It’s very hard to get people excited over the things we cannot see, feel, smell, hear, or taste. This is a problem for anyone involved in what is in fact quite thrilling, the evolution of electricity through smart grids.
A great lasagna can be exciting. So too are sporty, clean electric cars. For many of us, better lighting and air conditioning at a lower cost, sourced from renewables, make us happy to be alive. So let us start with each of these things and consider how a very specific form of smart grids—DC (for direct current) microgrids—is about to change life as we know it in all kinds of ways.
DC microgrids essentially can solve a problem that has always existed and has been getting worse as of late. It is that the predominant means by which electricity is transmitted by utilities to end users—homes and businesses—is by alternating current, or AC. It’s really the best way for electricity to travel long distances. But most appliances and devices in the home—LED lighting, air conditioning, computers, printers, phone chargers, flat-screen televisions, and some hybrid and electric vehicles—run on DC. This very often requires a converter, the box at the end of the electric cord that is attached to the plug prongs (called a “wall wart”). This brings the power down from a higher voltage to the lower, unidirectional flow of electric charge used by a majority of common electrical devices—especially those that serve our digital world.
The conversion from AC to DC involves a loss of almost 20% of electricity. By the predominant systems currently in place, that degree of loss can also happen between rooftop photovoltaic panels and the outlets and devices just a few feet below.
This is where the lasagna, lighting and cooling, and electric cars are directly connected to, and share excitement with, DC microgrids. The development of these grids essentially cut out this conversion process and the loss of electrical efficiency. Power from renewable sources (e.g., rooftop solar) and batteries (collectively known as “distributed generation”) can run your television (where you can watch a cooking show about lasagnas) and your electrical kitchen appliances, charge your electric vehicle, and light your home, all with greater efficiency. Scale up these features to commercial buildings and the savings become significant.
This is also where the EMerge Alliance plays an important role. The San Ramon, California-based non-profit creates standards for the development and use of hybrid AC/DC microgrid power in buildings. Their mission is to improve safety, better utilize cables and wires, increase electrical efficiency, and reduce the need for materials such as copper and steel in converters (for additional cost reduction). First and foremost, the use of DC increases the flexibility, modularity, and resiliency of the system on a building-by-building or cluster-of-buildings basis. The EMerge Standard defines a convenient and safe system of interfaces between interior finishes (ceilings, walls, floors, and furniture) and the devices that use and control power within that space.
A lasagna, a clean-running car, and a lower electric bill can all thrill the senses. The case studies here show us how, in tangible ways, this is starting to happen.
JLC Tech: Office Ceilings are Looking as Smart as They Function
Things should be getting brighter in workplaces soon. That’s because there’s a new way of lighting offices and similar spaces that look and operate smarter—and work optimally off DC microgrids.
This is the mission of JLC-Tech, a Pembroke, Massachusetts-based company and its T-Bar LED Smartlight system. Described as the “next generation green lighting solutions for suspended ceiling applications,” the product elegantly combines light-emitting LEDs with the familiar suspension system that otherwise supports ceiling panels. Gone are translucent panel sections that were covers over fluorescent or other types of light bulbs because the T-Bar LED lights are built directly into the ceiling grid. LEDs require direct current power sources; therefore within a DC system, these lights work at optimal efficiency.
“Our T-Bar LED offers a number of advantages,” says Mia Antonia, principle partner of JLC-Tech. “Designers can now almost paint with the light, placing the fixtures wherever light is needed in the space. A T-Bar LED installation in open spaces and hallways will provide a more even foot-candle distribution than traditional fixtures. Installation costs can be 40 to 50% lower, and because the ceiling tiles are consistently used everywhere in the room, a greater reflectance of daylighting can be achieved.”
The system was patented in 2010, introduced in North America at Greenbuild International/Toronto a year later and has been manufactured in the US since 2012. Sales and production levels doubled in 2014 and tripled in 2015, according to Antonia.
An installation of T-Bar LED Smartlights is featured at the 2015 Washington, DC Greenbuild Expo (November 18-19) Net Zero Energy Pavilion, which serves as a showcase of EMerge Alliance and microgrid technologies. The entire pavilion will be powered by solar energy as a demonstration of direct, no-conversion-necessary transmission from photovoltaic panels to end-use devices that includes lighting and appliances.
A permanent installation of the T-Bar LED Smartlight with a DC Microgrid system is at the Worthington Industries (Columbus, Ohio) conference and focus group rooms. The ceiling-lighting plan here demonstrates the integration of several microgrid technologies including Armstrong’s DC FlexZone Ceiling. Antonia explains that the T-Bar LED runs off of 24-volt DC power. With a normal AC installation the products would use one universal adapter for every 10 linear feet to bring the voltage to the products. With a DC microgrid the adaptation from AC to DC takes place one time only, saving a considerable amount of energy.
The minimalist aesthetic of the system is what stands out to the casual observer. Antonia adds that the light that replaces the grid minimalizes building materials (creating virtually zero waste on construction sites), and reduces installation costs by half. Additionally, with energy consumption savings of up to 50% (compared to a traditional lighting system), it’s the people in finance who might be most impressed. The T-Bar LED Smartlight system is an innovative solution for medical, educational, retail, and hospitality applications, in addition to offices.
