Fast Track Application Process for Integrated Micro Generation and Storage

The industry is experiencing a significant upturn in LV connected small scale energy storage.  Historically in GB, Engineering Recommendations (EREC) G83 and EREC G59 facilitated the connection of all generation, including energy storage; however, some manufacturers and installers considered that the requirements of those ERECs could sometimes be seen as a barrier in terms of application timescales and the potential high costs imposed for witness testing small scale domestic Energy Storage schemes.

This was further highlighted during the production of the IET Code of Practice for Energy Storage (CoP) where publication of the CoP was stalled until a mutual resolution to these obstacles could be found. Both BEIS and Ofgem voiced their concerns regarding the aforementioned and whilst they were understanding of the legislative/regulatory issues that existed and the need for visibility of what is connected to the networks they were keen that the industry worked together in finding both a suitable short-term solution and initiating work on a longer term resolution.

The Guaranteed Standards of Performance (GSoP) timescales for providing an LV generation quote/response are currently 45 days and whilst it is uncommon for the commissioning of small LV connected scheme to be witnessed there was evidence nationally where schemes as small as 1kW had the requirement for the commissioning to be witnessed by the DNO included within the customer’s quotation. In addition to the inconsistencies that existed around the requirements for witnessing there was also the uncertainty as to when to apply the requirement for an export limitation scheme (ELS).

To address the perceived barriers in the short-term, guidelines were initially developed to set out a process change for small scale schemes. These guidelines were published by the ENA and made available on the ENA website – the fast-track guidelines. With the application of the fast-track guidelines the customers’ experience was improved and the workload on DNOs was reduced. The guidelines have now been adopted into the new EREC's G98  and G99. A summary of the process is detailed below.

The generation owner may wish to install integrated micro generation and storage. Where all of the following conditions apply, the integrated micro generation and storage procedure can be followed:

  • The power generating modules are located in a single installation;
  • The total aggregate capacity of the power generating modules (including electricity storage devices) is between 16 A and 32 A per phase;
  • The total aggregate capacity of the power generating modules that are electricity storage devices does not exceed 16 A per phase and the total aggregate capacity of the power generating modules that are non-electricity storage devices does not exceed 16 A per phase. Note that if the total aggregated capacity of Electricity Storage and non- Electricity Storage devices is no greater than 16 A per phase, the single premises procedure described in EREC G98 applies;
  • All of the power generating modules (including electricity storage devices) are connected via EREC G98 fully type tested inverters;[1]
  • An EREC G100 compliant export limitation scheme is present that limits the export from the Generator’s Installation to the Distribution Network to 16 A per phase; and
  • The power generating modules will not operate when there is a loss of mains situation.

If all the conditions in the list above are satisfied, the generation owner should complete an application in a format as shown in G99 Form A1-2. Otherwise the generation owner should refer to the connection application procedure for type A power generating modules.

The planned commissioning date stated on the application form shall be within 10 working days and 3 months from the date that the application is submitted to the DNO. Confirmation of the commissioning of each power generating module shall be made no later than 28 days after commissioning (where commissioning tests and checks are not witnessed). Confirmation shall be provided in a format as shown in G99 Form A3-2. In addition to Form A3-2, an EREC G100 Export Limitation Scheme Installation and Commissioning Tests form shall be submitted to the DNO to confirm that the export limitation scheme meets the requirements set out in EREC G100. Confirmation shall be provided in a format as shown in ENA EREC G100 Appendix B.


Note that a number of sections of EREC G98 do not apply to electricity storage devices that are covered by this procedure. Refer to Appendix 1 of EREC G98 for details.

[1] Or Type Tested to EREC G83, where the Power Generating Module was connected prior to 27 April 2019.