How the tariff levels change for those installing systems after April 2012
Once a system has been installed and registered for the Feed-In Tariffs, the tariff levels are fixed and subject only to index-linking for inflation as described in our information on duration and variations.
Compensating for future cost reductions
Most renewable energy technologies are expected to get cheaper as volumes build in the future.
To compensate for this, and to ensure that the support costs decrease over time, the tariffs for new registrants will reduce progressively, through a mechanism called 'degression'.
The original intention was that this degression would be a fixed annual percentage reduction depending on the technology.
Evolution of the degression mechanism
The simple degression approach proved insufficiently responsive to keep up with the high rates of cost reduction experienced in particular by solar PV technology in the early years of the FITs.
A more complex degression mechanism was therefore evolved and operated intil the end of 2015, as further decribed in the Eligibility and Tariffs section here.
The degression approach changed again in 2016 as further detailed here.