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StoriesPlace: Suburb

The suburb as a power station

Rooftop solar, home batteries and electric vehicles turn a residential street into thousands of small generators. Observing them is how a distribution grid stays within its limits, and the interconnection standard already asks inverters to help1.

Systems
Distributed energy resources, Smart metering, Grid-edge telemetry
Toward 2030
Aggregated resources in wholesale markets, Vehicle-to-grid
Figures
4, field scene, systems diagram, timeline to 2030, simulator

Go to the references

01Field scene

A street of generators.

Each roof with panels and an inverter is a power plant the utility does not dispatch. In aggregate, a feeder can export at noon and import heavily at six, and its voltage moves with the clouds.

Smart meters report energy every few minutes through a standard metering data model2; inverters can report and respond far faster. The question is which of those signals reaches whom, how quickly, and with what authority.

Figure as text: A residential street with rooftop generation, a community battery and a feeder

Two dozen pitched-roof houses in rows, a low-voltage feeder on poles along the bottom edge, a community battery and an edge node joined by dashed red links to two metering points.

  • Meter and inverter
  • Community battery
  • Feeder
  • Edge aggregator

02Systems diagram

Who listens to the inverter.

An inverter tested to the grid-support supplement can ride through faults and regulate voltage on its own3. Above it, an aggregator speaks a utility protocol such as the smart energy profile4, and the distribution operator decides what the feeder can take.

Cut the link to the aggregator and the street keeps its autonomous functions: volt-var and frequency response live in the inverter, as the interconnection standard requires1. Switch the scenario to see which paths survive.

Figure as text: Grid-edge control, from the inverter to the distribution operator

A four-tier diagram: devices (inverters, a vehicle charger, a battery), the home gateway and meters, an aggregator at the edge, and the distribution operator. Red packets run from each device to the operator.

  • Devices: Inverter A, Inverter B, EV charger, Battery
  • Premises: Gateway, Smart meter, Gateway
  • Aggregation: Aggregator, Meter head-end
  • Distribution operator: DER management

11 links. Scenarios: Normal operation; Aggregator link lost; One gateway down.

03Timeline to 2030

From customers to market participants.

In the United States, wholesale markets must now admit aggregations of distributed resources5; the vehicle-to-grid protocol lets a charger negotiate power both ways6. Each step adds a party that needs trustworthy, timestamped measurements from the street.

Figure as text: Grid-edge standards and market rules

A timeline from 2018 to 2030 showing interconnection, protocol and market milestones.

  1. 2018 Smart energy profile becomes IEEE 2030.5 (IEEE 2030.5). An application protocol for utilities to communicate with distributed resources.4
  2. 2018-04 Interconnection standard revised (IEEE 1547-2018). Inverters must ride through disturbances and can provide voltage and frequency support.1
  3. 2020-09 Aggregations admitted to wholesale markets. Order 2222 directs market operators to let aggregated distributed resources participate.5
  4. 2021-09 Grid-support inverter certification (UL 1741 SB). A supplement that tests inverters against the 2018 interconnection requirements.3
  5. 2022-04 Bidirectional charging protocol (ISO 15118-20). The second generation of the vehicle-to-grid communication standard.6

04Simulator

What a community battery buys.

A battery shared by a street shifts the noon surplus into the evening peak. Its sizing is arithmetic: stored energy against load, and the daily harvest of the array against what the street draws. Set the values for a winter week and a summer week.

Figure as text: Battery autonomy and daily energy balance

A line chart of stored energy over fourteen days, falling or holding depending on the daily balance, with a dashed reserve line at 20 percent.

Battery autonomy and daily energy balance, at the starting values
Battery20000 Wh
Station load300 W
Solar array2000 W
Peak sun hours1.5 h
Autonomy without sun2.2 days
Daily energy balance−4,950 Wh
Days to empty at this balance3.2 days

Figure 1

Field scene

Figure 1. A residential street with rooftop generation, a community battery and a feeder. Two dozen pitched-roof houses in rows, a low-voltage feeder on poles along the bottom edge, a community battery and an edge node joined by dashed red links to two metering points.

References

  1. IEEE 1547-2018: Standard for interconnection and interoperability of distributed energy resources with associated electric power systems interfaces. IEEE Standards Association, 2018.
  2. IEC 62056 (DLMS/COSEM): Electricity metering data exchange. International Electrotechnical Commission, 2021.
  3. UL 1741 Supplement SB: grid-support inverters tested to IEEE 1547.1-2020. UL Standards & Engagement, 2021.
  4. IEEE 2030.5-2018: Standard for smart energy profile application protocol. IEEE Standards Association, 2018.
  5. Order No. 2222: Participation of distributed energy resource aggregations in markets operated by regional transmission organizations and independent system operators. United States Federal Energy Regulatory Commission, 2020.
  6. ISO 15118-20:2022 Road vehicles — Vehicle to grid communication interface — Part 20: Network and application protocol requirements. International Organization for Standardization, 2022.

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