With drastic global changes in weather patterns, hurricanes and a diminishing ozone layer, today investing in a clean, renewable energy source is the way of the future. In fact, generating energy from waste is a topic often spoken about in the fight against climate change and the role it holds in promoting longer term environmental impact is only getting more relevant. Here, Graham Sanders, Major Account Manager at Geotech, looks at this topic and how the recent changes in legislation are driving the industry forward.
Governments and councils worldwide are constantly faced with energy targets and we need more innovative ways of creating and using renewable energy.
Generating Energy from Waste (EfW) is a process that sees waste treated to produce energy in the form of electricity or heat. With energy targets constantly on government agendas across the globe, EfW is definitely an innovative way of dealing with the waste in the throwaway society we live in today.
Technology used to extract energy from waste has been evolving through the years and today there are varied ways to do this. Recyclable material must be removed from waste first, and energy is recovered from what remains, i.e. from the residual waste. Anaerobic Digestion (AD) – which uses microorganisms to convert organic waste into a methane-rich biogas – is one such method. Biogas or biomethane produced from this can be combusted to generate electricity and heat or converted to biomethane.
AD is an environmentally friendly, cost-effective solution of dealing with much of what we consider to be “waste material”. Instead of the organic waste being burnt or sent to rot at a landfill, AD plants could potentially turn that organic “waste” into 10% of the UK’s domestic gas demand. This means less landfill, stable energy prices, fewer carbon dioxide emissions, and financial savings across the country. According to the Anaerobic Digestion & Bioresources Association (ADBA), AD has the potential to provide up to 75 TWh of energy by 2032, which would be enough to heat a city twice the size of Birmingham and is equivalent to 30% of the UK’s domestic gas demand.
Change to legislation today has made EfW compatible with the UK Government’s Renewable Heat Incentive (RHI) – a UK Government scheme formulated to encourage the uptake of renewable heat technologies amongst householders, communities and businesses through financial incentives. As the first of its kind in the world, the UK Government expects the RHI to contribute towards the ambition to achieve 12% of heating from renewable sources by 2020. Biomethane which is produced by recycling organic wastes and treating purpose-grown energy crops in biogas plants to produce heat, is therefore eligible for support under the RHI.
After over a year’s delay, reforms to the RHI scheme were finally given the seal of approval from the House of Lords in May this year. On the 22nd May, the new tariffs came into effect, ushering in a better deal for AD plant operators and a much-needed push to get the UK investing in biogas.
The ADBA has welcomed these changes, with Chief Executive Charlotte Morton saying: “Green gas produced through AD not only produces much lower levels of emissions than natural gas but is also home-grown, allowing the UK to increase its energy security and be less reliant on energy imports from abroad. AD is already reducing gas imports by 2% and has the potential to reduce them by as much as 16%.
“The restored RHI tariffs will give a vital boost to the AD industry’s ability to produce green gas over the next few years, but with emissions from heat accounting for a third of all UK greenhouse gas emissions and no clear government strategy yet identified for decarbonising heat, it’s imperative that the government commits to long-term support for green gas beyond 2020 while the industry works to bring down costs to become financially self-sufficient.”
The new tariffs for biogas and biomethane are as follows, with the rates for biomethane being reset to 1st April-1st July 2016 levels:
- Biomethane Tier 1 – 5.60p/kWh
- Biomethane Tier 2 – 3.29p/kWh
- Biomethane Tier 3 – 2.53p/kWh
- Small biogas combustion (<200 kWth): 4.64 p/kWh
- Medium biogas combustion (200 kWth<600 kWth): 3.64 p/kWh
- Large biogas combustion (≥600 kWth): 1.36 p/kWh
However, there are a few T&Cs to be aware of – the tariff rates are applicable to new schemes or applications for additional capacity only. Biomethane installations registered between 14 December 2016 and 22 May 2018 also qualify for an uplifted tariff.
Under the revised regulations, at least half of the biogas produced by AD plants will have to be derived from feedstocks classified as wastes or residues (agricultural waste like manure, crop and food waste) in order to receive the full tariff.
The final word
According to the ADBA, the number of new AD plants being built in the UK has fallen in recent years, in line with decreases to the RHI tariffs.
With the new RHI regulations providing a much-needed boost to the amount producers can claim, ADBA forecasts that the restored tariffs will encourage between 40 and 50 new plants to be built over the next two years. This could generate up to an extra 2tWh of renewable heat per year, equivalent to an almost 50% increase in the biomethane industry’s output. www.geotechuk.com