The Dawn of the Microgrid

high voltage wiresWhat was once a broad system of cutting edge technology has grown into an antiquated system that we rely on implicitly. In many ways, the evolution of modern society has outpaced our means for the production and distribution of power to leave the state of our world’s infrastructure punctuated by a list of shortcomings. We are still overly dependent on fossil fuels for power production. There is a growing resistance to the new centralized infrastructure where utilities can rise to a monopolistic opportunity of being the only game in town. The changing nature of our global climate highlights needs for quality and resiliency, a benchmark of performance that much of our landscape cannot currently meet. Not to be forgotten is that we still have upwards of 1.7 billion people in the world without any access to reliable electricity. While there are numerous attempts to try and bolster the breadth of the grid by fixing pieces as they wear down, there is an alternative to making a bigger and more powerful grid: making a series of smaller grids that are more agile, more robust and more adaptable. Very small. Micro. 

The grid we grew up with can be characterized as a large system where power is produced by a small number of sources and then pushed through transmission in one direction to a vast number of customers. Our relatively fragile veins of power lines outside our homes are fed by arteries moving large amounts of power at high voltage and small disruptions in the system can have negative effects on large numbers of people. With a sea of public and private organizations coordinating to both produce and distribute power through existing infrastructure, the result can be a system that is prone to deficiency and very difficult to change.

Instead of trying to orchestrate a wholesale renovation of the entire existing infrastructure, there may be a new method for isolating small packets of the grid for upgrading them into working bodies that manage their own production, distribution and consumption of power. I got to listen to Brian Patterson of the Emerge Alliance address an attentive crowd to outline a vision of what the next generation of our grid could be like: breaking it into a large series of microgrids.

The Microgrid

The first step is to imagine a network of contributors rather than a distribution system.  As opposed to a system of large utilities producing power and pushing through a distribution system, Brian sees an integrated network of buildings that both produce and consume power, with different properties giving and receiving at different moments throughout the day. One microgrid could be anything from a collection of buildings on a university campus, to a new residential development or city blocks of a mixed use neighborhood. Its decentralized nature allows for an infrastructural transition to occur simultaneously at countless locations around the world, all at their own speed rather than regional overhauls of massive utilities that need a critical mass of financing and time to get operational.

Just as the demand of buildings changes with attributes of size, location, orientation and program, so too can the ways that buildings on different sites capture energy for consumption. One site in a group may be prime for solar PVs while another can harvest small scale wind. A geothermal well with ice storage at one building could be paired with a local source of small scale hydro to balance out microgrid fluctuations, while a small amount of battery storage (or even parked electric vehicles) could bring distributed storage space to the whole network when linked together. Where we now count on massive utilities to help fill in the gaps between these sources of production and consumption, we can trade that for a constructed ecosystem managed on the local level via a deployment of next generation smart meters, appliances and building systems.

Microgrid Utility Infrastructure

A key component to this new system would be the next generation of sustainable buildings that have a power-producing component. “I don’t believe in net zero,” Patterson said. “I think where possible buildings should be net-positive,” (producing more power in a day than they can use to leave an excess they can push into the micro grid). Patterson pointed out that even though we are completely able to create net-zero and net-positive buildings now, there is a sea of existing, historic buildings that will be here for some time. Even with dedicated upgrades in envelope and building systems, these buildings may never be net zero in their lifetime. Extra power from a new class of building will help the older stock that won’t reach net zero.

Though it only got a token mention, energy storage also has to be a key component to a well-functioning microgrid, especially as the size of the system grows to include more buildings, bringing with it an increase in real time variability in the demand vs. supply of power. This could be more of a benefit than curse to new microgrids. We have yet to develop means of storing power at the utility scale for quick release which becomes critical when numerous, large renewable energy systems are being linked together. A stable means of storage is necessary to offset the intermittant nature of sources like wind or solar power. We are, however, much closer to having smaller means of energy storage to help smooth out the difference between demand and supply on the building scale. Whether it is ice storage tanks in buildings like One Bryant Park or Tesla’s new Powerwall home battery systems, we are already beginning to deploy means for the relationship between building and grid to become more nebulous.

60 Hertz, Alternating, All the Time

In many ways, it is the very breadth of the grid, held in its synchronistic delivery of Alternating Current (AC) power at 60 Hertz that serves as one source of its drawbacks. Despite the fact that it is the way that it has always been done, the newer demands we place on using electrical infrastructure raise questions as to whether or not it is the best course for the future. Currently, when our our power comes out of turbines at power plants it is Direct Current (DC) power, before it is converted and increased in voltage to be pushed across long distances. From there, it is stepped back down before it reaches our home for us to plug into. Each one of those changes involves power lost to the conversion.

