An EPRI White Paper
DC Power Production, Delivery and Utilization
Example Application:Your Future Neighborhood
tion of energy without storage, a properly sized PV array would ordinarily produce no more power than the minimum load on the DC bus. Excess power cannot be used because it can’t be exported to the AC system.
Figure 20.A possible DC power system for tomor- row’s home
Adding DC power delivery systems to our homes, office build- ings, or commercial facilities offers the potential for improve- ments in energy-delivery efficiency, reliability, power quality, and cost of operation as compared to traditional power sys- tems. DC power distribution systems may also help overcome constraints in the development of new transmission capacity that are beginning to impact the power industry.
What might a future with DC power delivery look like? A num- ber of options are available. One includes stand-alone systems that can operate full time as off-the-grid “islands,” indepen- dent of the bulk power supply system. Hybrid buildings are also possible, with utility-supplied power as well as building- based generators such as a solar array, fuel cell, energy storage device, or even a hybrid automobile.
From the kitchen inductive charger to the PC to the air conditioner, appliances throughout the house could be DC powered.
DC systems can operate selected loads or critical subsystems, such as computers and lights. Or a DC charging “rail” such as
Figure 21. Hybrid vehicles may be able to provide power for the home
Figure 19.A DC-powered inductive charging system
Tomorrow’s homes may be blissfully cord free, enabling people to charge portable electronics using an inductive charging pad fed by rooftop solar cells.
Tests have been conducted to enable a hybrid Prius to operate as an emergency home generator and power a home for up to 36 hours. Shown above is a plug that can be used to deliver power into an AC system. DC power delivery options could also be feasible. Moreover, if plug-in hybrids that rely on batteries to a greater extent than today’s hybrids enter the market, then charging a car with DC power from a home generator will be possible.
Photo courtesy of EcoTechnology Solutions