When charging a battery from a natural source, i.e. solar or wind, is it a car battery you charge, or are there others?
How much power do you need to create to charge a battery as above, are amps inportant or voltage?
How do you use the battery afterwards, do you need to use a device in between to change the power to a more useful form?
How much power do you need to create to hook up to the national grid, are amps inportant or voltage?