The extreme weather events and power outages that taxed the nation the past year have signaled a ‘new normal,’ one in which access to resilient, reliable power is far from guaranteed. In California, intensifying fire threats resulted in intentional power cuts for millions – not once, but a handful of times. In the northeast, a record-breaking bomb cyclone wiped out power for more than half a million people across multiple states.
The confluence of a changing climate and an aging grid has left our energy supply vulnerable, spotlighting the stark lack of resiliency that exists in our current system and leading businesses on a quest for advanced power solutions. Proactively considering and managing these energy solutions is especially imperative for leaders tasked with safeguarding resiliency and ensuring business continuity, such as the CxOs of organizations.
Microgrids are one such energy solution. They operate as miniature versions of the centralized electric grid that dispatch, distribute, and regulate the flow of electricity. It is their ability to be ‘islanded’ from the main power grid, which is their key distinguishing factor, enabling them to operate through any grid disruption continuously.
"All microgrids are not created equal, but through evaluation of your facility’s power demand and investigation into the power supply that would best support it, you’ll uncover the path to true energy resiliency for your business"
But when it comes to microgrid solutions, one size does not fit all. Microgrids require collaboration and customization in order to meet the needs of a business. This can make the process of planning and building microgrids a complex, sometimes lengthy endeavor. The good news is, there is some evaluation and investigation you can do ahead of time to lighten the load, so to speak.
What to Consider When Designing a Microgrid
Designing a successful microgrid is about ensuring harmony between the power supply side and the power demand side.
Let’s start with the demand side. The first step is to fully understand your facility, your processes, and, most importantly, your load. Consider your reliability requirements – how much flexibility do you have in your power demands? Could you tolerate a dip in power quality? A one-hour outage? What would a day without power mean for your facility? How about a five-day outage event?
Begin associating a dollar value with the resiliency of your power supply. This will help you determine which loads are critical and which you can do without, which in turn, informs peak microgrid sizing.
A partial microgrid that keeps the power on for the most critical operations, while sacrificing the rest, might make the most sense for your facility. Cost limits come into play here, and more oftentimes than not, it serves you better to decide what part of your operations – if any – can go without power when the grid goes down.
For example, a supermarket’s mission might just be to remain open to the public during an outage to provide resources and food to its local community. In this case, only some portions of the retailer’s load needs to be carried by the microgrid, such as refrigeration to prevent spoilage and ensuring some of the registers and internal lighting stays on, while things like internal temperature control and parking lot lighting can be dropped.
Next, determine your load’s capacity factor requirements – perhaps your facility is only open during the day and closed at night, or maybe it is open 24x7. Discerning your daily usage or seasonal usage profile requirements will help you couple your power demands with the right energy supply.
If your business involves processes that run all day, every day, renewable energy sources such as solar or wind may not be practical solutions on their own. Because they are intermittent, their capacity factor is limited; consequently, they may not be able to supply all the power you need during the entire time you need it. For high tech manufacturers, data centers, or hospitals, that’s a risk they oftentimes can’t take.
This is why many microgrids incorporate an energy source with a high capacity factor – one that can run continuously, including solutions such as fuel cells, diesel or gas engines, as well as combined heat and power (CHP) systems. These systems serve as the foundation of a microgrid, and other resources like renewables and batteries can be integrated to serve additional purposes.
Finally, you must consider the fuel supply in your microgrid assessment. Diesel engines require reliance on onsite fuel reserves or delivery trucks. During storms and other widespread power outages when the entire region is looking for diesel, supplies will be prioritized for hospitals, and delivery trucks may be impeded by dangerous weather and road conditions.
Alternatively, the strong underground pipeline system that delivers natural gas is a mesh network, providing constant fuel and greatly reducing the risk of supply issues. Thus, fuel cells, CHP, and gas engines can offer greater reliability with more secure fuel supply and are typically recommended as the primary foundation of your supply-side resource.
Ultimately, a microgrid must be customized for your needs. All microgrids are not created equal, but thorough evaluation of your facility’s power demand and investigation into the power supply that would best support it, you’ll uncover the path to true energy resiliency for your business.