Microgrids: How to Prepare Energy Grids for the Next Superstorm

On October 22, 2012, Hurricane Sandy made landfall in New Jersey. It lasted for 10 days and caused $70B of damage, making it the second most costly hurricane in the US at the time.

Electricity, water, ANY utility you can think of went down. One family in NY describes being in *pitch-dark* for 8 hours after the power shut off and tying themselves to each other to avoid being separated in the strong winds. Another woman in NJ describes being trapped by flooding in her apartment for *three days* without power, before being rescued by the national guard.

Emergency personnel rescuing residents in New Jersey.

In all, the hurricane left 8 million without electricity and these outages lasted up to weeks. This massive weather catastrophe was just one reminder of the limitations of our energy infrastructure.

Definitely, we’ve made improvements in getting people access to electricity. We’ve built massive energy grids that sprawl across continents in the developed world. But when a disaster occurs, even the most developed countries are left vulnerable to losing this resource. Even in 2017, 35.7 million people in the US were affected by 3500 power outages.

And it’s even worse when we look at developing countries! In 2019, 840 million people around the world couldn’t access ANY energy. 80% of them lived in rural or isolated areas, where it was too expensive to build massive energy grids. Clearly, our energy systems have lots of issues, so what can we do to avoid disaster when the next major storm hits? 🌩️

The problem with our current energy grids is that they’re just too darn big and hard to control. If something goes wrong in one area, it affects all the other places connected to that energy grid. So researchers are trying to design smaller grids that don’t rely on each other (ie. if one breaks, the damage doesn’t spread to other communities).

They call these microgrids: smaller versions of our electricity grids that only power a few buildings or a small community. Each building produces some energy (often through renewables) and then sells/stores whatever it doesn’t need to others.

They work in ‘island’ mode most of the time, where they don’t need to rely on any other energy grids. When they can’t make enough electricity though, they do connect to diesel generators or the main grid to make up for extra energy demand (which is important for critical applications like medical equipment)

Here you see a store, office, and hospital making their own energy with solar panels. Their microgrid is also connected to the main (utility) grid and batteries in case they need more energy.

Back in 2012, there weren’t many microgrids being developed. Luckily though, we’ve improved since then! In 2019, there were 4475 microgrids in the world which could provide 27 GW of energy. Not a lot compared to the thousands of GW in conventional grids around the world, but it’s progress!😃

And there are reasons for microgrid development beyond just increased resiliency in case of natural disasters:

• Microgrids often use renewable energy, so they decrease the carbon emissions from energy systems.
• Because of their smaller scale, it’s easier to add energy storage and backups to microgrids to deal with typical renewable unreliability.
• It’s easier to manage microgrids because you can easily add infrastructure to deal with more/changing demand or meet renewables targets.

So how exactly would we go about making this technology the energy of the future? I was so excited to find out that I went to the l̶i̶b̶r̶a̶r̶y̶ (Internet 😁) to get up to date with current research!

Could you QUANTIFY Those Microgrid Benefits There…?

Luckily for me, I found just the right research paper to do that! It looked into the socio-enviro-economic 😎 costs and benefits of microgrids in Israel.

Why Israel you might ask? Well, the Israeli energy system is basically the opposite of a microgrid (researchers don’t stop at most-improved awards, they do most-room-to-improve-awards 😉). You have the giant Israeli Electric Corporation that controls the entire grid’s operations from top to bottom (vertically-integrated operations).

But the company hasn’t been doing well. Israel has had declining spending in energy Infrastructure, even though demand for electricity increases 2.5 to 3% per year (a LOT higher than other developed countries). So the researchers looked at how microgrids could come to the rescue! 🦸

The upside is that some legacy electricity companies in Israel used to almost work like microgrids and Israeli law doesn’t have a bunch of regulatory challenges for these kinds of projects. So the researchers could propose a project feasibly.

They suggest 10 MW microgrids that work on solar panels, thermoelectric generation, and gas turbines/backup systems. It would take about 1400 of these to power all of Israel, but the government would only have to invest in a few at a time.

• The biggest benefit of this is $13M through economic multiplier benefits (translation: jobs created 😉). Primary jobs would be created in extracting raw materials for the microgrid infrastructure and secondary jobs would be created by manufacturing the parts.

