Tariffs are indexed to the Retail Price Index
Each year the set level of the generation and export tariffs will be adjusted pro-rata to the retail price index change in the previous calendar year. The Tariff administrators then publish the updated tariff levels.
Aaahh! You’ll be sorry you asked. All tariffs used to go up every year in April based on the RPI in the previous calendar year. But now:
The tariff will index with effect from 1st April in the following year. Therefore for a system is installed in January 2013, the tariff was not indexed until April 2014. Why?
This got mixed up with the degression mechanism in April 2013, when the non-PV tariffs were increased in line with RPI, but the PV tariffs were not. Why?
The indices used so far are:
|Year beginning||RPI Index||Cumulative|
|1st April 2010||[base year]||0%|
|1st April 2011||4.8%||4.8%|
|1st April 2012||4.8%||9.8%|
|1st April 2013||3.1%||13.2%|
|1st April 2014||2.7%||16.3%|
|1st April 2015||1.6%||18.2%|