SUMMARY bill tracking utility is located in the heart of a program for efficient management of energy. simple comparison of utility bills can cause the wrong data on the level of savings from energy management programs through the influence of the lack of weather or other factors. Correcting the current account for weather data provide more accurate representations of savings that have accumulated. This paper presents the hows and whys of weather correction for those who want to become familiar with the concepts and methods.

What wrote invoice entry FOR YOU /> Jim Faes Jefferson County School District I

An energy accounting system is like the control panel of an airplane. To navigate your aircraft, you must understand where he is, where he was and where it goes. If you fly the aircraft without the control panel, you have a good chance the plane will crash. It’s the same thing with energy management. You need to know where you are, where you know where were you going, and how, where you are now in line with expectations. Their progress

With tracking systems electricity bills, energy manager:
– Enter the specific use and costs, and track their actual performance against targets
– Discover the significant increase in energy consumption and corrective actions
– Identify buildings that have more than $ / sqft than others, focus and energy on management activities building
-. Determine if your feet are the best deals
– Make sure you create, right by the utility
account – invoices to your tenants (if any)
– Determine whether you saved energy from your energy-saving measures
– aggregate your usage and costs, and to this aggregated data to the provider of potential energy
offer – creating budgets utility

more generally, when you click on the informed about the status of your utility accounts, you know where your installation and how it relates to your goals

following bills. Report Card for the equipment and facility managers
energy managers and managers at all institutions often have to justify their existence administration. How can we save in the last year? Is it more than we pay our energy manager? They make recommendations to meet at reasonable costs? Why do we need an energy manager?

There are several methods to determine whether you can use the energy of the energy-saving measures have saved as described in the literature, you wave your hands in the air, and usually a number. Calculate your savings based on point data logger and control; compare energy bills to determine savings, and finally with a building model (These are called Option A, B, C and D in IPMVP called “Guidelines for FEMP and other documents.)

Probably the simplest and more. to determine procedures, in agreement with the facility manager, is whether you save energy option C, compared to electricity bills. Why? Now, even if some managers utility calculations that they want from the friendly sales people, this method is unreliable because it can produce inflated numbers. Position data loggers and the existing control point seems simple enough, but the implementation of these inputs in a number of savings can sometimes be out of reach for the skillset manager of the establishment. Modeling of the building, then it may be useful, requiring hours to build the model can represent and how the building is using and can not really pose the question what the building really is. If these objections hold, so that electricity bills is the last method is to quantify your performance as an energy manager. Moreover, in the end it comes to bills, such as invoices reflect how much you pay.

As most facility managers are already monitoring their electricity bills, it is only a small additional step to see if you save energy and costs of your energy management program. Just compare the invoices prior year bills this year and see if you have registered.

Well, it’s not that simple. See why.

Why not work Bill comparison, or, Why should assume
correction forecast, you want the economies of the new effective system of ice water you have installed to see this January. A simple comparison of the accounts before and after the savings should not? Well, not quite. Let’s say last year was a relatively cool summer, and this summer was terribly hot. Do you see the savings? Maybe not.

There are two ways we can track the application from year to year. Suppose we have examined only the use of time, as do most people.

We scored two regions Figure 1 The bottom (dark) region, we call the use of non-weather sensitive. This use can on computers, lighting, pumps, adjusting volume and other charges which may be attributed to the weather. For each year of this amount is stable. (In this case, the use of non-sensitive to weather conditions is very low, as this unit is a factory mechanic. In general, the use of non-weather-sensitive would be higher.)

We call on the top (easier) use weather sensitive region. This is directly attributable to the use in this case, the cooling system. You can use in this region are attributed to cooling towers, water pumps, coolers, chillers Chilled water pump on condenser fans cycling fans, and maybe and pumps that cycle or a variable frequency drive.

If last summer was cool, and was hot this summer, then the use of non-sensitive to weather conditions would probably not change from year to year, but use sensitive to weather changes. Figure 2 is the same as in Figure 1 except it has two years of data. Note that in the second year, the weather-sensitive part of much larger because of the heat wave is increased cooling load.

Now suppose that the new chilled water system to reduce weather-sensitive by 20%. The amendment of the weather Figure 2 shows a comparison of annual energy savings may not use any, as shown in Figure 3. (In Figure 3 we found is 20% of use in weather-sensitive data from 2002, what we could with a cold water system renovation to do.)

