420 likes | 640 Views
The Smart Grid Enabling Energy Efficiency and Demand Response Clark W. Gellings. Chapter 11 : Efficient Electric End-use Technology Alternatives. Brevard Community College ETP1400 Distributed Electrical Power Generation and Storage Bruce Hesher 433-5779.
E N D
The Smart GridEnabling Energy Efficiency and Demand ResponseClark W. Gellings Chapter 11: Efficient Electric End-use Technology Alternatives Brevard Community College ETP1400 Distributed Electrical Power Generation and Storage Bruce Hesher 433-5779
There are many currently available ways to reduce power consumption and/or produce your own power1. • This chapter details existing and emerging technologies to both save money and to reduce fossil fuel consumption. And / or = 1. Never put renewable energy on an energy inefficient building - Do a good job of energy conservation and weatherization first.
Existing Technologies • Some ways to reduce energy consumption have been in use for a long time. Solar access has been a consideration for thousands of years when selecting a good place to build. Solar water heating (n modern times) dates back over 100 years. • Clothes lines for drying clothes have only recently been replaced by clothes dryers and would not have been if energy had not been cheap until recently. • Increased use of existing technologies will be more popular as their cost comes down iff the price of oil stays high (safe bet) and governments do not regulate them to death.
Lighting • There are many purposes for and types of lighting. Energy efficient lighting costs a lot more initially and needs to be financially justified through lower energy bills. • Energy efficient lighting requires more materials and labor to produce. LEDs require DC power but power to homes and businesses is AC; so, there is a power supply built in the base of an LED light or a power adapter that runs a string of LED task lighting. As technology evolves these differences will lessen. Sky lights and solar tubes are good alternatives to electric lights (when the sun is up). See Lighting Sciences Group.
Space Conditioning (heating, cooling, and dehumidifying) • The higher the air conditioner’s SEER rating the better. Weatherization makes a huge impact on heating and cooling costs. In Florida most homes and businesses do not have enough insulation. Recent building codes are better. To save energy costs: 1) Check attic insulation. The more the better but, do not block air flow. 2) Roofing type makes a difference: Metal or tile is best. If asphalt shingle, choose a light color to improve reflectivity and a textured surface (large granule) to improve emissivity. 3) Iff shingle roof install radiant barrier. 4) Consider an energy Audit (your utility might pay for it).
Insulation • Most homes in Florida do not have enough insulation. Inspect your attic. Fiberglass batting that is the depth of a 2x4 truss has about R-15. For R-30, run a second layer using care not to block soffit vent air flow. The DOE recommends that homes in zone 2 (Florida) have R-30 to R-60. Insulation improves both heating and cooling costs! Puncture the vapor barrier with a small pointed object like a nail, placing holes 2-3 inches apart to prevent moisture build up between layers.
Radiant Barrier • If you have a wood sheeting and asphalt shingle roof, install a radiant barrier. They block up to 97% of the radiant energy, so the attic stays cooler. If the A/C ducts are in the attic, a radiant barrier has the added benefit of keeping the conditioned air cooler while it travels through the ducts. A radiant barrier is meant to work with your attics ventilation system; do not block soffit air flow and use with a ridge vent or solar attic fan. See www.reflectixinc.com Do not put a radiant barrier in a building that has too little insulation; you will be cold in the winter!
Energy Audit • A professional energy auditor can examine and test your homes heating and cooling systems, insulation, windows, and etc. They test the AC ducts for leakage and the home for places where heat penetrates in summer or is lost in winter. A blower door test uses special fans to depressurize the home and pressurize the AC ducts to measure their performance and locate leaks.
See Where Heat is Penetrating • Thermo graphic pictures or video are sometimes used by energy auditors while a blower door test running. The blower door helps exaggerate air leaking through defects in the building shell. Thermal cameras are expensive. They are a tool of the trade for energy auditors.
Indoor Air Quality • Indoor air is getting a lot of press in recent years. The EPA says Americans spend 90% of their time indoors. An airtight building will be good for heating and cooling but, for air quality there are standards for air turnover. Chemicals, bacteria, and gasses build up if there is no outside air entering. Chemical and biological hazards/weapons are also a consideration. What can be done: 1) Filter the air: Keep air filters on AC units clean. Electrostatic filters are expensive (up front) but remove more particles from the air and are reusable. 2) Replenish the air: AC and heating systems must use some outside air to guarantee air quality.
