Table of Contents

Optimization of self-consumption

1. Optimization of Self-Consumption

The optimization system from Climkit allows for an increase in the self-consumption rate of a photovoltaic installation by controlling certain devices based on solar energy production.

The surplus fed back to the electrical grid is thus limited, and autonomy is also improved by producing, for example, hot water using solar energy.

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

It is also possible to control certain charging stations for electric vehicles (via Wi-Fi or Ethernet).

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Detailed Connection of a Relay on the I/O Module

The I/O relay module has 4 relays.

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View the relays

2. Operation of the Algorithm

The system evaluates every minute the power fed back or withdrawn from the electrical grid.

In the case of surplus fed back, it activates the various configured and connected devices.

For example, if there is a surplus of 1000 W or more, it activates the 1000 W water heater.

Conversely, if there is no longer any surplus and energy is being withdrawn from the grid, the system deactivates the necessary devices to limit the withdrawal.

The devices are activated and deactivated according to the selected operating modes, such as "Solar only" or "Solar and timer." See Configuration below.

It is not possible to set priorities for activation or deactivation among the devices; they are only controlled based on their nominal power to maximize self-consumption.

To be as flexible as possible, it is recommended to connect the least powerful devices so that they can be activated with minimal surplus.

For instance, each phase of a 3000 W water heater can be connected to an independent relay to benefit from three steps of 1000 W.

Special Notes

Minimum Power and Number of Phases of a Station

Generally, an electric vehicle requires a minimum of 6A to start charging. Some vehicles need 8A or 10A. Setting a minimum below this may cause an error on the vehicle.

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

Consequence on optimization: a vehicle plugged into a three-phase station requires at least 4140 W of solar surplus for the system to start charging.

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

It is therefore recommended in these cases to connect the 3 phases of the station to 3 relays or at least to 3 independent switches so that the user can easily switch from one to three phases. See the diagram above.

When changing the number of phases of the station, the main circuit breaker of the station must be turned off, the phases of the connection activated or deactivated, and then the station reactivated.

The optimization system does not allow for control of the phases and automatic switching from single-phase charging to bi- or three-phase charging.

Vehicle Standby

When a vehicle is connected to the station but the solar surplus is insufficient for charging to start, the vehicle enters a standby mode until the station provides electricity.

In some cases, the vehicle may completely go into standby after some time, and when the station provides electricity again, charging does not start until the vehicle is "awakened" by the user.

This situation is common when the vehicle is plugged in at night, and the solar surplus will only be available the next morning.

Some vehicles can be updated to avoid these unexpected standby modes. Consult the vehicle manufacturer.

The system has been tested on a limited number of electric vehicles, and since each manufacturer has its specifics, Climkit cannot guarantee the operation of its optimization system with all types of vehicles.
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 that, when closed, gives an instruction to the internal management system of the HP.

In general, it is possible to configure the HP 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 can be forced to activate when the photovoltaic installation produces surplus energy.

Consult the HP manufacturer.

Connection of a Three-Phase Water Heater

Many water heater resistors are connected in 3-wire configuration without neutral. It is therefore necessary to connect a neutral to control each phase individually.

Otherwise, at least two phases are always required for it to activate.

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

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