Grid connection and storage
G99 and G98 type verification, and the bench that can actually run it.
Who buys this: Inverter and storage manufacturers, and the consultancies that type-test for them.
Why it matters now
G99 Issue 2's requirements for Power Generating Modules incorporating Electricity Storage came into force on 1 March 2026. That is not a horizon to plan for — it is the regime a British storage or hybrid product is inside now.
What the work actually involves
G99 is unusually specific about method. Annex A.7.1.2.2 describes operating the module in parallel with a variable AC test supply, stepping voltage in increments of 0.5% or less, holding longer than the trip delay, then jumping in a single step so trip time can be measured — repeated across Interface Protection, LFSM-O, LFSM-U, RoCoF, Fault Ride Through and Vector Shift. The bench runs for days, which is where regeneration stops being a specification line and becomes an operating cost. The 16 A per phase threshold between G98 and G99 is a design decision, not a paperwork one.
Assessed against
Systems we build for it
- PAS-F regenerative AC source and grid simulator
The variable AC test supply G99 Annex A.7.1.2.2 describes, with the absorbed power returned to the grid rather than dissipated.
Equipment it usually needs
- PAS-F regenerative AC source and grid simulatorSupplied and integrated
45 kVA – 1.6 MVA · 0–300 V L-N · 45–65 Hz standard, 40–70 Hz optional · three-phase
- ANRGS(F) regenerative AC and DC sourceSupplied and integrated
3 kVA – 120 kVA · 0–350 V AC and −495 to +495 V DC · 30–100 Hz · single and three-phase · 21 models
- ANEVH(F) bidirectional DC power supplySupplied and integrated
10–21 kW per chassis · 0–300 V to 0–2250 V DC by model · ±225 A to ±25 A, source and sink · 10 models
Talk it through
Tell us the standard and the device under test. That is enough for an engineer to answer usefully instead of sending a brochure.