SMA EV Charger mobilizes surplus PV power and relieves the utility grid

SMA EV Charger solaroptimiert laden

The first 18 months of field experience with the charging solution SMA EV Charger have shown in Sunny Portal: more than half of the energy used for charging electric vehicles is provided by solar power from your own roof. It is no longer a secret that this allows you to be on the move in a particularly climate-neutral and cost-effective way. But did you know that it means you can even prevent expensive grid expansion and your contribution to the energy transition becomes even more valuable?

E-mobility using self-generated solar energy is an unbeatably affordable and particularly sustainable alternative, and this has not just been the case since the prices for fossil fuels have skyrocketed. The SMA EV Charger ensures that your electric vehicle is charged with the maximum amount of solar power available. In the PV-optimized charging mode, it even charges your vehicle exclusively using solar power. This means that you make better use of the electricity you generate, smooth out the load profile at the point of interconnection, and can get out and about at a particularly low cost. PV systems and electric vehicles are perfect partners: the PV system supplies the electricity for the car and the electric vehicle battery also serves as mobile energy storage for surplus solar power.

Easy on the wallet and the utility grid

Whenever you charge your vehicle with self-generated solar power using a smart charging station such as the SMA EV Charger, you are easing the burden not only on your wallet, but also on the utility grid. Why is this important? Electric cars are loads that can potentially put a strain on local distribution grids in particular. If, for example, a large number of charging processes take place in a district, such as after work, this places a particularly heavy burden on the local utility grid. Flexible charging and charging with self-generated solar power are the solution here. Or an expensive expansion of the existing utility grid.

Flexible charging ensures more even grid utilization

Flexible charging means that electric vehicles are charged at different times, staggering the load from electric vehicles over the course of the day. Grid operators also have an interest in ensuring that their utility grids are loaded as evenly as possible. More and more of them are therefore offering attractive conditions for controllable charging stations, which enable the grid operator to limit the maximum charging output from the grid when the grid load is particularly high at the time. The ability to control the charging station is also a prerequisite for many incentive programs. The SMA EV Charger can be controlled in this way via a digital grid operator interface.

However, the local distribution grid is also put under strain if, for example, all PV systems feed in solar power at the same time. If the utility grid cannot absorb the entire amount of electricity, PV systems have to be curtailed. If, on the other hand, the self-generated electricity ends up in an electric vehicle instead of the utility grid at peak times, this reduces the load and possible curtailment.  All in all, this even allows more renewable energies and more electric vehicles to be integrated into the existing utility grid.

The advantage for grid operators is that they have fewer costs and use fewer resources on grid expansion. And this, in turn, will also benefit us as electricity customers. After all, we share the costs of grid expansion and operation through our electricity bill.

The first 18 months of field experience with the SMA EV Charger show that this already works very well in practice.

Intelligent charging with the SMA EV Charger

Since the market launch of the SMA EV Charger in summer 2020, the motto for PV system operators has been “sunshine in the tank.” In fact, you prefer to charge your vehicle when your system is producing solar power, which then effectively flows directly into the vehicle via the PV system without even reaching the utility grid.

The graphic below shows how high the power demand of all SMA EV Chargers is during the course of the day (using hourly averages). The green bar means that 46% of this energy came directly from the PV system. The yellow bar says that 8% came from the home storage system. In total, more than half, exactly 54%, of the electricity you used to charge your electric vehicles did not come from the utility grid. This is quite remarkable despite the long winter months without significant solar power generation. This is where functions such as automatic phase-switching provide support. With this, the SMA EV Charger ensures that even small solar capacities in the early morning and evening hours or from smaller PV systems can be used to directly charge electric vehicles.

The first 18 months of field experience show that when charging with the SMA EV Charger, users refuel their electric vehicles with 54% self-generated solar power – and thus not only save money, but also contribute to the energy transition. The PV-optimized charging mode is particularly useful in the summer and transitional months. It is especially climate-neutral because it uses only self-generated electricity. In total, 2,787 tons of CO2 emissions were avoided in this way. This corresponds to the annual CO2 compensation of 334,440 newly planted beech trees, because each beech tree binds 12.5 kilograms of CO2 per year.

The benefits of PV-optimized charging with the SMA EV Charger:

  • Zero-emissions mobility with self-generated electricity
  • Charging at virtually no cost
  • Surplus PV electricity is used
  • The load on the local utility grid is reduced
  • Independence from rising electricity prices and energy imports


Bring on solar energy for the car. How to turn your PV system into a solar filling station

To charge your electric vehicle cost-effectively and sustainably, incorporate the SMA EV Charger in your plans for a new solar system from the outset or simply expand your existing system. The SMA EV Charger is quick to install and easy to connect to the utility grid as well as with a LAN cable (alternatively: via Wi-Fi). In addition to the PV system with inverter, you will need:

  • SMA EV Charger
  • Sunny Home Manager 2.0 for energy management
  • SMA Energy App for controlling the SMA EV Charger



SMA EV Charger: the wallbox with three charging modes

With the SMA EV Charger, you decide how your electric vehicle is to be charged:

  • You can charge your electric vehicle in a particularly cost-effective and CO2-neutral way with solar power from your own system. The PV-optimized mode takes care of this. It uses only self-generated solar power from your roof. This charging mode is particularly suitable at peak times, when the system produces a lot of energy, or when the vehicle is stationary anyway and it does not matter how long the charging process takes for a full charge.
  • If you have to leave at a certain time, the forecast-based charging mode ensures that the vehicle is charged and ready to go at exactly that time. The Sunny Home Manager 2.0 schedules the charging process so that as much solar power as possible ends up in the tank or, depending on availability, power from the utility grid is also used for charging.
  • If you are in a hurry, you can opt for the maximum available charging power via the fast charging mode. The SMA EV Charger flexibly uses utility grid or solar power for this purpose.

You can select the relevant charging mode either directly on the wallbox enclosure or via the SMA Energy app. The app also shows where the power used in charging comes from.


You can find out more about the solar filling station on your own doorstep here.

Refueling with solar power


Find out more about the SMA EV Charger in these blog posts:


  1. Ulf Bjurö
    Ulf Bjurö says:

    It would be interesting to see some more features.
    1. E.g in the morning when the car starts to charge there is a constant on/off if we use the microwave or toaster. So short periods of excessive load cuts the car charging with the subsequent pauses waiting for the home manager to decide to start charging again. If I set to allow a percentage of grid supply then the charger will use this grid supply for the complete charging cycle. Thus I have to buy energy unnecessarily.
    I would like to allow some grid power, for shorter periods, 1-10 minutes, to avoid halting when charging has started.
    2. When I select a charging target it would be nice if targets I have set before are shown as quick shortcuts to charge the same amount as previous days.

    • Christiane Keim
      Christiane Keim says:

      Hello Ulf,

      You will find more information regarding the SMA EV Charger in this post and on our Website.
      In case you need detailed technical support, please get back to our SMA Service.

      Sunny regards

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