The existing electricity grid in the U.S. works--for the most part. But activity to make the grid smarter with digital technologies (see this smart grid FAQ) has finally started to pick up steam. Although there may be varying definitions, the goal of the smart grid is to make electricity distribution more efficient and reliable. In practice, that means more information to help reduce consumption. With better systems to control the flow of electricity, the power grid as a whole can use more solar and wind power. Solar and wind are intermittent energy sources, but if utilities have better controls along the grid that allow them to store energy or switch sources quickly, they can rely on them more confidently.
What does tomorrow's grid look like? Here is an image showing the component pieces as seen by Pacific Gas & Electric, one of the most progressive utilities in the country. PG&E is in the process of installing millions of smart meters.
If the grid built in the 1940s and then upgraded in the 1960s was about central power generation and distribution, the modern grid is far more diverse, including distributed power generation, storage, and a network of sensors.
What does a smarter grid look like at home? Here's a clue. Tendril is one of a number of smart-grid start-ups that make technology for displaying a home's electricity. It works with smart meters, which have two-way communications, and a home network to gather data on appliances and run reports. Now companies like Tendril are trying to work with appliance makers, like General Electric, and makers of heating and cooling systems so that individual appliances can run more efficiently. The idea is that networked home appliances can receive information on fluctuating electricity prices to take advantage of discounted prices at off-peak times.
Software for consumers is certainly important to modernizing the grid, but networking hardware does the heavy lifting. Here is a wireless access point from Trilliant, which makes equipment that allows a smart meter in a home to send data back to a utility over wireless networks. It purchased former municipal wireless company SkyPilot Networks to get access to its WiMax technology for utilities.
The big Web and IT companies are pushing into the smart grid in various ways. Google made a splash earlier this year when it introduced PowerMeter, a Web application (or Google gadget) that displays how much electricity a home uses and how much each appliance consumes. It's the sort of information that's available once a smart meter or other gateway is installed and it helps consumers finds ways to trim their bills.
Not to be left out of the burgeoning energy efficiency area, Microsoft earlier this week released the beta of Hohm, an application that gives homeowners advice on how to cut their energy bills. The software giant is seeking partnerships with utilities so bill information can be fed into the Hohm application.
Yet another approach to the smart grid is to integrate energy-savings and automation into a home-area network built for entertainment. Control4, best known for its home control systems for managing media, on Wednesday said that it has raised $17.3 million to expand into the energy-monitoring business.
Demand response is what the electricity industry calls dialing down electricity consumption at homes or businesses during peak times. By "shedding load," utilities can avoid firing up expensive and polluting power plants.
Here is a photo of EnerNOC's network operations center in Boston, where they work with industrial and business clients on demand response. Based on a signal from the grid operator, EnerNOC makes changes at its customers' locations, such as dimming the lights in a supermarket or turning off a fan at a factory for a short time. Aggregating these events, which can last a few minutes, can save the utility a lot of money. In exchange, the customers are paid for participating in the energy-efficiency program.
For consumers, it might mean the utility turns down the gas heat on a drier or the thermostat. In a recent report, the Carnegie Mellon Electricity Industry Center recommended that consumers be given full control over demand response.
What about plug-in electric cars and the smart grid? If millions of drivers started charging their cars in the early evening, it would require construction of more power plants and potentially be more polluting, according to some researchers.
This is where "smart charging" comes in. Instead of topping off a car's battery right before dinner time, a smart charging system will charge at off-peak times, taking advantage of available power generation capacity. Although this isn't yet done, the idea is that the car owner could get a slight discount on the electricity rate for charging at off-peak times. The system should be smart enough to know when to charge and still ensure a car is ready to go when a driver specifies. Here is a photo of a system designed by the Pacific Northwest National Laboratories for smart charging.