(September 12, 2012) Which End of the Energy Rope to Pull On?
The ‘rope’ is a metaphor I like to use. The rope is the goal of reducing energy. One end of the figurative rope is more efficient equipment; that is, no changes to the end use, just the equipment serving it. The other end of the rope is in the user’s camp: using less to begin with. A key message is that both ends produce utility savings when doing both the two efforts complement each other and the savings are additive.
Examples.
Left end of the rope: More efficient HVAC, more efficient lights, more efficient air compressor, more efficient water heater.
Right end of the rope: Moderating temperature settings, insulation, window shades, reducing light levels, task lighting, lowering air pressure, repairing air leaks, shorter showers or restricting shower head. “Using Less to Begin With”
Focusing on just the equipment has pros and cons.
Pros:
Quick hit.
Easy to implement
Easy to quantify
Results occur all at once and will be visible on utility bills
Requires no knowledge of where the energy is used
Cons:
Large projects require capital
New equipment may be larger than it needs to be
If the downstream systems have problems, this method can result in ‘more efficient problems’
Insulates users from changing behaviors – problem is identified solely as “others”
Focusing on just the points of use has pros and cons.
Pros:
Some measures can be low cost
Avoids the expense of replacing major equipment that still has good life left in it
Measures can be spread out over time
Addresses user choices and how they influence energy use
Cons:
More difficult to quantify savings
If improvements are spread out over time, single ‘step’ reductions are not visible on utility bills
Spartan uses of energy are thwarted by inefficient equipment
Example: Consider a boiler replacement in a hotel that has single pane glass and poor insulation. Individually, each offers a 10% reduction. The nits get a little blurred when speaking in “percentage changes”, but the message is clear.
A. Focusing on just the equipment will yield a same-capacity unit of higher efficiency. Taking existing usage as “1” and a boiler with 10% better efficiency, the savings will be (1/0.8)-(1/(0.8*1.1) = 11.4%.
B. Focusing on just the building will yield less use but same heater efficiency. Taking existing usage as “1” and envelope improvements that reduce inherent usage by 10%, the savings will be (1/0.8)-((1*0.9)/0.8)= 12.5%.
C. Focusing on both ends of the rope, savings will be (1/0.8)-[(1*0.9)/(0.8*1.1)] = 22.7%
Then the economics. If choosing one or the other, the cost of windows plus insulation are compared to the cost of the boiler, since each offers the same savings. When doing both, note that the smaller boiler will cost less, as well as the pumps, piping and valves that serve it. Simple paybacks are used, with the assumption that windows plus insulation cost is equal to the boiler cost.
A. (Better boiler, same building). Cost = 1, Savings=1*(11.4/12.5), Simple payback = 1.1
B. (Better building, same boiler). Cost = 1, Savings=1, Simple payback = 1
C. (Both) Cost = 1+(0.9*1) = 1.9. Savings =22.7/12.5, Simple payback = 1.05
Messages:
1. Both ends of the rope are effective at reducing cost.
2. Choosing just one end leaves considerable savings on the table.
3. When ‘percentage’ changes are the same, conservation that results in using less to begin with saves a bit more than simply addressing the equipment end.
4. Pulling on both ends of the rope, the savings add and economies are available from downsizing the new equipment.
(July 6, 2012) Energy Auditing: Does it Require an Engineer?
Excellent question.
To answer it begins with what the task is. First let us define the audit and analysis as being commercial or light industrial (i.e. not residential). For right now, presume commercial. I don't mean a 7-11, I mean a 100,000 SF office building or a 500 room hotel or a 300 bed hospital.
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Does it involve rocketry or calculus? No.
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Does it involve turning wrenches? No.
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Does it involve basic college math and science? Yes.
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Does it include review of basic metrics for reasonableness? Yes.
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Does it involve blindly following a script or pre-printed checklist? No.
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Does it involve the principle that one size fits all? No.
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Does it involve intimate knowledge of building systems and controls? Yes.
