Loss of electric power to any organization can range from a minor inconvenience to challenges affecting data retention/ backup/retrieval to ultimately causing collapse of the services being provided. This is especially problematic during prolonged outages caused by a major storm or natural disaster such as Super Storm Sandy in 2012. One solution to backup power is the “microgrid.” This article will define a microgrid, the reasons for their deployment, and some key considerations should you design and install a microgrid at your plant or campus.
What is a Microgrid?
Business Continuity/Disaster Recovery professionals are aware of back-up electric power options including onsite diesel or gasoline-driven generators and batteries/uninterruptible power supplies (UPS), etc. However, a new, larger scale approach to back up power is surfacing called the microgrid.
According to the Microgrid Exchange Group – formed under the auspices of the US Department of Energy – a microgrid is a group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the main electric grid. A microgrid can connect and disconnect from the grid to enable it to operate in either grid-connected or island-connected mode.
Basically, a microgrid is larger than a single generator providing power to a home or office building. Instead, it includes several electrical loads (e.g., buildings, offices, etc.) powered by traditional power generators as well as batteries, photovoltaics, wind generation, etc.
An elementary view of a microgrid is included in Figure 1.
Types of Microgrids
Microgrids are not a new concept. In fact ever since electricity was introduced to a ship the concept of “microgrid” has been established. Similarly, villages in Alaska and on islands in the ocean or other waterways are essentially microgrids because they are separate grids and act as a single controllable entity.
A ship also has the ability to connect to the electric grid – also known as shore power – which shows that the shipboard power approach closely models this concept.
There are several distinct types of microgrids. Most of the key microgrids include:
- Institutional or Campus Microgrids – A university or industrial park that can generate its own power and operate separate from the main grid
- Isolated/Distant Microgrids – Operate in “island mode” all the time such as the remote villages in Alaska that rely on their own diesel generators for power
- Military Base Microgrids – Actively deployed by the military to focus on both physical and cyber security to assure reliable power without relying on the main grid – especially under wartime conditions
Business Continuity/Disaster Recovery Drivers for Microgrids
A driver for microgrids is to reduce physical vulnerabilities of the electric grid to terrorist attack and natural disasters. According to the report Terrorism and the Electric Power Delivery System1, microgrids and expanded use of distributed resources would help limit cascading failures and leave islands of power within a blacked-out region.
The biggest and most recent driver for microgrid deployment comes from the lessons learned following Super Storm Sandy. In many instances the news articles surfacing from this major disaster raise awareness of the increasing usefulness and application of microgrids to essentially “…stop power outages from the get go.2”
Following the events of Super Storm Sandy, Hurricane Irene, the Derecho that hit Northern Virginia, etc. several states are now placing emphasis on energy assurance planning – especially by critical service providers such as public safety. As noted by Mr. Rick Wornat in his article “Energy Assurance Planning: The business case for microgrids,3” in Smart Grid News, critical facilities such as police and fire stations, city hall and emergency operations centers, hospitals, and large critical facilities are centrally located.
This central campus may offer the potential for serving these facilities on a common microgrid circuit. Hence, this campus could island itself from the main grid and still run with “semi-normal” electrical service which would be especially useful during the post-disaster restoration.
As a follow up to Super Storm Sandy, the Obama administration has announced that it is working with New Jersey to improve the resiliency of the power grid. One approach under discussion is development of a microgrid plan for Hoboken and another plan is expanded deployment of Combined Heat and Power (CHP) plants.
For example, Princeton University – which normally gets its power from Public Service Electric & Gas (PSE&G) – was able to island its CHP facility from the main electric grid for approximately three days thus keeping the University powered and reducing the load on the already challenged grid until it was able to handle the “normal” power needs.
With this experience in mind, New Jersey has already set aside up to $100M to help promote CHP plants for microgrid implementation. On July 24, 20134, Governor Daniel P. Malloy of Connecticut announced that $18M in funding has been released for nine microgrid projects in the state. The program is designed to develop innovative ways to keep critical facilities powered during electric grid outages. Malloy has taken a major leadership position on this concept of implementing microgrids to improve the resiliency and reliability of government services and businesses that are critical during extreme weather events. Malloy envisions that the following would be covered by the microgrids: police, fire, emergency response teams, hospitals and health care facilities, state and town emergency response centers, grocery stores and gasoline stations. Malloy has recommended an additional $30M in funding for the state’s microgrid program to strengthen more Connecticut communities.