PNC: DC Microgrid Efficiency You Can Take to the Bank
Nana Wilberforce, energy manager for PNC Bank, is part of a very green effort going on within one of the biggest retail banking organizations in America. The financial services company has constructed more than 250 new and retrofit buildings to green standards since 2000. And thanks in part to direct coupling technology, developed by Nextek Power Systems, a new-build, 4,620-square-foot Fort Lauderdale, Florida branch is the company’s first net-zero retail location.
“It’s in our culture of innovation to strive for efficiency on every project,” says Wilberforce. “We are always looking for the next big thing.”
Direct coupling certainly can qualify as a big thing. While the vast majority of buildings with rooftop solar must convert the DC from photovoltaic cells to AC, which then is inverted back to DC at the device level, direct coupling regulates the solar array and the power to load. This reduces power loss and enables this branch to get more electricity for free from all that Florida sunshine.
The direct coupling technology facilitates photovoltaic production of between 60 and 120 volts (DC) through a maximum power point tracking controller to a constant output voltage for distribution through a power server module (PSM). Under high-demand circumstances, the PSM combines DC from the solar array with AC from the grid.
Note that this is hurricane country, where post-storm power outages can last for days and sometimes weeks at a time. Microgrids such as this enable buildings to generate their own energy and return to service regardless of the status of the utility grid.
Every location is different, cautions Wilberforce, such that one cannot project with confidence that every new or renovated PNC location from here on out will essentially have its own DC microgrid. He stresses that the climatic zone will determine the loads: in the subtropics, the air-cooling demand is greatest, as is the available solar energy.
Note that “plug loads”—for lighting (overhead, task, and parking), computers, printers, signage, etc.—constitute approximately 75% of electrical needs at a comparable bank building in Florida. But here LEDs were used, which also run most efficiently on DC. This particular building has achieved a LEED Platinum certification.
How might this system affect employees and customers? Wilberforce says it largely goes unnoticed. But he cites a 2012 study out of the University of Notre Dame, which found that LEED-rated PNC branches generate higher consumer deposits and loans. Given how microgrids can reduce long-term operating costs, it seems possible that the application of direct current might catch on the way direct deposit paychecks did a generation ago.
Next Energy: Why Motown is Where the DC Microgrid Action Is
If there is a nexus for thinking on DC microgrids, it’s here in Detroit. This is where NextEnergy is based, and it’s no accident that it’s in the city built around the automobile. Since the introduction of hybrid electric vehicles, the Motor City has been the place for developing the key components of microgrids.
Jim Saber, vice president, business & technology development for NextEnergy, is quick to point out that the inspiration for and applications of microgrids reach from huge wind turbines and photovoltaic systems to urban skyscrapers, storm ravaged residential communities, and remote military installations. The possibilities are sufficiently exciting such that the non-profit research accelerator and its entrepreneurial industry partners draw investment from the state of Michigan, corporations, and venture capital firms. They have created a setting where entities such as research universities, utilities, and private enterprises can take innovative electrical technologies through R&D to commercialization.
“This is a catalyst for economic development in Michigan, but the applications apply to cars, renewable energy sources, and smart grids anywhere,” says Saber, who adds that the hot topic of energy storage factors into the discussion as well.
The center, based in Midtown Detroit, is a small campus that includes R&D and office space for partners engaged in energy development (including Nextek Power Systems, see pg. 32), an alternative fuels platform, and what they call the Microgrid Pavilion (MGP). The facility also includes “NextHome,” an actual 400-square-foot house that is wired for both alternating (AC) and direct current (DC). It serves as a living lab within NextEnergy’s testing and validation platforms.
Having different enterprises and various thinkers together in one place produces an interesting cross-fertilization of ideas. For example, Saber offers how the control and management systems of cars (which provide for cabin comfort and entertainment features) can be transitioned to home and building management systems. Another example of how NextEnergy helped leveraged the region’s manufacturing capabilities into energy was when they dissected how wind turbines are built and determined that vehicle equipment companies had capabilities for manufacturing wind energy components. This led to new business opportunities for Michigan firms.
Of note to architects and builders is that the innovations with the NextHome and microgrids as a whole require very few changes to the design and construction of buildings. The current DC microgrid economics are currently best suited for commercial buildings because the commercial building owner/operator payback is typically shorter and more achievable than in residential. Suffice it to say, with so many ideas on how microgrids can be built and deployed, the Cadillac-level systems of today might well be considered “Chevy standard” in the near future.
Nextek Power Systems: DC Microgrid Innovation: Smarter Power for the First and Third Worlds
Nextek Power Systems is a tenant-partner in the NextEnergy Center in Detroit. This is a tenant any smart building should want—they helped build it to be the DC (direct current) microgrid showcase that it is.
