The Solar Micro Grid Solution and Beyond: Clean, Safe, and Reliable
Updated: Aug 29
Energy Independence and Beyond
A Microgrid that Powers this Building in Minneapolis, MN Source: https://energynews.us/2016/12/07/microgrid-powers-new-suburban-minneapolis-office- building/
Solar microgrids are becoming more relevant than ever. Given the indecision of that which is occurring around the world—not the least of which involves the invasion of Ukraine by Russia—alternative energy sources are of utmost importance and significance. As a result, many in North America and beyond are now looking more closely at energy generation via solar arrays and microgrids. It seems to be somewhat of a rhetorical question now, but we can ask the following: “How important is it to be energy independent?” As a larger entity the need is much more significant of course. But, arguably a degree of energy independence is important for so many other smaller bodies and corporate structures as well (eventually including individual households as well).
Photo Source: https://newmatworld.com/completed-projects/oati-2017-bloomington- minnesota/
Perhaps the best way to initiate our broader discussion today, though, is to briefly define a “solar micro grid.” So, what is a solar micro grid anyway? Well, Renewable World tell us this:
Solar Microgrids are integrated networks or ‘grids’ of power. Think of it in the same way that you and your neighbours receive your electricity – through a shared network. Using energy generated from the sun, the system captures, stores, and distributes clean electricity to an entire community. This is done by installing large, high quality solar panels and batteries in a central location. Once the technology has been installed, the solar microgrid is completed by connecting electrical wiring from the central power location to nearby houses, businesses, and farms.
Source: https://renewable-world.org/our-approach-to-renewable- energy/technologies/solar-microgrids/
Photo Source: https://www.photonenergy.co.uk/photon-energy-news/manchester-science-park
We can extract some bullet points from this description. Those bullet points tell us that solar microgrids are:
• Integrated networks • Shared networks, and • Mechanisms for energy generated from the sun that then:
a) Captures, b) Stores, and c) Distributes energy to an entire community.
Having said that, how is all of this done? As the article above states, usually by “installing large, high quality solar panels and batteries in a central location.”
The scale of the solar energy micro grid
We all need to assess our specific energy requirements. One key question that many have is this: Can this service my specific needs? Again, according to Renewable World magazine, we can garner the following:
Solar microgrids are an exciting renewable energy solution due to their application at any scale and their ability to be expanded later. Some of our solar microgrid systems have a capacity as small as 1.5kw, providing reliable energy to 25 homes and 5 businesses. Other microgrids are expected to have a capacity closer to 15kw, enough energy to power hundreds of households and small businesses. Should a community grow, the solar microgrid can be expanded to connect more families and businesses.
Source: https://renewable-world.org/our-approach-to-renewable- energy/technologies/solar-microgrids/
So, microgrids are “scalable,” and microgrids can be expanded to fit growing needs.
At the same time, the Center for Climate and Energy Solutions tells us that:
Microgrids commonly range in size from 100 kilowatts (kW) to multiple megawatts (MW).
Likewise, the International Energy Agency (IEA) prefers this calculation on a per capita basis (as measured in 2021):
... the International Energy Agency’s (IEA) current minimum standard, which is about 50 kWh per capita per year in rural areas and 100 kWh in urban areas.
What does that much energy give you? A few lightbulbs a few hours a day, a phone charge and the occasional running of a fan, according to the report, “The Modern Energy Minimum: The Case for a New Global Electricity Consumption Threshold.”
“For this reason, the current annual consumption threshold of 100 kWh is better thought of as an extreme energy poverty line, rather than as the international energy target for promoting development and greater incomes,” the report said. “Just as income is tracked above a poverty line and at other higher levels, the same framework could be applied to electricity consumption.”
Photo Source: https://www.popearch.com/project/oati-microgrid-technology-center
The U.S. Department of Defense (DoD), Energy “Surety,” and Microgrids
It seems that some of the new standards and new pressures are coming directly from the United States Department of Defense (DoD). There are probably no better agencies in government to understand the risk factors associated with energy independence than DoD. Again, and we see the scenario “playing out” in Ukraine in real time, this has become even more acute for us. So let us look at this from the National Renewable Energy Lab (NREL):
The U.S. Department of Defense (DoD) has long recognized the strategic value of energy to its missions, and the energy resilience of DoD installations has become of increasing concern. Department of Defense Instruction 4170.111 requires installations to be more energy resilient, and as a result, many installations are pursuing microgrids to meet their energy resiliency goals and requirements.
The goal ... is to outline a process to improve the quality, reduce the cost, and increase the speed and scale of DoD’s energy resiliency infrastructure investments. One strategy for improving the electrical energy resilience of an installation involves building a microgrid to serve as a backup power system in the event of a grid outage caused by an attack, equipment failure, or other contingency situation.
