AMI at Colorado Springs Utilities: a multi-service system


By Gina McCurley

Colorado Springs Utilities, in partnership with its vendor, has implemented an automated meter reading (AMR) system with an advanced metering infrastructure (AMI) network to cover its 1,300 km2 service area.

Springs Utilities is one of the first utilities in the nation to install a single wireless fixed network to collect reads from 100% of all residential and small commercial metering points consisting of three metered services, electric, gas and water. Due to the cost, complexity, and multiple functions the AMI system will provide, the project was implemented in five yearly phases starting in 2006. Currently in its fourth full year of implementation, project completion is scheduled for the Spring of 2010.

The electric system provides retail service to metropolitan Colorado Springs and surrounding areas through approximately 210,000 meters. The gas system operates a local distribution system supplying natural gas to approximately 187,500 accounts and finally, the water system serves water to the service area population through approximately 135,500 meters. All of the metering end-points, which currently total 533,000, will be converted to the AMI system.

The AMI system is key to supporting Springs Utilities’ smart grid vision, which incorporates all three metered services and provides focus on delaying new infrastructure, improving the environment, and reducing customer rate impacts.

Although planning for an AMR project had been in the works for over 10 years, it had not received serious consideration until 2003. At that time, the utility was piloting several mobile data metering solutions and had even launched a load cycling programme implemented with wireless technology. With many observations derived from such pilot projects, as well as some significant lessons learned, the utility committed to fully analysing automated meter reading potential in late 2003.

The following year, 2004, was largely a planning year. A small team of employees, including metering experts, engineers, financial, procurement and database analysts, was formed with the intent of evaluating the feasibility of an automated meter reading solution. By the end of the year, the combined efforts had produced a detailed business case, including financial projections and business impact analysis, Request for Information (RFI) responses, as well as a Request for Proposals (RFP) seeking technology partners for the project. Corporate approval (and accompanying funding) was granted to move forward with the project. The RFP was released to vendors in early 2005 with the expectation that multiple systems and vendors would be required to cover the entire range of topologies and the multiple services. A multi-vendor approach was also anticipated due to the fact that Springs Utilities was not the franchised utility for all three services in all areas. The service territory consisted of gas only areas, electric and water only areas, and areas of all three services.

The RFP received a tremendous response from the industry, and ultimately the field of prospective vendors/technologies was narrowed down to a select few. Landis+Gyr (formally Cellnet Technologies) was eventually chosen to provide a single wireless fixed network for the entire meter population. A contract was signed in late 2005, with the goal to begin deploying the communications network and the first meter end-points by the end of the year.

Springs Utilities began installing the first end-points in three target areas beginning in December 2005. The target areas were selected due to their geographically challenging attributes (one area is located up a winding mountain pass) or more expensive cost to read meters due to only one service being provided. Once the technology and field installation processes were proven in these initial target areas, deployment across the entire service area began in May 2006.

Currently, Springs Utilities has installed and is using for billing approximately 496,000 AMR end-points as follows:

  • Electric: 197,335 (94% of all electric meters)
  • Gas: 175,687 (93% of all gas meters)
  • Water: 122,818 (91% of all water meters)
  • Total: 495,840 (93% of entire meter population)

The meter end-points are supported by a two-way mesh network of radio enabled concentrators, which primarily allow one-way meter reads to be passed among and between them until they reach one of the “take-out points.” The take-out points connect to Springs Utilities’ fibre backbone and then connect to telecommunication circuits needed to support communications to Landis+Gyr’s Network Operation Center (NOC), located in Lenexa, Kansas (see Figure). The mesh network consists of approximately 850 concentrators and is supported by eight take-out points. As a two-way fixed wireless communication network, the mesh network serves as a platform to support not only the one-way endpoints, but also two-way devices to support time-of-use (TOU), demand resets, and remote electric connect/ disconnect meters.

Colorado AMI

The installation rollout plan of Springs Utilities’ AMI communications network can be characterised as atypical. The 21 bill cycle areas are arranged geographically with simultaneous implementation across all bill cycle areas. Therefore, the concentrators were installed throughout the service area using a “spiral” approach, rather than the geographical approach typically utilised by other utilities. This approach has allowed greater consistency in scheduling and balancing the meter reading workforce as end-points are incrementally installed over the life of the project, yet spread more evenly over the entire service area. The spiral approach also supports Springs Utilities’ goal of including new growth areas on the front-end of the project, thus allowing installation of AMR meter sets during new construction, eliminating the need for a return visit for AMR retrofits.

