Pushback…

As I mentioned in an earlier Post, the Big Thinkers from the City of Boston decided it would be a great thing for building owners and operators to document and submit their utility consumption data, which would allow properties to be publicly  “scored” based on the Environmental Protection Agency’s Energy Star Portfolio Manager benchmarking tool.

Portfolio Manager is a simple tool that essentially calculates utility consumption per square foot and ranks buildings on that basis.  We have discussed previously why such benchmarks are fundamentally flawed and unreliable in principle.   But now a report has been released that demonstrates such benchmarks to be flawed in practice.

Which, logically thinking, only makes sense.  How can a broken idea lead to a correct result?  Only by dumb luck.

There is a description of this study in today’s Boston Globe:

http://tinyurl.com/brngkca

If I find a link to the actual study I will add it as well.

I think this is it:

http://tinyurl.com/czk9sam

The money quote in the article is quite to the point:

“‘The benefits it [the reporting ordinance] achieves may be nil and the cost possibly significant,’ said [Robert] Stavins, who conducted the study in conjunction with Analysis Group, a Boston consulting firm.”

Hmm.  Well, that sounds helpful, no?

It is striking that the benefits are potentially “nil” according to this study,  given the huge investment in time and effort that has already been expended in collecting and entering data by various constituencies.  Surely someone, somewhere in the City of Boston carefully evaluated the Portfolio Manager benchmarking tool and employed thought experiments to examine a range of “what if” scenarios to prove the efficacy and reliability of benchmarks before rolling it out.

Right?

Now, no doubt, the study linked to above will be discredited by some because it was funded by a constituency that views the City’s reporting requirements to be burdensome and potentially deceptive when it comes to demonstrating their environmental stewardship.  “Ah, it’s motivated by self interest, ergo it can’t be valid.”

There are also stakeholders who have invested significant effort in establishing Portfolio Manager as the tool of choice for energy reporting and benchmarking for the City.  I have found it rare for people with that level of buy-in to reassess and change direction, even if bad results can be glimpsed on the horizon for those willing to look.

So it’ll be interesting to see if this report gets any traction.

If you’d like to see a description the ordinance itself, it is located here:

http://m.cityofboston.gov/news/Default.aspx?id=5997

If you’d like to read my take down of simplistic benchmarks like Portfolio Manager, you can find it here:

http://tinyurl.com/d2l5oy5

***

Please bear in mind that most facility owners and operators embrace efficiency improvements and  want to be good environmental citizens.  However, it is frustrating in the extreme for them to be forced to use reporting tools that demonstrably will not deliver the kind of intelligence and the kind of results that the city claims will be achieved.  If only the policy makers has worked with the stakeholders beforehand, the current climate of discomfort and concern might have been largely avoided.  Water under the bridge, I suppose, but hopefully others will learn from our experience.

In general, though, we can take away a good lesson.  If you are going to do something, make the effort to do it carefully, accurately, and well.

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A wee bit more on payback

While not very well written, and at the risk of becoming ridiculously self referential, here are a few more thoughts about energy projects and their value to the organization that I wrote several years back:

http://tinyurl.com/cymdq2b

Surprisingly, I have found variations of this approach to have gained currency in the energy conservation community recently.  Note that while this was presented as an IT article, the approach is quite widely applicable.

Payback!

I’ve worked in the energy conservation field for a long time, and it has frequently surprised me how inadequate the economic evaluation of energy projects tends to be.

Even very large organizations with significant investment in efficiency and “sustainability” often resort to “simple payback” as a way of assessing and selecting investments in energy savings.

It’s pretty easy to demonstrate why simple payback (SPB) is a lousy tool.  Let’s take a look, and then propose some better solutions.

Simple payback is simply (no pun intended, but there it is) the cost of the energy project divided by the anticipated annual energy cost savings (as an aside, I could argue that any annual maintenance savings should also be factored in, but they seldom are.)

Thus, a simple payback of three years means that the energy savings accruing over three years will cover the original cost of the project.

On the face of it, this has a certain appeal.  But simple payback is too blunt an instrument to make shrewd investment decisions.  Sort of like cutting cake with an axe.

As usual, a thought experiment is our tool of choice in probing for the soft spots of a metric like SPB.

Imagine two competing investment projects.  Both cost $100 and both save $35 per year, but one will last five years before needing replacement, while the other is expected to last 10 years.

