Polarstern

What Polarstern does

Polarstern GmbH is a Munich-based, privately-held German eco-energy supplier operating as a Certified B Corporation and member of the Gemeinwohl-Ökonomie (Common Good Economy). The company supplies 100% renewable electricity from German hydro, solar, and wind power (Ökostrom) and 100% biogas (Ökogas) to residential and commercial customers across Germany, alongside specialty tariffs for heat pumps (Wärmepumpenstrom), night-storage heaters (Nachtspeicherstrom), and electric vehicles (Autostrom). Its technical and product platform extends beyond commodity supply to decentralized energy solutions, including turnkey Mieterstrom (tenant electricity) project development — planning, financing via PPA, installation and ongoing operation — with more than 300 delivered projects covering approximately 10,000 households. Notable reference deployments include a 605.25 kWp rooftop PV system at Olympiastadion Berlin (€625,000 PPA-funded) and municipal partnerships with Freiburger Stadtbau and Stadt Esslingen, the latter housing the Green Hydrogen Esslingen subsidiary that pilots electrolytic hydrogen from surplus local solar and wind. Additional proprietary offerings include Kaskadenmessung (cascade measurement) for heat-pump/PV self-consumption optimization, dynamic Flex/Flex Plus tariffs, GEG-compliant gas tariffs, and THG-Quote services.

The business model is consumption-based subscription across private and commercial segments: long-tail residential acquisition flows through a self-serve website tariff calculator and a referral program offering up to €70 credit, while business and Mieterstrom deals are closed through dedicated direct-sales teams. For every kWh consumed, Polarstern invests 1 cent into renewable expansion in Germany and contributes €20 annually per customer to global energy-transition projects in Cambodia (biogas plants) and Madagascar (village solar), supporting approximately 65,000 people and ~410,000 tonnes of avoided CO2. Distribution is Germany-only commercially; the international footprint is impact-driven rather than revenue-generating. Recent strategic activity (2022–2025) centers on scaling Mieterstrom automation and project execution capacity, including an expanded €12.5 million DKB debt facility (Sep 2022), a strategic investment from biomethane trader Landwärme (Aug 2023), the acquisition of Renera Energy Germany's PV-rooftop team (Feb 2025), and partnerships with Ampeers Energy (Jul 2025) and Solarize (Sep 2025). The company carries multi-layered certifications — Grüner Strom-Label, TÜV Nord, B Corp, Robin Wood, Gemeinwohl-Ökonomie — and has been recognized nine consecutive times as Capital/Statista's "Innovator of the Year" and as a Financial Times/Statista Europe's Long-Term Growth Champion 2026, with a 4.9/5 customer rating on eKomi across 3,162 reviews.

Name

Polarstern

Legal name

Polarstern GmbH

Website

https://polarstern-energie.de

Company type

Private

Founded year

2011

Operating status

Operating

Headcount range

51–100 employees

Short description

Polarstern is a Munich-based, privately-held German eco-energy supplier providing 100% renewable electricity and biogas to residential and commercial customers, alongside turnkey Mieterstrom (tenant electricity) project development, commercial solar PPAs, and global energy-transition projects in Cambodia and Madagascar.

Ownership category

akta.pro rank

Product category

Renewable Energy Retail Supply

NAICS

Electric Power Generation, Transmission and Distribution (2211), Solar Electric Power Generation (221114)

SIC

Electric Services (4911), Cogeneration Services & Small Power Producers (4991)

akta.pro primary industry

Renewable Distributed Generation (Rooftop/Onsite Solar, Small Wind, Small Hydro) (EUACALAJ)

akta.pro secondary industries

Interconnection, Permitting & Grid Services for DERs (EUAMAJAH), Demand Response & Load Flexibility Services (EUAMAJAF), Onsite Low-Carbon Heat & CHP (Electrified CHP, Fuel Cells, Renewable CHP) (EUABAJAI), Grid Interconnection, Power Quality & Electrical Infrastructure Service (Transformers, Switchgear) (TLAKAMAM)

Keywords

• Renewable electricity supply
• Green gas supply
• Tenant electricity solutions
• Commercial solar installations
• Eco energy tariffs

