Tampa Electric has been actively involved in demand-side management with its residential and commercial customers since the early 1980s. Its demand-side management (DSM) programs include free home energy audits; heating and cooling equipment rebates; insulation rebates; incentives for sealing heating, ventilation and air-conditioning duct systems; load management; critical peak pricing and more.
Tampa Electric has performed more than 426,000 free energy audits and paid almost 444,500 rebates to customers who have participated in its DSM programs. This accounts for about as much electricity as it takes to serve 896,000 homes for a year.
Load Control History
Tampa Electric’s legacy residential direct-load-control program was initiated in 1982. In 2005, however, the Florida Public Service Commission (FPSC) ruled the program to be no longer cost-effective, thereby closing it to new business. Subsequent to that decision, the utility began to explore other options for residential load control and, ultimately, initiated Energy Planner, a critical peak-pricing program. With utilities across the industry beginning to use critical peak-pricing resources to reduce peak demand and provide stability to the electric grid, it became apparent Tampa Electric was embarking on a viable path by offering its customers the ability to have direct control over their energy usage.
The goal of the Energy Planner program was to create an interactive energy management system to give residential customers control over their energy purchases while providing Tampa Electric an alternative for load reduction during times of system peak demand. Using intelligent devices such as programmable thermostats, customers would be able to control the operation of their central heating and cooling systems, electric water heaters and pool pumps to take advantage of lower electricity rates that could lead to energy savings and reduced electric bills.
The utility determined its Energy Planner program would offer four rate tiers for electricity: low, medium, high and critical. The first three rate tiers (low, medium and high) were clearly defined by a tariff and corresponded to seasonal increases and decreases of system load shapes and correspondingly higher and lower costs of energy production. The fourth rate tier, or critical period, would be available for use by Tampa Electric at the discretion of its system operator and typically would occur less than 1% of the annual total of 8,760 hours. Tampa Electric’s critical peak-pricing tier would be activated only during times of extremely high demand, when Tampa Electric or other generating units in Florida experienced difficulty producing enough electricity to meet the level of customer demand.
The total price customers participating in Energy Planner would pay for electricity would be based on their kilowatt-hour usage, the time of day of that usage and the day of the week. Overall, the program would provide customers a rate lower than the standard residential rate approximately 87% of the time, including all hours on weekends and major holidays. During both the high- and critical-tier periods, customers would be strongly encouraged to reduce their energy usage to save on electricity costs.
Energy Planner Pilot
Tampa Electric initiated Energy Planner as a pilot program and used a sample group of approximately 250 participants comprised of former direct-load-control customers and new customers who had never used any type of energy management activity. For load-reduction and energy-savings analyses, the utility used a control group with a customer profile similar to that of the sample group. The pilot period was held from September 2005 through February 2007.
Through the pilot program, Tampa Electric had the opportunity to monitor participants and evaluate their consumption and response to the pricing tiers and critical peak-pricing events. The pilot also helped the utility to identify best practices for strategies to implement Energy Planner. Additionally, Tampa Electric was able to determine both the program’s cost-effectiveness, in accordance with FPSC standards, and how best to measure customer satisfaction with the technology and overall program focus.
Promising Results
At the end of the pilot period, the analyses and findings proved promising. Customers on Energy Planner consumed approximately 6.1% less energy on an annual basis. In addition, for a winter critical peak-pricing event — assuming a temperature of 31°F (-0.6°C) — the average demand reduction was 3.1 kW. For a summer critical peak-pricing event — assuming a temperature of 92°F (33°C) — the average demand reduction was 2.4 kW. Based on these results, Tampa Electric filed for permanent program status with the FPSC, which granted approval for the utility to offer Energy Planner as a viable conservation and load-reduction program to its residential customers.
Communications
Initially, the technology used to deliver Energy Planner required customers to have a landline phone for communication of critical information such as billing data, customer behavior during critical peak-pricing events and schedule changes that may impact participating appliances. In addition, a bulky gateway used to support the communication was mounted on top of the customer’s pulse-initiating meter. As a result, space for the equipment precluded customer participation in locations where meters were banked or mounted on poles. This generally eliminated customers living in multifamily and manufactured housing.
Additionally, Tampa Electric found it increasingly difficult to meet customer participation goals as customers migrated from landline phones to cell phones. The utility came to the realization it was time for a replacement technology that would encourage program growth while securing critical billing data in the absence of an automated metering infrastructure (AMI).
Technology Upgrade
In October 2011, Tampa Electric embarked on a technology upgrade with its vendor Comverge. The Comverge SmartPrice intelligent dynamic pricing solution adds new capabilities to Energy Planner that enable Tampa Electric to offer Energy Planner to nearly all of its residential customers. The bulky meter-mounted gateway was replaced with a ZigBee-enabled meter for data collection, allowing the utility to offer Energy Planner to a broader range of housing types.
IntelliSOURCE, the Comverge demand-response management system that is part of SmartPrice, enables Tampa Electric to communicate with ZigBee-enabled devices such as smart thermostats and digital control units in the home area network to automate control of appliances with large energy requirements such as central heating and air-conditioning systems, electric water heaters and pool pumps. A ZigBee-enabled Digi gateway collects metering information to calculate electricity bills and sends the data to Tampa Electric through the customer’s Internet or broadband service. Using the vendor’s billing module, the data goes to a customer information system billing interface for Energy Planner participants.
The ZigBee solution also provides customers with a Web portal to program their participating appliances to operate during off-peak periods so they are better able to manage their electric savings.
An additional feature of the portal includes graphs that allow customers to review their appliance run times and patterns to make it easier to control the temperature setting of their homes. Customers also receive useful information such as quick-tip guides for programming their thermostats and navigating through the web portal, as well as reminders to change the filters on their central heating and air-conditioning systems.
Win-Win
Since its implementation, Tampa Electric’s Energy Planner program has consistently delivered measurable DSM gains, including enabling the utility to execute a critical peak-pricing rate within minutes. Over time, the utility’s load research analysis results revealed an average load shed of 3.1 kW per customer during the winter peak and 2.0 kW per customer during the summer peak. This not only helps Tampa Electric to balance supply and demand but also increases the accuracy of its planning efforts.
In addition, Energy Planner participants enjoy greater control over their energy costs and average annual savings of 8% to 10% on their electricity bills. In periodic surveys, customers have consistently identified the benefits of having more control of their electricity usage and annual savings. The customers realize savings in two ways. First is the actual electricity they conserve because of the added knowledge about how much energy various devices in their homes consume. The second way they save electricity is by using certain appliances during off-peak times when the rates are lower than the standard residential rate.
A Bright Future
Looking ahead, Tampa Electric is optimistic about the latest technology upgrade, which allows the utility to deploy a price-response program without AMI. Marking a departure from the traditional rule book, this advancement will do more to help Tampa Electric achieve its DSM goals, established by the FPSC. Furthermore, the technology positions the utility nicely for a surgical deployment of Energy Planner customers in support of a future AMI project.
Drema Hughes ([email protected]) became the program manager of Tampa Electric’s Energy Planner program when it launched in 2005. Along with her team, Hughes is currently deploying a technology upgrade that will increase customer participation in Energy Planner and allow Tampa Electric to collect critical billing data through a home area network without the need for automated metering infrastructure. Hughes joined Tampa Electric with its customer services team in 1982. From there, she gained experience in energy management services, meter operations, demand-side management, load management and load research.
Companies mentioned:
Comverge| www.comverge.com
Digi| www.digi.com
Florida PSC| www.floridapsc.com
Tampa Electric| tampaelectric.com
ZigBee| www.zigbee.org
