one way to create free power is to connect up a couple of extra car batteries to you car alternator. Say for example a couple of 40 ah batteries should do, deep cycle marine batteries are even better. from two 40 ah batteries in parallel when fully charged you should be able to get approximately 960 whats for one hour. that could power a 100 what light bulb for 9 hours. maybe three or four hours of lighting in your house if you don't turn on all your lights at once.
By using your car alternator you are storing the excess electricity that is generated from your alternator as you drive. normally your alternator is used to charge your battery after you start, it also powers lights, radios ect, but once you have started it still generates power and most of this electricity is waisted. Think of this as more like energy recovery than free electricity. this system is relatively cheap and easy to install. All you need to do is place the batteries in your boot and get an auto-electrician to connect them up in parallel to your alternator or car batery. Or an even cheaper way is to carry them up front and plug them into your cigeret lighter. If you drive for a couple of hours each day, to and from work for instance, that should be enough to fully charge them.
You will also need to get hold of an inverter, this device converts the 12v dc into 110v ac, this is the mains power that your house uses. An electrician will need to connect a socket onto your power board so that you can plug your batteries and the inverter into your house wiring and us the free power. better still, if you can afford it is to get an ups ( uninterruptible power supply) then if you have a black-out your batteries will automatically take over and give you power until the electricity comes on again.
Obviously this is only a good idea if you happen to do a lot of driving, then it would make sense to recover the wasted electricity. It would be more expensive than getting it of the grid if you went for a drive just to charge your batteries. It is a simple and practical means of getting free electricity even if it is a relatively small amount. Dragging the batteries up the stars every day and plugging them in can be a bit of a bummer though, so get an extra socket installed on your car and use an extension lead.
another means of getting free electricity is to use the 12v supply that comes down your telephone line. when not using your phone this can be used to charge a set of nicad batteries. plug in an old telephone jack and connect a battery clip (9v type) to pines 2 and 5 (assuming that your jacks are RJ45 types) check to make sure that you have polarity around the right way. It is only a few millivolts but it could charge a couple of nicads.