CS-N0W research helps UK government to tackle emissions from Energy from Waste facilities
The UK Climate Change Committee’s Seventh Carbon Budget stressed the need for more stringent decarbonisation policies in the waste sector. Specifically, it recommended that all new energy from waste (EfW) facilities have a viable route to connecting to carbon capture and storage (CCS) technology.
A recent project delivered by Ricardo under the Climate Services for a Net Zero Resilient World (CS-N0W) programme has provided the government with foundational evidence to act on these recommendations via carbon pricing.
Greenhouse gas (GHG) emissions from the waste sector have declined in recent decades, as the UK’s landfill tax has reduced the amount of biodegradable waste being buried, and the capture and use of landfill methane has become more widespread. However, the reduction in emissions has stalled as waste is diverted to EfW facilities (see figure below).
Whilst electricity from EfW reduces the demand for fossil fuel power generation, it is a growing source of CO2. EfW now contributes the second largest share of waste sector greenhouse gas emissions after landfills.
Figure 1: Waste emission by subsector – historical (2008-2022) and Balanced Pathway (2025-2050)
Source UK CCC seventh carbon budget
By 2022, 57 EfW facilities were operational in the UK, contributing roughly 3% of total UK power generation. None of these facilities has CCS technology. The Climate Change Committee argues that by 2050, all of them should have CCS.
Against this backdrop, the UK government announced that from 2028, EfW facilities will be covered by the UK Emissions Trading System (UK ETS), a market-based mechanism designed to incentivise investment in technologies and operational practices that minimise GHG emissions.
The decision to include EfW facilities in the UK ETS represents a critical step towards aligning the waste sector with the UK's ambitious net-zero targets. However, it presents a series of challenges, including to develop measurement, reporting and verification (MRV) solutions to enable EfW to join UK ETS and achieve comparable levels of accuracy in fossil carbon emissions data to other participating sectors.
The challenge of measuring, reporting and verification of emissions for EfW
MRV for EfW facilities is technically more complicated than it is for other power plants. Most fossil fuel power stations apply rigorous fuel sampling and compositional analysis to determine the fossil carbon inputs to the unit, which are then used for UK ETS reporting. For EfW this option is far more challenging given the heterogeneous nature of the inputs to EfW, which vary by location and season. The routine and systematic sampling and analysis of Municipal Solid Waste needed to achieve the certainty required under the UK ETS is resource-intensive and presents health and safety issues.
The Municipal Solid Waste processed by EfW facilities is typically comprised of a mixture of part-fossil (e.g. plastics) and part-biogenic (e.g. biomass, biofuels, biogases, etc.) components. Under the UK ETS, waste incineration facilities will only need to purchase emission allowances for their fossil emissions, and not biogenic emissions. This distinction presents a specific challenge: how to develop a cost-effective MRV system that can distinguish between fossil and biogenic CO2.
To answer this question, the Department for Energy and Net Zero (DESNZ) turned to the CS-N0W programme, led by Ricardo. DESNZ tasked the CS-N0W research team to establish a MRV system for EfW that is suitably accurate, rigorous and proportionate.
Comparing MRV methods
The delivery team worked with the department to understand the evidence gaps and mapped the current landscape. To understand key challenges and evaluate MRV options, the team engaged widely with EfW operators, trade associations, policy makers, technology suppliers and laboratories that provide biogenic/fossil carbon analysis services.
Through this process, several available MRV options were identified, including:
- The manual sorting method – A representative sample is collected from incoming waste or the waste bunker, sorted into fractions, sieved, dried, then aggregated into categories (biomass, non-biomass, inert, etc.).
- The selective dissolution method – A representative sample of waste is collected and placed in a concentrated solution of sulphuric acid and hydrogen peroxide. The biomass materials will dissolve, while the fossil derived materials will not.