Headquarters

HQ city

Munich

HQ country

Germany

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B and B2C

Offering type

Services

Cost components

Operations, Personnel, Supply Chain, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. Residential Electricity Supply: Recurring revenue from supplying 100% renewable electricity to residential customers. Revenue is generated through monthly subscription-like contracts with customers paying based on consumption (kWh). The company invests 1 cent per kWh consumed into renewable energy expansion.
2. Residential Gas Supply: Recurring revenue from supplying 100% biogas to residential customers. Similar consumption-based model with 0.21 cents per kWh invested in renewable energy expansion plus €20 annually per customer for global energy transition initiatives.
3. Heat Pump Electricity Tariffs: Specialized electricity tariffs for heat pumps (Wärmepumpenstrom) and night storage heaters (Nachtspeicherstrom), offered at lower prices than standard household electricity due to interruptible meter arrangements.
4. E-Mobility / Autostrom: Electric vehicle charging tariffs and THG quota ( Treibhausgasminderungsquote) services for e-vehicle owners. Also includes fleet charging solutions for businesses.
5. Commercial/Industrial Energy Supply: Business tariffs for commercial electricity (Gewerbestrom), commercial gas (Gewerbegas), and commercial solar (Gewerbesolar). Includes Mieterstrom solutions for commercial properties.
6. Mieterstrom (Tenant Electricity) Services: Revenue from providing complete Mieterstrom solutions to property owners including planning, financing, installation and ongoing supply. Models include PPA (Power Purchase Agreement) arrangements.

Pricing tiers

Go-to-market motion2 records

Distribution channels4 records

Marketing channels7 records

Core offering

Polarstern supplies 100% renewable electricity (Wirklich Ökostrom) sourced from German hydro, solar, and wind power, and 100% biogas (Wirklich Ökogas) certified by TÜV Nord, to residential and commercial customers across Germany. The company also provides specialized electricity tariffs for heat pumps, night storage heaters, and electric vehicles, along with Mieterstrom (tenant electricity) solutions for multi-family buildings and commercial solar installations including PPA-funded projects.

Product overview

Polarstern is a 100% renewable energy provider offering a comprehensive portfolio of energy products and services for both private and business customers. The core offerings include 'Wirklich Ökostrom' (certified green electricity from German hydro, solar, and wind power) and 'Wirklich Ökogas' (100% biogas certified by TÜV Nord). The product lineup includes specialized tariffs such as flexible and dynamic electricity/gas tariffs, heat pump electricity, night storage electricity, and EV charging tariffs. Solar products encompass tenant electricity (Mieterstrom), commercial solar installations, and home solar solutions. The company also offers green hydrogen production, biogas plants for international development projects, and a digital impact calculator. For business customers, dedicated products include commercial electricity, commercial gas, and commercial solar solutions with charging infrastructure services. All products emphasize genuine sustainability with third-party certifications from Grüner Strom-Label, TÜV Nord, B Corp, and Gemeinwohl-Ökonomie, with investments directed toward expanding renewable energy in Germany and worldwide projects in Cambodia and Madagascar.

Differentiator

Problem solved

Functional benefit

Brands

• Wirklich Ökostrom: 100% renewable electricity product from German water, solar, and wind power, certified with Grüner Strom-Label
• Wirklich Ökogas
• Wirklich Autostrom
• Wirklich Gewerbestrom
• Wirklich Gewerbegas
• Wirklich Gewerbesolar
• Wirklich Mieterstrom
• Wirklich Wärmepumpenstrom
• Wirklich Nachtspeicherstrom
• Wirklich Eigenstrom