Now, it is obvious that the longer lived project is a better deal, since it will deliver almost 7 years worth of savings after the initial investment is recouped, whereas the shorter lived project only delivers savings for two years after the investment cost is recovered.

And yet, the simple paybacks are identical.

At the risk of being overly pedantic, let me spell this out explicitly.  Simple payback is completely and utterly incapable of distinguishing the life cycle value of an energy investment.

Which is why it’s a pretty inadequate tool for sorting out energy investment opportunities.  And yet, I’ve seen simple payback used as the sole criteria in accepting or weeding out projects with six figure price tags in otherwise sophisticated organizations.

Crazy, right?

In fact, the reason this topic came to mind was that I was reading some posts on an energy oriented site where someone was talking about how a four year simple payback was the upper limit for a project to be deemed acceptable.

But what if it is an extremely long lived asset like a chiller (a big machine that makes cold water for air conditioning) that might last 35 years?   Would you not evaluate the benefit of 28 years of savings in light of a seven year payback?  Apparently not.

So you can see, SPB is not only a blunt instrument, it can also inadvertently exclude from considerations investment opportunities that might deliver excellent overall benefits to the organization.

Fortunately, simple but much more informative evaluations of energy investments can be made readily.  Let’s do a little background to see what issues we need to address, and then carry out a simple example or two.  As is typical on this blog, I don’t delve into great detail, but I try to get the fundamental ideas across (and more or less correct), but details need to be pursued elsewhere.

Well, as we mentioned above, one thing we need to account for is the useful life of the energy project.  Now, we may not know this precisely, but we know that a motor is going to last 10+ years typically, while a conventional fluorescent lamp might last 20,000 hours.  And generally speaking, you can make an educated guess for most energy projects.

Also, because energy project require an investment of capital, it is useful to understand the organization’s cost of capital.  Now, cost of capital might be the cost to borrow money to carry out a project, or it might be lost opportunity value of the investment spend, or it might be something else, but most organizations have (or should have) a sense of this.

The important thing to remember when considering cost of capital (or discount rate) is that it allows you to understand what value the organization puts on future savings in today’s dollars.

For instance, if I offered to give you $100 in two years, or $80 right now, which would you take?  You might well take the $80, figuring that you could invest it in something that would deliver equal or better results two years out.  So that $100 promised two years out might have an equivalent present value of $80.  And you will observe that if I offered you that $100 in five years, you might be happy with something like $50 today.  Meaning that the present value of money diminishes the further away it is in time.

You will notice immediately that if an organization has a non-zero cost of capital, the paybacks reported via SPB are actually overly generous (i.e. too short) because future savings dollars are treated just the same as present dollars.  And even if the organization itself does not recognize it, this is not true.  Those future savings are worth less – a bird in the hand and all that.

***

Anyway, our general approach will be to look at the energy investment it today’s dollars, but we should discount the future savings, taking into account the organization’s cost of capital. We then develop a “net present value” for the project, which equals the initial energy investment minus the discounted savings flow over the life of the project.

Often, you compare the NPV of a “base case” versus a “high efficiency” case to assess competing projects.

Let’s see how we do that on a simple project.  To make it easy, we’ll assume the base case costs nothing.  Thus, we only need to evaluate an incremental cost and the associated savings.  Here’s what we’re working with:

  • Project Cost                             $100,000
  • Annual Energy Savings         $   15,000
  • Project Useful Life                              15 years minimum
  • Cost of Capital                                       5%

Now, you will note that the simple payback is almost seven years, so this project will get shot down in plenty of shops.  But imagine we have a real savvy  CFO who evaluates all investment opportunities in terms of the value placed on capital – in this case 5%

At this point, a little simple math is in order.  Note that while we are doing the math, tables are widely available (or can be easily be created in a spreadsheet) to make this evaluation methodology almost trivially simple.

We recall that the future worth (F) of a current investment (P) at interest rate “r” at year “y” is expressed simply as:

F = P * (1 + r)^y

So, for instance, $100 invested today at 5% interest will in five years have a value of

$100 * 1.05^5 = $128.

To get present value of money in the future, we just massage our equation to get:

P = F / (1 + r)^y

or

P = F * (1 + r)^-y

So, if my cost of capital is five percent, $100 in savings five years from now has a present value of:

$100 * 1.05^-5 = $78

Okay, that’s all we need.  Let’s look at our project.

