I am looking for lowest power consuming distro - even ubuntu new releases are going downhill. Yet it's a bit confusing - isn't the energy consumption dependant solely on the kernel not the actual distro?
Is there any new recommendations concerning distros with the best power consumption? Is there even one better than win7?
For instance, what about damnsmalllinux?

I don't think DSL would be a good choice, it uses a very old kernel and probably doesn't support many of the things needed to conserve power on a modern system.

I use Arch on my EeePC 901 with kernel-netbook from AUR that is supposed to have many improvements for power consumption over the stock kernel.

I took advantage of the "Super Hybrid Engine" that Asus has and can underclock and overclock the processor as I need, support for this is in all recent kernels. It goes beyond Speedstep, which I also have enabled, it is actually changing the FSB and in the powersave mode it drops nearly a watt.

I also use PHC to undervolt the processor, which gives me extra battery life under load, it doesn't help at idle since this particular system won't allow undervolting on the lower levels of Speedstep. This is about another watt in savings when at full load.

Sometimes factory fan configurations aren't the most efficient either, so overriding the BIOS can get you some savings. I run it as little as possible when on battery. Since I undervolted it, the temperatures have been staying lower anyway and most of the time the fan stays off, when it comes on it rarely goes above 20% speed.

Unfortunately there isn't really any power saving in the drivers for my Atheros wireless card at the moment. I've considered swapping for an Intel one, but haven't gotten around to it. I remember some decent savings on my Intel based Acer when enabling the power saving modes.

I also cut power to the camera, card reader and bluetooth when I am not using them.

In total, I've saved 4 watts at idle and 6 watts under load, which is huge on a system that runs under 20 watts under load. Unfortunately my battery is showing its age and only has 78% capacity now, so I'm getting the same 5 hours that this system got when it was new without tweaking.

Of course, on top of all of that, I'm running fairly light software to keep CPU and disk activity to a minimum.

Keep in mind that not all of these are possible on every system, but it should give you an idea of what is possible in Linux.

Hi,
Basically, uniform control of power will be dictated by the kernel interfaces be setup to the level(s) desired. Modern Linux kernels do allow users to setup control with ease. It is a Gnu/Linux that gets in the way, good example is Ubuntu. Any time you have interfaces between the user and kernel then the user(s) will be limited because of inherent differences between API/UI by the author with said system.

For myself, I do prefer to not have anything between kernel and control of systems. One of the reasons to use Slackware, minimum to no intervention therefore tweaks can be performed without worry or inhibitions.

For non-specific Gnu/Linux reference then;

HTH!