Some of us may have too many electric appliances operating at the same time so to pass the electrical power limit provided by our contract with the electric supplier. This leads to unpleasant "travels" to the energy meter to reattach the breaker. At least this is what happens in Italy. The last time I made up and down the stairs, I thought it would be really useful to have some device that would allow me to display the instantaneous power supplied to the household electric plant. So I would have been warned when the meter is going to "break away". From this idea the Energy Alerter was born. The project consists of two parts, a server and a client, both made with an Arduino, and a couple of ethernet shields. It is inspired to Open Energy Monitor.