5% Cost of Capital
$15,000 Annual Savings in Today’s Dollars
$100,000 Capital Cost
Year PV Factor Present Value
0 1.00 ($100,000)
1 .095 $14,286
2 .091 $13,605
3 0.86 $12,958
4 0.82 $12,341
5 0.78 $11,753
6 0.75 $11,193
7 0.71 $10,660
8 0.68 $10,153
9 0.64 $9,669
10 0.61 $9,209
11 0.58 $8,770
12 0.56 $8,353
13 0.53 $7,955
14 0.51 $7,576
15 0.48 $7,215
Total  10.38 $55,695

As you can see, this project delivers a positive net present value.  And from our savvy CFO’s perspective, carrying out this project is equivalent to putting $55,695 in the bank.  Thus, the project would be approved despite the nearly seven year simple payback.  In this case, the simple payback is a little too simple to identify the investment opportunity.

You should note that, in theory, even a net present value of just $1 can justify a project, since that is still a benefit over doing nothing.  As such, the magnitude of the NPV allows you to sort through a batch of attractive investment alternatives, but if they all have positive NPVs, they are all good investments.  You are simply picking out the best of the best.

One final note.

You don’t have to make a table for an investment that delivers uniform returns year after year.  Instead, you can calculate the present value of an annuity over y years at discount rate r as:

P = 1/r * (1 – [1 / (1 + r)^y])

This formula would calculate a value of 10.38 for 15 years at 5% for our example (again, you set this up in a spreadsheet once and you are done) which leads to:

NPV = ($100,000) + 10.38 * 15,000 = $55,695

Which is quite a bit simpler than bothering with tables all the time.

Hopefully this makes a plausible argument for net present value as a preferred metric when evaluating energy investments.

What is Joe Nocera Talking About?

On Saturday, the New York Times published an impressive hand waving exercise by Joe Nocera touting the benefits of gasified coal and carbon sequestration.  The article itself is here:

http://tinyurl.com/d432ll7

As is usual when it comes to energy discussions in the United States, there was negligible technical information in Mr. Nocera’s column.  Rather, he asserts that “… because the gasification process doesn’t burn the coal, it makes for far cleaner energy than a traditional coal-fired plant.”  He goes on to quote a representative of the Center for Climate Change and Energy Solutions who states that coal gasification plus carbon capture “is the only technology that can reduce CO2 emissions from existing, stationary sources by 90%.”

Well, that sounds pretty great, don’t you think?

Now, we can take issue with this in a number of ways, but let’s start with some plain horse sense.  As we know from our  posts on combustion, heat is liberated from fossil fuels when carbon and/or hydrogen combines with oxygen.  While it is true that coal may contain a small amount of hydrogen, the vast, vast majority of the energy contained in coal is contained in carbon.  The only way that coal gas makes sense is if there is plenty of carbon in it to burn.  And burning carbon results in carbon dioxide as the predominant byproduct.

Mr. Nocera perhaps thinks that because the coal is “gasified” that it is turned into real natural gas (CH4)  by this process.  He is wrong.  Coal gasification results in a carbon rich stew of chemicals (admittedly without many of the heavy elements contained in solid coal) that still must combine with oxygen to liberate heat.  And create carbon dioxide as a combustion by product.

Secondly, while he attempts to conflate coal gasification and carbon-capture as reducing emissions and being a game-changing clean energy solution, he seems (at least to me) to skirt by the issue of “carbon capture” which I take it to be the end game after the carbon dioxide emissions are utilized for “enhanced oil recovery”.  Basically, use the pressurized carbon dioxide gas to drive oil out of the ground, and then leave it underground where it will presumably stay forever.

Here too a little common sense is in order.  First, if we are trying to reduce carbon emissions, in what way does facilitating “enhanced oil recovery” help the cause?

Beyond this, Mr. Nocera may not realize that septic systems do not last forever, and the plan to dump our power generation waste underground and to assume it will remain sequestered for all time is simply childishly naive.  And to not openly admit that the carbon dioxide will physically be generated and stored in the earth seems an extreme oversight at best.

Then too there is the question of carbonic acid formation over time in moist areas where some of this gas might settle.  Recall that carbonic acid is already damaging ocean corals.  How might acidified soils affect the bacterial and animal life currently housed there?  The question goes unasked.  And the answer is probably not known.

