Smart Metering in Florida
Despite the millions of dollars invested in Automated Meter Reading (AMR), today less than 5% of the installed base of electricity meters resides on fixed network AMR!
However, the winds of change are blowing. Electric utilities planning to compete in today’s deregulated and re-regulated environments require higher performance AMR and power quality and power reliability (PQ/R) reporting solutions at lower costs. This is a challenge for the industry and for the AMR and PQ/R vendors who deliver these products.
The barrier to broadly accessible AMR and PQ/R has been price/performance of available technology options. Many technology solutions can deliver reliable AMR and PQ/R at a high cost. The determining factors for cost effectiveness relate to the efficient use of the transport layer/s or additional value achieved through proficient management of data transactions.
Under these conditions, the best solution uses public wide area networks for data transmission. This provides a cost-effective solution for high value data such as C&I metering, power quality/power reliability and utility automation.
This article describes the process we have gone though at Florida Power & Light (FPL) to implement a wireless AMR and PQ/R system.
A smart meter project team was established in the summer of 1998. The team’s mission was to investigate options for the replacement of FPL’s ageing solid state data recorders (SSDRs), while possibly pro-viding for advanced power quality monitoring and reporting capability. Representatives from all affected functional areas were invited to participate, although most of the team’s activities were conducted by a core group of about five members. The rest served as advisors and reviewers.
The team quickly decided to focus on metering/PQ devices that:
• Build on existing metering technology.
• Add power quality functionality to the meter, as opposed to using a meter with a PQ box to one side.
• Include a communications modem ‘under the glass’, as opposed to a modem box to one side.
• Are able to communicate during power outages.
TELEPHONE VERSUS WIRELESS COMMUNICATIONS
The team was interested in investigating opportunities presented by wireless techno-logies. The present mix of FPL SSDRs uses approximately 1500 telephone lines, mostly dedicated, to collect billing data on a daily or weekly basis. Meter readers equipped with handheld electronic meter reading devices interrogate the remaining 2500 or so SSDRs manually each month.
Wireless technologies had been investigated in the past, with a pretty close look at analogue, cellular and CDPD systems. However, FPL had stayed with telephone lines, for the following reasons:
• Initial cost of the wireless equipment was high – often $500-$1000 more than the cost of a telephone modem.
• Wireless modem ‘under glass’ was not available, which added another $100-$200 to install the modem box to the side.
• On-going airtime costs were higher than the cost of telephone lines.
• Lack of coverage was an issue – major holes existed in FPL’s service territory.
In order to take a look at the whole wireless situation, the team commissioned FPL’s information management R&D group to investigate a dozen or more wireless technologies. Public and private networks were evaluated, and by mid autumn 1998 several conclusions had been reached.
• Initial cost of the wireless equipment was high – often $400-$800 more than the cost of a telephone modem.
• Wireless modem ‘under glass’ was not available, thereby adding another $100-$200 to install the modem box to the side.
• On-going airtime costs ran anywhere from about the same to approximately half the cost of telephone lines.
• Lack of coverage was an issue – large holes existed in FPL’s service territory.
Their findings sounded familiar – better, but not quite good enough to justify the change from telephone lines.
In order to standardise the assumptions given, the team established functional criteria to calculate airtime (see table on page 29).
At the end of 1998, the team developed a set of specifications and a Request for Proposal (RFP) and sent the RFP out to potential suppliers – those in the marketplace with utility grade electronic meters and those with associated power quality devices.
Proposals were received and evaluated in the first quarter of 1999. FPL’s award was imminent when we were made aware of a project underway at Duke Power Company, which was similar to ours. Duke’s project looked so promising that we decided to put our decision on hold while we reviewed their findings. In particular, the Duke project used wireless communications under the glass – just what we were looking for.
Monthly Communications per Meter
|Type||Frequency||Time of Day||Amount of Information|
|Load Profile Data Collection||Daily||Typically at 2:00 AM||24 hours of one channel of 15 minute load profile data – Data content is approximately 144 Bytes|
|Power Quality Events||8 times per month||Random||Power Quality Notification – Short Message|
|Ad Hoc Queries||6 times per month||Typically 8:00 AM to 5:00 PM||Meter Reading – Short Message|
Duke Power was in the middle of an evaluation of smart meters using SkyTel two-way paging as the communications medium. For this evaluation, Duke had selected Siemens Power T&D as its meter provider and system integrator. CEPG (now Smart Synch) was selected as the wireless equipment provider. Duke, Siemens, SmartSynch and SkyTel established a relationship that allowed for:
• Utility metering functions to be provided by the Siemens S4 Smart Meter.
