Think of it like the biofuel mandate that already puts a small percentage of renewable fuel into every litre of diesel you buy at the pump – except applied to heating oil, gas, LPG and other fossil fuels used to warm homes, offices and factories. A Renewable Heat Obligation (RHO) requires the suppliers of fossil heating fuels to ensure that a set proportion of the energy they sell comes from renewable sources. If they fall short, they either buy compliance credits from suppliers who exceeded their target or face penalties.
Ireland has committed to introducing an RHO as a key tool for decarbonising its heat sector, which remains one of the most fossil-fuel-dependent in Europe. The Renewable Heat Obligation Bill 2025 is currently being drafted by the Department of Climate, Energy and the Environment, with the National Oil Reserves Agency (NORA) appointed as scheme administrator. Climate Action Plan 2025, published in April 2025, lists development of the RHO as a key action, and the first compliance year is expected to commence in 2025/26.
🌿 Why Heat Is Ireland’s Hardest Problem
Heat accounts for around 35% of Ireland’s total energy demand – some 50.6 TWh in 2024 – yet it receives far less attention than electricity or transport. In 2024, a striking 89.8% of Ireland’s heat demand was still met by fossil fuels, according to SEAI’s Energy in Ireland report. The renewable share of heating and cooling (RES-H) reached just 7.9% in 2024 – a new high, up from around 5% in 2021, but far below the EU average (over 22% in recent years) and nowhere near the 15.8% that Ireland needs to reach by 2030 under the EU’s recast Renewable Energy Directive (RED III).
Heat-related emissions amounted to 12.3 MtCO2eq in 2024, representing nearly 40% of all energy-related emissions. Residential use accounts for about 44% of heat demand, with industry at roughly 37% and services at 15%. Oil remains dominant in rural homes, natural gas in urban areas, and solid fuels still play a role in parts of the midlands and west. Ireland’s energy import dependency was 79.6% in 2024, significantly above the EU average of 58.3%, which makes the security argument for domestic renewable heat as strong as the climate argument.
🌿 How the RHO Would Work
The proposed scheme is modelled on Ireland’s existing Biofuels Obligation Scheme (BOS) for transport fuels, adapted for the heat sector. The core mechanics are:
- 🌿 Obligated parties – suppliers of fossil fuels used for heating, including kerosene, gas oil, LPG, natural gas, coal and peat. Electricity supplied for heat is excluded because it already has a relatively high and growing renewable share
- 🌿 Obligation rate – each year, obligated suppliers must ensure that a set percentage of the energy they sell comes from certified renewable sources. The rate will start low and increase annually on a trajectory aligned with Ireland’s 2030 climate targets
- 🌿 Compliance mechanisms – suppliers can meet their obligation by blending renewable fuels (such as biomethane into the gas network or bioliquids into heating oil), by purchasing Renewable Heat Certificates from other suppliers who have exceeded their target, or by paying a buy-out price. District heating networks supplied by renewable sources could also contribute to compliance, though Ireland’s district heating infrastructure remains limited compared to Scandinavian and central European countries
- 🌿 Sustainability criteria – all renewable energy counted under the scheme must be certified and meet the sustainability criteria set out in RED III. This is designed to prevent perverse outcomes such as unsustainable biomass sourcing
- 🌿 Green hydrogen multiplier – the Department has proposed applying a multiplier so that each kWh of green hydrogen counts as 2 kWh toward the obligation, incentivising early adoption of hydrogen in heat
The phased introduction is designed to give the market time to scale. The government’s second public consultation in August 2023 proposed no penalties for non-compliance in the first two years, with a multi-year assessment covering the initial three-year period.
🌿 The Biomethane Connection
The RHO is tightly linked to Ireland’s National Biomethane Strategy, published in May 2024, which targets the production of up to 5.7 TWh of indigenously produced biomethane by 2030. Biomethane – renewable gas produced through anaerobic digestion of farm waste, food waste and energy crops – can be injected directly into the existing gas network, making it a drop-in replacement for natural gas with no changes needed at the consumer end.
