Green electricity charging: how green is your charge?

Green electricity at charging stations: How green is the power you use?

An electric car is only as clean as the electricity used to charge it. That is exactly why it is worth asking: how much green electricity actually goes into your charging session? There is often a bigger gap between the green promise at the charging station and the reality of the power grid than many drivers realise. This article explains how green charging electricity is certified, how to recognise genuine quality and why green electricity at the charger is more than just a label.

What green electricity at a charging station really means

First, an important clarification: the term green electricity is not legally protected in Germany. Within the physical grid, green electricity cannot be separated from conventional electricity anyway. As soon as wind power, solar power or a coal-fired plant feeds electricity into the grid, it all blends into a common energy mix. Physically speaking, the electricity flowing from a charging station is therefore always a mixture.

Green charging electricity is therefore a matter of accounting. A provider undertakes to document a corresponding amount of renewable energy for the electricity supplied. How clean your charging electricity is thus depends not on the cable, but on the accounting behind it. For context: in 2025, more than half of Germany's gross electricity consumption came from renewable sources. A green electricity tariff goes beyond this average and certifies that 100% comes from renewable energy.

Guarantees of origin as proof of green charging electricity

The key instrument for providing this proof is the guarantee of origin (GO). A guarantee of origin confirms that a certain amount of electricity, generally one megawatt-hour, was generated from renewable sources. These certificates are administered by the German Environment Agency in its Guarantees of Origin Register (HKNR). The legal basis is the European Renewable Energy Directive (RED), implemented in part through Germany's Energy Industry Act.

A clear rule has applied since 2013: an energy supplier may label electricity as green only if it cancels guarantees of origin in the registry for the amount supplied. This prevents what is known as double marketing, where the same green kilowatt-hour would be sold more than once. Importantly, guarantees of origin are separate from the physical flow of electricity. They account for its origin on paper, not for the specific electricity flowing through your cable when you charge.

One detail provides additional reassurance: in Germany, the Federal Environment Agency does not issue guarantees of origin for electricity that has already received support under the Renewable Energy Sources Act. This prevents double counting in the registry.

Why genuinely green electricity is more than a certificate

Guarantees of origin are useful and legally sound. Even so, on their own they say little about whether your green electricity advances the energy transition. The reason is that a large share of the certificates used in Germany are imported, primarily from Norway, Iceland or Austria. On paper, even conventional electricity can thus be marketed as a green electricity product using inexpensive purchased certificates.

For a genuine contribution, another criterion therefore matters: additionality. If part of the price goes toward building new renewable-energy facilities, additional green electricity is generated. This is what distinguishes high-quality green power from mere green labeling. For the electricity you charge with, that means not every green promise at a charging station carries the same weight.

How to recognise high-quality green electricity

Independent quality labels offer guidance. Two labels are considered particularly rigorous and are also regarded as meaningful by Germany's Federal Environment Agency and consumer advice centres:

• Grüner Strom Label: Germany's oldest and strictest green electricity certification. For every kilowatt-hour sold, at least 0.5 cents must go towards expanding renewable energy.
• ok-power: backed by the EnergieVision association, with the involvement of the Öko-Institut. This certification requires binding investment in new facilities and excludes providers with stakes in nuclear and coal-fired power plants.

Be wary of certification marks that merely confirm guarantees of origin without requiring the construction of new facilities. In such cases, look for additional criteria such as a quota for new facilities or support for renewable energy. A self-designed logo without independent verification, on the other hand, is not a mark of quality.

More detailed guarantees of origin as the next step

Until now, green electricity has generally been accounted for on an annual basis. This means your green charging electricity is offset over the course of the year, rather than necessarily being generated during the hour in which you charge. A forward-looking approach aims to change that. In a pilot project, LichtBlick, Granular Energy and decarbon1ze issued the first granular guarantees of origin at charging stations on a quarter-hourly basis. This makes it possible to trace which plant supplied the charging electricity and whether it was generated at the same time as the charging session. That is an important step forward for the credibility of green electricity at charging stations, even though binding standards are still being developed.

You can also make your own charging greener by scheduling it for periods with plenty of wind and solar power. The higher the share of renewable energy in the grid, the cleaner each kilowatt-hour you charge actually is.

What green charging electricity means for businesses

For site partners, fleet operators and municipalities, the origin of charging electricity has long been more than an image issue. It directly affects their carbon footprint and ESG goals. Offering verifiably green charging electricity at your site strengthens your sustainability credentials and makes you more attractive to environmentally conscious customers.

This is also where JOLT's model comes in. JOLT's charging stations have integrated battery storage, enabling ultra-fast charging without costly grid expansion. As intelligent energy storage, the network can balance the supply of and demand for renewable electricity in real time. In this way, the infrastructure supports the integration of renewable energy in urban areas, with up to 360 kW of charging power, around 200 km of range in roughly 10 minutes and round-the-clock availability.

The bottom line on green charging electricity

How green the electricity you charge with really is depends not on the charging station itself, but on the evidence behind it. Guarantees of origin provide legal certainty, while high-quality certifications such as the Grüner Strom Label and ok-power ensure a genuine contribution to the energy transition. Look more closely at green electricity at charging stations and you can charge not only faster, but with a clear conscience. Green electricity at charging stations thus becomes a benchmark for sustainable mobility.

Discover how JOLT combines ultra-fast charging with the integration of renewable energy in the city!