Table of Contents

Self-consumption optimization

1. Self-consumption Optimization

The Climkit optimization system allows for increasing the self-consumption rate of a photovoltaic installation by controlling certain appliances based on solar energy production.

The surplus fed back into the electrical grid is thus limited, and autonomy is also gained by, for example, producing hot water with solar energy.

Appliances (water heaters, heat pumps, radiators, pool pumps, etc.) are controlled via a relay.

It is also possible to control certain electric vehicle charging stations (via Wifi or Ethernet).

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Detailed connection of a relay to the I/O module

The relay I/O module has 4 relays.

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View the relays

2. Algorithm Operation

The system evaluates the electrical power fed back to or drawn from the electrical grid every minute.

In case of fed-back surplus, it activates the different configured and connected appliances.

For example, if there is a surplus greater than or equal to 1000 W, it activates the 1000 W water heater.

Conversely, if there is no longer a surplus and energy is being drawn from the grid, the system deactivates the necessary appliances to limit the draw.

Appliances are activated and deactivated according to the selected operating modes, for example in "Solar only" or "Solar and timer" mode. See Configuration below.

It is not possible to set activation or deactivation priorities among the appliances; these are controlled solely based on their nominal power to maximize self-consumption.

To be as flexible as possible, it is recommended to connect appliances with the lowest possible power rating so that they are activated with even a small surplus.

For example, the 3 phases of a 3000 W water heater can be connected to an independent relay to benefit from three 1000 W steps.

Specific Notes

Minimum power and number of phases for a charging station

Generally, an electric vehicle requires a minimum of 6A to start charging. Some vehicles require 8A or 10A. A minimum set below these values can cause an error on the vehicle.

This 6A minimum is the same for single-phase and three-phase systems, meaning 1380 W for single-phase 230V or 4140 W for three-phase.

Consequence for optimization: a vehicle connected to a three-phase charging station requires a minimum solar surplus of 4140 W for the system to initiate charging.

In the case of small photovoltaic installations (5-8 kWp), the surplus required to activate the charging station will only be available in summer and during the middle of the day.

In these cases, it is recommended to connect the 3 phases of the charging station to 3 relays or at least to 3 independent switches so that the user can easily switch from one phase to three phases. See the diagram above.

When changing the number of phases of the charging station, you must turn off the main circuit breaker of the station, connect or disconnect the connection phases, and then turn the station back on.

The optimization system does not allow for phase control and automatic switching from a single-phase load to a bi- or three-phase load.

Vehicle Standby

When a vehicle is connected to the charging station but the solar surplus is insufficient to initiate charging, the vehicle remains in standby until the station supplies it with electricity.

In some cases, the vehicle may enter deep sleep after some time, and when the station supplies it with electricity again, charging will not start until the vehicle is "woken up" by the user.

This often happens when the vehicle is plugged in during the evening and the solar surplus will only be available the next morning.

Some vehicles can be updated to prevent these unexpected standby states. Consult the vehicle manufacturer.

The system has been tested on a limited number of electric vehicles, and since each manufacturer has its specificities, Climkit cannot guarantee the functioning of its optimization system with all vehicle types.
Older Vehicles

Some older vehicles (pre-2012-2014) do not support power variation during charging and are therefore not controllable via the optimization system.

Heat Pumps (SG-Ready)

Most modern heat pumps (HP) are equipped with a potential-free contact which, when closed, sends an instruction to the HP's internal management system.

Generally, the HP can be configured to increase its heating setpoint or produce more hot water when this contact is closed.

By connecting a relay from the optimization system to this contact, the HP's activation can be forced when the photovoltaic installation produces surplus energy.

Consult the HP manufacturer.

Connection of a Three-Phase Water Heater

Many water heater elements are connected with 3 wires without a neutral conductor. Therefore, a neutral conductor is necessary to control each phase individually.

Otherwise, at least two phases are always required for it to be switched on.

Two relays can then be used to control: phase 1 and 2 with the first relay, and 1 and 3 with the second.

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