Sustainable Energy Systems Sustainable Energy Systems EngineeringEngineering

Peter GevorkianPeter Gevorkian

Ch 4: Energy ConservationCh 4: Energy Conservation

Brevard Community CollegeBrevard Community College

ETP1401ETP1401

Bruce HesherBruce Hesher

General Energy Saving Measures General Energy Saving Measures p101p101

See See Home Energy Conservation Tips handout from handout from day 1 (posted on Angel).day 1 (posted on Angel).

See FSECs zero energy home in Lakeland:See FSECs zero energy home in Lakeland:

http://www.fsec.ucf.edu/en/research/buildings/zero_energy/lakeland/index.htm

Recycling is also a good thing. See Recycling is also a good thing. See http://www.brevardcounty.us/swr/

Power Factor CorrectionPower Factor Correctionp106p106

Electrical loads that are not purely resistive, have a load Electrical loads that are not purely resistive, have a load impedance that is at a phase angle. They do impedance that is at a phase angle. They do NOTNOT consume more energy because of it. They do however consume more energy because of it. They do however cause more current to be cycled back and forth between cause more current to be cycled back and forth between the power source and the load thereby causing greater the power source and the load thereby causing greater

losses in the system.losses in the system.

When the load is When the load is inductive (motors), the inductive (motors), the current in the circuit will current in the circuit will lag the voltage.lag the voltage.

Apparent PowerApparent Power

Work is done by the Real Power (Work is done by the Real Power (WattsWatts) but, the power ) but, the power source and load cycle some power back and forth. This is the source and load cycle some power back and forth. This is the Reactive Power (Reactive Power (VARVAR). The power supply and wiring must be ). The power supply and wiring must be large enough for the resulting Apparent Power (large enough for the resulting Apparent Power (VAVA). This large ). This large amount of energy transfer between the source and load amount of energy transfer between the source and load causes larger energy consumption.causes larger energy consumption.

note: This is why UPSs are rated in VA not Watts.

The Power The Power Factor (PF) is the Factor (PF) is the ratio of W/VAratio of W/VA or or the cosine of the the cosine of the phase angle.phase angle.

Reducing Power Factor LossesReducing Power Factor Losses

If a capacitor with a reactance equal to the reactance of If a capacitor with a reactance equal to the reactance of the inductive load (motor) is place in parallel with the load the inductive load (motor) is place in parallel with the load the the net reactance is 0!net reactance is 0! Calculating the size of the capacitor Calculating the size of the capacitor is left to other courses or the manufacturer of the motorized is left to other courses or the manufacturer of the motorized equipment. This topic is covered in EETC1025.equipment. This topic is covered in EETC1025.

If the losses due to the energy cycled If the losses due to the energy cycled back and forth are reduced, smaller back and forth are reduced, smaller gauge wire can be used, less heat is gauge wire can be used, less heat is created, equipment can last longer, created, equipment can last longer, and energy is saved.and energy is saved.

Power Factor Correction is typically Power Factor Correction is typically only done when there are a lot of only done when there are a lot of inductive loads.inductive loads.

Power Generation and Distribution Efficiency Power Generation and Distribution Efficiency p106p106

Only 20-25% of the energy that goes into an electrical Only 20-25% of the energy that goes into an electrical generation plant reaches end users! The main losses are: generation plant reaches end users! The main losses are: efficiency of the generation equipment and transmission losses.efficiency of the generation equipment and transmission losses.

Distributed generation Distributed generation significantly reduces significantly reduces these losses: sunlight is these losses: sunlight is an almost unlimited and an almost unlimited and renewable energy renewable energy resource conversion resource conversion efficiency is less of a efficiency is less of a factor than equipment factor than equipment cost. Also distribution cost. Also distribution losses are reduced.losses are reduced.

The BCC course EET1551 “Distributed Electrical Power Generation and Storage” covers “Smart Grid” technologies.

