Shaping the energy transition
was rarely so simple!

Green power directly from the roof –
without much effort!

EINHUNDERT is a Cologne-based energy supplier for tenants of multi-party buildings with photovoltaic systems or CHP units.

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Our promise

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Always green power

Without interruption: Either directly from the roof or, if the sun is not shining, drawn from the grid.


No effort

We take care of your change of provider – without you having to sit in the dark or worry about anything else.


Simply useful

The green electricity from the roof is cheap, transparently billed and CO2-neutral.

Our Tenant Portal

Our software platform combined with smart meters digitises the operation of tenant power systems and creates numerous added values for you and your tenants: With personal access to our Tenant Portal, your tenants have an overview of consumption and costs at all times and save themselves meter readings and non-transparent billing. In addition, your tenants benefit from monthly digital invoices and a real-time dashboard of the solar quota and electricity costs.

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    This is how it works

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    Your landlord commissions us to install your photovoltaic system on the roof.

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    The switch is very simple! Simply fill out the (online) form including your meter number and send it to us by post or email.

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    Done! We’ll take care of the rest.

    Reasons for multi tenant self consumption

    100% Green Power

    We supply you with 100% green electricity from our own roof. And when the sun is not shining, we draw directly from the grid.

    No effort

    We take care of the change of provider – without you having to sit in the dark or worry about anything else.

    Never pay extra again

    Thanks to installed digital electricity meters, we only bill you for the exact amount of electricity you have consumed each month. Without additional payments and deductions.

    Pioneer of the energy transition

    With 100% green electricity from your own roof, you are less dependent on large energy companies and also promote decentralised energy generation in apartment buildings – a win-win situation!

    Cheaper than the local basic utility tariff

    With 100.solarhaus you pay on average 10% less than with the basic supplier.

    100% green through residual electricity supply

    Residual electricity supply with 100% certified green electricity.


    What exactly does EINHUNDERT do?

    We develop smart services around a consistently green as well as a consistently digital energy supply for people in the city.

    To this end, we install and operate state-of-the-art green technologies such as solar systems, heat pumps and soon also e-charging stations – always together with digital electricity meters for full transparency on production, consumption and costs. In the online customer portal, every customer can see exactly what is happening at a glance and can always keep an eye on consumption and the corresponding monthly costs.

    Tenants without their own buildings should also benefit from the energy transition with us and be among the city’s pioneers: we simply supply 100% green, certified electricity and also offer individual portal access for full consumption and cost transparency.

    I live in a rented house and would like to become a 100.solarhaus customer - how does that work?

    We are pleased about the interest! We need more and more pioneers of the energy transition in the city. Another good thing about tenant power projects is that we are not bound by the contract terms of tenants’ previous electricity providers, as these projects are state-subsidised and we can therefore easily obtain early release from existing contracts.

    How does the switch to EINHUNDERT work?

    1) Fill in registration form including meter number

    2) Send the registration form to us by e-mail or post.

    3) Done. If a digital electricity meter has not yet been installed, we will replace it with your current electricity meter. This process can take up to 10 weeks. During this time, you will be supplied with electricity as usual by your current provider.

    Do I have to give notice to my current electricity provider? Am I bound to their contract period?

    You do not have to cancel your contract with your current electricity provider. We will take care of that for you. Since multi tenant self consumption projects are subsidised and you always have priority, you can make use of your special right of termination. This means that you are not bound to your current contract term.

    Will I incur extra costs for the installation/use of the digital electricity meter?

    No, there are no additional costs for replacing the digital electricity meter. Not even if you move out or terminate the electricity contract with EINHUNDERT.

    Do I have to be at home for the meter exchange?

    No, the meter is only replaced in the basement/floor of your house. In some cases, the electricity will have to be turned off for about 5-10 minutes.

    Otherwise, you will not notice anything about the meter exchange.

    What are my advantages as a tenant?

    As a customer of 100.solarhaus, you benefit in several ways: We supply you with 100% green electricity, which is usually cheaper than the conventional electricity of your basic supplier. In addition, we install a digital electricity meter and only bill you for the exact amount of electricity you have consumed each month. No more deductions and additional payments. In addition, you become less dependent on the large energy companies and promote the spread of decentralised energy generation in apartment buildings.

    Why is green electricity from the roof cheaper than conventional energy from the basic supplier?

    Energy that is generated on your roof and consumed directly in your home does not have to be transported from the power plant to you first, unlike regular electricity from the grid. This relieves the electricity grid, which is why you do not have to pay a fee for the use of the grid (so-called grid fee) for this share of the electricity. In addition, the state supports tenant electricity projects with a subsidy. We can pass these price advantages on to you and supply you with 100% green electricity for a favourable price.

    My bank details have changed. Where can I deposit this change?

    Soon this will work online in the personal area of the tenant portal – until then we will gladly take care of it.

    If your bank details have changed, we will send you an updated Sepa mandate form. Please complete this form with your updated data and return it by e-mail to


    Would you like to know whether we can also solve your individual challenges?

    We will be happy to advise yu.


    Louisa Treutle

    Head of Customer Service