Image: TGE Group.

A panel of UK solar asset owners has said that panel cleaning techniques used by O&M subcontractors must improve.

Speaking at this week’s Managing European Solar Assets conference in London the panel, which included some of the UK’s largest asset holders, bemoaned a perceived lack of quality within panel cleaning services.

Lee Moscovitch, partner at solar investors Greencoat Capital, said that he had been “appalled” by some of the techniques he had seen used on some sites.

“[It’s] really basic stuff that you think would be done, but isn’t. You might have a really good O&M provider but with a poor subcontractor,” he added.

Other contributors to the discussion also spoke of poor contracting quality within the panel cleaning subsector and cited cases in which mould had been left to grow on panels and associated equipment.

With asset owners increasingly looking to optimise sites and ensure performance ratios are as high as possible, panel cleaning has come under the microscope as owners investigate the cost/benefit analysis of regular panel cleans.

Speaking on the panel was Enerparc’s Stefan Müller, who remarked that his experience of the German PV market was that regular panel cleans were not necessary, as proven by various analyses conducted by holders of German assets in the past.

However the session’s speakers and audience were in broad agreement that panel cleans remained an important facet of O&M contracting in the UK.