Computerized Lighting Control Computerized Lighting Control p108p108

Accomplished by such devices Accomplished by such devices as: switches, dimmers, timers, as: switches, dimmers, timers, occupancy sensors, etc. If a occupancy sensors, etc. If a “Smart Building” does not detect “Smart Building” does not detect any one in the building it can any one in the building it can turn the lights off.turn the lights off.

Air handling, heating and Air handling, heating and cooling can also be adjusted to cooling can also be adjusted to meet varying needs. For meet varying needs. For example; a smart building can example; a smart building can save energy on weekends by save energy on weekends by reducing A/C and heating.reducing A/C and heating.

SeeSee Smart Grid and and Smart Home technology. These technology. These topics are covered in topics are covered in EETC1151 “Distributed EETC1151 “Distributed Electrical Power Electrical Power Generating and Storage”Generating and Storage”

Triac Dimmer Triac Dimmer

By cutting off the flow of power for part of the 60Hz 360° By cutting off the flow of power for part of the 60Hz 360° cycle power is saved. Works for lights and ceiling fans. cycle power is saved. Works for lights and ceiling fans. Not tested with CFLs. Has the common trade-off of saving Not tested with CFLs. Has the common trade-off of saving electricity but with higher up front equipment costs.electricity but with higher up front equipment costs.

California Title 24 Electric Energy Compliance California Title 24 Electric Energy Compliance p116p116

In response to the 2000 electricity crisis, California enacted In response to the 2000 electricity crisis, California enacted legislation requiring indoor and outdoor lighting energy legislation requiring indoor and outdoor lighting energy conservation standards. The standards include control conservation standards. The standards include control requirements as well as limits on installed lighting power.requirements as well as limits on installed lighting power.

An approach to consuming less energy for An approach to consuming less energy for lighting is education. lighting is education. CFL or better yet or better yet LED instead of incandescent light would reduce the instead of incandescent light would reduce the energy consumption and do it by saving energy consumption and do it by saving consumers money. consumers money.

Indoor Lighting ComplianceIndoor Lighting Compliance

Requirements for lighting design and installation are Requirements for lighting design and installation are addressed primarily to lighting designers, electrical addressed primarily to lighting designers, electrical engineers, and municipal building inspectors. Indoor engineers, and municipal building inspectors. Indoor lighting is a large power consumer in commercial lighting is a large power consumer in commercial buildings.buildings.

By limiting the allowed power for lighting, more efficient By limiting the allowed power for lighting, more efficient ways of lighting are developed. ways of lighting are developed.

Chapter 5 Chapter 5 details the USGBC’s LEED details the USGBC’s LEED programprogram

Outdoor Lighting and SignsOutdoor Lighting and Signsp123p123

See Lighting Sciences Group in Satellite Beach, Florida.

Street lights, road signs, parking lot lights, etc. consume a lot of electricity.

• Use More efficient lighting.Use More efficient lighting.

• Use sensors to turn lights off when sun is Use sensors to turn lights off when sun is up.up.

• Use solar powered lighting when practical.Use solar powered lighting when practical.

• Avoid light pollution.Avoid light pollution.

Solar Power Facts Solar Power Facts p127p127

• As of 2010 it is a very small part of US energy production, As of 2010 it is a very small part of US energy production, “drop in the bucket”.“drop in the bucket”.

• It is a demand side solution. It helps to off-set your It is a demand side solution. It helps to off-set your usage.usage.

• It is non-polluting except for the energy needed to It is non-polluting except for the energy needed to manufacture the equipment.manufacture the equipment.

• It is scalable and expandable.It is scalable and expandable.

• It can be deployed where it is consumed.It can be deployed where it is consumed.

• The USA is a significant manufacturer of the equipment.The USA is a significant manufacturer of the equipment.

• The USA is a leader in the development and R&D.The USA is a leader in the development and R&D.

• It is renewable!It is renewable!