The initial idea for U-SNAP emerged in 2007 when the California Energy Commission (CEC) was considering the concept of Programmable Communicating Thermostats (PCTs) as part of its Title 24 energy efficiency program. PCTs were deemed to be necessary for a statewide demand response system controlled by the CEC through a Radio Data System (RDS) installed in every PCT. Recognizing that utilities were rolling out AMI programs throughout the state and that the PCTs would need to communicate with the native AMI meter protocol as well, the U-SNAP concept was conceived as the ideal solution.

The idea is market proven and simple. Rather than force manufacturers to build and integrate thermostats for each communication protocol deployed, why not offer a simple circuit card that can be “plugged” or “snapped” into a thermostat to connect it to the native AMI network? That way, when one state or utility adopts protocol A and another adopts protocol B, manufacturers and retailers can offer the same exact product in multiple markets. The same standard for thermostats can be applied to other HAN devices such as in-home displays, load control modules, plug-in electric vehicles, solar energy systems and even kitchen appliances.

 
 
Like the USB port on a PC that allows a myriad of applications, the U-SNAP card provides a common connector between the communications module and the application (thermostat, energy display, load controller, PHEV etc.). The U-SNAP card enables any HAN (Home Area Network) standard, present and future, to use any vendor's Smart Meter as a gateway into the home, without adding additional hardware in the meter. By providing industry with a protocol independent serial interface, it is possible to extend the Smart Grid directly to energy aware consumer products.

The U-SNAP card provides an affordable solution that can be deployed during the manufacturing process or in the field. Utilities can continue deployment of their smart meters using their protocol of choice, knowing that HAN devices will be compatible today, tomorrow and well into the future. Utilities will save money by not having to bear the extra cost of HAN communication cards in their meters, while consumers will benefit from standardized products available from multiple suppliers, including traditional retail and DIY channels.

Utilities interested in extending AMI to the HAN can allow consumers to purchase standard products through traditional retail channels and ship a pre-configured U-SNAP card to their customers. Once received, consumers simply “snap” the card into the open slot in a compatible product. The utility can then connect, communicate and/or control the device using the existing AMI network.

The U-SNAP Alliance is rapidly gaining support by Smart Grid stakeholders worldwide, including utilities, metering & AMI suppliers, device manufacturers, industry consultants and regulators. In order to accelerate standardization efforts, a specification is nearly completed and consumers should be able to purchase compatible products early this year.