Mercury energy is offering me (and presumably others) residential power for 3 years fixed at 113c/day and 23.5c/kwh. For me that'd be an extra $18/month above their current standard rates now, but in three years I could be paying less than market rates if power goes up. I've just come off a 3 year plan with them, it saved me $30 this month compared with their standard rates. For comparison I could save $15/month just by switching to a different supplier (Meridian), so the fixed price thing has probably saved me a small amount over the past three years.
I guess it only makes sense if power prices increase at a faster rate than in the past 3 years. Thoughts?
For reference the early months of winter we used 950kwh in a month, I think in the middle of winter that'll go up to more like 1300kwh, and in summer it drops to about 400kwh. I use http://www.powerswitch.org.nz/ to work out the best provider.