1 Goal and basic principle of the installation

For a joint generation facility (GEA) or a renewable energy community (EEG) to be controlled in real time, all relevant producers and consumers must be equipped with the appropriate Reduxi components.

There is no limit to the number of participating producers or consumers. What matters is only that the required measurements can be captured at the respective meter points and transmitted to the Reduxi system.

2 Participants with a generation plant or battery storage

For participants with controllable generation or storage, a Reduxi Controller is installed. This includes, among others:

• Solar (PV) systems
• Battery storage
• Other controllable energy producers
• Combinations of a PV system and battery storage

The controller is installed wherever the respective generation plant or storage system can be technically connected and controlled. It handles communication with the existing devices and enables control of the generated or stored energy.

Recommended

DIN rail variant

Mounted directly in the meter cabinet — space-saving and without a separate enclosure.

Stand-alone variant

Free-standing installation outside the meter cabinet, e.g. when there is no space inside it.

Multiple producers within the same GEA/EEG

If several producers exist within a community, each producer gets its own Reduxi Controller. Example:

A detailed step-by-step installation guide can be found in the linked article:

⚙️ Reduxi Controller — First-Time Setup 

3 Participants with pure energy consumption

For households or participants without their own controllable generation plant, a Reduxi Controller is generally not required. A P1 Ultra is sufficient to capture current consumption.

Standard

P1 Ultra Plus

Connects via Wi‑Fi. First choice whenever Wi‑Fi is available on site.

P1 Ultra Pro

Also offers a SIM card option — for sites without Wi‑Fi or when a Wi‑Fi connection is deliberately avoided.

Connection to the smart meter / electricity meter

Every pure consumer must be able to capture its current energy draw at the respective smart meter or electricity meter. For this, the P1 Ultra is connected directly to the meter. Depending on the meter model, the connection is made via:

• P1 port — direct digital interface on the meter
• Infrared interface (IR) — optical readout, when no P1 port is available

The P1 Ultra reads the meter's current measurements and makes them available to the Reduxi system / Reduxi Cloud for real-time calculation and control.

An overview of all supported meter models can be found in the linked article:

📖 Compatible meters & smart meters 

Power supply for the P1 Ultra

Depending on the installation situation, the following options are available:

• AC adapter into a wall outlet — the most common option; a power outlet near the meter cabinet should be planned for.
• Via RS485 — with a local connection, the P1 Ultra can be powered directly over the RS485 link.
• Via a USB-C adapter to 2 pins (+/-) — for connecting to an existing DC power source.

Before installation, check the following:

• Which electricity meter is installed?
• Is the meter compatible with Reduxi? (if not: free integration into the Reduxi system after a check — a meter replacement is necessary in individual cases)
• Is a P1 port or an infrared interface used?
• Which of the three power supply options is most practical on site?

A detailed guide to connection and LED status can be found in the linked article:

🔌 P1 Ultra Plus/Pro — connection & LED status 

4 App and cloud access

All Reduxi users can download the Reduxi app on their smartphone, create an account, and use it to view their own consumption or generation. In the app — as well as on desktop — a visual distinction is made between electricity that comes from the EEG or the joint generation facility and electricity drawn directly from the public grid.

Authorized bodies of an EEG thus get aggregator access to the Reduxi Cloud with a view of all participants, while individual participants only see their own components and the additional information relevant to them.

Participant access — only the participant's own components and additional info are visible

Aggregator access — overview of all participants in the EEG (names in the list redacted)

5 System setup overview

The current measurements from all participants together form the basis for real-time control of the jointly generated energy. From here, the rest of the setup differs depending on the configuration — see Point 6⁠ (EEG) or Point 7⁠ (GEA).

6 Setting up the EEG (P1 Ultra connection via MQTT)

Architecture

In a renewable energy community (EEG), participants are often spread across several meter points or sites. So that all measurements can be brought together centrally, every P1 Ultra communicates via MQTT with both the Reduxi Cloud and the community's main controller. The main controller handles real-time control across all participants, while the cloud provides data storage, assignment, and app/web access.

