Seattle City Light takes a holistic approach to grid modernisation


Metering & Smart Energy International takes an in-depth look at some of the grid modernisation programmes at Seattle City Light such as microgrids, distributed energy resources (DER), automation, demand response and others.

Under the leadership of CEO Larry Weis, Seattle City Light (City Light) has created a technology innovation division to explore grid modernisation technologies such as microgrids, distributed energy resources (DER), automation, demand response and others within the utility.

Some of City Light’s earliest grid modernisation initiatives include converting existing substations to ‘smart’ stations, capable of remote monitoring, near real-time information collection and distribution, and improved performance. The utility serving over 750,000 residents also upgraded its power delivery and distribution systems, reduced distribution losses and energy consumption by optimising voltage and reactive power flow. It has also begun to prepare for large-scale advanced meter infrastructure rollout.

Michael Pesin, former chief technology adviser and smart grid architect at Seattle City Light, stated that “it is important to note that smart grid is not defined by what technologies it incorporates but rather by what it can do.”

He added: “While there is a set of enabling technologies, each utility will have its own portfolio of systems and technologies based on the unique factors that define the utility. City Light’s advanced grid will not emerge from a single rollout of a revolutionary technology but from strategic planning and initiatives all aimed at a long-term vision.”

DER and EV integration

At the customer-end, City Light has modernised its grid connections to support offsite power generators and storage units such as solar panels, wind turbines and battery systems. It is also working to integrate plug-in electric vehicles (EVs) and establish vehicle charging infrastructure to enable controlled charging of EVs.

City Light has launched a pilot project through which it will install charging stations for electric cars in several hundred homes, as well as 20 fast-charging stations around the city where motorists can charge their vehicles in as little as 30 minutes. Seattle Mayor Ed Murray has set a target whereby 30% of all vehicles on Seattle’s roads will be electric by 2030.

In August this year, City Light was announced as one of five utilities to receive a grant issued by Washington Governor Jay Inslee for projects focused on renewable integration and grid modernisation.

Seattle City Light has proposed a solar-powered microgrid at a community centre which is designated as a priority one emergency shelter. The microgrid will provide resiliency for the residents of Seattle during a large storm event or natural disaster. Having the microgrid located at a community centre provides an opportunity for City Light to engage with the community and provide educational displays on what a microgrid is and how it works “up close”.

City Light views the project as an invaluable learning opportunity for the utility’s engineers and linemen to get comfortable with a microgrid operating in its service territory. Moreover, City Light believes that learning how the various components of the microgrid interact with each other and the utility itself, will prepare it for ‘Utility 2.0’.

Microgrid development supports outage management

In an interview with Metering & Smart Energy International, Benjamin Rushwald, City Light’s interim director of technology innovation, said that the utility is “currently working through the contract details for the microgrid project.”

The location of the $3.5 million City Light microgrid is still to be determined, but “the utility intends to build the project where it can support more vulnerable members of the community in times of crisis. The grant will provide a portion of the funds for the project. Terms of the grant contracts have not been finalised yet.”

During normal operations, the solar panels will charge the batteries and provide power to operate the building. When the solar panels are not generating power, the batteries will support the delivery of electricity from City Light’s distribution grid or, during periods of high demand, they will be used to reduce the amount of energy City Light has to purchase to meet customer needs, thus minimising costs for all its customers.

After a storm, earthquake or other emergency, the solar panels, emergency generators and battery system will power a portion of the building even if damage to the distribution grid causes outages in the surrounding area.

Murray praised City Light, saying “projects like this demonstrate that Seattle is an innovative city with a forward thinking electric utility.

“I applaud City Light for its foresight and leadership in developing microgrids that could someday enhance the reliability of electricity service across our community.”

Rushwald added: “City Light is very excited about this microgrid project. It is going to provide us with the opportunity to support the city during times of emergency as well as a chance for the utility to become more familiar with microgrid technology and gain specific experience with regard to integrating the different parts of the microgrid.

“The integration of solar PV, a battery system, generator and controls is complicated. This project will provide City Light with hands on experience and knowledge in dealing with these challenges. This is important, as we see microgrids being part of the utility of the future. An opportunity to learn and become familiar with the system will be important across the utility from engineering to operations to customer service.”

Improved energy management

City Light has also recently announced its participation in a pilot project led by the Electric Power Research Institute (EPRI).

City Light will be field testing a smart energy circuit breaker, called the energy management circuit breaker. The breaker plugs into a home’s circuit breaker box to provide the utility and the homeowner with information about energy use on each circuit in the home. Along with a mobile app, it will ultimately allow customers the opportunity to monitor their energy use and turn devices connected to the breaker on or off remotely.

The pilot programme would provide an opportunity to investigate how this new technology might be used and what its potential was, said Rushwald.

Some of the possible applications for this technology are demand response programmes and Time-of-Use rates that could be provided specifically for electric vehicles.

While advanced metering was the first step for many utilities toward modernising grid networks and infrastructure, in February this year City Light announced its plans for mass meter installations in 2017. City Light will install up to 450,000 meters by the end of 2018.

The $94 million is an initiative that falls under City Light’s strategic plan.

Timing has been dependent on budgetary approvals within capital improvement programme funding and completion of installation of a new customer information system that went online in September.

Rushwald concluded: “The City of Seattle is an innovative, environmentally conscious city and its utility is looking to partner with the citizens to prepare and provide the interactive advanced grid of the future and uphold its ‘carbon neutral’ status – which it has maintained since 2005.” MI