The Pilot Landfill Solar Report Feasibility Study project sought to investigate the technical and financial feasibility of building solar on landfill sites in Australia.
Report extract
1.1 Opportunity
Landfill sites have very little utility once capped due to issues of land settlement and presence of landfill gas. This makes them potential locations for solar development. Solar generation systems on landfills, and adjacent buffer zones could provide an economically viable reuse for sites that may have significant clean- up costs and little potential for commercial or residential development.
1.2 Benefits
Some potential benefits of having solar developments on capped landfill sites are a reduction of post closure maintenance costs, turning the landfill into a “renewable energy park” and supporting council environmental policies.
1.3 Challenges
Installation of solar generation systems on capped landfill sites can present a series of unique and difficult challenges. The challenges and implications will have an impact on the design of each solar system. Project proponents must be mindful of the following when preparing landfill solar projects.
Hazardous Environment
Unlike regular solar installations on virgin land, you are installing a solar system in a hazardous area which potentially has explosive levels of landfill gas. This must be taken into consideration at all phases of development.
Landfill Gas System
The majority of landfills around Australia have substantial landfill gas systems in place.
The solar system must be designed in a way to avoid interfering or causing damage to the landfill gas system. Damage to the landfill gas system can have significant environmental impacts.
Land Settlement and Final Cap Integrity
Landfill sites are further limited in what kinds of mounting systems are possible due to the potential of land settlement and the need to maintain the integrity of the final cap.
The capping method used, the thickness of the cap, the thickness of the vegetation, the slope of the landfill, the age of the waste material underneath and weight bearing capacity of the soil all have implications for the design.
Breaches in the caps seal as a result of incorrect mountings can cause landfill gas to escape and can compromise the effectiveness of the landfill gas extraction system.
Environmental Regulations
It is imperative that any solar installation installed on a landfill remains compliant with all environmental regulations and standards related to that landfill site.