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Does it involve experience and reasoning? Yes.
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Does it include strategic measurements, equipment assessment, and user behavior review? Yes.
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Will someone with an engineering degree automatically be good at energy auditing? No.
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Will someone without an engineering degree automatically not be good at energy auditing? No.
So, it comes down to the two most hated words from a professional's mouth: it depends.
Energy auditing and energy management in general is a technical field. Numbers, geek speak. Anyone in the field that is not technical is either faking it or is the boss of the people doing the work (which doesn't count).
The case for engineers:
Engineers are not automatically great at this, but are naturals to be good at it. Why? Engineering training includes heavy review of science and math, economics, and a variety of subjects that come into play for power requirements and energy use; thus the basic training makes them easily adaptable. This is significantly true for mechanical and industrial engineers; electrical and civil to a lesser extent although it is all learnable. And it should be obvious that energy project proposals that are complex, iterative, and deep down the academic rat hole will be most appropriately assigned to the engineer...especially the seasoned one.
The case against engineers.
If the skill set is limited to academic and does not include field work, the engineer's benefit will have shortcomings. For example, the only way to really know how a particular HVAC system "'behaves" is to hang around with one. Thus, to be on "speaking terms" with the variety of systems that could exist in the building requires field experience. Some mix of design time, construction time, troubleshooting time, and energy auditing/management/calculation time are the ticket; and I'm talking years of it, not weeks of it. It is no coincidence that this is echoed in the AEE CEM qualifications matrix. The case for non-engineers.
Depending (there it is again) on the background, these folks can have excellent insight to the building systems. Take, for example, a buildng operator; these folks live with the building systems, and by osmosis and over time they have reached "speaking terms" with them. Repair personnel similar given enough time. Installation personnel to a lesser extent. Sales personnel can also have good awareness, especially when involved with retrofits and outside selling where they meet building operators and hear the dirt on how things are running. For anyone with basic college math and science skills and such awareness, the training gap is no harder than learning a new language (remember the first bullet.)
The case against non-engineers.
While the technician and technologist can more quickly identify equipment in the field compared to a newb engineer, they are more likely to be ill equipped for the analysis piece, which then limits their potential. Thus a skill level of at least college algebra, physics, and thermo (non-calculus) are a pre-requisite to going anywhere in this field. It is possible, but unlikely, that a technician with 10 or 20 years experience as a technician will return to college for a year to raise the bar of math and science skill.
Double talk? I don't think so. The key is system knowledge built upon basic college level math and science. Utopia is an engineer with umpteen years of appropriate experience in a field closely related to building energy systems. For these folks it is a short stretch to become CEM and good ones; however this is a 20-year path and hardly a straight line to CEM. A technician with a spark for detail and a willingness to learn the new lingo and add a layer of math and science skill can be very effective at most energy auditing tasks; and I do not mean holding the dumb end of the tape measure. Assessing good candidate measures, taking measurements, and calculating savings potential are all reasonable expectations, and technologist is a more fitting term for these folks. A good technician can do probably 2/3 of what an engineer can do in a commercial building.
The key word is good.
Does one replace the other? No.
Which is worse: an engineer who has never lifted the hood of their car or ventured out from the lab, or a technician that doesn't understand heat transfer, the refrigeration cycle, degree days are or how to use a spreadsheet? Tough call, but it is sure that neither will be very effective in energy auditing.
Which is better: an engineer with field experience related to energy or a seasoned technician who goes back to college for energy training. I say both are good candidates and working as a team would be awesome.
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(June 7, 2012) Arm Waiving.
This is the term I use for the good folks with ideas on energy saving projects. Sometimes the physics are sound, sometimes not, but their heart is definitely in it, which is good. We see the waste, and the earth's natural resource 'gas tank' steadily moving toward "E", so there is anxiety fueling the attempt. I get it, and feel it.
I call it arm waiving because that is usually as far as it gets. Except on TV, a key ingredient in getting things to happen is convincing someone with a checkbook to write the check. To do that requires some explaining (arm waiving, just more formally), and also quantifying the associated savings and cost.
