Controlling energy consumption is a goal on the minds of nearly everyone right now, business executive and consumer alike. Much of the impetus for this initiative is coming from recent smart grid energy policy.

Many industrial companies have agreements with utilities to throttle back consumption during peak demand, but residential customers are still mostly charged a flat rate, regardless of time of use. With a smart grid, consumers can actively participate in energy savings. By observing real-time rate information, they can turn off energy-consuming appliances during high rate periods while benefiting from reduced rates.

Studies show that if consumers receive real-time usage information as opposed to a monthly utility bill after the fact, electric usage could be cut by at least 10 percent due to simple consumption awareness. That reduction could double if the consumer gave the utility permission to turn off the water heater or pool pump for a short period of time or raise or lower the thermostat set temperature by a degree or two at peak times.

Energy-aware appliances

The Utility Smart Network Access Port (U-SNAP) Alliance aims to create a mass market of Home Area Network (HAN)-based products supporting consumer energy awareness as well as provide an automated means to conserve power. A consortium comprising utilities, AMI suppliers, HAN vendors, industry consultants, academics, and regulators, the U-SNAP Alliance seeks interoperable, secure, and cost-effective solutions for extending the smart grid to energy-aware consumer products.

One of the group’s recent developments is a Wi-Fi U-SNAP module that allows consumers to connect their home appliances with their Wi-Fi networks for remote monitoring and control. GainSpan Corporation, Our Home Spaces, and RF Digital recently introduced this low-power Wi-Fi U-SNAP module, which simplifies the process for smart grid customers to “just add Wi-Fi” to their applications.

The beauty of this module is that Wi-Fi is the de facto wireless technology of choice for consumers. Consider the statistics: More than 2 billion certified devices are deployed using Wi-Fi; 75 percent of DSL or cable modems ship with integrated Wi-Fi access points; and more than 40 percent of smart phones are equipped with Wi-Fi. Wi-Fi Direct, which was recently introduced by the Wi-Fi Alliance, will further extend the use of Wi-Fi in the home by turning TV sets, picture frames, and even smart phones into soft access points. Therefore, it is logical to regard Wi-Fi as the ideal technology to connect nearly every appliance in the home, from thermostats to washing machines, to the smart grid. The Wi-Fi U-SNAP module (Figure 1) makes connectivity simple and secure, building on extensive industry experience in Wi-Fi.

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Features of the U-SNAP Wi-Fi module include:

·    The ability to operate with line- or battery-powered devices, running for years on a single AA battery.

·    Easy to provision either via the Wi-Fi protected setup push-button method or through a USB interface connected to a computer.

·    Remote antenna capability that lets the module be placed behind an appliance or near a wall outlet.

·    Industrial temperature range (-40 °C to +85 °C) allowing use in indoor or outdoor equipment.

Software-adaptable hardware I/O

The U-SNAP specification defines the hardware interface, physical dimensions, data transfer, message contents, and protocol specifics for HAN devices. The root of the specification relies on the Serial Peripheral Interface (SPI) port found on most communication chips.

The design takes advantage of the System-on-Chip (SoC, block diagram shown in Figure 2), expanding the SPI to support a variety of other hardware interfaces over this connector. The interfaces include:

·    Asynchronous Serial Interface (UART): Many existing appliances and solar inverters already support UART interfaces.

·    General-Purpose Input/Output (GPIO): This is an important interface for sensing external digital (on/off) circuit conditions such as sensors, relays (mechanical and solid-state), and so on. It is also capable of exerting digital control over the external environment for motor on/off, lighting on/off/dim, LED status indicators, and other functions.

·    Analog[]/digital converters: Analog-to-digital conversion is useful for recording, in a digital format, physical world voltage domain parameters such as voltage, sensor outputs (often in analog voltage), and current measurements derived by current transformers or Hall Effect devices.

·    Digital/Analog converters: Digital-to-analog conversion allows control over a wide variety of physical world circumstances such as motor speed, audio, light dimming, servomechanisms, and shades.