But enough common sense, what about the numbers?  Let’s go the Texas Clean Energy Project site located here:

http://www.texascleanenergyproject.com/

You will note that this is a 400 MW plant.  Let’s assume it’s going to run 97% of the time.  Then each year it will generate:

400 MW x 8,500 hours = 3,400,000 MWh

Now they say, right there on the page, that 3 million tons of carbon dioxide will be used for “enhanced oil recovery”.  They also say that this is roughly 90% of the plants carbon emissions, meaning the total emissions are about 3,300,000 tons.

Well look at that. 

This plant emits about 1 ton of CO2 per megawatt-hour.  Or about 2 pounds of CO2 per kWh.

This is higher, by the way, than the current average emissions in Boston, which has a supply mix that includes hydro, nuclear and solar.  So this “Clean Energy” project is actually a step backwards from the status quo in Boston.

Thus, the Texas Clean Energy Project may be better than a conventional coal fired plant, but to call it a game changer is magical thinking.

Pretty magical that this got published in the New York Times, now that I think about it.

I think there are a few useful ideas we can take away from this column.

  1. Hiding waste products underground does not mean that they do not exist.  Let’s stop the mendacious practice of calling carbon capture “clean”.   If carbon dioxide is generated as a byproduct, it exists and should be counted.  Where it is located is irrelevant.
  2. Ignoring the qualitative difference between natural gas and coal gas obscures the fact that the products of combustion are not the same, and that natural gas is a more energy-dense, clean burning fuel.  To not state this up front is misleading.  In discussing energy, words need to be specific and defined.
  3. Let us not conflate technologies in a confusing “bundle” (gasification, enhanced oil recovery and carbon capture) and then claim a result that is tenuously linked to the overall package of solutions.  It is not necessary, and engineering doesn’t work that way.  We deserve the details.

I think that Mr. Nocera sincerely believes that the Texas Clean Energy Project is a good thing that will deliver tangible results.  But he owes it to his readers to explore the technical issues, including the chemistry of the combustion reactions, before promoting a “solution” that could be an environmental disaster.

Energy Conservation in Buildings 1 – Overview

I’ve been thinking about thermodynamics way too much in recent posts, so let’s get back down to earth for a few posts.

I am not going to argue the merits of conserving energy (or entropy) here.  Rather, we will take it as axiomatic that conserving energy is a good thing.  And it is – financially, environmentally and morally.  But what I’d like to outline here is the way that some energy engineers think about saving energy in rough outline.  The details may or may not come later.

The way I see things, investigating/monitoring/improving how energy is used simply requires that we look at

  • Stuff
  • Systems
  • Documentation

I will discuss how we look at these things some other time, but first let’s deal with these three things.

Stuff are individual pieces of equipment.  A motor, a light bulb, a computer screen, a transformer, a (lacking) blanket of insulation, a pump.  Energy evaluations should always confirm that the most efficient, cost-effective (yeah, we’ll need to conjure up a meaning for cost-effective at some point soon) technologies are in place.  Stuff upgrades, e.g. inefficient lighting to efficient lighting systems upgrades, are what people just love to call low hanging fruit.  Any junior engineer – hell, any trained high school graduate – can be taught to identify low efficiency stuff and be taught to identify and calculate the energy savings associated with alternate high efficiency stuff.

As an aside, I have always found it curious that while energy conservation programs will often provide incentive money for high efficiency motors [for pumps] that save a percent or two in energy use, I have never seen an incentive for an updated pump selection that might deliver several percentage points in pump efficiency improvement.  Maybe it isn’t cost effective.  But I worked running a conservation program for a utility company for a little while, and I don’t think I ever saw the fan or pump selections scrutinized to see if the selections were optimal.

Note that if stuff is operating when it does not need to, we may want to embed it into a system so that the hours of operation can be controlled.

Systems are ensembles of stuff, unexpectedly, and evaluating such systems identifies whether the interactions, or synergies, of the various components making up the system are operating at peak efficiency.  This sounds a bit abstract, but an example or two can quickly demonstrate what I mean.

Perhaps the simplest example I can think of is the light switch.  Replacing a conventional light switch with an occupancy sensor creates a system, whereby the lights will be turned off after a predetermined delay whenever the room is not in use.  This can greatly diminish the energy use of our lighting system.  Evaluating this system would simply be confirming that the sensor works, and that the predetermined delay is not overly long.