Domestic Water Heating (DHW) • Many homes and businesses have electric water heaters, they are the worst in terms of electricity usage. Electric water heaters are inexpensive for builders to install in new homes and cheap to replace. Tankless heaters are the worst. Solar water heaters use only 20% as much and natural gas heaters don’t use any. • The Florida Solar Energy Center has a Hot Water Systems Laboratory that publishes studies of the energy consumption, cost, reliability, and etc. of various systems types. The time to upgrade to a gas or solar water heater is when the electric tank needs replacing. Lame alert: Do not read page 226
Hyper-efficient Appliances • The president of the Association of Home Appliance Manufacturers (AHAM) testified before the U.S. Senate in support of legislation to enact appliance efficiency standards. • The hybrid electric/heat pump water heater is an example of new efficient technology. New clothes washers have improved spin cycles that remove more water and enable the clothes dryer to do less work. • The Energy Star program identifies the best 25% in a particular category in terms of energy consumption.
Ductless Residential Heat Pumps and AC Ductless Split Air Conditioner & Heat Pump products offer wide versatility in solving your cooling and heating requirements. The Indoor unit (evaporator) is mounted inside the room, enclosed in a handsome space saving cabinet. • It is connected to the outdoor unit (condenser) via refrigerant lines & inter-unit wiring through a 3 1/2" opening in the wall. Since no ductwork is required, installation is simple. fast & efficient. There’s no need to use window space or cut large openings in existing walls, which could undermine the integrity of your structure, and even pose security risks. Since the Rotary compressor is located in the outdoor unit, compressor operating noise is virtually eliminated from the indoor. In addition, rotary compressors provide efficient, powerful cooling at the lowest noise levels in the industry.
Variable Refrigerant Flow (VRF)Air Conditioners • Ducted AC units with fixed speed motors have been used for a long time. Energy is lost both in the ducts and in the single speed motors. VRF units send the refrigerant to the heat exchange units instead of cooling/heating the air then send it through air ducts. Coolant (liquid) piping can be much better insulated than air ducts. The Co-efficient of Performance (COP) can be better than conventional systems. http://www.hitachi-ap.com/support/image/sales/pdf/pacakged/HR-E568T.pdf
Heat Pump Water Heating (HPWH) • HPWH’s are three times as efficient and have the potential to deliver fives times as much hot water. They require installation in locations in the 40º–90ºF (4.4º–32.2ºC) range year-round and provide at least 1,000 cubic feet (28.3 cubic meters) of air space around the water heater. Cool exhaust air can be exhausted to the room or outdoors. Install them in a space with excess heat, such as a furnace room. Heat pump water heaters will not operate efficiently in a cold space. They tend to cool the spaces they are in. • Heat pumps have been around for decades, but a heat pump water heater is a new concept. They work like conditioners but instead of dumping the heat outdoors, put it into the water. DOE article on HPWHswww.alpinehomeair.com
Hyper-efficient Residential Appliances • Because the European and Asian markets have high electric prices, hose countries have developed appliances that use up to 50% less electricity than their American counterparts. There are however issues with acceptance in the U.S. market and with product performance. • There are some initiatives in the U.S. to encourage appliance efficiency beyond the Energy Star program. The Consortium for Energy Efficiency (CEE) is a non-profit DOE and EPA funded public benefits group that develops initiatives to promote the manufacture and purchase of energy efficient products and services. • If the work CEE does is good, why do companies need to have a giving them direction in their product development.
Data Center Energy Efficiency • In data centers today, only 100 usable watts result from every 250Watts delivered to the facility. The losses result from inefficiencies: • UPS’s 88-92% • Power distribution 98-99% • Power supplies 68-75% • DC to DC conversion 78-85% • Additionally, data centers are air conditioned. Any energy reduction improvements in inefficiencies are doubled. • Q; What can be done to reduce Data Center power consumption?
Light-Emitting Diode (LED) Street and Area Lighting • There is a move in the U.S. to replace existing street and area lights -normally mercury vapor, high pressure sodium, or metal halide lamps - with LED lights. This is a main product for Lighting Sciences Group Corp and their principle competitors.
