Edison

Edison is a nice little program to manage your computer's power usage.
It can calculate how much you will save in a month / year according to the settings.

We can specify the price per unit of our electricity tariff, and it will automatically calculate all the savings we would make depending on the setting of high / low power usage.

It will do the calculations on Money savings in U.S.D. and Energy savings in Kilo Watt Hour. Also, CO2 emission in Pounds. Anyway, this is just a rough calculation not much accurate. If you were using your computer for many hours a day and have the habit of leaving it on for some time, this program can save a lot of energy. Otherwise, it is just a minor / no saving at all.

All you need to know is to set the power options in control panel to save electric energy. Also, windows Vista makes it very easy to manage the power settings for a computer.

So, this program is really not a necessity to save energy. All it does is schedule the program to define a "Working Time" for the computer. Other hours are considered as Non-Working hours. And, we can set the program / schedule it to turn off monitor, turn off hard disk and to suspend the computer (Sleep / Stand By) in 15 minutes, 30 minutes or some custom times for all.
We can specify different setting for Working Hours (more power usage) and Non-Working Hours (power saving settings).

One serious lack of the program is that it doesn't include any setting / feature to maintain the working of processor or memory and graphics memory, etc. It must have included some feature to reduce processor usage (by 10% for example). Also, real time monitoring of memory to decide which all data must be in the main memory and in virtual memory and also to automatically maintain it would have been good. Some tips to maintain the power usage, like disabling the unused parts of motherboard (LAN for example), should also be included.

Anyway, this is a freeware. If you really know to manage or set the power saving settings of windows, this program is not needed. We may expect some future enhancements to the program (in the coming versions).