Earth, Wind and Fire

Nicki Minaj has spoken out to defend her bizarre performance art show at the Grammy Awards on Sunday, revealing the alter-ego she introduced to the world has been a work in progress for over two years - and ceremony bosses insisted she bring him to the stage.The hip-hop star had many Grammy guests and TV viewers scratching their heads as she debuted the track Roman Holiday onstage at Los Angeles' Staples Center, surrounded by dancing monks and a man dressed up as a priest.She began the performance with a clip from a movie she is working on about the exorcism of her alter-ego and ended it by appearing to levitate high above the stage.And Minaj accepts it may have seemed an odd performance to many casual fans.Speaking to DJ and Grammys presenter Ryan Seacrest on Monday, she explained: 'Roman was created two years ago... Yesterday was just a coming-out party... It was very literal and streamlined if you know who Roman is and if you know what he's all about, if you don't know the Roman character then you have to digest it.'But she insists the outlandish performance, during which she appeared to be more than a little crazed and manic, was a complete success: 'It's the most comfortable I have been on stage in my entire life... because, first of all, the Grammys chose Roman Holiday... and I could not play them another record after they heard that.'Further explaining her latest creation, Minaj continued: 'I had this vision for Roman... People around him tell him that he's not good enough because he's not normal and he's not blending in with the average Joe... He wanted to show that not only is he amazing... and he's confident but he's never gonna change, he's never gonna be exorcised.'Minaj is currently in the process of creating a movie about her latest concept with director Todd Williams. SLIDESHOW: Grammy highlights

How much power could we extract from sun, wind and geothermal sources, and at what cost compared with the government's preferred solutions - nuclear power and clean coal?