Frequently asked questions about the grid

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Electric grid: Then and now

Did you know?

In 1930, only 25% of America was electrified, but, with help from SRP, 80% of Valley homes had electric service.

The grid refers to the interconnected networks that carry electricity from the power facilities where it is generated to the consumers who use it. It is made up of power generating stations, transmission lines, substations, transformers, and other equipment that deliver electricity to homes, businesses and industries.

The United States actually has three major grids, the Western Interconnection, the Eastern Interconnection and the Electric Reliability Council of Texas. These are often referred to as the Western System, the Eastern System and the Texas System. Arizona belongs to the Western System. For simplicity's sake, information on these pages will refer to the three grids combined as a single grid.

The grid is transforming into a more interactive system by incorporating a class of technology that uses computer-based remote control and automation applications to enhance utility electricity delivery. The application of these leading-edge technologies and tools has the potential to make the grid operate more reliably and efficiently, and to benefit consumers. This enhanced, more efficient grid features two-way communication technology and computer processing that has been evolving for decades.

The need for an updated grid

While today's power grid is one of the most impressive accomplishments of the past century, it has limits. Until recently, the grid had changed little since it was first pieced together in the early 1900s.

For many decades, the grid has operated in a one-directional model where large, central power-generating facilities produce energy and deliver it to customers. There's been limited information for the utility about the real-time status of the grid and power use.

Because of population growth, bigger houses, more energy-hungry electronics and appliances, and the growth of high-tech industries and processes, electric peak demand has outpaced transmission system growth every year since 1982. This has burdened the grid – three of the five largest blackouts of the past 40 years have occurred since 1996.

While the grid continues to meet our growing demand for electricity – with an average annual system reliability of 99.97% in the United States– the system's aging infrastructure must grow and be updated to meet future demands.

Another reason the grid is changing is the rapid growth and use of distributed energy resources. These include small natural gas-fueled generators, combined heat and power "co-generation" plants, solar panels on rooftops and in larger arrays, and wind turbines. With distributed generation, power flows in two directions – when consumers produce more than they can use and power flows back into the grid for resale.

This change has the potential to alter the utility grid model, especially in Arizona, where solar panel use in residences and in larger arrays is growing and should continue to flourish.

Did you know?

Electricity on a utility scale can't be stored. It must be produced at the exact instant it is needed.

It's not a matter of "bigger is better." The grid as previously designed was not equipped to handle the on-demand needs of our digital economy, when even a momentary interruption of power can affect the country's banking, communications, transportation and security systems.

The traditional grid was not designed for efficiently absorbing power from distributed energy resources like rooftop solar, or from utility-scale renewable sources such as wind and solar. If the wind suddenly calms, or clouds cover the sky over a solar array, hundreds of megawatts could become unavailable within seconds.

Improvements to today's grid are allowing more of these intermittent sources of power into the system, and will allow more distributed generation from individual sources.

The Electric Power Research Institute estimates that by 2020 an enhanced, updated grid could reduce the cost of power interruptions by 75%, saving the United States economy about $150 billion a year. The EPRI study was published in 2011.

Benefits of the new grid

Two-way communications and information-gathering will mean less guessing and a clearer representation of what's happening and where it's happening on the power system. The power grid is changing from a one-way channel to a two-way network, resulting in more information at different junctures.

Chief among the benefits will be increased reliability. As technology is deployed in the field it improves the ability to isolate outages, minimize the number of customers impacted, identify potential hazards and speed restoration efforts.

An example of better information-gathering is installing monitors on critical parts of the system to track performance and gain early warning signals of potential equipment failure. This not only helps identify possible reliability issues, but also detects potential hazardous situations that could impact the safety of our customers, the public and our employees.

Yes. The promise of improved, updated grid technology means the consumer can become a major participant in the electric power system. Grid upgrades will give consumers more resources to make more informed energy decisions.

A yearlong U.S. Department of Energy study showed that, as a result of grid improvements, consumers were able to lower overall electric consumption 10% and peak consumption 15% — showing that grid technology investment does reap dividends.

The challenge today: about 39% of all CO2 emissions in the United States come from the power generation sector and America spends more than $200,000 per minute on foreign oil. We must lower our carbon footprint.

With improvements and updated technology, the newer version of the grid can reduce our dependence on fossil fuels and lower our CO2 emissions by:

  • Allowing more renewables, such as wind and solar PV, to be easily integrated into the grid
  • Allowing energy resources like cogeneration plants, where process heat is used to generate electricity, to be integrated into the grid
  • Increasing the efficiency of the delivery of electricity – enabling us to do more, with less, maximizing the use of limited natural resources
  • Empowering residential and business consumers to make smarter energy choices by providing them with real-time information about their energy use
  • Preparing the grid to integrate and optimize plug-in electric vehicles.

Yes. For example, as SRP has implemented certain updated grid technologies, we have decreased the carbon footprint of our business.

We're driving fewer miles because we can check on system operations remotely; we don't have to send out an employee in a service vehicle all the time. Consequently we're saving about 210,000 gallons of fuel annually. We also have eliminated about 1,867 metric tons of greenhouse gas emissions from vehicles — equal to 4,342 barrels of oil consumed or the annual gas emissions from 366 passenger vehicles or the energy use of 162 homes in a single year.

