We have just merged commits to the xeto and haystack-defs repositories that help improve elec metering for Project Haystack.

Thanks to Keith Bishop for reporting Xeto elec specs used the incorrect units for power factor. Also, thanks to Stephen Frank and members of the Labs working group for their contributions.

In the coming months we hope to stabilize the Xeto API for elec point specs. So now is still a great time for more feedback!

Hi Rick/Community,

I have a few questions:

1. What is the difference in intended use cases between the ph.points.elec/sensor.xeto & ph.points/elec.xeto libraries? It seems there are similar concepts within both.
2. What is the distinction betwen how the demand and power tags should be used? As related to the SkySpark v3.1.11 Build Notes and Project Haystack Demand definition.
3. As an example, how should a point that will carry the monthly peak demand values be tagged? This data may come from billing data imports, or calculated from trended power readings.

Please let me know if these questions should be posted elswhere.

Thanks, Sade

Hi Sade,

What is the difference in intended use cases between the ph.points.elec/sensor.xeto & ph.points/elec.xeto libraries? It seems there are similar concepts within both.

We placed what we felt were the most common electrical point specs into the ph.points library. For example, these specs include total energy and demand.

The remaining specs have been placed into the ph.points.elec library for more advanced electric power monitoring applications.

What is the distinction betwen how the demand and power tags should be used? As related to the SkySpark v3.1.11 Build Notes and Project Haystack Demand definition.

Please refer to the definitions for power and demand in the docs here.

As an example, how should a point that will carry the monthly peak demand values be tagged? This data may come from billing data imports, or calculated from trended power readings.

Assuming electricity is only in the import direction, you might want to use the Xeto spec ElecTotalImportAcActiveDemandSensor defined in the ph.points library for interval data. Please note we will likely soon be modifying this spec to clarify it is for power demand and not current demand. This change will also change how instantaneous power measurements are queried.

I am not sure what the best practice according to Project Haystack would be for modeling peak demand presented by the electric utility in a bill. Also, I am curious what others in the community think about this topic.

-Rick