Baseload Electricityquantify, address, manage

2a) Lighting baseload: effective & efficient use to shape & affect

Presenter

Todd Hoener, LEED accredited professionalEnd-use energy specialist

Renewable energy program administrator Certified home energy rater &

Light commercial energy auditor

Golden Valley Electric AssociationFairbanks, Alaska907 451 5607 w

tmhoener@gmail.com

Lighting shapes & affects baseload

Lighting is baseload electricity use Powered-up lamps Year-round behavior, choicesBut lighting is more. It’s…visual

Residential lighting profile

• Virtually 100 % of all households use electricity for lighting

• Average annual cost ~ 8 – 10 % of all household electricity

• Lighting use increases with household members & number

Comparison of light efficiency

What to consider about lighting?

Energy efficiency, performance Lower costs & reduced waste Control Comfort

Quality, ability to see Mood, e.g., SAD Sensitivity, age, eyes Health & safety

Functions & effective uses

Lamp & fixture

Lamp: Device converting electricity to light, produces lumens

Fixture: Holds lamp

Energy consumption

Watt: Standard measurement of lamp

Luminous Efficacy: Ratio of light produced to energy consumed, measured as number of lumens produced divided by rate of electricity consumption (lumens per watt)

The higher the ratio, the more efficient the light

Measured Lamp Lumens [Lumens] ÷

Measured Input Power [Watts]

Light quantity

Illumination: Distribution of light on horizontal surface (purpose of all lighting is to produce illumination)

Lumen: Measurement of light emitted by a lamp

As reference, 100-watt incandescent lamp emits about 1750 lumens.

Light quantity

Foot-candle: Intensity of illumination measured by amount of light produced by one lumen distributed over a 1-square-foot area

Recommended fc levels

Parking areas 1 to 3

Laundry 10 to 15

Hobbies & shops 100 to 200

Recreational activities 15 to 20

Kitchen w orkarea 20 to 100

Dining 10 to 30

Bedroom, makeup, grooming 30 to 50

Conversation 5 to 10

Hallw ays, stairs, public assembly 5 to 10

Storage, inactive 5 to 10

Reading & studing 50 to 100

Light quality

Color temperature: Color of light source, measured in Kelvin (K) temperature

Higher Kelvin temperatures (3600–5500 K), blue-green colors (e.g. overcast sky light), are considered “cooler” & produce higher contrast

Lower color temperatures (2700–3000 K), yellow-red colors (like flames of fire), are considered “warmer” & preferred for living spaces

Approximate color temperatures

Light quality

Color rendering: How colors appear when illuminated, generally considered more important lighting quality than color temperature

Color rendering index (CRI) is a 1–100 scale that measures light source's ability to render colors same way as sunlight

Light source with CRI of 80 or higher considered acceptable for most indoor residential applications

~ CRI for various lamps

Lamp source Color Rendering IndexSunlight 100Halogen / Incandescent 95 - 100Fluorescent (new technology) 95Standard metal halide 65Delux high pressure sodium 60"Cool white" fluorescent 50 - 55Mercury vapor 35Standard HPS 5Low pressure sodium -40

Light quality

Glare: Excessive brightness from direct light source

Glare primarily result of relative placement of lamp source and object being viewed

Types of lamps

Incandescent (includes halogen)

Fluorescent (includes compact fluorescent lamps)

High intensity discharge (HID) (includes metal halide, high-pressure sodium, mercury vapor, low-pressure sodium)

Light emitting diode (LED)

Other

Comparing lamp life costs

electricity cost per kwh= $0.15

lamp type Incand CFL

watts 60 15

life (hrs) 1,000 10,000

electricity costs ($) $90.00 $22.50

lamp cost ($) $1.00 $20.00

relamp cost ($) $9.00 $0.00

total cost ($) $100.00 $42.50

comparative cost ($) $57.50

Useful economic formulas

Simple payback on an investment (in years) == net installation costs ($) ÷ annual energy

savings ($) Simple return on investment (in

percentage, %) == annual energy savings ($) ÷ net installation

costs ($)

Lighting use

Ambient lighting: Provides general illumination for daily activities, safety and security

Defines space

Ambient lighting

Lighting use

Task lighting: Light to work by Place task light beside task, not in front Under-counter kitchen lights, table lamps,

or bathroom mirror lights For reading, paper work, food preparation,

laundry, games, hobbies, shop work Should be well diffused, coming from sides

to eliminate shadows

Task lighting

Lighting types & uses

Accent lighting: Draws attention; provides interest

Usually 3 times level of ambient light

Accent lighting

Lighting use

Natural lighting: Through windows, skylights, doors

Varies in intensity & brightness depending on time of day, season or weather

Use Low-E glazing to keep heat inside in winter & outside in summer

Most important indicators of window's performance are U-factor and solar heat gain coefficient (SHGC)

Natural lighting

Tubular skylights

Natural lighting: Through tubular skylights

Used where windows are not practical,

Reflects light through a metal or plastic tube with a highly reflective interior coating and guides sunlight to a diffuser lens mounted on interior ceiling surface

Can be used in windowless bathrooms, hallways, stairwells and closets

Zero operating cost

Natural light through tube

Matching efficiency & luminance

Cost of lighting is often evaluated by 5 criteria:

Initial cost of fixture, lamp & placement

Needed light output of fixture

Lamp replacement costs comparisons

Lumen output per input watt comparisons

Energy costs comparisons

Lighting controls

Dimmers – adjust level of light Occupancy sensors – offers automatic

switching Timers –switch at predetermined times

Before purchasing & using any lighting controls, understand type of lamp to control to narrow selection

Options vary

Maintenance & operation

Clean regularly Eliminate unnecessary light by relying on day-

lighting whenever possible Replace two bulbs with one having a

comparable number of lumens to increase lumens per watt

Place fixtures on separate switches so they can be operated independently of each other

Efficient & effective lighting

Starts with good design & energy efficient lighting

Benefits extend above & beyond efficiency & money

Poor planning presents problems

How & what to light

How much light

Remember the human element: needs & behavior

Useful lighting resources

US DOE Building Technologies Program National Lighting Bureau NAHB Green Home Building Guidelines ToolBase Services, c/o NAHB Research Center Partnership for Advancing Technology in

Housing (PATH), supported by U.S. HUD