15.2 Integrated Energy Management and the Smart Grid

Quick Answer: Handbook v1.3 outcome 6.1.2 says an integrated Electrical Energy Management System (EEMS) allows micro-generation to work alongside electrical energy storage, V2G, V2H, energy company infrastructure and the Smart Grid. The goals are maximising grid independence; minimising costs by leveraging lower tariffs through arbitrage; and taking advantage of tariffs and export payback during local or regional demand peaks by providing grid support services, supplying power from local battery storage, and using EV battery energy to support the grid. EEMS set-points must not violate G98, G99 or G100 export limits. This OpenExamPrep section is independent study material for 2922-34; it is not a City & Guilds publication.

What integrated means on a 2922 job

Section 15.1 named the EEMS as the coordinator. Outcome 6.1.2 asks what it is allowed to sit alongside. Integrated means the PV inverter is not an isolated box that dumps every spare kilowatt-hour through the meter. The EEMS can see storage, a vehicle used as a store, the supplier or DSO systems that send prices and instructions, and the Smart Grid that the public network is becoming. Micro-generation remains the PV (and any other small generator on the PEI). The EEMS is how those parts share one connection without fighting each other or the DNO agreement.

LO6 is still only three questions on Unit 301. The paper will happily test whether you can list the 6.1.2 partners and the 6.1.2 goals, then refuse a set-point that exports more than G100 allows because a half-hourly outgoing rate looks attractive.

Independent OpenExamPrep teaching keeps those goals inside the connection rules already taught under G98, G99 and G100. OpenExamPrep is not an energy supplier and does not operate the Smart Grid.

The five partners micro-generation works alongside

Learn the handbook list as a set, then attach a 2922 meaning to each line.

Electrical energy storage. The EESS soaks surplus PV, supplies the house later, and can discharge at peak. Without storage, an EEMS can still throttle export and stagger loads, but it has no kilowatt-hour buffer. With storage, self-consumption, time shifting and arbitrage become controllable rather than accidental.

V2G. The vehicle is a store that can discharge to the public network or provide grid support through that connection. The EEMS must treat that discharge as generation: same aggregated AC counting, same export cap, same anti-islanding when it is in parallel.

V2H. The vehicle supplies the dwelling. Grid-parallel V2H offsets import. Island-mode V2H, if designed, still needs the changeover from 15.1. The EEMS decides when the vehicle charges from PV or cheap-rate electricity, and when it supports house loads, without using the car as an unisolated street generator.

Energy company infrastructure. That is the supplier and DSO world the installation talks to: smart meters, tariff messages, flexibility or export-payback signals, maybe a scheduled discharge window. It is not a second DNO connection offer. A price API does not replace G99 permission or a G100 scheme.

The Smart Grid. The public network with monitoring, control, and two-way power and data. Constraint signals, regional peaks, and requests for local support land here. The EEMS may reduce export, hold export, or discharge storage when asked, but only inside the agreed envelope.

Do not add a sixth partner such as disabling protection. Do not collapse the five into the inverter has an app.

Three goals — independence, cost, peak support

Maximising grid independence means the PEI covers more of its own demand from local generation and storage, so import falls. It does not mean going off-grid, defeating anti-islanding, or claiming the house is islanded whenever the sun shines. A 2922 PEI is still a parallel installation unless a designed island-mode changeover has operated.

Minimising costs by leveraging lower tariffs through arbitrage is the 6.1.1 price strategy running as an EEMS objective. Charge the battery or vehicle when the import rate is low (or when PV would otherwise export for little value). Run house loads, or hold discharge, so you avoid expensive import. That is arbitrage implemented by set-points, not a new physics.

Tariffs and export payback during local or regional demand peaks is the outward-facing goal. When the network or the supplier wants energy at a peak, the PEI can provide grid support services by supplying power from local battery storage and by using EV battery energy to support the grid. That may be a high outgoing rate, a scheduled flexibility event, or a DSO constraint window that pays for a defined response. The handbook is describing controlled discharge at the useful time, not unconstrained lunchtime export.

Those goals can pull in different directions. Midday PV wants to charge the battery for evening independence. A peak outgoing window may want that same battery to export. The EEMS resolves that only inside the DNO cap and the state-of-charge the customer still needs for island-mode backup, if backup is specified.

Set-points must not violate G98, G99 or G100

This is the line that turns a clever tariff into a failed commissioning.

G98 / G99 decide whether you may connect the aggregated AC generation at all, and on what process. The EEMS cannot invent a G98 notification for a 7 kW vehicle inverter by setting a software export slider to 3.68 kW. G100 can limit export; it does not rewrite the generation-capacity test.

G100 (and any agreed import limit) is a hard ceiling at the boundary. If the DNO offered 3.68 kW export, the EEMS discharge target for a 16:00 regional peak must stay at or below 3.68 kW at the point of connection, after house load is accounted for. A £2/kWh outgoing rate does not raise the cap. Turning off fail-safe so the battery can dump 5 kW through a 3.68 kW agreement is not grid support; it is a limiter failure.

Set-points the EEMS may own: charge windows, discharge windows, minimum state of charge for backup, self-consumption versus export preference, response to a supplier signal. Set-points the EEMS may not own as an override: registered generation larger than agreed, export above the G100 value, island-mode without changeover, loss-of-mains disabled so backup works.

If the agile tariff says discharge now and the G100 scheme says you are already at the export cap, the limiter wins. Surplus stays in the battery, goes to a house load, or is not generated.

Actor versus what the EEMS coordinates

Scenario: Octopus-style agile tariff with a hybrid inverter

A single-phase house has a hybrid with a 5 kW AC rating and a battery. The supplier uses an Octopus-style agile import tariff: half-hourly prices, cheap overnight, occasionally expensive early evening. An outgoing product pays more for export at regional peaks. The DNO connection is G99 because 5 kW is about 21.7 A, with G100 holding export at 3.68 kW.

At 02:30 the import rate is very low. The EEMS may charge the battery from the grid (arbitrage, time shifting). That charge is a load. It does not use up the export cap.

At 13:00 the hybrid would otherwise convert 4.5 kW. House load is 0.5 kW. Unconstrained export would be 4.0 kW, above 3.68 kW. The EEMS must divert about 0.32 kW into the battery (or throttle PV). That is self-consumption plus G100 compliance, not a missed outgoing opportunity.

At 17:00 a regional peak makes outgoing valuable. Grid independence still wants energy left for the evening kettle. The EEMS may discharge the house battery and, if contracted and wired as V2G, the vehicle, to provide grid support. Combined export at the boundary must remain ≤ 3.68 kW. The 5 kW hybrid nameplate is not the export target.

Wrong answers on this scenario: raise the G100 slider because the tariff is high; treat agile as permission to skip G99; call the house off-grid at 17:00 because import is zero; disable anti-islanding so a later cut keeps the street on. The tariff is a price signal. The EEMS may follow it. G98, G99 and G100 still bound every set-point.