The lightbulb is pretty much a universal symbol of a great idea—but really, what’s new about lightbulbs? In Detroit, there’s plenty…
Way back in Thomas Edison’s day, in the early days of electrification, there was a huge debate whether DC (direct current) or AC (alternating current) was the best way to move electricity around to all the newfangled electric devices being invented at the time…and even though Edison favored DC, most systems eventually went AC….until now. Thanks to a grant from the State of Michigan, the innovative technology of Detroit based Nextek Power Systems and the willingness of NextEnergy to give it a try, a DC-based power system is powering lighting at the NextEnergy Center in Midtown Detroit. And to make the whole technology prove-out even more interesting, roof mounted Solar Photovoltaics (PV) are integrated into the DC power system, creating a local DC power grid.
You ask, so what’s so great about this idea? Plenty…Electricity is generated as DC and is typically used at the device as DC. But, because today most power is generated at large central station generation plants and then distributed over distances of many miles to the various end users, the DC-generated electricity must be converted to AC, travel over high voltage transmission lines, be stepped down to low voltage distribution lines then connected with user loads where the various electric devices typically convert the AC power back to DC to be useful. This DC-AC-travel a long distance-DC conversion costs plenty of energy. As long as the economics for generating electricity favor large central station generation, this “cost to travel” is tolerated. In today’s world, with the possibility of distributed renewables like Solar PV and Wind, these travel costs are no longer necessary. The economics are shifting from large scale central generation plus conversion plus travel to small scale generation at the load, and no travel or conversion costs. The demonstration at NextEnergy Center is designed to measure just how much energy is saved in order to better understand how far and how fast the economics are shifting.
People who support renewables like Wind and Solar PV typically tout environmental benefits (it’s not fossil or nuclear) and energy security benefits (we won’t run out). But in the US, where electricity from traditional fossil fuel, nuclear and hydro sources is pretty inexpensive, and a reliable grid is already built, it’s tough to advocate the economics of renewables. If DC power networks can reduce overall power needs by 20-30%, the economics of building and using distributed renewables are dramatically improved and may help accelerate the spread of renewables in the US. In areas of the world where reliable electricity is not widely available, the combination of distributed renewables and DC power networks may be the equivalent of the “cell phone leap frog over land lines”.
Of course, shifts in our energy infrastructure will take more than one demonstration, and more than one set of technologies. While Nextek Power Systems is focused on DC power networks, device and equipment manufacturers are part of the picture too. Lighting fixtures, electronic devices, fans and motors are pretty much all built with AC-DC conversion devices because the developed world’s installed electric grid is AC. As the economic benefits of using locally generated DC power are better understood, expect plenty of innovation among device manufacturers too. In fact, a number of manufacturers are already working on DC devices and, perhaps more importantly, standards for DC power distribution through the EMerge Alliance > Home.
Local generation and DC power grids may not be right for every building, but if the savings are anything like what we expect, it’s possible that Thomas Edison may get his DC power networks after all. We here at NextEnergy are working with innovators throughout the industry—maybe even the next Thomas Edisons…