- Flue gas sampling and radiocarbon C14 analysis – Waste incineration generates a mixture of gases that are channelled into the atmosphere via a flue. C14 analysis is conducted on flue gas samples collected from stack. The half-life of C14 is used to determine the biogenic and fossil fuel components of the emissions. Fossil fuel material will contain close to zero C14, whilst biogenic materials will contain trace levels.
- The balance method - Uses a mathematical model that establishes a set of mass and energy balances to describe the waste incineration system. Inputs to the model consists of real time operational data and values from literature for multiple input and output stream parameters.
For each method, information was gathered on (i) costs, (ii) likely sampling design/frequency to achieve different levels of uncertainty per approach, and (iii) practical considerations for each operator (e.g. sampling access requirements). The team elaborated field-testing protocols to validate the different methodologies by reviewing available data and sources uncertainty in estimating fossil CO2.
It was determined that continuous flue gas sampling using C14 analysis is the preferred MRV method for EfW sites.
Alternative methods were deemed overly labour intensive and less accurate. EfW operators viewed C14 sampling as simpler than alternatives and more transparent as it uses direct measurements. Several of the large operators either already have C14 equipment installed or are trialling it with the intention to roll it out across their fleet. The costs of C14 installation and operation were seen as minor compared to the upcoming cost of the UK ETS.
The ability to distinguish between fossil and biogenic CO2 in the flue gases requires specialist sampling and analysis techniques. Samples of flue gases are collected at the stack and sent to a lab for C14 analysis. An important step in establishing this MRV system will be to build up the laboratory capacity with the accreditations to perform C14 analysis of stack samples.
The analysis delivered by CS-N0W provided DESNZ policy teams with a baseline of institutional knowledge on the available methods for measurement, reporting and verification and the stakeholder engagement and workshop gathered insights from across the industry regarding the challenges and opportunities for implementing each option.
The final report fed directly into the UK government consultation on the UK Emissions Trading Scheme Scope Expansion: Waste.
Joint Consultation on UK Emissions Trading Scheme Scope Expansion: Waste
This joint consultation of the UK Government, the Scottish Government, the Welsh Government and the Department of Agriculture, Environment and Rural Affairs for Northern Ireland was published on the 23rd May 2024. The purpose of consulting on the implementation of how waste incineration and EfW will be included in the scheme from 2026 for the MRV only period, with full inclusion by 2028. The report cites the CS-N0W study on MRV directly:
“The Authority has been working with stakeholders to explore the emissions monitoring methods that are available to waste incineration facilities to determine the fossil and biogenic split of their emissions. This work has included an external report by Ricardo assessing the accuracy, cost, and practicality of the following methods: feedstock sampling and analysis, flue gas sampling and analysis, and predictive (balance) methods”.
What EfW operators should do to prepare for the UK ETS
The expansion of the UK ETS in 2028 to include EfW facilities presents a series of challenges, including complex MRV requirements. However, these challenges can be overcome with careful analysis, evidence-based policy design and systematic stakeholder engagement.
By proactively addressing these challenges, the expansion of UK ETS provides an opportunity. The carbon price will create a market signal to promote more sustainable waste management practices and the uptake of CCS technology, without which, warns the Climate Change Committee, EfW facilities risk becoming stranded assets.
EfW Operator Readiness Checklist for UK ETS
✔ Start planning for MRV compliance now
Review your current emissions monitoring systems and identify gaps against UK ETS requirements.
✔ Engage with MRV solution providers
Explore options for Carbon-14 flue gas sampling and ensure access to accredited labs for analysis
✔ Budget for ETS Costs and MRV implementation
Factor in allowance purchase costs and MRV system investment into financial planning
✔ Assess CCS readiness
Evaluate technical and commercial feasibility of connecting to CCS infrastructure to future-proof assets.
✔ Participate in industry consultations
Respond to government consultations and engage with trade associations to influence policy design.
✔ Train operational teams
Ensure staff understand MRV requirements, sampling protocols, and reporting requirements.