For the AMI endpoint installations, each service had a different implementation philosophy and challenge. For electric, all mechanical meters were replaced with solid state one-way meters which included integrated radio modules. The electric meter installations also included the selective deployment of two-way solid state meters allowing for future advanced features and functionality. For gas, the existing meter population was either field retrofitted with one-way modules or replaced with new meters which included a factory installed module, if the current meter could not be retrofitted. Water installations were the most challenging since 90% of the water meters are installed indoors and, therefore, required remote one-way modules to be installed on the outside of homes and hardwired to the meters. The other 10% were pit installations with the one-way modules mounted in the pit covers.

On each of the 21 bill cycle days every month, Springs Utilities receives a billing upload file from Landis+Gyr containing reads for each of the meters requested. This billing interface is just one of many that support the project. The monthly read performance of the system has not dipped below 98%, with the average successful billing read performance currently holding steady at 99.5% each month. The system also delivers daily reads for all automated meters with a typical daily delivery performance of 98%.

Springs Utilities expects to realise significant benefits from completion of the AMR project, primarily in the areas of improved customer service, cost savings and employee safety. Customers will see several positive impacts of AMR including improved billing accuracy and fewer visits to their premises. Full implementation of the AMR system will also significantly reduce expenses related to off-cycle and monthly billing reads.

AMI will open the utility to other opportunities such as custom billing, TOU pricing, energy management, the ability to provide customers with energy and water usage profiles, outage notification, real time bill complaint resolution, and load research to improve system design and pricing/tariff flexibility.

The AMI system installed can support the following functions:

  • Retrieval of periodic billing data
  • More accurate bills due to fewer estimations
  • Electric outage notification
  • Meter tampering notification
  • Meter diagnostic information
  • More frequent collection of billing or consumption attributes
  • Data collection for use in load research and distribution system design.

The AMI system will also provide a communications platform that can support the following:

  • Energy management systems with communications interface from the utility
  • Mandatory or voluntary load cycling programs 
  • Expanded use of TOU, critical peak pricing or other more complex rate structures, potentially without using a more sophisticated and expensive meter
  • The smart grid vision.

Being a multi-service utility, Springs Utilities’ smart grid vision needed to encompass all services and not just focus on the electric side of our business.

The smart grid vision is as follows: “Springs Utilities’ interactive utility system, Multi-Service Smart Grid, benefits customers by giving them real-time access and control over their usage of natural gas, electric and water resources. The system also enables Springs Utilities to more effectively and reliably deliver utility services to customers, delaying or avoiding the need for new infrastructure, benefiting the environment and reducing customer rate impacts.”

The smart grid drivers are to:

  • Deliver customer value
  • Meet evolving energy and water requirements
  • Improve operational efficiencies.

There are four current and future components of the evolving multi-service smart grid.

The system consists of the Landis+Gyr GridStream mesh wireless fixed network supporting both one-way and two-way smart meter endpoints and the MV-90 multi-vendor data collection system for the largest commercial and industrial customers. The future will consist of the continued selective deployment of two-way smart meters with advanced features as remote electric connect/disconnect, TOU with demand reset, and Zigbee gateways.

Distribution automation
Springs Utilities partnered with General Electric to install an Outage Management System (OMS), PowerOn, to help respond quicker to power outages and provide customers with timely restoration estimates. The OMS will expedite the restoration process by identifying outage locations and immediately dispatching crews. The future will provide more monitoring and automation closer to the consumer’s home by capitalising on the AMI system network capabilities.

Customer energy management
Through the deployed air conditioning load cycling programme, residential customers on the programme can benefit from reduced loads and have the benefit of adjusting their central air conditioning thermostat via the internet. Commercial customers on the Energy Information System programme can view their consumption data up to the previous day, providing them with consumption data up to the day before. The future will provide residential customers greater access to the daily and hourly consumption data via the internet with possible in-home displays, and additional end-use control devices.

Distributed and renewable generation
Springs Utilities is helping customers establish hydro, wind, solar, and geothermal systems for added efficiency, cost savings, and environmental protection.

With completion of the AMI system at Colorado Springs Utilities and the implementation of smart meters, the foundation for smart grid initiatives has been laid. The company now has the ability to monitor, control and better manage its utility systems to provide operational, financial, and environmental benefits.