Solar PV R&DProject Pilot Landfill Solar Project
This lesson learnt report discusses the construction phase of the Pilot Landfill Solar Project and the potential explosive risk of landfill gas.
A key lesson learnt during the construction phase of the Pilot Landfill Solar Project was the potential explosive risk of landfill gas. As waste decomposes it creates landfill gas which is generally 60% methane and 40% carbon dioxide. This combination of gases creates an explosive risk. Hence, unlike regular solar installations on virgin land, landfills have explosive levels of gas which must be taken into consideration at all phases of development.
The presence of landfill gas meant the entire system needed to meet strict safety standards. The trenches and conduits installed as part of the solar system have the potential to create gas pathways and gas build-up can occur in electrical equipment creating a dangerous explosive risk. During the installation of the solar system, it was identified that the electrical equipment needed to be redesigned as the standard equipment was not suitable for solar installations where there was an explosive risk.
A site meeting was called by our electrical engineers and gas extraction experts who discussed the best options for reducing the explosive risk. It was decided that the trenches and conduits did pose a serious threat to safety in terms of creating a pathway for the gas which could lead to gas build-up in the electrical equipment. To combat this risk the decision was made to install gas ventilations cages on all our electrical equipment which had trenches and conduits running into them as can be seen in the photo 1.
The explosive risk of landfill gas also highlighted the need to only engage contractors who have an understanding of the potential health and safety issues associated with landfill gas and have had experience working on landfills. This need became obvious when the electrical contractors tasked with installing the electrical equipment for the project did not consider the potential explosive risk created by the trenches and conduits leading into the inverters. It was Joule’s own electrical engineers and gas extraction experts who identified this risk due to their experience in regards to working on landfills.