The microgrid creates more than 10x more benefits than the current electric grid.

• There are also $1.5M in savings because microgrids don’t have to transmit and distribute electricity over long distances like entire countries. Less energy is lost and fewer transmission lines, etc. have to be developed.

$1.5M are saved in transmission and distribution.

• Based on what consumers would pay to avoid losing electricity (value of lost load), there are $1.6M in reliability benefits with the microgrid.

• And finally, there are also $290K in t̶r̶e̶e̶h̶u̶g̶g̶e̶r̶ ̶b̶e̶n̶e̶f̶i̶t̶s̶ environmental emissions savings for CO₂, NOₓ, and SOₓ gas emissions. 🌿☮

The microgrid has over 4x fewer emissions than the current energy grid.

BUT there is a catch, because microgrids are more expensive to develop. They don’t have the economies of scale of large energy grids and they’re not as cheap as having conventional fossil fuel plants. 😟

The costs for a microgrid are about 2.25x higher than current energy grids.

All in all though, the proposal would create a net benefit for the Israeli energy grid. This takes into consideration:

Net microgrid benefits = Economic benefits + Reliability benefits + Environmental Savings + Transmission and Distribution Savings - Additional generation and construction

This shows that the current energy grid actually LOSES more money than it makes 😅

The Israeli Electric Corporation invests $1B every year in their energy infrastructure to install 166 MW of capacity. These researchers found that microgrids would be a better way to do that than traditional energy grids (because of jobs created, decreased transmission and distribution costs, increased reliability, and decreased environmental emissions). That’s a score of 1–0 for the microgrids! 🎉

But the REAL Test is… Can it Help People in Rural Areas???

To answer that, I looked into a study on how solar microgrids could be used on the continent of Africa. This is a HUGE deal because there are hundreds of millions in Africa that currently have NO energy whatsoever. And 140M are expected to gain electricity through microgrids in Africa by 2040.

The microgrids that the researchers studied are based only on solar panels (unlike the hybrid microgrids before). Since the African continent has a LOT of sunshine, solar is a great renewable for the job! It’s been continuously becoming more efficient, becoming cheaper, can be installed quickly, doesn’t need much maintenance, AND is modular so it can be adjusted to meet the biggest or smallest of needs!

All this graph says is the sun shines more consistently around the equator and in deserts. It took the researchers 3 pages of microscopic text to explain how more-consistently-around-the-equator-and-in-deserts the sun shines… 😫

The catch, however, is the fluctuating production from just using solar panels. Usually, if the sun’s not shining, the wind might be blowing or the water might be flowing 🌊. But if we only use solar panels, they produce electricity intermittently which makes it hard for microgrids to meet demand cheaply and have a low risk of failure.

The researchers call this intermittency “variability in solar irradiation levels” (translation: more/less sunshine). But it’s more complicated than that because you have two causes for this intermittency:

1. Where the weather changes day-to-day (ex. with more or less cloud cover)
2. Where the weather changes seasonally (ex. when monsoon season hits in Africa)

The first kind is easy to solve — you have batteries store energy when the sun is shining and save it for when it isn’t. But the second kind is more dangerous, because you can be left with rainy weather and no sun for weeks at a time (solar production droughts).

Solar’s worst enemy: monsoon season in June, Burkina Faso (Western Africa) 😢

Currently, the only solution is to frequently use large diesel generators as backups for these time periods, but this ruins microgrids’ environmental benefits. And if you tried to go without them and still meet electricity demand, you would have to oversize solar microgrids by 2.5x (just for these few seasons) to meet the demand on 95% of days.

The researchers ended off by proposing a way to forecast future patterns of bad weather where solar output would decrease. Then, they would set a pricing structure to incentivise people to use less energy during low production periods (like some energy prices are set higher in the evenings with current grids).

HOW the weather would be predicted is full of complicated computer models that are beyond the scope of this article (and my head 😄). Overall though, this research shows a really intriguing solution that could enable hundreds of millions to access energy via simple solar cells — we just have to deal with the inconsistency.

Now That we Have the Parts… How BIG do we Make the Whole?

