electricity and energy management chapter 5 (c) 2014 by john wiley & sons, inc
TRANSCRIPT
Electricity and Energy Management
Chapter 5
(c) 2014 by John Wiley & Sons, Inc.
In this chapter, you will learn to: Track energy usage and determine annual electricity
costs Identify the proper terms used to select appliances and
decipher utility bills Describe basic electrical principles: how power flows
into your building and equipment Identify tips for choosing energy-efficient equipment Explain how foodservice operations are using
renewable energy Identify tips for saving energy in all phases of a
foodservice operation.
Learning Objectives
(c) 2014 by John Wiley & Sons, Inc.
Understanding Energy Use
The best way to save both energy and money is to plan and implement an Energy Management System, which consists of six components:
Energy accounting
Energy audit
Retrofitting
Low-cost and no-cost ideas
Capital project
Continued surveillance
(c) 2014 by John Wiley & Sons, Inc.
Energy Audits
Utility providers will perform simple, walk-through audits at the request of customers Usually free of charge Some suggestions (replacing an appliance, adding
insulation) may involve cost Analysis audit is more complex. Requires gathering
more info about all heating and cooling systems, appliances Not free; pay a fee Recommendations may include:
Structural or design modifications to building Replacing or retrofitting some equipment A target electric rate that is “best” for your
business (c) 2014 by John Wiley & Sons, Inc.
Energy Audits
A financial analysis of each energy conservation measure (ECM) allows you to compare cost to potential payoff over time. For example, if an energy audit says recessed lighting in dining room is inefficient, options to compare might be:Change to more energy-efficient bulbs: reflector (R) or ellipsoidal reflectors (ER).Paint room a lighter color: more reflective, requires less lighting.Install more light switches or dimmers for better control of individual areas or rooms.Lower the ceiling height.Install skylights or light tubes.
(c) 2014 by John Wiley & Sons, Inc.
Understanding/Measuring Electricity
How much electric current flows through a circuit
The driving force that pushes an ampere through
an electrical wire
Represents actual consumption of electrical
energy, the amount of power in a circuit
A unit of electrical resistance
(c) 2014 by John Wiley & Sons, Inc.
How Electrical Systems Work
The Basics: AC and DC
A building's electrical system uses either alternating current (ac) or direct current (dc) Equipment costs to use ac power are lower than for
dc ac doesn't tend to overheat equipment like dc does
The number of ac cycles varies from country to country
The most common ac type in U.S. is 60-cycle Equipment made outside U.S. might run on 50-
cycle Appliance nameplate should include cycle
info (c) 2014 by John Wiley & Sons, Inc.
Voltage Combinations/Load Factors
Voltage and phase specifics are also on appliance nameplates. Many large or heavy-duty appliances require dual voltage. Be sure that sure the building’s wiring can handle the
challenge, and that equipment voltage matches service voltage of the building.
Can be an issue even when replacing old equipment with new.
How to find out specifics of building’s electrical capacity? Call your electric utility and ask. Look at the electric meter. Most are labeled as a Delta
(120/240 volts) or a Wye (120-208 or 277-408 volts) Check nameplates on cooking equipment. Ask electrician to check large electrical wall outlets with a
voltage meter.(c) 2014 by John Wiley & Sons, Inc.
Tracking Energy Consumption
To develop an energy index, convert all types of energy used into a similar form: the British Thermal Unit (Btu).
Electricity: Multiply kilowatt-hours by 3413. Natural Gas: Multiply cubic feet by 1000. Oil: Multiply gallons by 140,000. Steam: Multiply pounds by 1000.
Add these amounts for the total, which will likely be in the millions of Btus.
Charting Annual Utility Costs
(c) 2014 by John Wiley & Sons, Inc.
Renewable Energy
The U.S. Environmental Protection Agency (EPA) defines renewable energy as “electricity produced from resources that do not deplete when their energy is harnessed.”
Water and ocean waves, wind, sunlight, geothermal energy from natural hot-water sources, and anaerobic digestion – use of natural decay to produce gas at landfills.
Before selecting a renewable energy source, determine how much power is necessary, and how much you could potentially generate using this alternative.
Depending on your target clientele, there may be a public relations benefit to using renewable energy.
(c) 2014 by John Wiley & Sons, Inc.
Purchasing Renewable Energy “Credits”
Most utility companies also have options for customers who want to support renewable energy development even if their homes or businesses are not suitable for solar panels or wind turbines
If a “green power” program is not available, an alternative is to purchase Renewable Energy Certificates (RECs)
RECs can be purchased based on a specific site where the “green” power was generated, on the date the generation occurred, or on the specific type of resource (solar, wind, geothermal) used. (c) 2014 by John Wiley & Sons, Inc.
