After a century of using Alternating Current to transmit electricity over long distances, the restrictions that kept Direct Current out of the running early on are disappearing

For instance, solar photovoltaic (PV) panels, fuel cells and batteries produce DC power and residential, commercial and industrial electronics loads use DC. But if a power source is to be used “on the grid” it must first be inverted to AC at the source and transmitted to the load, then rectified back to DC at the end use device. This arrangement adds expense, increases losses (including “vampire load”), degrades AC power quality and reduces power transfer capability due to reactance.

If homes and businesses could use solar PV, fuel cells and batteries for DC power directly for their electronics needs, including lighting, entertainment and computing, they could not only increase efficiency but also cut grid reliance. Many electronics devices such as LED lights actually work better on DC. They last longer because they're not going through thermal cycling, have lower losses because there is no AC skin effect and provide higher quality light (i.e., no 60 Hz flicker).

Lower ohmic losses is just one of many advantages for DC power transmission. DC lines don’t introduce reactance or susceptance, meaning greater power transfer capacity and less voltage variation. DC power is not subject to frequency variation or leading/lagging power factor. And electrical engineering students and professionals everywhere will rejoice in the elimination of the complexities of symmetrical components and multiphase analysis for planning and operations.

With the cost of DC power becoming less than AC and the technology for DC power transmission and generation improving quickly, it makes sense to begin introducing DC grids to our energy transmission system. While it would be too costly to convert our current infrastructure completely to DC, introducing DC microgrids that can function both independently and in concert with the infrastructure could help bridge this gap and start the conversion to a DC power infrastructure.

To read the entire article, head over to The Energy Collective.

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