A more complicated example would  be so-called air side economizing.  Large buildings often require air conditioned ventilation air even in the winter.  There are times in the year when it is possible to use cold outdoor air from the environment rather than mechanical cooling (i.e. air conditioning equipment.)  However, it is not at all uncommon for air side economizing to have not been implemented (only older buildings, economizers are now required by code), or to not be functioning properly due to bad sensors (that check the building and outdoor air conditions), bad actuators (that manipulate how much outdoor air is admitted) or bad control logic.  Air side economizing can save huge amounts of energy.  Evaluating this system would include physical inspections of things like dampers, actuators and temperature or enthalpy sensors, investigation of air flow to assure flow is not physically stratified in the air handling systems (which can cause freeze trips), and review of the control sequences.  This review would also investigate the opportunities to turn the entire system off, or to at least reduce the airflow, when the building is unoccupied or lightly occupied.

As you will have noted in the air side economizing example, evaluating systems is much more difficult than evaluating stuff, so the expertise you throw at it needs to be greater.

I would also point out that, while building systems are not overly complex from a technical engineering perspective, solutions that maximize energy performance in such systems can be remarkably cunning and unexpected.  Ideally, a junior engineer should not be doing systems evaluations, though in reality many consultants will throw their junior engineers into the fire, with diminished results.

I have heard PhD types disparage energy engineering as too simple to be interesting, but I do not personally find that to be the case.  One reason is that engineering conservation solutions is not theoretical.  It is real world.  And that means that you are acquiring and manipulating real data.  Or are at least trying to.  The imperfection of the data, the physical limitations to what you can see and measure, the inability to do much empirical experimentation, all lead to a need to interpret incomplete data.  Thus there are many apparently possible solutions that require consideration in a systems energy assessment.

Documentation.  In discussing documentation, what I mean is that implementing energy efficiency projects includes finding a way to record not only what projects were done, but also what they were supposed to accomplish and that the savings continue to accrue.

While this may sound like a pretty trivial piece of bookkeeping, it can actually be quite difficult to do.  There are few reasons why.

First of all, energy projects are often done piecemeal, by different people using different methodologies.  Therefore, information pertaining to conservation can come in all kinds of calculation methodologies and presentation formats.  Finding a way to consistently and concisely document multiple project can therefore get messy.

Secondly, actual performance requires field data, so this is more than an accounting exercise.  Data from building automation systems and/or data archiving systems must be periodically reviewed, and depending upon how that data is structured, may even require interpretation to establish what is actually going on.

Finally, it should be borne in mind that discussions of energy savings may need to be tailored to different audiences.  A chief financial officer might be interested in financial performance, a sustainability officer might care principally about carbon emissions, while a fellow engineer might care about real-world energy performance.  This can’t all be done with one monster spreadsheet.  Well, it can be, but it ain’t pretty.

In my opinion, trying to document projects and generate reports tailored to specific audiences is madness without using a database.  If you need to record and manipulate large volumes of stored data and have never learned how to use a simple database like Microsoft Access, you are creating an awful lot of unnecessary work for yourself.

I would like to say one more thing about documentation.  There is growing emphasis in large enterprises on energy use, carbon emissions, and sustainability in general.  I predict there will be a concomitant increased emphasis on documenting and reporting services for these sustainability initiatives, and that current industry practices are going to be exposed as inadequate.

So there’s the overview.  Stuff, systems and documentation.  The question is, when you walk into a building, what do you do?  I’ll offer one proposed approach in a future post.

Enthalpy, Our Somewhat Strange Friend…

Thus far, we have thought about the internal energy (U) of a substance.   Enthalpy is a very close cousin, and enthalpy is used in many engineering calculations, unlike internal energy.

While we have not physically described it, the internal energy is (or is a manifestation of) the molecular energies within a  substance.  This would include kinetic energy, potential energy, vibrational energy, spin energy and so on.

Enthalpy is internal energy plusPlus what is what this post is about.

We recall that for a material, the differential change in a substances internal energy is codified as:

dU = dQ – dW

Where dU is internal energy change, dQ is heat flow into or out of the system, and dW is work done by or to the system.  You will note that I am now writing dW as a negative term.  Why?  Because as heat is added to a material, the material will, if unconstrained, tend to expand and do work on the atmosphere, thereby lessening the internal energy somewhat.  This is the typical form of this expression.

We also recall that this expression can be rewritten as:

dU = dQ – p * dV

Rather than try to start by describing what enthalpy is, let’s do a calculation and see how it differs from internal energy first.