A microgrid is a group of interconnected loads and distributed generation that act as a single controllable electrical entity and can operate in both grid- connected and isolated modes (Ton and Smith, 2012). Microgrids can add additional resiliency beyond the current DoD practice of building level backup generators.
Microgrids can enhance energy resiliency by providing energy surety (i.e., loads have certain access to energy) and survivability (i.e., energy is resilient and durable in the face of potential damage).
Microgrids are typically composed of distributed energy resources that can provide independent power to designated critical loads upon loss of their primary source of energy.
Photo Source: https://www.military.com/veteran-jobs/veteran-clean-energy-job-help- veterans.html
Photo Source: https://guidehouseinsights.com/news-and-views/unpacking-the-value-of- resiliency-that-microgrids-offer
The “Bounce-back” Factor
Resiliency—as mentioned above—is a primary issue when considering the implementation of a microgrid. As a result, we will want to understand the “bounce back” factors at play. These factors address issues associated with a whole host of problems that may emerge. Let’s see this for more:
The main driver of microgrid development in the United States has been their potential to improve the resiliency (the ability to bounce back from a problem quickly) and reliability (the fraction of time an acceptable level of service is available) of “critical facilities” such as transportation, communications, drinking water and waste treatment, health care, food, and emergency response infrastructure. One major area of activity is the Northeastern U.S., where aging infrastructure and frequent severe weather events have led to billions of dollars of losses in recent years.
Due to recent advancements in technology, these microgrids are now much more robust and resilient, meaning that one can “bounce back” from an adverse event much quicker.
Where are most of the microgrids based in the U.S.?
Of the 160 microgrids in the United States, most are concentrated in seven states: Alaska, California, Georgia, Maryland, New York, Oklahoma, and Texas.
Now, for some people who are familiar with just the solar panel part of this equation, they might justifiably and reasonably ask this question: What’s the difference between a solar panel and a solar micro-grid? For an answer to that, we may want to explore this explanation as a start:
The difference between solar and solar microgrids
What is the difference? Both generate power with solar, but a solar microgrid also can island from the grid, a crucial ability.
Envision a storm where trees and branches are knocking down power lines. The electricity goes out in one neighborhood, then the next, then the next.
Interconnected to the grid, the solar panels stop working too.
Most advanced microgrids are grid-connected too. But when their control software senses the disruption coming, they can disconnect and rely on their own solar and other distributed energy resources. So even when those around them are in the dark, microgrid customers have power.
In simplest terms, solar offers green energy; solar microgrids offer green energy plus electric reliability.
To drive home a key point here, we can center on this statement to provide us with some solace in the solar space (from above):
Microgrids offer green energy plus electric reliability.
Interconnection, reliability, and safety
Understandably, we are—and perhaps we all should be— concerned with issues related to interconnection, reliability, and safety. Can we really rely on this as a major source of clean energy? To address this, we look to a viable authority, Solar Build Magazine, to shed more light (all pun intended) on our concerns:
The point of interconnection must be monitored and grid connection managed based on utility stability. And battery inverters must offer multi-mode operation, from grid following to grid forming to manage a power outage.
The industry has made excellent progress on the technology side of the microgrid equation, making now better than ever to implement grid-optional systems that are often more safe, reliable and cost effective than traditional utility power in many parts of the world.
Source: https://solarbuildermag.com/energy-storage/what-makes-a-microgrid-a- microgrid/
That which we can extract is as follows:
a) We must monitor the interconnection. b) We must manage grid connection based on utility stability. c) Battery inverters must offer multi-mode operation. d) Finally, engage in “grid following” and “grid forming” to manage a power outage.”
To add to all of this (and to corroborate my information), let us look at a few statements from our very own United States Department of Energy:
Simply put, we need a reliable and secure energy grid. Two ways to ensure continuous electricity regardless of the weather or an unforeseen event are by using distributed energy resources (DER) and microgrids. DER produce and supply electricity on a small scale and are spread out over a wide area. Rooftop solar panels, backup batteries, and emergency diesel generators are examples of DER. While traditional generators are connected to the high-voltage transmission grid, DER are connected to the lower-voltage distribution grid, like residences and businesses are.
Microgrids are localized electric grids that can disconnect from the main grid to operate autonomously. Because they can operate while the main grid is down, microgrids can strengthen grid resilience, help mitigate grid disturbances, and function as a grid resource for faster system response and recovery.
Source: https://www.energy.gov/eere/solar/solar-integration-distributed-energy- resources-and-microgrids
Here is what I “pull” from the above statements to soothe my mind:
“Because they can operate while the main grid is down, microgrids can strengthen grid resilience, help mitigate grid disturbances, and function as a grid resource for faster system response and recovery.”
As a manager of these resources, I want to be sure that I can effectively and efficiently “mitigate grid disturbances.”