Example installation: EEG with a PV system (245 kWp) and storage (400 kWh) as master, approx. 25 participants — every P1 Ultra communicates with the Reduxi Cloud and the main controller over the internet

Prerequisites

• Internet access at every meter point (Wi‑Fi or SIM connection via P1 Ultra Pro)
• The Reduxi Controller is already set up as the community's main controller
• P1 Ultra devices are already connected to the respective smart meter (see ⁠Point 3⁠)
• Access to this EEG's MQTT credentials from Reduxi Cloud — the username and password can be requested from Reduxi Support; ideally do this before installation begins

Preparing MQTT credentials & the main controller

The credentials for the MQTT connection are entered directly at the main controller via its web interface (Reduxi Configurator). In the left-hand menu, follow this path:

Reduxi Configurator: Settings → System → Connector → MQTT v3 (credentials redacted in the image)

Under MQTT v3 connection, fill in the following fields:

• Host & Port — address of the Reduxi MQTT broker (mqtt.reduxi.energy, port 8883)
• Username & Password — the credentials provided by Reduxi for this EEG
• Use SSL & Verify server cert — set both to Yes
• Readout interval — 1 second is recommended for RECs (default value in the field: 60 seconds)

The currently valid server certificate for the one-time upload is available for download here:

⬇ Download server certificate 

Once the credentials are saved, the Connector page shows the active connection to the MQTT broker: Client ID, Host, and a green checkmark next to Connected. This can take up to about 1 minute to appear after saving.

Configuring the P1 Ultra for MQTT

In addition to the main controller, every single P1 Ultra must also be set up for MQTT via its own web interface. To do so, open the Services tab in the menu (point 1 in the image).

P1 Ultra web interface: Services → MQTT (username redacted in the image)

In the MQTT section (point 2 in the image), enter the same credentials as at the main controller:

• MQTT broker address — mqtt.reduxi.energy
• Username & Password — the credentials provided by Reduxi for this EEG
• Use TLS & Verify server — set both to Yes (point 3 in the image)
• Server certificate CA (PEM format) — install (upload) the server certificate

This is the same server certificate used at the main controller — download it again here if needed:

⬇ Download server certificate 

Next, note down the Unit ID of the P1 Ultra in the System tab (point 1 in the image) — it is needed in the next step when adding the device at the main controller.

P1 Ultra web interface: System — note the Unit ID, save, and restart the device (Unit ID and MAC address redacted in the image)

Then:

• Use the Save icon (point 2 in the image) to save the configuration
• Restart the device using the Restart icon (point 3 in the image)

After the restart, the connection can be checked in the Services tab. If the MQTT connection is active, the MQTT section shows a green Active badge — data is then continuously sent to the MQTT server. Here too, this can take up to about 1 minute to appear after the restart:

Assigning participants in the main controller

Finally, every P1 Ultra must be added as a device at the main controller. To do so, select Add device in the left-hand menu (point 1 in the image).

Add device: set Device type, Type, and Name

In the Basic settings step, enter the following:

• Device type — Energy meter (point 2 in the image)
• Type — P1 WiFi / Ultra (point 3 in the image)
• Name — a label for the meter/participant (e.g. unit number or participant name) (point 4 in the image)

Then continue to the second step with Next:

Add device: Connection MQTT, enter the P1 Ultra's Unit ID (Unit ID redacted in the image)

• Connection — select MQTT (point 1 in the image)
• Unit ID — enter the Unit ID previously noted at the P1 Ultra (point 2 in the image)
• Device ID & Modbus unit ID — leave at the default value 1 (point 3 in the image)

Finish with Done (point 4 in the image) — the participant is now created and assigned in the main controller.

Real-time control & priorities

In the main controller, go to Strategy → Energy manager → the Included items tab to define which devices are measured and which are actively controlled.

• All pure meters/measurement devices (e.g. a consumer's P1 Ultra) must be listed under Measurement devices and strategies (point 1 in the image).
• All devices that are to be actively controlled (e.g. inverter, wallbox, heating rod) must be listed under Regulated devices and strategies (point 2 in the image).
• Assignment is done via drag & drop from the left-hand list Devices and strategies into the desired column.
• Changes must always be saved via Save (point 3 in the image).

In addition, the Optimization modes tab (point 1 in the image, within the respective strategy) is where the export/import limit and the control strategy are set:

• Export limit & Import limit — maximum feed-in or draw power for the plant, in kW (points 2 & 4 in the image).
• Goal — the control goal, usually Self-consumption for RECs (point 3 in the image): the electricity consumption of all participants is jointly covered by the generation plant(s).
• Here too: confirm entries via Save (point 5 in the image).

Function test and commissioning

The function test for the EEG essentially consists of a plausibility check of the values configured previously:

• All P1 Ultra devices show an active MQTT connection under Services (Active), and at the main controller the connection is marked as Connected under Connector (see ⁠Point 6.2⁠/⁠6.3⁠).
• If Active or Connected doesn't appear, check the MQTT credentials, TLS settings, and server certificate at both the P1 Ultra and the main controller again — and make sure the configuration was confirmed via Save in each case.
• Every participant is correctly assigned as a measurement device or a regulated device (see above).
• The export/import limit and control goal (Self-consumption) match the plant's real-world conditions.
• The incoming measurements from participants look plausible — no obviously incorrect or missing values.

Once all points are met, the EEG is set up and ready for operation.

