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Basic Industrial and Commercial Electrical Energy Audit Training for Utility Personnel Draft. Robert Scott Frazier, Ph.D., CEM. Assistant Professor, Renewable Energy Extension Engineer Biosystems & Agricultural Engineering Oklahoma State University (405) 612-3641.
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Basic Industrial and Commercial Electrical Energy Audit Training for Utility Personnel Draft Robert Scott Frazier, Ph.D., CEM. Assistant Professor, Renewable Energy Extension Engineer Biosystems & Agricultural Engineering Oklahoma State University (405) 612-3641
What We Will Cover Today • Utility Background Data • QuickPEP® Software • Motors • Lighting • Compressed Air • HVAC • Process Heat
What You Should Come Away With Ability to produce general recommendations for the facility Ability to generate a nice cover report with graphics for the customer regarding energy use Ability to spot some of the more common energy areas for opportunity
ENERGY AUDIT WORKSHOP Before we begin … There are two ways to look at a facility's energy conservation (savings) potential: (1) A general view – without much effort – how much might we save and in what general areas? (2) A detailed view – with more effort – at what specific points in the plant can we place improvement efforts and how much can we expect to gain from these efforts?
Eight (Typical) Key Energy Issues in Auditing Facilities • Current situation -- getting a grip. • Process heating and cooling. • Steam and steam delivery. • Compressed air and air delivery. • Building and HVAC. • Lighting. • Electrical motors and systems. • System x system interactions (not specifically discussed, but very important in overall assessment).
Eight Key Questions for Commercial and Industrial Systems • What function(s) does this system serve? • How does this system serve its function? • What is the energy consumption of this system? • What are the indications that this system is properly functioning? • If system is not working properly, how can it be restored to proper operation? • How can the energy cost of this system be reduced? • How should this system be maintained? • Who has direct responsibility for maintaining and improving the operation and energy efficiency of this system?
What Equipment is Needed for Basic Energy Auditing? • Inexpensive IR Thermometer • Digital Camera • Data Loggers (Onset, etc.) • Steel toe boots/shoes • Side shields for glasses (get your own) • Ear plugs (get your own) • Good notebook and multiple pens • Business cards
What Else Should You Know? • What Federal Incentives are there? • What State Incentives? • Visit http://www.dsireusa.org • Stay on top of it – it constantly changes with the whims of Washington and state government
Current Situation – Getting a Grip • Facility Background • Personalities • Rate Schedule • Billing Analysis • Energy Profiles – As a whole • Energy Profiles – By systems/processes (if you can)
Start a File (Hard and Softcopy) • Everything goes in… • “Google®” company • Photos • Hand notes • Emails (Print if important) • Correspondence • Newspaper articles • Napkins with notes • Anything at all that has to do with this customer
Pre-Visit Phone Information I • Primary Contact Name: • Street Address of the plant we will be visiting: • Principal products Produced: • # of Employees: • Annual Sales ($): • Annual Energy Expenses ($): • # of Building we will be looking at: • Plant Area (square feet): • Production/yr (lbs, pcs…../yr): • Number of Shifts per day per week (and hours): • Primary Energy Users: Boilers ….How Many, approx capacity (MMBtu, lbs steam, etc.)…Fuel type Chillers….How Many, approx capacity………Size Furnaces…How Many Air Compressors…..How Many……What HP? • Type Of HVAC in Plant/Offices: • Type of Lighting in “ “ : • Other Energy Users of Interest (Blow Molders, etc.) ……..Energy Size (kW, Btu, etc.): • Other: (Things you would like us to look at) Do we need to bring safety Equipment? Don’t show up in open toe shoes or 3-piece suit. Leave jewelry at home.
Pre-Visit Phone Information II You may need to get copies of originals bills. You are the utility so you may have this in-house… • Energy bills (gas also possibly) for the past 12 consecutive months. • Water and sewer bills for the past 12 consecutive months. • Simple plant layout (8.5x11) (if they have it) • Process flow chart (if they have one) • List of primary energy consumers (e.g. motor list with horse powers's, etc. if they have it) ** Part of this is to show the client – this is stuff they should have and be aware of!
Personalities • Who is your main contact? • How important are they? • Are they threatened by this visit? • Plant manager knows the plant… • CEO can make sure projects get implemented… • Closing meeting – who is responsible for any possible recommendations? • Implementation and progress calls (let’em know you will be calling)
Rate Schedule • You are the utility person • If you know nothing else, you should be able to explain their rate schedule and bills • Make sure you know if they are on a “special” internal schedule • If it’s a big customer, ask (internally) if there is anything special you should know about these folks • Ask engineering if there is something unusual about their service or metering before you go out to the plant (look like the company speaks as one)
Billing Analysis • One of our most important tools. • Get data for all meters at general location. • Assemble data into spreadsheet (next slide). • Break into columns showing: kW, kWh, Fuel charges, taxes, PPCA, etc.