Again, I would like “peace of mind” knowing that if and when the “main grid is down,” microgrids can help manage, adjust and/or mitigate the problems. We also see many entities that are now involved with the private and public financing of microgrids. Let’s examine this from NREL:
[NREL] defines a microgrid as "a group of interconnected loads and distributed energy resources that acts as a single controllable entity with respect to the grid. It can connect and disconnect from the grid."
The International Energy Agency projects that 42% of new energy generation capacity additions will need to come from microgrids to achieve United Nations Sustainable Development goal of 100% energy access by 2030.
Source: https://www.nrel.gov/state-local-tribal/blog/posts/financing-microgrids- that-can-have-a-mega-impact.html
The Australian Shopping Center Model
In and throughout the United States, we can now look to a model that seems to be embraced in Australia with shopping centers. This can prove to be an efficacious application for many of us who are interested in this sector:
A growing number of shopping centers in Australia are being transformed into power-generating facilities with the addition of embedded renewable-based microgrids. These hybrid systems allow owners to provide tenants with cheaper, cleaner power. The rooftops of large retail buildings are ideal locations for solar panels as they are flat, spacious, and almost always exposed to the sun. In response to rising energy costs, consumer pressure, and declining equipment costs, a growing number of shopping mall owners in Australia are turning the rooftops of commercial spaces into power plants with on-site solar arrays and energy storage.
The Narellan Town Centre (NTC), a shopping mall outside of Sydney, is the latest retail center to embrace this trend. NTC owners, Dart West Retail, recently shared plans for a 29.9 million dollar solar + storage microgrid made possible through a partnership with CEP Energy.
NTC is one of Australia’s largest privately owned shopping centers, with 76,000 square meters of commercial space with over 220 specialty retail outlets, a cinema complex, and parking for 3,000 cars. Dart West Retail says that the solar and battery embedded network will provide its retail tenants access to renewable electricity at a roughly 20% discount to grid power.
The project ... will include a 50,000-square-meter array of solar modules that will provide 10 MW of capacity, supported by a 20 MWh battery storage system, making it the biggest single solar and battery system to be installed on any shopping center in Australia to date.
Source: https://microgridnews.com/retail-power-solar-powered-shopping- centers-provide-cost-savings-and-clean-energy/
Photo Source: https://www.energynewsbulletin.net/new-energy/news/1401356/cep-energy-to- build-australia’s-largest-shopping-centre-microgrid
Photo Source: https://microgridnews.com/retail-power-solar-powered-shopping-centers- provide-cost-savings-and-clean-energy/
So, with the Australian shopping center model, we are basically looking at the following in terms of energy generation and corresponding consumption:
a) A 50,000 square meter array (roughly 500,000 square feet). b) Powering 76,000 square meters (about 760,000 square feet) of commercial space. c) 10 MW capacity supporting a 20 MW battery storage system. d) Investment of $29.9 million Australian (approximately $22 million US) for the solar + storage microgrid.
Photo Source: https://techcrunch.com/2016/11/21/tesla-officially-acquires-solarcity/
It’s Not Just Shopping Centers and the Like: What about Tesla Anyways?
Then, of course, we have the Tesla example. Unbeknownst to many perhaps, Tesla has over 120 microgrids around the world. Just take a look at this for more insight:
Tesla has over 120 operational microgrids around the world using its batteries and renewable energy, according to a new comment from an executive.
Ever since the launch of Tesla Energy and its stationary energy storage products, Tesla started working on microgrid projects.
The idea is to have a self-sufficient energy system using self-produced renewable energy stored in batteries and supplying a small community or facility.
After the acquisition of SolarCity, it made even more sense for Tesla to get into the microgrid business since it now had expertise with both batteries and solar power.
Photo Source: https://electrek.co/2020/10/19/tesla-120-operational-microgrids- world/
No matter your specific needs, today may be a good time to explore microgrid technology, if for nothing but peace of mind and an effective backup. One company emerging in this sector is MGES in metro Kansas City (http://www.mg- es.com); that company seems to be on the cutting edge, but there are many others as well. With war raging in Europe now (and with the likelihood that some elements will spill over into the energy sector in North America), it is probably a good time to be prepared for energy independence—on many levels.
P.S. Below are a few financing sources for solar as well.
Some Solar Financing Sources: 1. Sustainable Capital Finance (PPAs, etc.) https://scf.com
2. National Renewal Energy (NREL) https://www.nrel.gov/state-local- tribal/blog/posts/financing-microgrids-that-can- have-a-mega-impact.html
3. U.S. Department of Energy https://www.energy.gov/sites/prod/files/2020/08/f7 7/financing-microgrids.pdf
4. National Association of Regulatory Utility Commissioners https://pubs.naruc.org/pub/E1D94D36-155D-0A36- 3149-DFEB9D24715D
5. Federal Solar Tax Invesment Credit / Duke Energy https://sustainablesolutions.duke- energy.com/resources/calculate-solar-tax-credit/