7 Setting up the GEA (P1 Ultra connection locally via Wi‑Fi/RTU)

Architecture

In a joint generation facility (GEA), all meter points are usually located at the same site or in the same building. Each meter point is likewise equipped with a P1 Ultra, but the devices communicate locally and directly with the Reduxi Controller — without the detour via MQTT and the cloud used for an EEG. Two connection types are available for the local link: Wi‑Fi or a wired RTU connection (Modbus RTU / RS485).

Example installation: GEA in a residential complex with 6 units and EV charging points — each unit's P1 Ultra connected to the Reduxi Controller locally via Wi‑Fi or RS485

Prerequisites

• The Reduxi Controller is already installed and running on site (see ⁠Point 2⁠)
• P1 Ultra devices are already connected to the respective smart meters (see ⁠Point 3⁠)
• For Wi‑Fi: a shared local Wi‑Fi network for the controller and all P1 Ultra devices
• For RTU: RS485 wiring between the P1 Ultra devices and the controller is in place or planned

Choosing a connection type: Wi‑Fi or RTU

Connecting the P1 Ultra locally

For the Wi‑Fi connection, the IP address of the respective P1 Ultra is needed (point 1 in the image). It can be found directly on the device in the System tab:

This IP address is then entered when adding the device at the controller, under Connection: TCP/IP (see ⁠Point 7.4⁠).

After the RS485 wiring (see ⁠Point 1⁠), RTU is activated directly at the P1 Ultra: open the Modbus section in the Services tab.

• Enable — set to Yes (point 1 in the image)
• Modbus register structure — set to Reduxi (point 2 in the image)
• The status at the top right switches to Active (point 3 in the image)
• Device address — enter the P1 Ultra's unit ID here (e.g. 1) (point 4 in the image); you'll need it later when adding the device at the controller

Assigning meter points in the controller

Every meter point is created in the Reduxi Controller via Add device in the left-hand menu (point 1 in the image).

Add device: set Device type, Type, and Name

In the Basic settings step, provide the following:

• Device type — Energy meter (point 2 in the image)
• Type — P1 WiFi / Ultra (point 3 in the image)
• Name — a label for the meter point (e.g. unit number or participant name) (point 4 in the image)

Then continue to the second step with Next — there, depending on the chosen connection type, set TCP/IP (Wi‑Fi) or RTU:

• Connection — select TCP/IP (point 1 in the image)
• IP — enter the IP address noted at the P1 Ultra (optionally, search automatically via Scan for IP) (point 2 in the image)
• Port — default value 502, can be checked with Test port (point 3 in the image)
• Modbus unit ID — default value 1 (point 4 in the image)

• Connection — select Local serial port (point 1 in the image)
• Port — select the RS-485 port used (e.g. RS-485 port 1) (point 2 in the image)
• Modbus unit ID — must match the unit ID stored on the P1 Ultra under Services → Modbus (see ⁠Point 7.3⁠) (point 3 in the image)

Finish with Done — the meter point is now created in the controller.

Real-time control & priorities

In the Reduxi Controller, go to Strategy → Energy manager → the Included items tab to define which meter points are measured and which devices are actively controlled.

• All pure meter points (e.g. a unit's P1 Ultra without its own generation) must be listed under Measurement devices and strategies (point 1 in the image).
• All devices that are to be actively controlled (e.g. inverter, wallbox, heating rod) must be listed under Regulated devices and strategies (point 2 in the image).
• Assignment is done via drag & drop from the left-hand list Devices and strategies into the desired column.
• Changes must always be saved via Save (point 3 in the image).

In addition, the Optimization modes tab (point 1 in the image) is where the GEA's export/import limit and control strategy are set:

• Export limit & Import limit — maximum feed-in or draw power for the plant, in kW (points 2 & 4 in the image).
• Goal — the control goal, usually Self-consumption for GEAs (point 3 in the image): the electricity consumption of all participants is jointly covered by the generation plant(s).
• Here too: confirm entries via Save (point 5 in the image).

Function test and commissioning

Finally, the values configured earlier are checked for plausibility: correct assignment of meter points to measurement devices or regulated devices, and a plausible export/import limit and control goal for the plant. Since the P1 Ultra devices of a GEA communicate locally (Wi‑Fi/RTU) directly with the controller, a direct communication test is also available per meter point.

At the created device, test the connection via the Test communication button (next to Save) (point 1 in the image):

• A successful response (Successful readout from device) shows the values just read (including active power, meter reading, meter model) — this confirms correct communication for the respective meter point.
• If no response appears or an error occurs, check the IP address/port or wiring, and the Modbus unit ID, again.

Once all meter points have been tested successfully and the values are plausible, the GEA is set up and ready for operation.

✓ Summary

→ Common issues

→ Related articles

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