The grid technology we have deployed, plus what we plan to implement, will significantly improve our response to power outages. In some cases, the new equipment can quickly detect, identify and isolate electric system troubles, and restore service quickly to as many customers possible.

And since the updated grid components we've installed on the electric system in many neighborhoods is capable of two-way conversation with computer systems back at SRP, we already know more about outages than we knew just a few years ago. This helps us respond faster to restore your service.

For severe monsoon storms, digital grid technology will be extremely valuable to isolate specific areas where outages have occurred. We will be able to restore service via alternate feeds and pinpoint outage causes for quicker repair for remaining customers out of service.

According to recent work done by the Electric Power Research Institute, power grid connectivity provides five primary benefits to consumers:

  • Reliability – The grid is a reliable source of high-quality power, and is a crucial balancing resource available to offset variable and uncertain output from distributed resources such as solar or wind power. Through instantaneously balancing supply and demand, the evolving grid provides electricity at a consistent frequency, which allows appliances and motors to operate efficiently and correctly.
  • Startup power – The grid provides instantaneous power for appliances and equipment such as air conditioners that require a strong flow of current when starting. Air conditioning systems, for example, need a peak current roughly six to eight times the standard operating current to start. And in Arizona's climate, most AC units cycle on and off several times each hour. This feature of the grid enables equipment to start reliably without severe voltage fluctuation and possible equipment damage.
  • Voltage quality – The grid's high-fault current level results in higher-quality voltage by limiting harmonic distortion, which is required for the operation of sensitive equipment. In contrast, voltage from a distributed system that is not connected to the grid will generally have a higher-voltage harmonic distortion, which can result in malfunctions and reduction in the life of equipment and appliances.
  • Efficiency – Grid connectivity enables certain systems to operate at optimum efficiency, just as automobiles achieve the best gasoline mileage when running at a steady optimal speed. Without grid connectivity, the output of a distributed energy resource will have to be specially designed to match fluctuating output, reducing system efficiency as much as 20%.
  • Energy transaction – A utility grid connection enables consumers with distributed generation such as rooftop solar panels to transact energy with the utility grid. This means getting energy when panels don't produce enough to meet the home's energy demand, and selling excess energy back into the grid when a customer's system is producing more than needed.

SRP upgrades the grid for you

You already are benefitting. SRP has been updating grid technology, bit by bit, for a number of years. Immediate benefits include improved ability to pinpoint and isolate outages, make repairs more quickly and increase customer access to money-saving tools and information.

Benefits include:

  • Customers have new online tools and more information to better understand their energy usage and manage their monthly energy bills; most of these features exist within SRP My Account.
  • Two-way communication capabilities within our system helps us complete orders more quickly.
  • Advanced metering enables expanded, money-saving price plan options such as our popular EZ-3 price program, where customers save money by shifting energy use to off-peak times.
  • We have more precise information about outages than we have had in the past, which will help us respond faster to restore service. Log into SRP My Account to view our detailed outage maps.
  • We are continuing to improve our ability to detect problem areas to better prevent outages.

We have been investing in leading-edge grid technologies for years.

SRP became one of the few utilities offering advanced metering services to all customers when we completed a two-year project in early 2013 to install digital meters throughout our service territory. This investment created one of the nation's largest wireless, advanced metering networks.

The newer metering technology and support systems are encouraging increased use of customer web resources, including web-based account information and automated notifications. As a result, customers become more knowledgeable, savvier consumers and stewards of their energy use.

The digital meters we've installed allow SRP to offer innovative price plans, such as Time-of-Use and EZ-3, that help customers to save money by reducing power use during peak hours. New metering technology also helps us reduce peak demand through efforts such demand-response program for commercial customers.

SRP's core grid investments go far beyond advanced metering. Given our customer base and variety of generation assets, SRP developed a solid network of fiber-optic and wireless communications. SRP offers the market's densest metropolitan-area carrier network – 1,600 route miles with 30,000 strand miles available for license across 15 municipalities in metro Phoenix.

This fiber allows SRP to operate our local grid with advanced digital technologies that require very fast data speeds. With this communication backbone, SRP now has the ability to deploy technologies within neighborhoods to quickly detect potential trouble spots in our grid and increase the reliability of the electric service we provide.

According to industry analysts, advanced metering deployment and broadband penetration are two of the top metrics to boost enhanced grid development. SRP has invested in both.

Other ways you benefit from updated grid technology include:

  • eNote alerts, in the forms of e-mails and text messages, provide bill estimates and notify you when usage exceeds customer-set thresholds or when an outage occurs
  • Daily usage, weather and other information available for view in the online My Account feature
  • Outage maps available for all customers, aside from the My Account feature, provide information and updates during outage situations via social media
  • The availability of all of these options on personal devices such as smart phones.

The future of the grid

The electric grid connection provides unique and valuable services; it's also different from cellphones vs. landline service, which some use as a comparison.

It's true that more than 38% of landline consumers have now opted solely on cellular service. By contrast, virtually all consumers that install distributed generation remain connected to the grid. The difference is that the cellular telephone network provides overall service equal to landline service, while a consumer with rooftop solar still needs the grid to retain the same level of service. Unlike a cellphone user, operating without interconnection to the grid would require significant investment for on-site control, expensive energy storage and redundant back-up generation capabilities.

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