Imagine the management of these results shows, After investing half a million dollars. It is difficult to inspire confidence in the management of graphics, like 3 in Figure So much to compare electric bills.

To explain these results, you can create a graph of DC (as in Figure 4), then they could see that the post-renovation year (2002) in fact was much hotter and need more cooling and thus leads to increased utilization. These can be spin, but you still need to quantify how much you have saved, right? Accept management arm waving so long.

can you save your savings by adjusting your power bill equation for weather. Did you do, you may be shown in Figure 5, Figure 3 instead of

as local CORRECTION />

When we tried the use of in the past year using this year we have seen in Figure 3, and a disastrous project, we used to compare the equation. Use

= savings last year – this year users>

When we use air-correction, we end up with Figure 5, and the use of equation:

Savings = How much energy do we use this year – how much energy we used this year

** * * is to use this year of the first equation in which the same as the amount the energy we is earlier this year by the second equation

The next question is how do we know how much energy we would have used this year. This is done with the help of the weather-correction as indicated below.

First we select a year in electricity bills, we want to search for future use. This is usually the year before your energy efficiency program, the year before you, the new plant manager, were employed, or a selected year. In this example we would select the year of the user data before the installation of chilled water system. We call this year the base year.

As shown in Figure 6, we use simple graphical years of Weather Report (in the form of cooling degree days or heating degree days). The blue dots are the electricity bills.

Next, we find the best-fit line between use and weather. The best-fit line is the line that is shown next to all the electricity bills as in Figure 6. We can say he is the best fit line are looking for some statistical indicators (like the R2-value, and average net CVRMSE bias errors that are not covered in this primer).

The best fit line has an equation that we call the Fit Line Equation, or in this case, the baseline equation. Once we have this equation, we finished with this process of regression.

We want to what we have done:
– We diagram of a base year utility data from />
-. The best-fit line equation, which provides best represents the Fit Line, which means the base year payload The Fit Line Equation, as your plant energy use during the reference year. and there is still energy in the future (depending on the changing weather conditions) assuming no significant changes in consumption patterns of the building, such as machinery, new area or hours

accounts base year. – Best Fit Line = Fit Line />

basic equation = Fit Line Equation />

What? You take a bill a certain payroll period after the reference year. You (or your software) than the number of days and the number of heating degree days of the invoice in your base equation. Remember, the basic equation, as your building for energy consumption used in the base year. So, with new entries and the number of days the number of degree days, tells the basic equation of how much energy is used, the building this year based on usage patterns and base year this year, conditions (weather and number of days) . We call this use by the basic equation determines basic operation.

Now, to get a fair comparison of this year compared to last year, we compare: Save

= How much energy we used this year – What amount of energy we earlier this year />
or if we the terminology a bit: use

basic savings = energy – the real energy use

where baseline energy consumption calculated is the basic equation and weather the current month and the number of days and the actual use of energy, a bill of this month. The two equations are one and the same base = How much energy we used this year, and actual spending, how much energy we used this year.

CORRECTION want other variables
facility managers in the industry, you may correct for the production instead of (or more) of meteorological data. It works if a single variable that have quantified their production. For example, a car factory track number of cars produced. If your plant produces various things, such as hard drives, desktops, printers and mainframes, it is difficult for a single variable, which could arrive represent the performance of the entire system. But if your unit production of the printer of one meter or sub-meters, as the other units has been served, you can specify the number of the printer as a variable for the meter (or submeter), the printing plant.

CORRECTION WEATHER EXCEL VS. Box Software
weather correction can be performed in Excel, but it can be tedious and often not as strict as when you are done using special software. Excel will show regressions own equations of the line, and statistical indicators, such as the use represented by the curve fit. However, it is difficult to find the best balance in Excel, you can specialized in software. Excel may require that you select a single equilibrium point, and maybe then you go with different balance points, while the boxed software allows you to easily find the best fit line with different equilibrium points. Additionally, if you give your weather data at high temperatures and low average temperatures, it can be difficult to apply the right weather data with the correct accounting periods. Try it out.

correction software available local OFFICE
All utility bills head tracking software will be corrected for meteorological data. Almost all correct your own variable. The core Office programs, the energy of the CAP, Metrix, Stark Essentials and Utility Manager Pro. Here you will find information on each line.

CONCLUSION The weather varies from year to year. If the desire to use the electricity bills to show energy savings from the programs of energy management with any accuracy, it is important to correct your utility bills for weather fluctuations.


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