The Problem of Spotting an RHI Application Peak

Over the last couple of weeks, there have been many comments from officials and political representatives about the RHI spike in the 10 weeks from early September 2015 to November 2015. 

Continually quoted is that 984 applications out of 1,946 came in during this three month period and that this spike was unprecedented and impossible to predict!  Was it really?

The GB RHI has tiering and degression. This means there has been continuous review and adjustment to the rates paid to renewable heat generation.  Surely it would have been a good idea to check how the GB market reacted at each change in tariff announcement?

Luckily GB are very open about their RHI data and publish everything.  Below is a table showing when changes were announced, when they will apply, what technologies are affected and the rate changes.

This tariff table is compared with the spikes in the applications to the GB RHI scheme in the graph below. The cumulative applications are shown in red and the month by month applications shown in blue.

The peaks clearly correlate with the month before the new tariffs are applied.  A rate change was proposed in NI on July 15 internally in the department.

By this stage, GB had 8 significant tariff changes with corresponding peaks in applications.  Most noticeably December 2014 when there was a spike in applications 10 times that of the month before!  Did the AME fog hide these 8 peaks?