framework 1.0 Sept 2009

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Demand Response Programs - Who Administers it?

Independent System Operator (ISO)Regional Transmission Operator (RTO)

– Control the operation and stability of the Electric Grid

– The distribution system of the electricity industry

– Facilitate demand-side management – Most DR programs require a minimum of

100 KW to participate.– Certifies Curtailment Service Providers

(CSP)• A company authorized to act as an interface

between the ISO/RTO and end-use customers • Also known as a Demand Response Provider or

Energy Aggregator.

Grid OperatorISO/RTO

Curtailment Service Provider Electric Utility

End User

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Demand Response Programs - How do they work?

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Normal Usage

Actual Usage with Demand Response

Demand Response (DR)– Demand response can involve curtailing power used or through on

site generation. – Current demand response schemes often implement the use of control

systems to shed loads. Load shed is the action to demand Response– Most DR programs are manually implemented

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Commercial Electricity Usage

Load Shed Reduction Strategies– Lighting and HVAC account for over 2/3 of all electricity in

commercial buildings with lighting being the biggest contributor– Lighting and HVAC are the number 1 & 2 loadshed strategies

• Load Shed Reductions Should Consider– Productivity impact

• Average Building Costs– Personnel: $200.00 to $400.00/ft2– Energy: $2.00 to $4.00/ft2

– Management and control• Lighting is the easier strategy

– Little Management– Little Productivity impact

Source: DOE 2003 Commercial Buildings Energy Consumption Survey

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HVAC MANAGEMENT– HVAC, by definition, has multiple

components that are interdependent• Humidity / temperature / air movement

– HVAC has a recovery period exiting DR • It can take hours to bring a building back to

desired temperature after it has been shut off. • If recovery too severe peak charges can occur

– Load shed for AC depends on the time of day and weather conditions making the amount of load shed unpredictable.

– Temp reduction can damage equipment that relies on continuous cooling.

– Complex systems often use both heating and cooling systems simultaneously. Increasing temp set points can results in higher energy costs.

Demand Response and Management of HVAC

recovery

recovery

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Demand Response and Management of Lighting

Lighting MANAGEMENT– Lighting control is linear and predictive

• Light Power Density = Watt/Ft2

• Electrical Power in Watts = Voltage x Current– No recovery period or time delay with Lighting– Lighting is almost a “SET IT AND FORGET IT” DR strategy

• HVAC entails a strong amount of management compared to Lighting.

TIMEIlluminationCurrent

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Demand Response and Productivity Impact of HVAC

HVAC PRODUCTIVITY– Peak to peak variation > than 2 degrees F = no influence on the

comfort. • Higher peak variations may decrease employee comfort.

– There is a complex relationship between humidity, temperature and individual comfort. In addition to temperature and humidity, air movement and radiant temperature (from exterior glazing) have large influences on personal comfort.

– Recovery is not instantaneous• It can take hours for an air-conditioner to bring a building back to desired

temperature after it has been shut off.

Maximum change in temperature Period of time

±1,1 ºC(2.0 ºF) 15 minutes

±1,7 ºC(3.0 ºF) 30 minutes

±2.2 ºC(4.0 ºF) 1 hour

±2.8 ºC(5.0 ºF) 2 hours

±3.3 ºC(6.0 ºF) 4 hours

Acceptable Temperature Change Rates

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Demand Response and Productivity Impact of Lighting

Lighting PRODUCTIVITY– The human eye compensates for lower light

levels by allowing more light to enter the pupil

• 25% measured is perceived to be at about a 50% level

– The eye’s response to light is “square law”• Measured light = (perceived light)2

– Most areas in a building are over-illuminated to start with because of space flexibility

– Consider granularity of reduction• Multi-level switching or step dimming has a

disadvantage over continuous dimming that occupants regard sudden change in light level as disruptive.

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Demand Response and Productivity Impact of Lighting

Lighting PRODUCTIVITY– Demand Response studies show with inhabitants knowledge

• 50% of inhabitants could not detect a 15% luminance reduction for paper tasks and a 20% for computer related tasks even with a knowledge of pending reduction.*

• 80% of inhabitants would accept a demand response program reduction on 30% for paper tasks and 40% for computer related tasks.*

– Lighting does not have a recovery period• Recovery is exact and instantaneous

*Understanding Light Levels for Load Shed, Lighting Research Center, Rensselaer Polytechnic Institute

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Permanent Demand Reduction Lighting Strategies

“permanent improvements in efficiency were discovered through the planning and implementation of “temporary” demand responsestrategies.” Strategies for Demand Response in Commercial Buildings, Lawrence Berkeley National Laboratory

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Demand Response In New Standards

Section 7.4.5.1 of ASHRAE 189.1 – 7.4.5.1 Peak Load Reduction/Load Factor. Building projects shall contain

automatic systems such as demand-limiting or load shifting to reduce electric peak demand of the building by not less than 10%. Standby power generation shall not be used to achieve the reduction in peak capacity.

Section 605.4 of INTERNATIONAL green CONSTRUCTION CODE®

(IgCC®) – 605.4 Lighting. The Auto-DR system shall be capable of reducing total

connected power of lighting in Group B, office, spaces by at least 30 percent.

LEED 2012 BD+C, ID+C, EBOM – Pilot Credit 8 EA: Demand Response– Option 1. Demand Response Program– Option 2. Permanent Peak Load Shifting

• Implement electrical load shifting measures that permanently transfer regulated electricity demand from daytime hours to off-peak hours. Demand shifting measures must result in a reduction of 10%

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Power System to remaining at a steady state is a manual endeavor

Central GeneratingStation

Step-Up Transformer

DistributionSubstation

ReceivingStation

DistributionSubstation

DistributionSubstation

Commercial

Industrial Commercial

Gas Turbine

DieselEngine

Cogeneration

CogenerationTurbine

Fuel cell

Micro-turbine

Wind Power

Residential

Storage

Photovoltaic systems

1.Power System Infrastructure

Source: IEC TC57 Information Models - CIM & 61850.ppt

Demand Response Today

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Power System and Information Infrastructure of tomorrow will change everything

Central GeneratingStation

Step-Up Transformer

DistributionSubstation

ReceivingStation

DistributionSubstation

DistributionSubstation

Commercial

Industrial Commercial

Gas Turbine

DieselEngine

Cogeneration

CogenerationTurbine

Fuel cell

Micro-turbine

Wind Power

Residential

Storage

Photovoltaic systems

Control Center

Operators,Planners & Engineers

2. Communications and Information Infrastructure

1.Power System Infrastructure

Source: IEC TC57 Information Models - CIM & 61850.ppt

Demand Response Tomorrow (Smart Grid)

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Demand Optimization with Lighting

“The key to the potential of a demand-responsive lighting system is that it provides a simple, reliable, and painless way to decrease load.”

Energy-Efficient Load-Shedding Lighting Technology California Energy Commission.