Infinitas Design

Renewable Energy System Design & Development


Non-Domestic Renewable Heat Incentive Tariff Guarantee Process

Posted on 15 April 2020


Infinitas design - Non domestic renewable heat incentive guarantee 2


Tariff guarantees are a useful way to request a guarantee for a project that has not yet been built or commissioned. It allows the risk of future tariff degression to be removed at the early stages of a project, giving confidence to project developers.

The tariff guarantee is a 3-stage process. Stage 1 involves creating an RHI account as normal and then creating a new application with basic details of the project including:

  • Source of energy & technology type
  • Business address, phone number and email address
  • Location of plant (address & postcode)
  • Expected commissioning date
  • Estimated total annual heat generation kWh
  • Expected capacity of plant kW
  • Evidence of proposed heat use – photos, sketch, text, etc
  • Evidence that any necessary planning permission has been granted or evidence that it is not required

Ofgem will then allocate an RHI number, which will remain the same throughout the entire process.

Ofgem will check that there is sufficient budget for the TG application. Once budget is allocated and any Stage 1 documents are submitted, Ofgem will issue a Provisional Tariff Guarantee Notice (PTGN).

Stage 2 covers financial close information. Once a PTGN has been issued, the system owner has 3 weeks to provide information on the project’s financial close to Ofgem as follows:

  • Proof that funds are available to cover the complete construction of the proposed project
  • Proof that the funds are formally committed to the project

Proof may come from investment agreements and some other form of legal or contract documentation AND must be verified and supported by a report from an independent auditor who is not a ‘connected person’.

Financial close information should be sent to

Stage 3 converts the TGN to a full RHI application once commissioning has taken place.

Tariff Guarantees can be revoked in the following circumstances:

  • The installation capacity is 10% greater or smaller than Stage 1 statement
  • The installation capacity is such that a different tariff would apply
  • The plant does not commission before the date noted in the TGN
  • There is a failure to provide information during the TGN to Ofgem if requested

Tariff guarantees are available for:

  • Biomass boilers >=1MWth
  • Biomass CHP all sizes
  • GSHP >=100kWth
  • WSHP >=100kWth
  • Geothermal all sizes
  • Biogas >=600kWth
  • Biomethane all sizes

Infinitas Design is able to carry out Tariff Guarantee applications on a client’s behalf, please contact us to discuss your application.