| Let's say ai live in a city where there are 4 electric providers. | | In January, i switch to the provider A. | | in February, still at the same house, i switch to provider B. | | In April to provider D. | | My question is: since i did not move from my house, and none came to | change any cable or wires at home, how does it happen that with a | telephone call i'm provided with electrical energy from one provider | to another apparently with no work around my house? | | Thanks.
You did not necesarily actually get electricity from the provider you have your account with. Some are resellers only. They buy electricity from the generators in bulk at discount, and sell to consumers. Those who generate electricity just dump it into grid. The delivery provider (the company that manages the wires) delivers electricity to you and probably does metering. The seller gets the metered amounts, pays the delivery provider some part, and bills you for that and their profits.
It doesn't even have to be in the same grid. If I generate electricity in Texas, I can dump it into the Texas grid, but sell it to someon in New York, as long as there is someone in Texas buying electricity from a generator (or reseller of one) that dumps it into the Northeast grid (such as generating it on Long Island or in Ohio). If it doesn't exactly balance out, some money is exchanged somewhere.
Electricity is bought and sold as commodity and futures.