Solar power can be used for heating water, heating or cooling air. It can be incorporated into building design (an advantage over wind turbines). Solar is relatively low-maintenance. Challenges include: Solar panels must compete with vents and other necessary
items already installed on rooftop. Up-front cost estimates: $15,000 to $20,000 for a system that
may meet up to one-third of a quick-service restaurant’s peak power needs
Solar Technology in Foodservice
Almost any foodservice business can benefit from using a solar hot-water heater. The most common types:
Batch Heater
Thermosiphon DirectPump
(c) 2014 by John Wiley & Sons, Inc.
Wind Power in Foodservice
Few foodservice businesses have installed actual wind capacity, but wind energy can be purchased as part of an REC.
Challenges: Zoning and public input Expensive installation costs
Unreliable without storage capacity
Also consider: Turbines are noisySome feel turbines are unattractive hazards for birds and planes (c) 2014 by John Wiley & Sons, Inc.
Biomass & Geothermal Technology
Biomass = Organic materials (from plants or animals) used
to create a fuel source
Geothermal power = Uses heat from naturally warm water
(from 45° to 55°F.) found in some areas beneath earth’s
surface
Foodservice grease traps and trash output are good sources
of raw material to produce biomass energy
About one million American homes and businesses use geothermal
heat pumps (for heating and cooling), requiring about 20% less
electricity than without heat pumps.
(c) 2014 by John Wiley & Sons, Inc.
Most energy conservation methods fall into one of these four categories:
Energy Conservation
1. Improve the efficiency of equipment.2. Reduce equipment operating time.3. Recover otherwise wasted energy.4. Use a cheaper energy source.
Cooking efficiency means maximizing the quantity of heat transferred from equipment to the cooked product rather than the surrounding environment.
Primary causes of inefficient cooking:Preheating equipment too long.Keeping equipment turned on when it is not being used.Using higher temperatures than necessary.Opening appliance doors frequently, letting heat escape.
(c) 2014 by John Wiley & Sons, Inc.
Top tips for saving the most power:
Energy Conservation
Cooking in the largest possible volume at a time Cooking at the lowest temperature that can still give satisfactory results Carefully monitoring preheating and cooking temperatures Reducing peak loading, or the amount of energy used during peak demand
times (usually between 10 a.m. and 8 p.m.) Using appliances (ovens, dishwashers) at their full capacity Venting dining room air into the kitchen to meet kitchen ventilation
requirements Using a heat pump water heater, which heats water as it cools (or
dehumidifies) the kitchen Using an evaporative cooling system Recovering heat from equipment (refrigerators, the HVAC system, kitchen
vents) for reuse Increasing the hot-water storage tank size Keeping equipment clean and serviced (c) 2014 by John Wiley & Sons, Inc.
Cogeneration
Save energy and money by capturing and reusing heat that would otherwise be wasted. This is called combined heat-
power (CHP), heat recovery, heat reclamation, or cogeneration. Waste heat sources include HVAC systems,
refrigeration compressors, and computers.
Hot exhaust air can heat
incoming cold air
Hot exhaust air
can heat water
Hot refrigerant can heat air or another liquid
Heat from a boiler can be used to make steam or to heat air or
water
(c) 2014 by John Wiley & Sons, Inc.
If you really intend to “go green,” there are two major advantages to building a new structure instead of moving into an existing one.
Constructing an Energy-Efficient Bldg.
You are free to select the most energy-efficient systems and designs on the market.
You can design every facet of the building to minimize its use of energy, water, etc.
The downside: The “sustainable construction” trend is spendy. The specialized experts, consultants, materials will cost more than traditional building design and construction
The upside: Your future energy bills can be 30% to 50% lower than they would otherwise have been.
(c) 2014 by John Wiley & Sons, Inc.
Check the blueprint and designs against this list of items. Are you saving as much energy as you could be?
Constructing an Energy-Efficient Bldg.
Plenty of daylight; minimizing use of artificial lighting Light switches and dimmers, for flexibility in turning off lights that are not
needed The most efficient types of lamps and fixtures; energy-efficient ballasts for
fluorescents High-pressure sodium lights in parking areas Efficient exit signage Timers or computerized or photoelectric controls for indoor/outdoor lighting Occupancy sensors for storerooms Glazing for windows to reduce incoming heat and increase daylight
penetration Use of sufficient insulation for roof and walls Use of light colors, both inside and outside Positioning of building so that, if possible, trees or landscape provide an
insulating shield from wind and weather (c) 2014 by John Wiley & Sons, Inc.
Constructing an Energy-Efficient Bldg.
Are you saving as much energy as you could be? (cont’d.) Awnings or overhangs to shield windows from direct sunlight Spectrally selective window film that cuts incoming heat in hot-weather
areas Adjustable shades or blinds and, if appropriate, windows that open Caulking and weather-stripping around doors and windows Double doors or revolving doors at entrances Energy-efficient hot-water system, with tank located near main point of use
and insulated pipes Low-flow and dripless faucets Efficient HVAC system, organized in zone, with programmable wall
thermostats and adjustable vents Locking covers on wall thermostats Heat pumps, where appropriate Restroom exhaust fans wired to go on/off with lights Installation of a computerized Energy Management System
(c) 2014 by John Wiley & Sons, Inc.