What does the future hold for the hundreds of closed landfill sites across the UK? Luke Prazsky, waste resource management specialist at Wardell Armstrong, argues that any with grid connections could be ideal sites for solar PV – enabling them to support the generation of renewable energy
The many hundreds of closed landfill sites across the UK seem at best to present no more than a long term financial burden to their owners. Many will have permit obligations way beyond the sixty years (or fewer) for which they’ve made financial provision, funded by a proportion of the gate fee put aside for each tonne of waste that has passed through.
At worst though, some landfill sites will present a serious risk to the environment for hundreds more years. What happens when the aftercare funds dry up? Who’s going to pay for the ongoing monitoring? Are sites at risk of being effectively abandoned when the owners can no longer cope with the never ending costs?
We need to find effective and imaginative answers to these questions to avoid future generations being saddled with a hazardous and unwelcome environmental legacy that’s caused by our inability to think and plan ahead.
There’s the dream of landfill mining, of course – but this is beset with hurdles before it can ever become viable. Active closed landfills could theoretically be turned into public open spaces, but operators would naturally worry about the risk of vandalism and lose any opportunity to generate income. Agricultural options are limited because landfills tend not to be flat due to uneven settlement and fluctuating landforms. Nor can developers build houses on such sites.
By contrast, solar PV developments on closed landfill sites could provide a bright and promising answer. Intriguingly, those that present the longest term risk include many that will currently be producing landfill gas that’s combusted in a CHP engine to generate electricity which is mostly exported to the national grid. As landfill sites age the gas yield naturally falls, as does the amount of energy that’s generated. But the grid connection remains available – with the opportunity to install and connect a solar PV system on the same site to harness the energy from the sun and export it using existing infrastructure.
In the past, installing a solar PV system on a landfill site with continuing settlement may have looked like an insuperable hurdle. But recent technological advances in panel mounting and framing using telescopic racking systems mean that solar panels can now be kept flat and level while mounting mechanisms have minimal impact on the engineered cap.
At least one of the big five landfill operators are already looking at this option. We’re already involved in helping sites to assess some of the opportunities. And there are plenty of others that would be suitable.
Taking advantage of existing grid connections means that solar PV developments could provide an ideal way of boosting the bank balances of sites with no income, and making landfill owners far more likely to be able to secure the financial returns needed to cover their ongoing obligations to monitor and manage their sites through the aftercare phase.
The added bonus, needless to say, would be the contribution they would make automatically to the UK’s renewables targets and to the carbon reduction targets of their sites.
Even where a site is still generating some landfill gas, the national grid connection could be optimised by using the solar farm to generate and export electricity during daylight hours, while still using the landfill gas engines at night.
And even a possible future reduction in the financial incentives for solar PV that might reduce the overall growth of the sector wouldn’t necessarily prove to be such a barrier to solar development on former landfill sites, given the strength of argument for boosting the aftercare fund.
In fact, here’s a thought. How about making a special case to DECC to provide higher financial incentives for solar PV on landfill sites in recognition of the bigger picture of environmental protection that such schemes would provide?
And here’s another thought to end with. Should the Environment Agency (and Natural Resource Wales and SEPA for that matter) be looking at making the installation of solar PV systems a stipulation wherever practical on gassing closed landfill sites?
As well as enabling operators to generate new funds for long term aftercare, it could play a new and important role in helping the UK’s contribution to achieving renewable energy targets.