Number crunching

Reducing carbon footprints is the talk of the alternative town these days. Swap those old wolfram lightbulbs for the green fluorescent types, use LED's, turn down the heating and wear an extra sweater etc. You know, doing your bit for the environment. So last year all the bigwhigs that came up with the idea of Live Earth jumped on the easy-to-cash-in-flow and wanted to raise awareness. But did they do any numbers besides counting pennies? (Read all about it in the blogosphere btw).

Let's back that up with some actual numbers shall we? What about the power consumed at your average concerts? Let's focus on some big bands. U2, Rolling Stones, Genesis. These music icons all have standard humongous lighting and sound rigs. Let's crunch some numbers for the latter band.
Power was generated by 4 synchronised gennies. 900 Amps per phase. These babies are running for seven hours each show.

So if we do the math: 4 (gennies) x 3 (phases) x 900A = 10800 Amps power consumption per hour.

So we are looking at P=U.I to know the Capacity in Watt. @ 240V this is 2592 kW per hour. For seven hours. Which is 18144 kWh a show.

Average consumption for a household varies but lets pick a round number: about 4000 kWh a year.
So a run of the mill Genesis show equals electricity for 4 households for a whole year.
Or 10,95 kWh a day a household (4000/365). This could power around 1655 families every night.

How many shows, how many bands, how many tours?
I'm no eco-warrior but I was mightily impressed when doing this quick calculation.