The latest solar PV deployment figures from the Department of Energy and Climate Change (DECC) have continued to cause confusion after they recorded a gap of over 8MW compared to official Ofgem statistics for April, and dramatically revised upwards its forecasts for total Q1 deployment.

In its latest bulletin released this morning, DECC has claimed that 10MW of solar was deployed last month in Great Britain through systems ranging up to 5MW, predominantly from 0-4kw systems (7MW).

However, Ofgem’s monthly report on feed-in tariff deployment for April, released on 9 May, showed that over 18.5MW of solar PV was deployed under the scheme, suggesting more capacity was added than DECC have today claimed.

The shortfall between the two data sets was down to a discrepancy between the figures for covering commercial installations over 50kW, which Ofgem claims were responsible for adding almost 8MW (7.76MW) in April. DECC’s figures however suggest that no systems within this range were completed last month.

In response to questions put forward by Solar Power Portal on this point, a DECC spokesperson said Ofgem’s >50 kW figures are based on ROOFIT applications, many of which are pre-accredited applications and will therefore not have been deployed. The department also claimed that any others will not have been fully accredited and so would not have been included in the figures, suggesting no systems over 50kW were completed and fully accredited last month.

Data for the other system ranges were broadly in line, with only a 0.8MW gap for systems within the 10-50kw band being the biggest difference between the two sets of figures.

Today’s official figures also reveal the inaccuracy of DECC’s previous estimates for deployment in the first quarter of the year. The department claimed at the end of April that 370MW of solar PV was deployed in the first three months of the year however today’s numbers show 517MW of capacity for this period.

DECC has often been criticised for the inaccuracy of its deployment data, particularly since the implementation of the new FiT regime at the start of the year. Differences between government stats and Ogfem’s were reportedly down to the latter recording projects during the pause period before the new FiT rates on 8 February.

SPP was assured at the end of March by DECC the difference between Ofgem’s figures and its own would “only really exist for February”.  However, today’s discrepancies suggest DECC is still having trouble recording accurate deployment data, particularly for the growing commercial sector.

Despite their contrasting figures, both DECC and Ofgem make clear that deployment has fallen substantially since the same period last year. In contrast to last month’s 10MW quoted by DECC, April 2015 saw around 64MW deployed.

Leonie Greene, head of external affairs at the Solar Trade Association (STA), told SPP this morning: “The bigger issue is these are very small deployment  figures, consequently suggesting the turmoil in the industry. It's essential to understand what is happening in the industry and that is why we are conducting an analysis with PwC. The concern, apart from company & job losses, is retaining the brilliant skills & efficiencies achieved by the UK industry.”

The joint study between the STA and PwC closed yesterday with results expected later this summer.