Table of Contents

Optimization of self-consumption

1. Self-consumption Optimization

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

The surplus fed back into the electrical grid is thus limited, and autonomy is also gained 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 WiFi or Ethernet).

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Detailed Connection of a Relay on the I/O Module

The I/O relay module consists of 4 relays.

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View the relays

2. Algorithm Operation

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

In case of surplus, 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 drawn from the grid, the system deactivates the necessary devices to limit the draw.

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 devices that are as low powered as possible so that they can be activated with little surplus.

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

Special Notes

Minimum Power and Number of Phases of a Charger

In general, an electric vehicle requires at least 6A to begin charging. Some vehicles need 8A or 10A. A minimum set below this can cause an error on the vehicle.

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

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

In the case of small photovoltaic installations (5-8 kWp), the surplus necessary for activating the charger will thus only be available in summer and during the day.

It is recommended in these cases to connect the 3 phases of the charger 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 wanting to change the number of phases of the charger, the main breaker of the charger must be turned off, the phases of the connection must be activated or deactivated, and the charger must be reactivated.

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

Vehicle Sleep Mode

When a vehicle is plugged into the charger but the solar surplus is not sufficient for charging to initiate, the vehicle waits until the charger supplies electricity.

In some cases, the vehicle may enter complete sleep mode after a while, and when the charger supplies electricity again, charging does not start until the vehicle is "woken up" 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 sleeps. 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 tolerate variations in power during charging and thus cannot be controlled 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, it is possible to force the activation of the HP when the photovoltaic installation produces surplus energy.

Consult the HP manufacturer.

Connection of a Three-Phase Water Heater

Many water heater resistors are connected with 3 wires without neutral. It is therefore necessary to connect a neutral to control each phase individually.

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

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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