Welcome to the heart of Snapmeter, the best interval data browser in the world (if we do say so ourselves)!
This is where you can visualize your building’s energy use over time, overlay it with environmental factors such as outside air temperature, and spot anomalous use patterns.
The chart initially shows the most recent seven days of data available. Depending on whether you are viewing data for an individual meter, a building, or a meter group, the chart will display one or more load curves at a time.
For the most part, the chart behaves the same whether you are viewing a single meter or multiple meters. However, the following data elements are available for individual meters only:
- Bill periods (indicated by vertical green lines)
- Alert beacons (pulsing orange circles)
- Schedule data, such as start-up and shutdown time
The load curve graph
The load curve graph shows your interval data with the vertical Y-axis for kW and the horizontal X-axis for time. Trace your cursor along the graph for details on individual data points.
The historical load curve summary
Directly below the chart, you will see a smaller load curve showing the complete history of energy data available for a meter or meter group. To jump to a particular time range, simply click and drag a selection box along the smaller load curve. The main chart will update to the data range selected. You can also click on the selected date range and drag it left or right.
The historical load curve summary is the quickest way to spot the biggest spikes in demand, which sometimes correspond to billing errors.
Showing temperature data on the graph
Snapmeter analyzes your building’s relationship with weather in a handful of ways, but a popular first take is simply charting temperature alongside your energy interval data. To do this, click the Temperature button located above the load curve graph.
A secondary, right-hand Y-axis is used to indicate temperature values. Or you can position your cursor directly over the chart to see details about individual data points.
Displaying use vs expectation analytics on the graph
Snapmeter learns from your building’s historical energy use and related weather data to calculate an expected load curve for each of the meters in your Snapmeter account.
Simply click on the Expected button located above the load curve graph. Demand below expectation will be shaded in blue, while demand above expectation will be shaded in orange. Mouse over the graph for details.
Expected and Schedule analytics shading is not available for load curve graphs showing greater than seven days of data: the two buttons will not be clickable until you press the 7 days button or manually select a narrower date range.
Displaying scheduling analytics on the graph
To display schedule data on the load curve, click the Schedule button. Four types of analytics are overlaid on the load chart:
–On/off hours: Snapmeter automatically calculates the days and the times of day when your meter is typically “on” or “off.” For a normal office building, the off pattern is generally overnight and on the weekends, and will be displayed on the load curve with a light gray shading. This makes it easy to spot energy use when otherwise the meter shouldn’t be using very much at all.
–Startup and shutdown: By looking closely at changes in your meter’s load curve, Snapmeter can make an accurate estimate of when it starts up and when it shuts down. Startup and shutdown times are highlighted in orange.
–Baseload: The baseload line, colored in red, displays the typical minimum level reached by the meter during off hours, such as nights and weekends. The baseload level will change over time, as Snapmeter’s model of your meter’s energy use learns and updates to changes in the building over time.
–Use above baseload: Snapmeter combines its understanding of your meter’s off hours time with its expected baseload level to automatically highlight energy use above baseload, shaded in light red. Total excess off hours use is calculated, per calendar day, in the summary data below the load curve at the bottom of the page.
Displaying multiple meters on the graph
Available for Buildings and Groups, the Show meters button will trace on the graph constituent meter data lines, each with their own color. As you mouse over the graph, the additional info box will show each meter’s reading at that interval.
Summary table of meter data analytics
For individual meters, energy use data is summarized in a table at the bottom of the page:
–Use (kWh): This is the total amount of kWh electricity used throughout the calendar day. The percentage figure reported in parenthesis shows the difference between actual and expected.
–Demand peak (kW): This is the high water mark for peak demand set during the calendar day. The variance figure in parenthesis compares the actual peak to the expected peak, and the two don’t have to line up in time.
–Excess off hours use (kWh): This quantifies, in kWh, all of the energy use that’s shaded in dark red when you click on Schedule analytics: the area between baseload and actual energy use during off hours.
–Start time: Using your meter’s data and some math, this is the time when Snapmeter estimates the meter started up for the day. If you turn on the Schedule analytics, the start time interval can be spotted at the beginning of the yellow shaded region.
–Shutdown time: Just like start time, but towards the end of the day! The analytics shading is easier to see if you zoom in on one calendar day.