Switch to Green Star Energy or stick with npower fixed rate?

Wammer

I have been on fixed or capped rates with various companies for years and always been quids in, especially when energy price rocketed a few years ago. It was a bit of a shock when one particular fixed rate ended and the next one was based on the new, higher rates, but I had made considerable savings.

I switched to npower Price Protector December 2017 in January this year. I understood that the unit price was slightly higher than other rates, but I reckoned that if energy prices continued to rise, they could end up considerably higher than my fixed rate.

I have received an email from the MSE Energy Club saying I could save £129 / year by switching to Green Star Energy, but that is only for 12 months.

Should I switch to Green Star, and take the gamble that energy prices won’t rise so quickly between 2015 and 2017, or do I stick with the surety of the fixed rate with npower?

I realise a crystal ball would come in handy, but would appreciate some opinions.

I do a comparison regularly so it’s not that I need a long term fix because I am too lazy to keep checking