No matter whether you’re trying to deploy microgrids across all of Israel or all of the African continent, you’ll have to choose how big they are. After all… what does ‘micro’ really mean??? To explore that, I looked into this paper on how to optimise the size of Tokyo’s microgrids!

It looks into how you can find the optimal scale for a microgrid based on changes in demand for electricity and sunshine levels (solar irradiation levels, if you remember the fancy terms 😉). Since this is looking at individual microgrids in just a single city, it has more granular details.

The obvious result was that sunshine levels don’t really change all that much in a small region being studied. So basically, all you need to worry about is how much energy demand there is to determine the size of the microgrid. And here, there were a bunch of interesting correlations:

• They found that the microgrid size increased around railway stations 🚂because there was a higher population density which caused higher energy demand. (That’s as Japanese as any anime I can think of! 😍)
• In contrast, you could have smaller grids in the suburbs. This isn’t just because of lower demand, but also more possibility of renewable energy production (since the small, detached houses are great for rooftop solar panels).
• The type of renewables you use also matter. If you used monocrystalline photovoltaics on rooftops, the investment would be paid off in 1.5 years instead of 2.2 years for polycrystalline ones on the ground (resource explaining the different types of solar panels)

The areas in red need bigger microgrids. They’re often located near main railway stations (black squares). The results don’t differ much when you have the maximum or minimum sunshine levels.

Overall, this smaller-scale study (y’know… only the largest city in the world instead of an entire continent 🤷‍♂️) shows good news in planning for microgrid development. You don’t have to worry about climate variations… only energy demand.

Can you REALLY Trust Microgrids’ Environmental Benefits?

According to the Internet, yes… but researchers have a habit of digging deeper than Wikipedia 😁. They questioned the impact of microgrids on habitat loss, hazardous pollutants, and forest depletion. So they looked into the lifetime environmental costs of microgrids vs. conventional solutions.

Specifically, they studied the costs of the first microgrid in Hong Kong, located on an island off the mainland. It used to be powered by diesel generators that ran for a few hours a day, because they were cheap and easy to install. But it was hard to get fuel to the island and burning diesel releases harmful emissions, so a new solution was needed.

The island considered a grid extension from mainland Hong Kong which would be easier to operate and be more stable than diesel generators. But, the construction would be complicated because a 6.7 km-long submarine cable would have to be built. So the island instead built a hybrid microgrid with wind and solar!

The microgrid can produce 190 kW and store 1100 kWh of energy (through batteries). It has two 6 kW wind turbines (for research only, because Hong Kong’s climate doesn’t have much wind) and 672 solar panels that each produced 200 or 280 W. This was great to study because there isn’t much research on environmental costs for hybrid microgrids.

The Blue and Orange represent two different wind turbine sites. Usually, the wind turbines operated less than 15 days per month (only about a third of all days in fact).

The study focused on parts of the microgrid’s lifetime like raw materials extraction, manufacturing, and operation to measure environmental costs. But what exactly are these costs 🤔??? They cover these key areas:

• The global warming potential of the emissions released
• Toxicity potential for humans and the environment
• Ozone depletion potential and particulate matter released in the air
• Land use, deformation, and acidification

Since they had a LOT more solar panels or batteries than wind turbines, they broke down the costs per kWh of energy instead of looking at the total costs (to compare the results accurately). Here are some interesting details:

• Comparing the different technologies used, the solar panels were responsible for over 50% of all the environmental costs except those related to toxicity. There, batteries created over 50% of the problems because of the heavy metals they use like lead, arsenic, and antimony 😷. The wind turbines had relatively low impact for most categories.

The Blue and Orange represent the impact of solar energy for different environmental costs. They caused over 50% of most types of environmental costs.

• When comparing the OVERALL impact of the new microgrid to the old diesel generators and the proposed grid extension, microgrids are the most environmentally-friendly option by more than 5x.

The different colours show environmental impacts on humans, ecosystems, and resource use. Microgrids are the most environmentally-friendly option in all categories.

• That being said, there are some areas of impact where microgrids aren’t the best option. Specifically with toxicity potential to humans and the environment, diesel generators have lower environmental costs compared to microgrids because they don’t need as many heavy metals/chemicals.

The specific environmental costs in human toxicity potential are higher for the microgrid than the diesel generator. This is due to the complex materials and manufacturing processes.