Industrial • Industrial electricity use is dominated by electric motors, lighting, and process heat. Lighting has been addressed; this section concentrates on motors and process heat. • Also, additional opportunities for industrial energy reduction are explored: • cogeneration • thermal energy storage • industrial energy management programs.
Motors and Drives • Electric motors and drives use 55% of all electricity in the U.S. and 67% in the industrial sector. Induction motors account for 90% of all motors 5HP or greater. It is best to view motors as motor driven systems and address losses in each part of the system. The efficiency of motors and drives can be improved by better operation and maintenance practices. These measures are inexpensive and offer immediate payback. • PG&E has an article entitled: Efficiency Opportunities through Motor Maintenance.
Motors • The following actions and procedures will help reduce the energy consumption of a motor: Better lubrication: The correct amount of high quality lubricants is needed. Improved cooling: Cool motors are more efficient. Proper ventilation and clean cooling surfaces are important. Spillage Prevention: Water (and other contaminants) should be kept out of motors. Keep area and any filters clean. Minimized Low or No load operation: efficiency goes down as percentage of rated load goes down. Do not run motors with no load, shut them off. Motor matching: The right size motor is important. Quality Rewinding: Operation: analyze continuous versus batch operation. i.e. small motrs in continuous or large motors in batch?
Drive Train(what the motor is connected to) • Belt Operation: Properly align and tension belts. • Minimize Friction: check gears, bearings, belt drives, and clutches. • Lubrication: Lubricate chains and chain drives with the correct type and quantity of lubricant. • Synchronous belts: Use synchronous belts instead of V-belts. • Chains: Convert roller chains to silent chains. • Direct driven loads: Use direct driven loads without belts ,chain, or gears when possible. • Quality bearings: Last longer, are quieter, cause less vibration, and use less energy.
Electrical Supply • Operation at rated Voltage: Use the motor at the voltage it is designed for. • Phase Balance: Balance 3-phase power supplies. This reduce vibration, wear, breakdowns, and energy consumption. • Efficient Power Systems: Loses can occur in the power systems that supply electricity to motors.
Equipment Retrofit and Replacement • Heat Recovery: Capture and use or vent waste heat so AC systems do not work harder. • Controls for Scheduling: Turn motors off when not in use. Schedule large motors to run during off-peak hours. • Other Controls: Install Power Factor control on large electric loads. • Variable Speed Drives (adjustable Speed drives): Match motor speed to the equipment it drives. • Replacement of throttle-valve with VSD: See article on energy savings at waste treatment plants. • Replacement of pneumatic drives: pneumatic drive use electricity to compress air then turn it to mechanical energy. Conversion losses make systems use more energy. • Replacement of steam jets: • High-efficiency Motors: Use newer more efficient motors in new designs and for replacements. Motor manufacturers have made significant improvements since the 70’s.
Process Heating • There are 4 main ways of doing process heating: fuel, electric, thermal recovery, and solar collection systems. Eclectic systems are a small percentage but will likely increase due to convenience, controllability, cleanliness at pint of use, safety, scalability, and small size. Also more expensive fuels will drive use of electric heating. • The next few slides detail opportunities in process heating.
Cogeneration(Combined Heat and Power (CHP) • A cogeneration electric plant uses a fuel to run a generator which makes heat that is captured and used to run a second generator or be used for process heat. They are sometimes called combined cycle.
Thermal Energy Storage (TES) • TES can be considered an energy source. TES requires a storage medium like steam, water, solids, etc. Energy stored can be used to provide peak load coverage. When production is good, energy can be stored for when it is needed. • One drawback to TES that must be countered is the energy loss in conversion. Actually, all energy storage methods are susceptible to conversion losses. See http://en.wikipedia.org/wiki/Thermal_energy_storage
Industrial Energy Management Programs • An energy management program is a crucial part of achieving energy reduction goals. Management must be an active part. a program must be customized to each aspect of what the business does. • Recommended steps: • Appoint energy managers and steering committee. • Gather and review historic energy use data. • Conduct energy audits. • Identify energy-efficiency opportunities. • implement cost-effective changes. • Monitor results. See BCC Four-day workweek article.
