One of the downsides of USB is the relatively limited amount of power that can be transmitted through the cables. USB 2.0 only allowed for a 500 mA load if the device is also transmitting data, while USB 3.0 set the upper limit at 900 mA. Both standards can handle up to 1.5 amps strictly for charging purposes, but not while data is being transmitted. This puts a sharp upper limit on the types of devices that can be powered off USB 3.0 ports — or, at least it used to.

Now, Renesas has demoed the first example of the USB Power Delivery standard, which it hopes to begin commercializing next year. The company has demoed an FPGA version of a USB 3.0 hub powering a system board and hard drive. The drive in question was a standard desktop 3.5-inch drive, which typically draws more current than a standard USB port can provide while maintaining data transfer.

USB Power Delivery (PD), when finalized, will provide up to 100W power at 20V — more than enough to power monitors, external graphics cards, drive arrays, and other hardware without independent power cables and AC adapters. More than that, however, the spec is designed to provide a more flexible solution for moving power between devices. Power can flow in either direction — a laptop could, for example, be powered directly by its external display. USB PD allows devices to adjust their own power consumption — a compatible device might charge at one rate, drop down to a lower charge rate while transmitting data, and then step back up to full, flawlessly.

The hubs are also designed to be flexible at the port level, meaning you can plug a variety of devices into the system without worrying about one product burning out the rest of the devices. Hook up a laptop and an iPhone, in other words, and your iPhone won’t get zapped by the laptop’s far higher power draw. The idea is to create a flexible standard for future USB devices, in which USB can power virtually anything from virtually any source.

USB PD will be included in USB 3.1, which means it should debut along with the new (reversible!) connector style and with full backwards compatibility with older devices. While current chips are being emulated in FPGA, we could see shipping silicon by 2015. Much depends on how quickly motherboard manufacturers move to offer the technology — it’ll be several years before we see the function integrated at the chipset level by the likes of Intel or AMD.

Update: An earlier version of this story claimed this was the first demo of USB PD technology. The first demo boards for USB PD were actually built by Obsidian Technology, which has shipped early test boards to multiple customers.

Now read: How USB charging works, or how to avoid blowing up your smartphone