Why a separate group for these four
The Energy Routes (R1 through R4) all run on ETT and they all deal with grid-tied or grid-adjacent electric generation. The Carbon Routes (R5 through R8) all run on GRO and they all deal with land-use carbon. Both groups share a common evidence token and a common methodology family within the group.
The Complex routes don't fit that pattern. R9 issues avoided-emission tonnes but the underlying generation is electric, so it uses ETT (the energy token) rather than GRO (the carbon token). R10 issues thermal attributes (RTC and GO-Heat) on a different external-registry infrastructure than the electric attributes from R1 and R2, and it needs a heat-side evidence token (HTT). R11 covers methane, a non-CO2 greenhouse gas with its own measurement and accounting discipline, and uses a methane-specific evidence token (PRO). R12 covers engineered removals, an emerging asset class with methodology infrastructure still being finalised by integrity bodies and voluntary registries.
What unifies the four is the protocol pattern. Every route runs through a binary gate, a locked accounting plan, route-specific evidence collection, mandatory retirement of overlapping claims, ex-post verifier sign-off, and the consumed-to-carbon discipline at issuance. The infrastructure underneath is the same PoV Gate, the same One-Claim Ledger, the same Attestor Registry that the energy and carbon routes use. Only the evidence schemas and methodology references change between routes.
The four routes at a glance
Each card below is one complex route. The Asset column shows what generates the evidence. The Evidence token column shows which on-chain receipt the route uses (the parallel to ETT for energy or GRO for carbon). The Math or Methodology column shows the locked accounting basis. The Stacking column shows what the One-Claim Ledger allows to coexist with the route.
R9 reuses ETT (same as R1/R2/R4) because its underlying generation is electric. R10 introduces HTT for the heat side. R11 introduces PRO for the methane side. R12's evidence token is part of the design work still pending and is class-specific to the engineered-removal type.
R9 - Diesel-Solar Microgrids
R9 (Diesel-Solar Microgrids) converts measured diesel displacement into verified avoided-emission tonnes. The site must be off-grid or diesel-dominant; the PV and BESS must demonstrably displace diesel generation rather than simply add capacity (additions route to R1 or R2). The carbon math is either fuel-based (using the 2.68 kg CO2 per litre diesel constant) or kWh-based (using a diesel emission factor in the 0.67-0.80 t/MWh range, sized to the genset SFC profile). Pricing reality for well-metered conservative R9 packets typically clears the $20-50 per tonne band (illustrative, not guarantees).
R9 is the lane for mines, island resorts and island utilities, telecom base-station clusters with weak grids, construction microgrids, humanitarian and emergency-deployment sites, remote research and defence outposts. Wherever diesel is the default and a real PV-plus-BESS displacement is in place, R9 turns the measured fuel reduction into an audit-grade tonne. Read the R9 page for the full seven-stage flow, the two accounting paths, and the worked scenarios.
R10 - Renewable Thermal
R10 (Renewable Thermal) monetises useful heat from heat pumps, solar-thermal, and geothermal, plus thermal flex from controllable heat loads and thermal storage. Heat is metered at the EN 1434 standard (flow rate × temperature differential between supply and return); for heat pumps the electric input is also metered for COP audit. HTT mints at 10 kWh-th granularity, with 100 HTT rolling up into 1 MWh-th of issuable thermal attribute. The external registries are M-RETS (which operates the Renewable Thermal Certificate scheme in North America) and the EU AIB framework (which extends Guarantees of Origin to heat under the Renewable Energy Directive).
Heat is roughly half of global final energy consumption and a major source of energy-related CO2; the thermal-attribute rails are maturing as part of the broader decarbonization of heat. R10 plugs renewable heat assets and thermal flex into those rails with on-chain evidence anchored to certified metering. Read the R10 page for the protocol flow, the EN 1434 metering details, and the flex side of the route.
R11 - Methane Avoidance
R11 (Methane Avoidance) converts measured methane reductions into verified avoided-emission tonnes. Three sub-paths share one protocol skeleton. The Flow path covers landfill gas capture and destruction, with flow meters and CH4 analyzers on the gas stream and runtime meters on flares or engines. The Biogas path covers anaerobic digestion and manure management, with feedstock-to-reactor-to-engine tracking and lab analysis of CH4 fraction. The Rice path covers paddy methane suppression, with field telemetry and remote sensing per the registered plot plan.