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With its ability to adapt to any of the aforementioned interfaces, the Wi-Fi U-SNAP module can be readily integrated as a stand-alone controller or with another processor. The module can thus monitor and control any number of energy-monitoring or -consuming devices – compressors, refrigerators, hot water heater relays, in-circuit power, whole home consumption, PV generation, chemical sensors, and others – and then transmit that information back to a central site or server.

The Wi-Fi of things

Pick up your favorite smart phone – chances are it supports a Wi-Fi interface. WebTV, which will make its debut in late 2009, supports a Wi-Fi interface. Many in-home displays or even digital picture frames already support Wi-Fi. This rapidly expanding list of Wi-Fi-enabled things at home or work offers users exciting new ways to interact with their energy use in near real time.

With the proliferation of Wi-Fi-enabled devices, companies such as Our Home Spaces have begun to provide energy dashboard display options on products in the home. Radio Thermostat Company of America recently debuted its first Wi-Fi-based smart thermostat, the CT80. The Wi-Fi module is based on the GainSpan GS1011 SoC design. Figure 3 shows the Web portal to this smart thermostat.

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As of December 2009, ENERGY STAR ratings will be removed from programmable thermostats. Studies show most consumers do not live a programmed day, let alone a week. Instead, thermostats are set to one or two temperatures. With communicating energy devices, however, users can decide to turn their temperature up/down or to a preset state anytime and from anywhere.

Even more exciting is the opportunity to receive energy use estimates before energy is consumed. Utilities can accumulate energy information and push notifications to users’ smart phones, alerting them that they are about to spend or save money, based on the actions they are trying to perform. For example, if you leave work early to go home on a hot day, you may or may not decide to turn your temperature down (and your AC on) at 3 p.m. if you understand the decision’s cost impact.

With the graphical nature of many smart phones and mobile Internet devices, users will be able to not only see, but also quickly and easily control what’s going on in their home. They might even find it fun.

Smart energy homes

The smart grid and the Wi-Fi-enabled home present an immense opportunity from which both the utility and consumer stand to benefit. Adding intelligence and networking capabilities to appliances, thermostats, heating, and A/C systems will allow homeowners to monitor their energy consumption and reduce their utility bills with little effort and take advantage of incentives provided by the utility for energy conservation. Meanwhile, utilities will be able to more effectively manage peak demand.

By offering tools to consumers and utility companies, the smart home will change the way consumers participate in energy consumption. Using tools that integrate with devices consumers already own and leverage the Wi-Fi infrastructure that already exists in their homes provides a cost-effective means to encourage consumer participation, which is critical to the success of the smart grid deployment.

Who doesn’t want the capability to learn their energy usage on their smart phone and discover that the utility is actually paying them for the excess solar energy they recently generated or had available in storage?

Bernard Aboussouan is VP of marketing for GainSpan, where he leads marketing and application engineering functions. Before joining GainSpan, Bernard was VP of marketing and business development at Sequans Communications, where he was in charge of the company’s expansion in the United States. Prior to Sequans, he served as VP of marketing and business development at BeamReach Networks, and held senior marketing and engineering positions at Harris Corporation and Nortel Networks.

Janet Peterson is CEO of Our Home Spaces. With more than 30 years of experience at software and service companies, she specializes in business development with an emphasis on core strategy conception, technology assessment, new market development, and OEM/channel alliances. Prior to OHS, Janet was cofounder and president of Spyrus, a leader in Internet-based PKI security, and served as VP of engineering at Ultron, working in the field of cryptographic techniques. Janet has been actively involved in Internet and IEEE standards, and was part of the 802 committee before it had a dot after the name. She holds a BS from Illinois Institute of Technology.

GainSpan
408-454-6630
bernard.aboussouan@gainspan.com
www.gainspan.com

Our Home Spaces
415-883-8051
j_peterson@ourhomespaces.com
www.ourhomespaces.com