We've seen Onstar from General Motors. We've heard about iPhone apps that allow you to keep tabs on how your 2011 Nissan Leaf or Smart Electric Drive are charging too, and some energy companies are wanting to develop services that keep you updated on the status of your EV.

Smart-Grid technology is on the rise and EVs are right at the forefront. Now Toyota is plugging in to the idea with a system known as Toyota Smart Center.

Smart Center goes one better than the usual systems though. Currently, systems such as the iPhone apps you might use for a Leaf or Smart keep you updated on your electric car's state of charge, and some have options to pre-warm or cool the car in different weather conditions before you get in on a morning.

How does it work?

Toyota's new system, co-developed with its little known housing business (Toyota sold 5,300 homes in Japan last year), pairs all the car-related functions with utilities throughout your house, allowing you to keep track of your total energy usage.

Users will be able to access information via televisions or mobile handsets and make adjustments to their energy usage, switching off electronic gadgets when they aren't being used, starting or stopping the charge on your EV, or using presets to make use of cheaper electricity rates at off-peak times.

What are the benefits?

According to Toyota, all the little changes the system will allow you to control can add up to significant savings - the smart-grid home technology used in conjunction with a 2012 Toyota Prius Plug-In Hybrid can save as much as 75 percent over regular homes with gasoline cars, the company claims.

Centralizing the data from all the utilities in your home can save you money then, but it can also save a lot of time and effort. You can have your electric car ready to go in the morning, but should you get to work and realise you've left the oven on, you could conceivably turn it off remotely.

Or, you could have the house pre-warmed or pre-cooled ready for when you return home from work, just as your car had been in the morning. Not needing the heating or air conditioning on all day would save huge amounts of energy.

When will it be implemented?

Toyota says the launch of the Smart Center technology will coincide with its plug-in hybrid cars going on sale in 2012.

For the time being, roll-out hasn't been confirmed for overseas markets so it's difficult to say whether we'll see it in the U.S, although companies such as Ford and General Electric are working on their own versions of the technology and it's not beyond reason to assume that other companies are considering it too.

Shigeki Tomoyama, managing officer of the project at Toyota, said "Linking the home and the car will reduce global-warming gases, that will become our social duty."

Check out more information on home recharging in our guide to charging your electric car at home.

[ABC News]