This blog post is around seven or eight years overdue. Anyway, I had been musing about energy grids at the time and thinking about things like long-distance alternating current (AC) power transmission, the rise of solar panels, and electronics. I figured in 15-20 years (so about 7-12 years from now), we’d start seeing direct current (DC) power being more available from the wall. Before that can happen, people need a supply of DC power and devices that use DC power.
Presently, we use AC power for mains because it’s easier/cheaper to build transformers to raise/lower the voltage for transmission/delivery. However, a the price of solar panels (which produce DC power) and batteries (which store and deliver DC power) drop, solar power for homes becomes a more viable option. As that becomes more prevalent, the need for efficient long-distance delivery drops. Right now, all that locally-produced DC power usually gets converted back into AC power to supply mains (wall outlet) power.
On the demand side of the power equation, many of our devices nowadays use DC power: cellphones, computers, and even electric cars with their DC motors. A backup power supply for when there are blackouts stores stores power delivered via AC to a DC battery and converts it back to AC for the plugged-in devices — many of which, as we’ve established, will need to convert it back to DC! Having to deal with AC just seems like an extra step.
I realize that many of these devices operate at different voltages and perhaps that might be the biggest obstacle to mostly-DC households — at least in new constructions. That, and, of course, the availability of DC-powered items. The DC-powered future seems to be approaching slower than I expected, but I still see signs it’s coming. Delivering power over ethernet (PoE) — that is, power through networking cables, though niche in households, is used in offices and commercial locations to provide power to devices such as wireless access points, security cameras, phones, store displays, and even room lighting. PoE standards are evolving to allow higher power uses and we are on the verge of finalizing standards to power even the most power-hungry laptops. I’ve seen outlets in airports, busses, hotels, and even wall-outlets that provide power to USB devices (DC!). Not only that, Apple, Asus, Dell, HP, Samsung, and others offer laptops, tablets, and phones which charge themselves using USB type-C connectors.
The last big obstacle to the widespread adoption of DC power in households is probably appliances. I don’t purport to be an expert in things electrical by any means (maybe fooled you so far in this post?) Things like AC washing machines, ovens, and fridges might take a while to be phased out (ha ha!) in favour of DC versions, if at all. Perhaps the compressors used in fridges and the motors in washing machines will be replaced by brushless DC motors due to the falling cost of microcontrollers and the higher efficiency and reliability of these motors. In the meantime, I eagerly wait for the day where most of my devices plug directly into a wall outlet using a single type of standard cable without having to buy/replace/carry around a bulky adaptor.