In the first instalment Wallace is taking a shower when his boiler breaks down.
Viewers will see the inventor naked for the first time.
Gromit fails to fix the boiler and ends up calling npower's Home Team to come and make the repairs.
The campaign launches this weekend on Saturday March 28th, just ahead of the Switch off for Earth Hour 2009 at 20:30 GMT, when the World Wildlife Fund is encouraging consumers to switch off their lights for an hour.
Wallace & Gromit have already appeared in press adverts for npower, which played on this winter's poor weather and heavy snow.
npower was the last of the big six energy suppliers to cut its electricity prices, which it dropped by eight per cent in March.
Click here to run an energy price comparison, and see if you could be paying less for your gas and electricity.