The accounting math uses the methane density at STP (ρ_CH4 = 0.000716 t/m³), the IPCC GWP100 factor of 28, and the destruction efficiency of the flare or engine (typically 98%). Oxidation defaults, engine slip, parasitics, and leakage are all explicitly deducted. Pricing for credible R11 projects typically clusters around $10-30 per tonne (illustrative, not guarantees). Read the R11 page for the three sub-paths and the path-specific math.
R12 - Tech Removals (roadmap)
R12 (Tech Removals) is the lane for engineered removals: Direct Air Capture, enhanced mineral weathering, mineral carbonation, ocean alkalinity enhancement, and BECCS (bio-energy with carbon capture and storage). The market for engineered removals is small but growing fast on the back of long-tenor forward deals from buyers with deep decarbonization budgets (Microsoft, Frontier, hyperscaler coalitions). Engineered removals typically clear at substantially higher prices than nature-based routes, reflecting the durability premium.
R12 does not yet have a finalised protocol spec. The page is framed as design intent: the 7-stage skeleton applies, but the specific methodology bridges, the durable-removal verifier panel composition, and the evidence-token configuration per removal class are part of the design work still pending. Readiness signals R12 tracks are ICVCM CCP labelling for engineered classes, methodology development at Verra and Puro.earth, and the maturation of independent durable-removal verifier capacity. Read the R12 page for the design intent and the dependencies.
What's shared (and what isn't)
What the four complex routes share is the protocol pattern, not a common evidence token:
Binary gate. Every route starts with a binary additionality or eligibility verdict. R9's gate insists on off-grid or diesel-dominant status; R10's gate routes to the right thermal-attribute lane and confirms metering class; R11's gate confirms causality and uncontrolled CH4 baseline; R12's gate (as designed) routes to the right engineered-removal methodology.
Locked accounting plan. Every route locks the methodology version, the factor sources, and the buffer or uncertainty parameters at issuance. Re-issuance SOP applies for material restatements; settled batches are never repriced.
Route-specific evidence collection. R9 uses ETT plus a diesel baseline pack. R10 uses HTT from EN 1434 heat meters. R11 uses PRO from calibrated flow meters and CH4 analyzers. R12 will use a class-specific evidence token from the engineered-removal facility's process metering.
Mandatory retirement of overlapping claims at S04. The One-Claim Ledger enforces 'one unit of benefit, one claim' across every route. If overlapping energy attributes, RNG certificates, biodiversity offsets, or other instruments exist for the same kWh, MWh-th, m3 of methane, or tonne of removed CO2, those instruments are retired or immobilized in their source registry before the protocol will mint any tonnes.
Ex-post verifier sign-off. Every route requires an independent accredited verifier to sign the vintage batch dossier before the CARBON_TONNE contract mints. The verifier panel composition varies by route (different specializations for diesel-displacement vs heat-flow vs methane MRV vs engineered-removal durability assessment).
Consumed-to-carbon discipline. Evidence tokens are stamped consumed at issuance and rendered permanently non-transferable. ETTs used for R9 cannot be sold as energy attributes; PROs used for R11 cannot back another claim; HTTs used for R10 retirement are permanently retired.
Where it stands
R9 builds on the existing ETT infrastructure (the same token the energy routes use) plus a diesel-baseline-pack evidence schema. The verifier panel for R9 needs members specialised in microgrid MRV; the panel onboarding is geographic.
R10 introduces HTT as a new evidence token, parallel to ETT but for heat. The HTT contract follows the ETT design but is configured for the 10 kWh-th granularity and EN 1434 evidence schema. Registry bridges to M-RETS and to the EU AIB GO-Heat hub are the readiness dependencies.
R11 introduces PRO as a new evidence token specialised for methane MRV. Three sub-paths share the same token but with different evidence schemas (flow meter vs biogas concentration vs rice paddy telemetry). Verifier panel members for methane MRV are a different group from the forestry or coastal verifiers used in the carbon routes.
R12 is the design-intent route. The protocol pattern applies, but no specific methodology is currently operational. The readiness signals R12 tracks are emerging from ICVCM CCP working groups on engineered removals, methodology development at the voluntary registries (Verra and Puro.earth are the most active), and the maturation of durable-removal verifier capacity. The page is honest about this status rather than claiming R12 is ready.
For the protocol-level architecture all four complex routes depend on, see Proof-of-Verification, One-Claim Ledger, and Attestor Registry. For the parallel Energy and Carbon route sections, see Energy Flow and Carbon Flow.