The integration of renewable energy sources is another sticking point and Patterson points out that it wasn’t necessarily what the grid was made for–especially from smaller distributed sources like solar and wind on the scale of a home or neighborhood. Solar panels and wind turbines produce DC power, leading to the inverters that are an expensive component of new home systems (again with a sacrifice of some power in the conversion). Using that power on site is relatively easy, but the larger utility grid isn’t usually as eager to get it. “It’s hard to harvest power and inject it into our current power system,” Patterson asserted. Most of the time “it takes more energy to try and put energy into system than you harvested.”

The same goes for battery storage. Batteries store and release power in DC, meaning the conversion for AC needs to happen both going in and going out, costing us 3-4% on each transition. Even large building systems draw their power in DC, setting the stage for a new system that delivers DC power to the site and focusing on a conversion to AC power only for the plug loads that we need it for.

Enter the Enernet

Brian uses the analogy of the internet over time to highlight some of the benefits that a system of microgrids could bring and why it might work well. His series of connected microgrids is called the “Enernet.” The Enernet would be an infrastructural system that exists as a framework for using transactional relationships that allow it to exist without hierarchy. While the internet spends the day trading packets of information, the Enernet would be constantly exchanging electrons through a transmission of digital DC power with the majority being produced locally.

Unlike the linear distribution system of our current grid, a network of producers and suppliers could lend itself to a more resilient, self-healing system. Where a problem at a central power plant can black out an entire town, the loss of a single building contributing power to a micro grid can be offset by all of the other buildings with healthy systems. A smaller system with more contributors could also lead to less need for regulation. For all of its size, the internet can operate without a great deal of centralized management and oversight. These networks of smaller components could be easier to upgrade over time while larger amounts of the production and transmission infrastructure would be under the purview of individual building owners rather than large scale utilities responsible for tens, if not hundreds, of thousands of homes.

So what about those utilities that we have now? At first glance the proposal could come across as discouraging the existence of large utility companies. While there may be some time in the future were power production is easy enough, reliable enough and small enough for a surplus to be created at the building scale, Patterson isn’t pitching doing away with utilities. On the contrary, he assured listeners that while they may begin to evolve more, they will continue to be absolutely critical to help manage larger loads and serve as a back up for smaller microgrids they are connected to. “Think of them as ‘the cloud’ in the computing equivalent.”

What is the Hold Up?

When asked what were some of the hurdles to the realization of this grid transition, red tape made an early climb to the top of the list. While many municipalities have tried to make it easier for buildings to harvest renewable energy for their own consumption, fewer have made it easier to push excess power back into the grid with fewer still helping to facilitate groups of buildings constantly exchanging electrons.

Given that a new Enernet would arguably be turning groups of buildings into small, independent power authorities, once again we are asking a system (in this case our regulatory landscape) to do something it wasn’t designed for. From the local to federal level, power production and distribution is a heavily regulated process that will require a municipality to step outside of precedent in order to facilitate the test of a working microgrid model. Put simply, Patterson noted that, “the grid is currently managed by relatively few people and they view the world through their optics. Now we’re going to add about 100,000,000 stakeholders.”

These kind of headwinds are part of the innovation process and while it makes sense to always try and utilize what you have to its greatest extent, the difficulty is what presses innovators to create new options. Once again, Patterson draws a parallel between the dawn of the computing internet and what now may seem like the distant past. At the time, the prospect of such a wide web of digital connections was unprecedented and its pursuit utilized the existing communication network of telephone cables–designed to carry vocal tones over long distances.

As a result, the first modems converted digital information into tones to transfer communication from one computer to the next (most reading this will probably remember the jumble of beeps and buzzes that was produced by early modems in order to get us “online.” At the same time, this meant deriving a solution so that a system could do work it wasn’t made to do. Today, we have a swiftly growing fiber-optic network–a new system made specifically for transferring digital information that brought us more bandwidth, more speed and more reliability to a vast network of devices. An enernet of microgrids could evolve in a similar way.

The scale of the proposed change was striking about Patterson’s comments, different from many sustainability proponents that err on the side of safety by encouraging small changes with relatively minor improvement. The goal of our culture becoming more sustainable requires change, regardless of our collective dislike for the notion of diverting from the status quo. In Patterson’s words, “We have to do something more fundamental about power than just turning lights off when we don’t need them.”