Supplement to Proposal to Use EDI for Meter Data

In my original proposal for transfer of end-user meter data using
ANSI-standard Electronic Data Interchange (EDI), posted to the PSWG3 Web
site on March 23, I recommended the optional availability of a subset of the
Utility Industry Group's (UIG) Implementation Guideline for EDI transaction
set 810 for transfer of some types of end-user meter data, in additional to
standard use of transaction set 867 for all types of meter data.  (The UIG
guideline for 810 states that transaction set 867 should be used instead if
interval meter readings are required.)  A revised draft of UIG's guide for
810 was released on March 9, 1998, and is available at
http://puc.paonline.com/electric/DEW/UIG.htm.

After reviewing this implementation guideline, the only "subset" that is
needed, other than usage that should be sufficiently clear as parties
implement this guideline for meter data, is to note the following about the
applicability of transaction set 810 in the context of transferring meter
data.  While transaction set 810's purpose is nominally for invoices, it can
be used in ways that do not require the "invoice" to be paid, thus allowing
an MDMA to send a data file to a UDC or ESP in 810 format for further
processing before an actual invoice is sent to another market participant.
This capability can be provided by using codes ME ("memorandum") or PR
("product") as the "transaction type code" in the EDI header section's
"beginning segment for invoice" (data element BIG07).  The data elements
used for rate information (e.g., data element SAC08, "rate", in the EDI
detail section) are optional according to the UIG implementation guide,
meaning that they can be omitted when the MDMA does not have pricing
information.  Finally, although the EDI summary section's segment TDS
("total monetary value summary") is mandatory in transaction set 810, using
a value of 0 would prevent an implication that a payment is required.

There are pros and cons on the issue of whether transaction 867 or 810 is
the best format for simple usage data.  First, in California interval
metering is required for direct access customers over 20 - 50 kW, and for
customers who want hourly prices (or ESPs who want hourly prices used in
financial settlements).  Thus, most ESPs will probably be getting hourly
meter data for at least some of their customers.  It could then add to their
cost of operation if they had to implement the 810 format to get the rest of
their meter data, when 867 is capable of handling the simpler meter data in
addition to handling interval data.  (810 could be adapted to interval meter
data, but possibly only in a rigid manner, while 867 is flexible enough to
accomodate various lengths of interval periods.)

On the other hand, some ESPs might be small and only serve customers who are
eligible for load profiling, and they might have some method other than 867
to receive load profiles.  They might have already implemented 810 for
invoicing and don't want to add the cost of additional transaction sets, or
they might find that less expensive software is available for the older,
more common 810 format than for 867.  These ESPs could then opt to receive
the 810 format from their MDMA, and operate more cost effectively.

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