Design of Prosumer electrical installations

From Electrical Installation Guide
HomeEnergy Efficient and Prosumer electrical installationsDesign of Prosumer electrical installations

Integrating local renewable energy sources, typically solar photovoltaic (PV) production, into building electrical distribution systems and using it to power the building loads is one way to decarbonize and increase energy efficiency. It is becoming more common for both new and existing buildings. However, the use of local sources for self-consumption raises questions and new challenges.

During the last decades up to the 2020s we have seen the electrical installations change from a pure consumer supplied by single centralized production system (sometimes including a back up generator) to more complex architectures. This change happened in Commercial & Industrial Buildings, and in residential buildings, in particular.

The first move came with PV panels starting to cover roofs of houses and Commercial & Industrial buildings, but usually with a dedicated connection for PV production to feed the Distribution Network (DN).

Installation rules such as IEC 60364 has followed this trend, in particular with part 7-712 for PV. (First edition of 7-712 was published in 2002, then Ed 2 in 2017.) See Chapter P - PhotoVoltaic (PV) installation.

Then, these local renewable sources become more and more connected inside the private installation for self-consumption instead of feeding the grid. It can be supplemented with Battery energy storage system for resiliency purpose or flexibility. This change in the architecture of PV feeding mode is directly influenced by regional or national policies for PV feed in tariff: when kWh price from PV paid by utilities is lower than the kWh paid for building loads, self-consumption becomes more relevant. See Chapter P - Fig. P2.

This move is transforming all legacy electrical consumer installation in to Producer and Consumer = Prosumer.

Fig. K37 – Example of Prosumer Electrical Installation (PEI) integrating self-consumed PV (Wind) energy production, storage, EV charging ...

This Prosumer Electrical installation is now covered by IEC 60364-8-82 (2022 edition). Note that the first edition (2018) was named IEC 60364-8-2: this naming was modified in the 2022 edition.

Note: The Electrotechnical vocabulary (IEC 60050 series) defines:

  • prosumer (electrical installation) as "network user that consumes and produces electrical energy" [IEV 617-02-2]
  • microgrid as "group of interconnected loads and distributed energy resources with defined electrical boundaries forming a local electric power system at distribution voltage levels, that acts as a single controllable entity and is able to operate in either grid-connected or island mode. Note 1 to entry: This definition covers both (utility) distribution microgrids and (customer owned) facility microgrids." [IEV 617-04-22]

In this section, as in the IEC 60364-8-82, we use the term Prosumer, as we don’t address distribution (utility) microgrid. Note that an islandable Prosumer in island mode can be called a microgrid or nanogrid.