Green Plug Strives Toward Universal Power Adapter

Frank Paniagua has 42 different power adapters in his home, many of them incompatible. With his new company Green Plug of San Ramon, CA, he's trying to change all that. The company is trying to come up with a universal power adapter that is compatible with Universal Serial Bus (USB) plugs (which now power roughly half of the world's devices) but is more efficient at charging devices.

"It's nuts," says Paniagua."The industry ships 2.8 billion of these a year. You get one with every new product that you buy."

Sony has to keep thousands of chargers in stock. It doesn't have to be that way. Gus Pabon, chief technology officer at Green Plug, helped design the attractive power adapters for the Apple iPod. At Green Plug, the designs for power adapters balance both utility and efficiency. The new trick the company came up with is to put power supplies under digital control using a low-cost microcontroller. For demos, the company shows a working three-port hub that delivers 90W of power.

The company is giving away its Greentalk protocol for adapters in hopes of creating a standard, but it has created its own chips that power the adapters and must be embedded in each adapter. The Green Plug firmware must also be put into the hardware of the end user's device in order to make the communications work. That means the entire industry has to shift over to Green Plug's solution. It's an ambitious effort for a company with nine employees that has raised only $1.5 million in capital. But its backers include Intel.

Green Plug's working four-plug power adapter can charge devices with a wide range of power requirements up to 140W. The devices have a thin power cord that can plug into the adapter hub, carrying both data and electricity. The data helps identify what the device is, what its charging requirements are in terms of wattage and when it is fully charged.

"We have created a real-time configurable power supply," says Pabon.

Surge protection is built in. By relieving the burden of power on the grid, Green Plug can save energy worldwide.

This way, Pabon says, the devices can be charged round-robin style, one after the other, where one device charges at a time until it is fully charged. A display can tell the user how to charge most efficiently; for instance, it can indicate the optimal time to charge in the middle of the night to get the lowest electricity costs.

Pabon says USB 2.0 can only deliver 5W to a device and USB 3.0 won't do much better at 7.5W. That's not a very efficient way to charge a 90-W laptop. Since Green Plug has designs for eight-port charges, companies can eventually just ship new wires, but no new adapters with every product.

Paniagua says he realizes it may take a decade to get a universal standard. But he did this once before as the leader of the VESA video standard more than two decades ago. He notes there are big companies preparing to get behind Green Plug's standard.

Paniagua says his target price for a four-port charger is less than $99. The devices are expected to hit the market in the second half of 2008.