How can I enable Smart Charging to maximize solar consumption and minimize energy costs? How does it work?

Prerequisites

  • Measurements of both Grid and Solar panels
    • In case of the EV Wall Business and EV Base products you need an additional Smappee Infinity to measure this
    • In case of the EV Wall the package contains the necessary equipment to do the measurements
  • A decent Solar Forecast (This requires measurements for at least a week)
  • (Optional: Custom Tariffs on the Charging Square service location)

 

 

How does it work?

Smappee Smart Charging can optimize your charging sessions by maximizing self-consumption of energy produced by solar panels, and by charging during the cheapest possible periods. Enabling Smart Charging can be done either by using the 'Charge with solar' option in Scan and charge, or if you are the charging station owner, by going to the Smart Devices section in the app. Generally, Scan and charge is used in a commercial setting while changing the smart device settings is most useful for residential applications.

 

To change the smart charging settings using the Smappee app, go to 'Control' - 'All' - 'Smart devices', and select the charging station you would like to edit.

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On this screen, you will be given three options:

  • Normal charging: charge at the maximum available current. You can easily change the maximum current using the slider. Overload protection will still be active and reduce the current if needed.
  • Smart charging: optimize charging based on solar production and electricity tariff.
  • Stop: the EV stops charging. Even when a new charging session is started, the EV will not charge as long as this is activated.

Important: changing this setting will change it for the current charging session AND all future sessions. Don't use Smart charging or Stop without informing all users of this charging station. We recommend that publicly available charging stations are always left on 'Normal charging'.

 

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When you activate Smart Charging, you can choose 3 different strategies:

  • Surplus only
  • Schedules only
  • Schedules and surplus

 

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Surplus only

Your car will be charged using excess energy from your solar panels or other source of production. On cloudy moments when there is not enough solar power available, the EV will not charge. It is based on total power instead of current per phase, so if you have a 3-phase solar installation and you have a surplus of 5A per phase (so 3.5 kW) then a single-phase car will be able to charge with 15A.

Note: EVs need a minimum current of 6A (per phase) to start charging. Therefore there is a minimum power at which your car will start to charge; 1.4 kW for a single-phase system and 4.1 kW for a three-phase system. This is determined by the standardized communication protocol between the EV and charging station (IEC 61851-1) and we unfortunately cannot change this.

 

 

Schedules only

When smart charging has been activated, Smappee's optimization algorithm knows how many kilometers of range need to be charged and by what time this is needed. The kilometers are recalculated into energy, using a conversion factor of 0.2 kWh/km. Note that this is a good estimation for most EVs but it may not be perfectly accurate depending on weather conditions and your driving style.

 

Once the required energy and remaining time is known, the optimization algorithm will determine the optimal periods to charge in the next 24 hours. This is based on a combination of forecasted solar production, forecasted consumption, and electricity tariffs. This planning is adjusted in almost real-time depending on the live consumption and production. The algorithm will always favor the usage of excess solar energy. If it is not possible to fully charge the EV with only solar energy, it will use energy from the grid but at the cheapest possible tariff. In any case, the priority is to always deliver the requested energy so that the driver is never left with an empty battery.

 

Please note that some time is needed to be able to calculate an accurate consumption and solar production forecast for new installations. Smart charging will be less accurate during the first few days after installation of the Smappee monitor, because we still need to learn about your energy usage. Moreover, the optimization only plans for the next 24 hours. If your departure time is more than 24 hours in the future, it will be ignored and your EV will start charging immediately.

 

 

Schedules and surplus

This is a combination of the two above methods. Your car will be charged with a minimum energy according to the schedule you have set. If more surplus energy is available, your car will be charged with more than the requested energy.