It's time to improve on a technique (first seen in the December 2001 ES) for viewing electric load profiles as a 3-D "landscape" using Microsoft Excel. The "old" way required some rotating and zooming around to determine date and time of an anomaly. Excel can, however, produce a 3-D "loaf" of sequenced load profiles (Figure 1) that are sensitive to cursor contact that reveals exact day, time, day of the week, and load at any point. To read the 3-D landscaping article, go to: www.esmagazine.com/es/cda/articleinformation/features/bnp__features__item/0,2503,70990,00.html.

Making The Magic Happen

Start with a month of interval data from your utility interval meter (typical for accounts with peak demands of 1,000 kW or more) or EMS. For a sample file, e-mail me at Lindsay Audin, CEM, CEP .

Then:

  • Highlight the data cells to be charted and click on the chart wizard. Under "chart type," choose "area" and the "chart subtype" in the lower left hand corner (called "area with a 3- D visual effect").
  • Click next to see the "chart source data" box. Under "series in:" select "rows."
  • Click next to see the "chart options" box. Choose the "legend" tab and uncheck "show legend" (you can always retrieve it later). Click on the "titles" tab and fill in the fields. The data on the X and Y axes (time and day/date) are self-explanatory; titles are unnecessary. Label the Z axis as "kW/4" to remind yourself later to multiply any data taken from it by 4. Why? Because most interval data is actually kWh consumption during a quarter-hour period. To translate that into average kW demand during that quarter hour, multiply by 4.
  • Click next to see the "chart location" box. Select "as object in:" Its field may already say "Sheet 1," which is the worksheet holding the interval data. Click finish.
  • The chart then appears superimposed on the data table. To enlarge, place your cursor on a corner of its border and stretch it diagonally.


Making The Chart Easier To Read

Now, for a more pleasant experience working with this information:

  • Move your cursor to the top of any "slice" until you see a box showing "series," "point," and "value." Right click to see a drop down box, and choose "format data series."
  • Choose the "options" tab. Increase the "chart depth" number to 500 (or more) and see the chart rapidly gain depth, making it easier to differentiate the slices. Do the same for "gap depth" to make the slices thinner.
  • To change a slice's color, choose the "patterns" tab in the "format data series" box.
  • To further separate the slices, click on the "chart" command (not the chart wizard) and choose "3-D view." Raise the "perspective" value to 60 (or more) and click "OK." Rotate the chart by moving the cursor onto a corner until the word "corner" appears. Holding down your left mouse button, move the cursor to the left or right and release the mouse button to see your chart in a new orientation. To make changes in 5-degree increments, click the arrows in the "elevation" and "rotation" commands in the "3-D view" box.
  • To make the slices stand out further, change the color of the walls. Move your cursor across the wall, when "walls" appears, right click to see "format walls." Choose a different color (a light beige is good for creating contrast).
  • To look closer at a slice, click on it and see its row of data cells bordered in blue. Click on the row number to highlight that data. Click on the chart wizard, choose a "line" chart type and one of the 2-D versions of chart subtype. At Step 2 ("chart source data"), the chosen slice appears in 2-D.
ES