Let us imagine a glass jar holding about 13 cubic feet of air (Why 13 cubic feet?  ‘Cause that weighs about 1 pound.)  Because the volume of the jar does not change, the work term in our formula goes away and we are left with

dU = dQ

Now, it turns out that the internal energy of a material and it’s temperature are directly related via the specific heat of the material (see earlier post if you want a little background.)  Thus, we may rewrite our equation as:

dU = Cv * dT = dQ

Change in internal energy equals specific heat at constant volume times temperature change, which is equal to the energy flow Q.  Remember, we are not allowing any work to be done because the volume is fixed.

Well, lets do the math.  Under normal temperature and pressure conditions, the constant volume specific heat of air is about 0.17 Btu per pound-degree-Rankine.  You will recall that for changes in temperature, Fahrenheit degrees may be substituted for Rankine.

Let us imagine we add enough heat to raise the temperature of the air by 50 degrees.  The change in internal energy would be:

dU = 1 pound-air * 50 degrees * 0.17 Btu/Lb-degR = 8.5 Btu.  So the internal energy has increased by 8.5 Btu.

Now it turns out that when we did this, the enthalpy of the air also changed.  The enthalpy is calculated with the constant pressure specific heat.  In the case of air, Cp is approximately 0.24 Btu per pound-degree-Rankine.  Let us designate enthalpy as h.  Then:

dh = 1 pound-air * 50 degrees * 0.24 Btu/Lb-degR = 12 Btu.  40% more than the change in internal energy!

So what’s up with enthalpy?  And what do we do with it?

Well, the usual description is as follows:

Most thermodynamic processes of interest do not occur in balloons and jars, they occur in systems that have materials flowing through them.  For example, a cooling coil has water continuously flowing through it.

Sticking with our coil example, it takes energy (work) to induce flow through a coil.  The enthalpy (and Cp) accounts for this flow work.

You may recall that work is a force times a distance, and that this can be algebraically manipulated to become a product of changes to volume and pressure.  For the flow work, this work is:

dW = d(pV)

For reasons we won’t get into in this blog (but may be sort of intuitive), this flow work expression can be rewritten as:

dW = p * dV + V * dP

Now, I said above enthalpy and internal energy differ by the flow work, so we can express enthalpy as follows:

dh = dU + p * dV + V * dp.

But wait, dU = dQ – p * dV, so

dh = dQ – p * dV + p * dV + V * dp

or

dh = dQ + V * dp

Compared with internal energy:

dU = dQ – p * dV

We can see by inspection that enthalpy changes will be bigger than internal energy changes when heat is added or removed from a material – just look at the sign of the work term and think about what adding or removing heat will do.  In the case of our jar of air, we observe that heating the air included pressure energy that would allow the air to be transported were it in an “open” system.  Open systems allow materials to flow through them.

To me, internal energy is a bit more intuitive than the enthalpy, but that may just be me.  In any event, enthalpy, not internal energy, is generally used when making calculations.

Note, by the way, that if you have a material such as water sitting in a jar at some pressure p, and you have a hose running with the same pressure p, the temperature of the water in the jar should be higher.  The intuitive reasoning is that the flowing water has to expend some energy to move through the hose, so that deducts from the internal energy and, therefore, the temperature.

More formally, we realize that if they are at the same pressure, the internal energy of the water in the jar equals the enthalpy of the flowing water.  Therefore, the internal energy must be higher in the jar of water, and therefore the temperature must be higher too.

Now let’s start finishing up.

We have talked around specific heats a little bit, but now we can get a little more detailed.

Cv, specific heat at constant volume, captures the change in internal energy relative to the change in the material’s temperature.

Cp, specific heat at constant pressure, describes the change in enthalpy relative to the change in the material’s temperature.

Engineering calculations use Cp, which makes sense.

***

Some of these prior posts have been a little heavy for what is intended as a general blog, but the pieces are almost in place for us to really think and wonder about energy in intelligent ways.

Why I am Not a Fan of Most Energy Benchmarking

Benchmarking in the energy industry is generally capital-H Horrible, with all sorts of unexamined assumptions and presumptions that can readily  be shown to lead to incorrect conclusions.  I have railed against tools like Energy Star Portfolio Manager, but to no avail.  It is a bill of goods that has been sold to upper management and many consultants – who always likes things to be short, sweet and simple.  In this case, way too simple.

As a management tool, most benchmarks are awful.

My reasons for benchmarking skepticism are located here:

http://tinyurl.com/d2l5oy5

This is not to say that good benchmarking metrics can’t be created.  But we need to take the process away from the well intentioned policy types and have a discussion about what rigorous and accurate metrics should look like.