The RHO is intended to be the primary demand signal that makes biomethane production commercially viable. Without a guaranteed market created by the obligation, developers of anaerobic digestion plants would struggle to secure financing. The government has also announced a EUR 40 million Biomethane Capital Grant Scheme for plant developers, with the Programme for Government 2025 committing EUR 100-200 million in capital funding for biomethane through the Infrastructure Climate and Nature Fund for 2026-2030.
For farmers, the biomethane opportunity is significant. Anaerobic digestion can process slurry, silage and other agricultural residues into gas while producing digestate as a nutrient-rich fertiliser, potentially reducing both emissions and purchased fertiliser costs. Agriculture accounts for 37.7% of Ireland’s national greenhouse gas emissions (EPA final 2023 inventory), and biomethane offers one of the few pathways to reduce agricultural emissions while maintaining productive farming.
🌿 How the RHO Differs from Existing Supports
Ireland already has several policy tools aimed at decarbonising heat, but each works differently:
- 🌿 The SEAI grant schemes – these provide direct financial incentives for homeowners to install heat pumps, upgrade insulation and carry out deep retrofits. They target the demand side by improving building efficiency
- 🌿 The Support Scheme for Renewable Heat (SSRH) – this provides ongoing payments to commercial, industrial and public sector heat users who install renewable heating systems, but operates as a grant-style scheme with a fixed budget
- 🌿 Building regulations (nZEB) – these require new buildings to source a proportion of their energy from renewables, but only apply to new construction
The RHO is fundamentally different because it operates on the supply side. Rather than paying consumers to switch, it obliges fuel suppliers to change the composition of what they sell. This creates a market mechanism that scales automatically with fuel sales and does not depend on annual government budget allocations. It also reaches consumers who may never apply for a grant – particularly those using kerosene or heating oil in rural areas where alternatives have been slowest to penetrate.
🌿 What It Means for Homeowners and Businesses
In practical terms, the RHO means that a small proportion of the cost of compliance will likely be passed through to fuel prices, similar to how the biofuel obligation adds a modest cost to petrol and diesel. The Department’s analysis has examined the consumer cost impact as part of the scheme design process. The trade-off is between a marginal increase in fuel costs now and the larger cost – both financial and environmental – of continued dependence on imported fossil fuels with a rising carbon tax (heading to EUR 100 per tonne by 2030).
For businesses in the renewable energy sector, the RHO opens a significant new market. Biomethane producers, bioliquid suppliers, renewable heat certificate traders and anaerobic digestion developers will all benefit from the guaranteed demand the obligation creates.
🌿 Frequently Asked Questions
🌿 When will the Renewable Heat Obligation start in Ireland?
The Renewable Heat Obligation Bill 2025 is being drafted, with NORA appointed as scheme administrator. The first compliance year is expected to commence in 2025/26. The scheme has been delayed from its original 2024 target due to the complexity of scheme design and the need for further stakeholder consultation and data gathering.
🌿 Will the RHO increase my heating bills?
Some compliance costs are likely to be passed through to fuel prices, similar to the existing biofuel obligation on transport fuels. However, the rising carbon tax (EUR 63.50 per tonne on heating fuels as of early 2026, rising to EUR 71 from May 2026 and heading to EUR 100 by 2030) already increases fossil heating costs each year. The RHO is designed to create a market for cheaper renewable alternatives that can reduce long-term dependence on these increasingly expensive fuels.
🌿 What is the difference between the RHO and the SEAI heat pump grant?
SEAI grants operate on the demand side – they help individual homeowners pay for specific equipment like heat pumps. The RHO operates on the supply side – it requires fuel suppliers to ensure a proportion of what they sell is renewable. The two are complementary. Grants help those who actively seek them; the RHO changes the fuel mix for everyone, including those who never apply for a grant.
🌿 How does biomethane fit into the RHO?
Biomethane is expected to be one of the primary fuels used for compliance. It can be injected into the existing gas network as a direct replacement for natural gas, requiring no changes at the consumer end. Ireland’s National Biomethane Strategy targets 5.7 TWh of production by 2030, and the RHO is the main demand mechanism to make that target commercially achievable.