The tariffs apply immediately to all installations registered after 31st March 2012.

However any installations after 12th December 2011 will receive the existing tariffs only until 31st March 2012, whereafter they get the new reduced rate.

The government consultation said:

44. The new tariffs will come into force from 1 April 2012 but will apply from that date to all new PV installations with an eligibility date of on or after 12 December 2011 (the ‘reference date’). Existing generators with an eligibility date before the reference date will not be affected by the proposed change in tariffs.

45. The effect of this is that, depending on the result of the consultation, installations with an eligibility date that falls between the reference date and 31 March 2012 will receive the current tariff for that period only, and will then move to the new tariff from 1 April 2012. Those installations with an eligibility date on or after 1 April 2012 will start immediately on the new tariff.