Practical Next Steps to Consider Microgrid Options for Your Organization
As noted above the idea of a “microgrid” is really not that new; however, with the push for the “Smart Grid” and improved grid resiliency following major disasters like Super Storm Sandy or Hurricane Irene the options for microgrid implementation at your company are increasing and evolving. Don’t forget that implementing a microgrid requires funding as well as power engineering. It is not a simple matter of just buying a new suitcase generator and circuit breaker. Here are some ideas to consider for your next moves with microgrids:
Study the Microgrid Concepts and Ascertain How They Would Work for Your Organization
- Take some time to work with your electrical and power engineering staff and/or contractor to get a grasp on the benefits and limitations of a microgrid for your organization and local region.
- Take a look at resources from:
- Galvin Electricity Initiative: www.galvinpower.org/resources/microgrid-hub/microgrid-resources
- Sandia National Laboratories: http://energy.sandia.gov/?page_id=819
- National Renewable Energy Laboratory: www.nrel.gov/tech_deployment/microgrids.html
- Homer Energy Modeling Software: www.homerenergy.com/
Talk to Your Local Utility to Better Understand How You can Isolate Your Company/Campus from the Main Grid
- Does your utility/electricity provider have any expertise on microgrid deployment and implementation?
- What is the utility’s opinion of microgrid deployment by its customers?
- What are the reasons for being against microgrids? (Note: some utilities view microgrids as competitive and may not be willing to support local deployment.)
Work with your State /Federal Legislators to Obtain Funding for Microgrid Pilots and Full-Scale Deployments
- Use Connecticut as a model with New Jersey as a follow up.
- Talk to your state energy and emergency preparedness offices to ascertain future opportunities for funding, pilots, etc.
- Talk to the Federal energy offices and Federal Emergency Management Agency (FEMA) with similar questions.
Understand Your Design Options for the Microgrid
- What are the electric loads you can expect under normal and emergency conditions inside your microgrid? Don’t forget to consider starting currents for large motors and equipment.
- What will be the power resources inside your microgrid? Batteries? Fossil fuel generators? Wind and solar generation? What about mini-hydro?
- How will you control connection and disconnection to the power grid? How is this coordinated with the power grid owner/operator?
- What are the power quality requirements needed by your own microgrid customers? What are the boundaries for power quality such as frequency and voltage and harmonics? Would filters need to be installed for a self-developed microgrid?
How Will You Operate The Microgrid Under Emergency/ Extreme Conditions?
- How will you refuel the generator? Especially when ground transportation is hindered due to downed trees, flooding, etc.?
- When do you reconnect your microgrid to the main grid? How is this coordinated with the utility?
- How do you assure the microgrid will function during a major disaster or even physical or cyber-attack?
- What about cooling water for your generators? Is it adequate or can the failure of the cooling flow shut down your microgrid?
Understand How You’ll Secure The Microgrid5
- What are your plans for physical security – especially securing the breakers that isolate the microgrid from the main electric grid?
- Ensure that Cybersecurity is designed into your microgrid control systems. Take advantage of the Sandia Labs Microgrid Cyber Security Reference Architecture6 for your design.
- Don’t forget classic security controls such as access management, instrumentation and control diagram classification, and personnel background checks.
Conclusion
Microgrid deployment may be an optimal solution for your organization to protect it from the next “100-year storm.” It is a new way to look at how you can isolate your facilities from the main electric grid and still sustain your operations until the main grid is available to provide service. Remember that the microgrid is not new, advanced technology but instead is a new way of thinking about how to best protect your company or organization in preparation for, and during, a major natural or man-made disaster.
1 Terrorism and the Electric Power Delivery System, by M. Granger Morgan, et al and published by the National Research Council of the National Academies, 2007. Link: http://www.nap.edu/catalog.php?record_id=12050
2 “Microgrids Keep Power Flowing Through Sandy Out-ages,” MIT Technology Review, November 7, 2012. www.technologyreview.com/view/507106/microgrids-keep-power-flowing-through-sandy-outages/
4 http://www.ct.gov/malloy/cwp/view.asp?A=4010&Q=528770
6 http://prod.sandia.gov/techlib/access-control. cgi/2013/135472.pdf
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