The technology firm is all about developing means to save on energy. They devise systems to leverage high-efficiency power converters that optimize energy usage—particularly from renewables such as rooftop solar, as well as from batteries and the standard utility grid. The goal is to improve ROIs and functionality in lighting systems. In a world migrating to the use of LEDs, DC microgrids provide the best and most efficient means to optimize the use of electricity in these systems.
“We consolidate the AC to DC conversions, moving them upstream from each device to a converter for whole parts of buildings,” says Paul Savage, CEO of Nextek. “This creates an ideal point for solar photovoltaic inputs or battery inputs to the building’s power system. We don’t look at buildings as collections of devices anymore; we think of them as devices themselves.”
The long transmission lines of the utility grid generally still operate on AC. As Savage explains it, “In the conventional synchronous AC grid architecture, large economies of scale must be reached, and generation must always equal consumption—otherwise the system is unstable.” But as buildings, communities and special installations (think of remote military operations or disaster emergency camps) strive for more efficient and independent electrical systems, microgrids configured to run on direct current make more sense. “A DC power system is asynchronous, and therefore can easily and efficiently buffer electricity inputs and outputs.”
The NextEnergy Center’s Next Home installation helps demonstrate Nextek’s own patented technologies. “We think having renewable energy inputs, battery storage, electrical vehicle charging, and DC loads all on a common bus is the optimal set-up for a net zero energy home,” Savage says. “We will have lots of opportunity to license this arrangement to developers and integrators in the US.”
This is not just about the über-cool homes or gleaming skyscrapers of coffee table magazines. For the approximately 25% of the earth’s population that currently lacks an electric grid altogether, microgrids using direct current might be a way to bring them into electrical modernity. “We feel like we are onto something world changing, with large benefits available to both the top and bottom of the economic pyramid,” says Savage. “For the highly developed world we bring high efficiency, easier integration of different power generating technologies, greater safety, and flexibility. For the developing world, these scalable DC microgrids can bring real infrastructure to people who have none today, much faster than the hub-and-spoke grid model.”
The New Enernet: A Guest Column by Brian T. Patterson, President of the EMerge Alliance
We now live in a new “Electron economy.” Since the invention of the solid-state transistor in 1946, we have experienced a mind-boggling transformation from an electro-mechanical to an electronic world. To power this new world, we consume almost 18 trillion kilowatt hours of electricity each year—mostly generated and distributed by 100-year-old technology.
Personal computers, tablets, smartphones, flat screen TVs, the Internet, electric vehicles, data centers, and a host of other new uses of electricity, many of which are intended to reduce or replace the unsustainable, unclean consumption of fossil fuel (and added to by the simple growth of the world’s population) have put us on a seemingly runaway path of electric consumption. Consider that half of all electricity ever generated by man has been consumed in the past 15 years. And despite a focused effort at conservation, this growth continues at a double-digit rate.
But even increased centralized utility scale production of alternate energy sourced electricity, delivered by a “smart grid,” leaves us with increasingly troublesome issues, mostly centered on the unsolved challenges of synchronizing and transmitting electricity over considerable distances. Transmission loss, the environmental, social and economic impact of overhead power lines, and the vulnerability of these exposed and unsecured lines to natural and man-caused disasters simply is not the perfect solution.
So consider an expanded role for the building industry. Commercial and residential buildings alone consume 65% of all electricity. Currently almost 20% of the electricity delivered to those buildings is wasted on unnecessary conversions of AC electricity to DC electricity, the kind we need to power our expanding digital electro-active built environments.
We also need to sharply and immediately focus on the prospect of net zero energy buildings, the kind that produce as much energy as they consume. This emphasis will significantly reduce our overreliance on the utility grid for economic and environmentally responsible energy surety.
At the same time, we need to apply the lessons of the Internet. It demonstrates an architecture—one that has allowed us, as one world community, to be connected, and to utilize even the smallest bits of information created. It equally treats and accommodates its users, from big data crunchers to the smallest of tweets and text messages.
This incredible network of information creation and distribution simply didn’t exist just 30 short years ago. And its bio-mimicked neural topology continues to fuel the information age’s innovation engine, one that it moving on to empower an “Internet of Things,” not just people with computing and other personal information devices.
We need a similar network to support local electric power creation and distribution by buildings. While we might have to change a few things, like allowing the hybrid use of both AC and DC power in the same network—sort of like having iOS and Android devices to live in the same Internet—we could have the enormous ability to realize the full potential of today’s power technologies, and spark the same kind of innovation that continues to advance the Internet. Connecting power creation to power consumption in a true mesh network of massively distributed local building microgrids would give us the power of an ‘Enernet’ or electric energy network.
If you’re having trouble imagining such a system, I invite you to visit Greenbuild 2015 being held in Washington DC this month to witness a live hybrid AC/DC microgrid, a core node in the new Enernet of Electricity, provide locally harvested power to a tradeshow floor. As an example of the fundamental building block of the future Enernet, it will power the Greenbuild 2015 Net Zero Zone pavilion of exhibits that demonstrate the latest in Net Zero products and technologies. Come see the future, come see ‘Greenbuild Unplugged!’