In a way, it's good that not too many people have what it takes to put numbers to this stuff; makes us feel useful. And I don't mean counting light bulbs. I mean the ability to estimate the energy use of a machine that sees a variable load and has a variable efficiency, including how it may interact with other energy uses. Of course, this is more than math; to get it right requires knowing the characteristics of the machine and the load it serves, even when that load shape looks like a roller coaster.
System knowledge, the underlying science, and quantifying energy use and savings - these are the essential tools of the trade. With them, we can fuel change by providing business owners the numbers they need. Without them, it's just more arm waiving.
These skills are at the core of the Energy Management Technology curriculum.
(May 1, 2012) Sustainability in Business.
A buzz word if there ever was one. Strictly speaking, sustainability is an absolute: leave no trace / leave the camp and its resources in at least as good of shape as we found it / perpetual. Business models always include "growth" which, by definition, is not sustainable. All processes have waste, entropy increases, and effort always results in heat. Personally, I think we can slow the messing of our nest, and I believe in that, but in the end, mess it we shall. But to the point: What does sustainability mean in a business environment?
One part of the sustainability concept fits literally: continuance; businesses want to survive and go on. So one form of sustainability all will agree on is staying in business, which has been Rule #1 all along. Note how this form of sustainability has no environmental requirements attached to it.
Carbon (CO2) is one target of sustainability. Conventional wisdom for being carbon neutral is to reduce as much carbon emissions on site as practical, and offset the rest. Imagine if everyone did that: there would not be enough acreage to plant trees in. Maybe I'm naive, but this seems much more like a worthy goal and a true reality.
Sustainable practices are a healthy habit for modern businesses. But remember Rule #1 and you can quickly see how green choices necessarily get tempered and diluted. In many businesses, customers stay because of lowest price; therefore if a sustainable practice increases business cost, it is suicide. Businesses with the luxury of prestigious brand recognition will pursue moderate does of green, while watching their competition very carefully.....not to be outdone, nor to over-spend and lose a competitive edge. A cold, hard spreadsheet would say no to most of it, but there are also intangible forces at work. In the end, businesses will provide what their customers want, according to Rule #1.
Recognize also that not all businesses are blue chip megatrons. For smaller and struggling businesses, it should be no surprise that sustainable practices take a back seat to making payroll that week; I would do the same thing. So, then, it seems natural to tolerate the budding businesses' practices as they seek to put down roots. And when they grow up to be tall, proud, successful pillars they can give back with more sustainable practices. Can you really gripe about the candy wrapper in the paper boy's pocket not being printed on recycled paper? Extrapolating, doesn't this apply to emerging countries as well? Well, this kind of discussion is "beyond my pay grade", but I keep circling back to this:
- Businesses behave selfishly to satisfy Rule #1, and we can't blame them for that.
- Businesses provide what their customers want, so if their behavior is objectionable, remember it is a reflection on our collective request.
The free market theory is used by many, and will be tested on sustainability. It will be coaxed by legislation, prodded by competition, and driven by what customers ask for. It is possible, and a concern, that change will be forced by the pricing of dwindling resources and changes from free market pressures may arrive too late. Eeyore claims it's already too late, but he would. The alternative is to mandate everything from the top down. But there is no worldwide government, so compliance is optional and if we decide to fix the planet next week, will end up trading with ourselves....and maybe France.
(April 18, 2012) Behind the Meter. (Launch)
A utility provides the energy customers use. The source of energy savings in a building is not the utility, any more than the transformers that power the building or the motors turning the fans and pumps. The term 'behind the meter' is the line in the sand between the customer usage and utility supply. Think of the utility as the gas tank in your car. How quickly it is emptied depends on how you drive and the size and condition of the car; if your car gets bad gas mileage, don't blame the gas tank. I think you get the point.
This page is about the things that use energy in commercial buildings...behind the meter.
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