• A wireless communications board to be built by SmartSynch under the glass of the S4 meter.
• Wireless communications to be provided by SkyTel.
• SmartSynch to provide their M32 Master Station to collect and process the metering data.
The FPL team had several discussions with Duke Power; their programme appeared promising in terms of meeting FPL’s needs. Many interactions with the Siemens/SmartSynch/SkyTel team followed. FPL’s power quality monitoring needs were addressed; existing functionality within the S4 was utilised, and new functionality was developed for the SmartSynch communications board. A contract was signed and the first PQ smart meters were delivered early in 2000.
Smart meters with wireless communications are also able to satisfy a need of FPL’s EDMpro.com energy data management (EDM) business. EDM is a utility bill processing, bill auditing, bill payment, analysis and services business aimed at national accounts. The emphasis on using data to find savings for customers is fundamental to the services offered.
Hourly load profile data on customer usage patterns is vital for thorough rate and efficiency analysis. Because EDMpro.com customers are located all over the country, it is desirable to have a drop-in load profile meter solution that is national in scope. The Siemens/SmartSynch/SkyTel Smart Meter gets us there.
WIRELESS COVERAGE VERIFICATION
Our investigations into wireless communications revealed that there were striking differences in the coverage provided in FPL’s service territory by each of the different systems. Nobody even claimed to offer 100% coverage! The FPL information technology R&D group was again commissioned to help validate the wireless technology.
For this evaluation, SkyTel was given a list of addresses for the 4000 existing FPL SSDR sites. SkyTel estimated that between 80% and 85% of our locations should be within good two-way coverage areas. Further, they believed we should be able to achieve good coverage at approximately 90% of our sites within a year, based on their expected infrastructure build-outs.
This was more than acceptable, but as a conservative utility, we naturally responded: “Show us”. FPL retained a wireless consultant, who with all parties (SkyTel, SmartSynch, Siemens, and FPL) developed a methodology and plan for actual field validation of SkyTel’s coverage estimate.
The plan included the following elements:
• Approximately 65 locations, spread throughout FPL’s service territory.
• Locations in good, poor and questionable areas, as determined by the SkyTel maps.
• Higher weighting given to questionable coverage areas.
• Field equipment closely resembling the hardware to be deployed in a full rollout.
• Measurement of received signal strengths.
• Sending of many messages from the meter to SkyTel.
• Mix of short, medium, and long messages.
• Sent over 10-15 minute period per location.
• Capturing the specific GPS co-ordinate of the site.
• Picture of each site and test equipment in place.
• Capturing the number of base receiver hits by each message.
• Formal documentation of all the above.
The testing revealed that SkyTel’s original estimates were valid. The field measurements confirmed that we had a sound communications infrastructure, and should proceed.
The R&D group also provided an evaluation of Skytel’s communication technology. SkyTel’s Reflex Telemetry Service was a good fit for our needs. The ability to send messages of different lengths was viewed as quite attractive in making effective use of airtime.
GOALS OF THE SMART METER PILOT
• Test technology applications.
• Compare data to that obtained through FPL’s MV-90 billing system.
• Generate revenue for FPL through enhanced service offerings.
• Test and demonstrate all the PQ features.
• Test customer acceptance of these services.
• Verify the ability to collect Load Profile (LP) metering data via Skytel.
• Verify that the LP data matches the existing data.
• Verify that the LP data can be passed to billing.
• Verify that the PQ operates as intended.
• Upon completion of the pilot, immediately move towards full implementation of the remaining 4000 SSDRs.
• Investigate opportunities to expand into commercial/industrial load control.
FPL is now in the middle of a pilot to demonstrate the benefits of smart meters with power quality monitoring. The pilot also provides for the implementation and testing of interfaces to other FPL systems.
Florida Power & Light is well on the way to implementing wireless AMR and PQ/R. We are working with our partners in technology to get it right and get the system to our exact specifications. The process has been arduous, but the results will be well worth the effort in terms of quality of service and sheer survivability in a deregulated world.