Client* Billing Analysis (cont.) What's going on here? *Confidential
Billing Analysis (cont.) • Know the definitions and relationships of kW and kWh. • Understand what tariff the customer is on and determine if it is the correct one (they will ask). • Understand the “fine print” items on the tariff and how they work (e.g. power factor adjustment, ratchet clauses, etc.)
Electrical Energy Management • Electrical energy management is unique due to the nature of electrical power. • Almost impossible to store significant quantities of this energy source (Maybe hydrogen in the near future). • Must have sufficient capacity to meet instantaneous demands (kW). • Odd characteristics such as power factor. • Issues such as power quality.
Electrical Demand Control • Partially because demand (kW) is a separate portion of the bill, we can look at specific methods toward reducing this charge (and impact on electrical system). • Try to keep in mind however that demand (kW) and consumption (kWh) are closely related.
Electrical Demand • The thing to keep in mind is that demand is a kind of “snap-shot” of the maximum electrical draw – at any particular time of the month from your facility. • Recall also that this snap shot is not really instantaneous but usually averaged over some interval like 15 minutes • That’s good for the customer – shorter intervals are worse. Try to imagine why that is…. • Still, “Demand” is a reflection of how much electrical equipment was on at a particular time in the facility.
Electrical Demand & Load Factor • There is a “Load Factor” column in the billing analysis spreadsheet • Load Factor = Total Month’s kWh divided by 720 x measured monthly max demand • If load factor is <<0.30 for a one shift operation or <<0.6 for a three shift operation, there may be demand control opportunities • Load factor indicates how even/uneven the electrical usage is during the billing period (demand peaks), LF=1 is a perfectly consistent load
Demand Control (cont.) • Many demand reduction strategies will be aimed at moving some of the load to different times of the day so we don’t get a coincident peak. • Other strategies might include going to different types of equipment. • Lets look at some of these demand control methods.
Demand Control (cont.) • Demand Shedding: In simplified form, the facility operator will identify the high electrical draw pieces of equipment that can have their operations rescheduled to other times of the day. • The operator (or software) will be monitoring the facility or sub-area total demand (kW). • At some agreed-upon kW point, the operator, or software, will reschedule the previously identified equipment to avoid a demand peak. • Various automated systems available (web search for “electrical demand control”)
Demand Shedding (cont.) • In a simpler scenario, schedules of the equipment, or processes, are adjusted so that the peaks are avoided ahead of time. • The problem is: Get it wrong once during the month and a high demand charge may be set.
Demand Shedding (cont.) • Examples of equipment that can be Demand-Shed: • Chillers. • Air handlers. • Large pumps. • Large Grinders. • Recharging Stations (fork trucks, etc.). • Large unnecessarily illuminated areas. • Any large electrical load is a candidate…
Demand Control (cont.) • Duty Cycling (different than demand shedding) • Long uninterrupted equipment run times lead to a higher probability that coincident loads will produce a “peak” demand. • Imagine what types of equipment this sounds like (hint – Air Handling Units) • Duty cycling uses a signal (time, temperature or other controlled parameter) for the on/off operation.
Demand Control (cont.) • Other demand and energy control methods • Optimum start/stop. • Night setback. • Hot water reset. • Chilled water reset. • Boiler and chiller optimization. • Chiller demand limiting controls. • Free cooling.
Power Factor Improvement • This is an area that you (as a utility person) need to be somewhat familiar with. • The reason is that your customers may be billed for Power Factor and you are the utility rep, therefore … • You will still defer most technical problems to engineering but lets be able to “talk-the-talk” a bit
Power Factor • Basics: • Induction loads (big electric motors) cause current to lag behind voltage so more kVA is needed to get the same kW. Yet, we are paying for kW. (???) – Bottom line…Power Factor – BAD! • Charge is applied when PF exceeds the minimum level usually around 80 or 90% (95% for you folks!). • Power factor is kW/kVA. See power triangle next page. • Correction is (usually) made by adding capacitor banks
Power Factor • Power triangle (kV) x (I) x (√3) kVAR kVA kW Motor load example: (kVA) x (PF) or (HP load) x (.746 kW/HP) x (1/η)
Power Factor Example • A plant has 2,000 kW demand and a power factor of 80%. How much capacitance is needed to correct this to 95%? (Why did I use 95%?) ΔkVAR = 2000 (.421) = 842 kVAR ΔkVAR 2500kVA Table Next Page 2000/.8 = 2500 kVA 2000 kW
THE GENERAL VIEW • QuickPEP® • http://www1.eere.energy.gov/industry/quickpep/(wu24wh55es44h1550shxdjby)/default.aspx • Plant Energy Profiler • Quick “Expert System” that gives: • Estimated Breakdown of Energy Use • Estimated Savings Potential • Suggested Areas for Improvement • Graphics in a report type template
We will talk about where this data comes from in a bit… Must use blended kWh & kW Cost