The Windows 8 Consumer Preview is just weeks away from being released to the world, and one of the biggest concerns about any operating system, is how it will handle energy consumption.

Microsoft has written in the past about how Windows 8 will be more efficient in terms of battery life. In the latest post on the official Windows 8 blog site, Microsoft's Sharif Farag and Ben Srour write about how Windows 8 will improve the energy efficiency in the OS's applications.

In the blog post, Farag and Srour write:

For Windows 8, we started off with a rule that would apply to the large majority of Metro style apps: if an app is not on screen, and the screen is not on, it should not impact your battery life. That doesn’t mean WinRT and the user model preclude multi-tasking. There’s a new way of thinking about how and when code takes into account modern hardware capabilities, networking demands, form factors, and reliability/security/privacy. There are going to be some exceptions (e.g. background email syncing, desktop tools), but for the majority of cases, we expect the app to do most of its work while you are actively interacting with it. When an app is not in the foreground, we wanted to ensure that it would either suspend completely, or use limited resources based on a set of common background capabilities (like copying files), which the app can access.
Windows 8 blog talks about power efficiency for apps -