Microsoft’s latest iteration of the Windows client is less hungry when it comes to energy compared to its precursors. In this regard, Microsoft and Intel demonstrated at a recent event how Windows 7 bests both Windows XP and Windows Vista when it comes down to energy consumption. In addition to the obvious environmental benefits, the fact that Windows 7 consumes less power, it also means that mobile computers running the operating system will be able to deliver prolonged battery life to end users.

In fact, for a Windows 7 vs. Vista comparison, the Redmond-based company’s latest version of Windows will allow newer computers to deliver between 10% and 20% more battery life compared to machines running the previous release of the OS (via Beyond Binary). The scenario used for the platform measuring contest involved the two computers playing back a standard-definition DVD.

However, neither Microsoft nor Intel rushed to boast the exact figures of battery time improvement with Windows 7 compared to Vista. The duo explained that there are additional factors to consider. In this regard, end users might not see a full 20% more battery life, but they are bound to notice a positive difference.

And fact is that Windows 7 has Vista beat in every aspect, so why not also energy consumption. According to PCMag, while Windows 7 consumes 16.53 watts when playing back the DVD, Vista SP2 ate 18.35 watts, 11% more.

Microsoft and Intel also compared Windows 7 with Windows XP. The two companies used a couple of identical ThinkPads T400s with the same configurations, except that one was running XP SP2 while the other Windows 7 RTM. According to the data made public, the XP SP2 machine swallowed an average of 20.2 watts. The Windows 7 computer was satiated at just 15.4 watts. For the end user, the difference translates into almost one hour and a half of extra battery life.

Windows 7 RTM Enterprise 90-Day Evaluation is available for download here.