Microgrids: A Resilient Option for Tomorrow
Jacobs is working with clients from around the globe to ensure mission critical operations can withstand unexpected emergencies.
Jacobs is working with clients from around the globe to ensure mission critical operations can withstand unexpected emergencies. Jacobs Principal Roger Copeland shares how below.
In last few years, we’ve seen the weather erratically fluctuate and directly impact how industries, cities, healthcare facilities, universities and other mission critical organizations maintain operational readiness. For many local municipalities and regions, the question of how to prepare for the unknown remains.
As more of these entities prioritize building resilience, microgrids solutions are gaining traction.
At their core, microgrids are analogous to back-up generators for a local power system. At a deeper level, a generator controller must balance the generation output to the load in real-time and serve as a balancing authority to control voltage and frequency, not unlike the larger grid operator.
These microgrids are typically operated in parallel with the local grid to provide additional supply surety, complicating the generation balancing approach. Microgrid owners possess the assets and must control the grid with technology, engineering, and operations to manage the generation and distribution to maintain the supply both with and without the grid support.
Mitigating environmental impacts
As the world transitions from carbon intensive fossil resources to a greener electric grid, the shift to date has been led by solar and wind renewable resources. Unfortunately, these resources do not produce energy when called upon but rather when the wind blows or the sun shines.
A microgrid (and the larger grids for that matter) require flexible, dispatchable resources that can match generation output to load in real time. Developing a microgrid solution with limited dispatchable resources requires careful attention to the potential energy available either in fuel resources (typically carbon-based) or in large scale stored energy that can be dispatched to respond to load needs real-time. With the use of a storage-only solution, designs can be flexible and respond to load, but only allow a definite time of emergency response capacity without external grid support.
As such, resilient microgrids require a fossil-based anchor resource to ensure more reliability. While fossil resources aren’t usually known for being environmentally-sound, potential impacts can be optimized through thoughtful application of a combined heat and power system.
These systems are often found in locations where a predictable demand for heat energy coinciding with the electrical demands, such as higher education or healthcare campuses. Combined heat and power systems provide resilient, efficient thermal and electrical energy for campuses both during steady state and emergency conditions.
An additional approach being deployed to minimize the carbon impact of microgrids is applying fossil-based flexible resources that are future-proofed to plan for deployment of hydrogen fuel in a traditional fossil resource. Many manufacturers are already developing these hydrogen capable solutions, and as the hydrogen economy and infrastructure mature over the coming years, the solutions may be able to transition from fossil through a blend with hydrogen to eventually a pure hydrogen (zero carbon) application.
Withstanding unpredictable weather
As with any power system, microgrid systems are vulnerable to extreme weather and climate events and must be adequately weatherized and prepared for a full realm of weather and system conditions.
For example in early 2021, according to Johns Hopkins, the state of Texas faced its coldest winter weather in more than 70 years and simultaneously experienced state-wide utilities failure. When temperatures dropped lower than temperatures in Alaska, more than 4.5 million homes and businesses lost their power and at least 70 people lost their lives.
The Electric Reliability Council of Texas (ERCOT) manages the flow of electric power to more than 26 million Texas customers—representing about 90% of the state’s electric load. As the independent system operator for the region, ERCOT schedules power on an electric grid that connects more than 46,500 miles of transmission lines and 710+ generation units. The uncharacteristically Arctic temperatures exposed the weaknesses in an electricity system designed when the weather’s seasonal shifts were more consistent and predictable — conditions that most weather experts believe no longer exist. As a result, ERCOT relied on rolling blackouts.
Experts suggest rolling blackouts as a last resort when power demand overwhelms supply and threatens to create a wider collapse of the whole power system. Usually, utilities black out certain zones before cutting off power to another area. Luckily, hospitals, fire stations, water-treatment plants and other key facilities are usually spared, but as many Texans experienced, the blackouts can be devastating for residential neighborhoods during extreme weather.
In contrast, the microgrid deployed at the University of Texas at Austin was able to maintain electrical supply, heating, and even cooling as odd as it sounds to a campus of over 20M ft2, research, campus housing, dining, and the on-campus hospital during the entire winter storm event. This advanced microgrid is one of the most efficient in the world and boasts uptime envied by most of the globe’s high-end datacenter campuses, with only four outages in the last 54 years. Their ability to remain operational throughout provided lifesaving heat to students that live on campus as well as minimizing damage from frozen assets in buildings. UT’s microgrid is one based on natural gas, but they are integrating on campus solar thermal and solar PV resources as well as investigating adaptation of these generation resources to blend and convert to hydrogen over time.
In New Jersey, Princeton University had a similar success story with their microgrid in the wake of Superstorm Sandy in 2012. The campus was able to leverage their microgrid to sustain through the unpredictable storm and provide a safe place of refuge. Their system combined a heat and power system based on natural gas. The University is currently integrating renewable resources and optimizing the deployment of the fossil assets to minimize the impact without sacrificing the resilience that the system affords.
Both success stories stem from clients that were proactive in investing in resilient on campus generation sources that were optimized to steady state operation but flexible enough to deploy without grid connectivity. They were also funded through optimized supply of thermal and electrical energy through the application of combined heat and power solutions with projects that pay for themselves through energy savings while providing incalculable value from the inherent resilience. Being proactive and considering the long-term utility solutions is key to justifying and deploying a resilient and efficient microgrid installation.
In 2020, net zero carbon commitments roughly doubled, with many countries embracing the opportunity to deliver “green stimulus” to support economic recovery from the COVID-19 pandemic. Microgrids can help deploy more zero-emissions energy sources, make use of waste heat, reduce energy lost through transmission lines, help manage power supply and demand and improve grid resilience to extreme weather.
As a thought leader in Jacobs’ Energy & Power Solutions group, Roger Copeland is focused on energy and utility systems and the detailed understanding of system dynamics and response as well as projects that require optimization for market participation and / or grid stability. Since his early days as a student worker in his university's power plants and utility access holes, Roger has continuously been involved in helping develop solutions for developing, operating and maintaining ever-changing and rapidly growing electrical grids. With experience including the design of numerous thermal and electrical generation, combined heat and power and boiler plants and utility distribution systems for clients across the country, Roger’s clients span public and municipal utilities, transportation, oil and gas, higher education and healthcare. He has designed the electrical and generating systems for central stations, substations, hospitals, laboratories, industrial facilities, central plants, rail transit, PJM grid restoration, wastewater treatment plants and pump stations.