Manufacturing Processes • Modern manufacturing is highly dependant on automation and computers. This requires high-quality power. Also manufacturing uses a lot of energy and can have negative environmental impacts. • Process improvements through reduced rework and waste, improved quality, energy management, and etc. can result in greater yield for the same or less raw material and energy. Most factories aggressively push these ideas because they improve their bottom line.
Electrotechnologies • Many new electrotechnologies allow the substitution of an electric process and/or electrical equipment for applications using other fuels or less efficient electric equipment. Electrotechnologies are systems and equipment using electricity to produce and process consumer goods. It can also be used in various industrial processes such as heating, drying, heat treatment and smelting. • They are often end-use technologies that use electricity efficiently enough to justify losses in electricity production an delivery.
Electrotechnology Opportunities by Sector p239 • Residential: Heat pump clothes dryers, air source AC and heating, ground source AC and heating, pool/spa heating, water heating. Electric induction range tops, electric convection ovens. • Electric instantaneous water heaters will save energy IFF usage is low. They are the most energy wasteful method for the average home! Hot water of any method that is stored locally then distributed through the homes foundation are wasteful and increase the cooling load. • Refer to the text for Commercial and Industrial sectors
Induction Process Heating • induction heating systems use electromagnetic energy to induce electric currents to flow in appropriately conductive materials. This heats the material similarly to how a microwave oven works. They use lower frequencies (500-800KHz). • With induction cooking, energy is supplied directly to the cooking vessel by the magnetic field; thus, almost all of the source energy gets transferred to that vessel See Induction Cooking.
Dielectric Process Heat • Dielectric heating is accomplished with the application of electromagnetic fields. The material is placed between two nodes that are connected to a high frequency generator. The electromagnet fields excite the molecules in the material thus heating it. • There are both RF (1 to 100MHz) and microwave (100MHz to 10GHz) systems. RF systems are less expensive and can penetrate deeper into materials but, are not as well suited for materials with irregular shapes. • Dielectric heating is good when the surface area of the thing to be heated is small. See http://en.wikipedia.org/wiki/Radio_frequency_heating
Infrared Process Heat • Infrared heating is used in many drying and surface processes. It is good for surface applications but because of the high frequencies involved it penetrates only a few millimeters. It is used to dry paper, accelerate chemical reaction. Copier machines use it to fuse/dry the toner. Microwave Heating Microwave ovens operate at 2.45GHz. They excite the material to be heated and thereby heat it. Water reacts well to microwave energy at 2.45GHz which is why that frequency is used. Note that 802.11 WiFi uses 2.4GHz or 5GHz depending on the version.
Electric Arc Furnaces • The primary metals industry uses electric arc furnaces. There are a number of improvements developed over the years that have improved their efficiency. • By using waste heat to preheat the material less electricity is required. Waste minimization by particle recovery and ladle improvements have also contributed. Recycled materials required only 40% of the energy that raw ores do in an oxygen furnace. Electric Arc Furnace
Efficiency Advantages of Electric Process Heat Systems • Quick start-up: fuel furnaces require long warm-up periods, equipment is often left on continuously. Electromagnetic systems have quick startup. • Faster turn-around: Electric systems do their job in less time resulting in higher production rates and shorter heating times. • Less material loss: faster heating and less process time mean less scaling and reaction with air or other materials. • Direct heating process: Direct heating process are more energy efficient than indirect ones that rely on heat transfer mechanisms. Heat generation inside material: Induction and dielectric heating generate heat inside the material. Radiative of conduction heating have losses associated with the materials that transfer the heat. More process control: Electric systems can be turned on or off very quickly. Also the frequency of the heating systems can be customized to the material being heated.
Merits of Electrotechnologies Beyond Energy Efficiency • In addition to energy savings electrotechnologies offer the following benefits: • Urban Emissions Reduction:Getting combustible fuels away from residences is a good thing. • Heat Pumps Leverage Ambient Heat: In combination with the sun as the primary heat source they can save money! • Dehumidification: Heat pump water heaters cool and dehumidify the surrounding air. • Manufacturing Development: IFF U.S. Companies are able to capitalize on electrotechnologies, more U.S. jobs will be created.