Engineering Recommendation (EREC) G99 Application Process: The TNEI Guide

24 Jun 2019

With the implementation of Engineering Recommendation (EREC) G99, the application process has remained largely the same for most generation sites.

EREC G99 came into force on the 27 April 2019 replacing the previous EREC G59 regime. Existing generation sites that have been commissioned under the EREC G59 regime are still valid and do not need to re-apply.

If additional units are added to the site, these new units must comply to G99 but will be considered separately to the G59 commissioned units. Distribution Network Operator (DNO) licence condition SLC15 has not changed. As such, generation applications remain aligned with the existing timescales and are still submitted directly to the relevant DNO.

New to the EREC G99 Application Form

The majority of the required input data is, by – and – large, the same, with a few notable additions and changes;

  • The G99 application form is different from the G59 form as it is an iterative, live document which acknowledges that all information pertaining to the site is often not available at the time of the initial application submission. Therefore, a version control entry is found at the beginning in order to keep track of the application stage of the project.
  • The network has seen a large rise in connecting embedded generation and in particular, electricity storage – which may behave with the characteristics of either demand or generation depending on its operating regime which is dictated by the service(s) being provided. There is now a section dedicated to electricity storage systems in the application form alongside questions regarding the proposed behaviour of the energy storage system and the services it will be providing.
  • The updated G99 definition of Electricity Storage in the electricity system is “the conversion of electrical energy in to a form of energy which can be stored, the storing of that energy, and the subsequent reconversion of that energy back into electrical energy”. This is different to Energy Storage, which may “convert electrical energy into another form of energy but does not reconvert it back into electrical energy”, instead using it in that form and therefore may be treated as a demand from an electricity operation point of view.
  • New fields in the G99 form include all information pertaining to electricity storage including commercial service(s) provided.
  • Part 3 includes a section for Generating Unit Voltage Control, although this is to be agreed with the DNO so may only be completed after the first issue. This includes power factor settings and voltage and reactive power set points.
  • HV connected PGMs are required to specify their frequency response Droop setting in Limited Frequency Sensitive Mode (LFSM). This is a mandatory requirement for these generators. For Type C and D PGMs the frequency response mode also needs to specified if it is the more onerous Frequency Sensitive Mode (FSM) instead of LFSM.

What information will you need to prepare and submit a successful G99 application?

In order to complete a G99 Standard Application Form with the minimum amount of information necessary, applicants will need to have the following information;

  • Letter of Consent from the land owner;
  • Location map of the generation site with the substation clearly shown;
  • Full address of the site, including the post code and OS Grid Reference coordinates;
  • Details of any existing connection agreements at the site;
  • Single Line Diagram detailing electrical configuration of the generating equipment and interface with the DNO’s network;
  • Name of applicant; the exact name of the legal entity that will contract with the DNO;
  • Name of the generating site;
  • Type(s) of technology;
  • Preferred energisation date;
  • Preferred active power export capacity of site (MW), number of generating units and overall site capacity (MW);
  • Generating unit datasheet (if available);
  • Preferred active power export capacity of the site (MW).

Some of this information can’t be entered into the form and will need to be provided as part of the application pack.

It should be noted that, unrelated to EREC G99, one other change has been made to the application process: application fees are now being levied on Extra High Voltage (>22kV) distribution connected generation projects, in accordance with the newly introduced Electricity (Connection Offer Expenses) Regulations 2018.

You can read more about the main differences between EREC G99 and EREC G59 hereFrom generator applications through to compliance verification, system studies, design and commissioning, TNEI can help you understand the changes and how they will impact on your project.

TNEI are also offering G99 training courses throughout 2019 which will bring you up to speed with the changes and the new application process. Please get in touch to find out more or to book your place.

For more information please contact Callum Dell or any of our grid connection experts.

Key contact

Jonathan Oguntona

Jonathan Oguntona

Senior Consultant and Grid Connections Lead

Jonathan is a Senior Consultant and Grid Connections Lead with 10 years’ experience working as an electrical engineer and grid connection specialist. Jonathan has experience managing the delivery of grid connections for onshore wind, large biomass and battery energy storage projects within the UK. He has also overseen the delivery and construction of Contestable Works. He also has significant experience in power systems analysis specifically providing power quality grid compliance studies (P28 &Harmonics). Jonathan has good communication skills and has provided technical, commercial and regulatory advice to clients. He has significant project management experience, and a pragmatic approach to problem solving.