• Microgrids have the greatest environmental costs during manufacturing and raw materials extraction (ex. when you purify quartz into solar-grade silicon). In contrast, both diesel generators and the grid extension cause most environmental costs while they’re in operation.

When comparing the three options for costs with global warming potential, the microgrid has lower total and operational costs. But, it does have higher costs in raw material extraction and manufacturing.

• And finally, the microgrid had a longer energy payback time (how long it takes for the project costs to be offset by energy produced) than diesel generators, but it paid itself off more quickly than the grid extension.

When comparing the three options for the energy system, the island would recover initial investment costs for the microgrid one year before the grid extension and 3 years after the diesel generators.

Overall, it seems like the microgrid was a good eco-conscious investment for the island 😉. They won’t have to rely on diesel generators that can only run a few hours a day AND they didn’t have to go to the trouble. of building all the infrastructure that’s needed for a grid extension!

So How Ready are Microgrids to be the Future of Energy?

Well, all this research shows that they’re pretty darn ready! Not only do they have environmental benefits, but they’re also easier to manage and save monetary costs compared to conventional solutions. Of course, the researchers did also bring up some challenges that have yet to be resolved.

For one, we already have issues with meeting demand because of changes in renewable output because of weather patterns. It’s hard to predict how climate change will add on to that to influence renewable supply, electricity demand, seasonal variation, etc. Microgrids decrease the damage of occasional extreme weather events, but what if that weather became normal?

Also, it’s hard to create a generalised approach to planning microgrid development, which slows down development. They have to use different renewables in Hong Kong than in continental Africa, because of different climates. And because of economies of scale with microgrid development, it’s also hard to estimate costs/benefits without custom-built solutions.

Finally, the last problem is that it’s just so hard to keep up with all the positive developments! Okay, that doesn’t sound like a problem at first… 😅 But think about how hard it is to give a price estimate for renewable microgrids when battery and solar prices keep on falling all the time. This just adds to the need for custom-built solutions.

Even with these challenges though, microgrids are ready for larger uses! We know they have proven advantages of all sorts over conventional solutions… now it’s just a matter of figuring out the best way to scale them up (starting with the rural areas that still can’t meet their energy needs with large grids).

And it doesn’t necessarily have to be that complicated of a solution. For instance, when you’re planning which renewables to use in an area, you have to consider the weather patterns there to determine what could be effective. With publicly-available data (ESPECIALLY in rural areas), it used to be a challenge to find reliable trends. 😕

But now, we have more and more private companies entering the space with new monitoring approaches. Take IBM’s Weather Company for example. It uses IoT to increase the granularity of weather data and then analyses it with its AI platforms. Through platforms like this, it’s becoming easier and easier to conduct that background research and transform it into key statistics on the feasibility of a microgrid project.

As for the scale of these solutions, there’s key work being done where private companies are partnering with governments to create modular set-ups for microgrids. For instance, Powerhive has developed management software to analyse the most promising sites for microgrid development in Kenya and then partnered with the Kenyan government and power companies to essentially install solar microgrids as a big loan.

The impact of Powerhive’s work in creating access to farming technology, lights, and solar farms. 😃

The microgrids are installed with no up-front costs and they enable rural communities to develop and grow economically. As they use electricity produced by the microgrids, they gradually pay back that initial investment to the company.

This business model decreases the need for lots of risk analysis of whether a microgrid is economically feasible. You mitigate risk with partners at a large scale and by providing the benefits of electricity without typical barriers from up-front costs, you enable communities to prosper economically so they have a higher chance of paying back the ‘loan.’

So given these ongoing advancements, who knows… maybe the next time a superstorm hits, we won’t be reliant on massive, failure-prone energy grids. Maybe we could instead contain the impact and increase resiliency through the microgrids of the future. Maybe we could reduce both the billions of dollars of damages and people left vulnerable from power outages during these natural disasters.

Key Takeaways

• Microgrids are miniature versions of current electricity grids that connect small communities with renewable sources of power.
• They have costs savings from economic benefits, are easy to manage due to modularity and resiliency, and decrease environmental impacts.
• The biggest challenges for microgrids are changes in climate and weather patterns, changes in renewables, and a need for custom-built solutions.

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