Products and services

• Wirklich Ökostrom 100% renewable electricity sourced from German water, solar, and wind power, certified by Grüner Strom-Label and TÜV Nord, for residential customers. For each kWh consumed, 1 cent is invested in expanding renewable energy in Germany.
• Wirklich Ökogas 100% biogas product for residential heating, certified by TÜV Nord, produced from biogenic residual and plant-based materials, free from fossil natural gas.
• Wirklich Wärmepumpenstrom Specialized electricity tariff for heat pump owners, offered at lower prices than standard household electricity due to interruptible meter arrangements (§14a EnWG), with 60% reduction in grid fees and Umlagen exemption.
• Wirklich Nachtspeicherstrom Electricity tariff with day/night (HT/NT) structure offering lower night rates, designed for night storage heaters in older buildings.
• Wirklich Autostrom Electric vehicle charging tariff for private customers, enabling EV owners to charge with 100% renewable energy from Polarstern.
• Wirklich Eigenstrom Home solar electricity solution enabling homeowners to generate their own electricity, with rewards for self-generation and usage.
• Wirklich Mieterstrom Tenant electricity solution for property owners, housing associations, and developers, providing planning, financing, installation, operation, and supply of locally generated solar power to residents of multi-family buildings under various Mieterstrom models.
• Wirklich Gewerbestrom Green electricity tariffs for commercial customers, supporting business energy transition with 100% renewable supply.
• Wirklich Gewerbegas Sustainable biogas supply for commercial and industrial customers seeking renewable heating solutions.
• Wirklich Gewerbesolar Turnkey commercial solar power solutions including rooftop PV installations for businesses, parking structures, and venues (such as the 605.25 kWp Olympiastadion Berlin system), available with PPA financing options.
• Ladelösungen für Unternehmen Customized EV charging infrastructure solutions for businesses including fleet charging, corporate charging networks, and public charging stations.
• THG-Quote Service Service allowing electric vehicle owners to monetize their GHG (Treibhausgasminderungsquote) quota certificates for additional income.
• Biogasanlagen (Cambodia) Biogas plant solutions developed in partnership with local Cambodian organizations, enabling families to generate eco-energy from animal manure for cooking and gas lamps, producing organic fertilizer as byproduct.
• Wärme-Contracting Heat contracting services bundled with Mieterstrom solutions, providing comprehensive heating solutions for residential and commercial properties.
• Wirklich Wasserstoff (Green Hydrogen) Green hydrogen production project through subsidiary Green Hydrogen Esslingen, producing hydrogen from surplus local solar and wind power, fed into the gas grid as part of the climate-neutral Esslingen Weststadt district pilot project.

Quantifiable outcome

• ~410,000 tonnes CO2 saved through customer base
• +5 more outcomes

Named customers4 records

Segments4 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Seven partnerships are on record, tiered core and minor.

• SolarizecoreTechnology or Integration · 23 September 2025Strategic partnership to automate the Mieterstrom supplier switching process. Enables scalable processes for tenant electricity delivery through system integration.
• Ampeers EnergycoreStrategic or Co-development Partner · 2 July 2025Joint offering in the Mieterstrom supply chain model (Lieferkettenmodell) for the housing industry. Enables efficient integration into corporate climate strategies.
• Renera Energy GermanyminorStrategic or Co-development Partner · 4 February 2025Polarstern took over Renera's PV rooftop team to strengthen offerings around PV, heat, and e-mobility solutions for the real estate industry.
• Neckar-EnergieverbandminorStrategic or Co-development Partner · 27 January 2022Cooperation partner in green hydrogen project in Esslingen Weststadt, along with Stadtwerke Esslingen and Polarstern.
• Stadtwerke EsslingenminorStrategic or Co-development Partner · 27 January 2022Cooperation partner in green hydrogen project in Esslingen Weststadt, along with Neckar-Energieverband and Polarstern.
• KOCO Energy AGminorImplementation/ SI/ Consulting Partner · 21 January 2022Project developer and installer for the Olympiastadion Berlin PV project. Experienced in complex stadium installations including the original 2006 World Cup membrane roof.
• Green Hydrogen Esslingen (Subsidiary)coreOthersPolarstern subsidiary producing green hydrogen from surplus local solar and wind power. Hydrogen is fed into the gas grid as a research project.

Scale indicators6 records

Recent moves6 records

Expansion highlights6 records

Direct peers

• EWS Schönau: Citizen-owned renewable energy cooperative from Schönau supplying green electricity across Germany, with deep roots in decentralized generation and citizen participation. Comparable to Polarstern's social-business model, Mieterstrom heritage, and German retail focus.
• Naturstrom: German green electricity and gas supplier owned by Naturstrom AG, with strong credentials in citizen-owned renewable projects and ecological sourcing — directly comparable to Polarstern's certified, impact-investing positioning in the German residential and SME market.
• DZ-4: German Mieterstrom specialist providing tenant electricity solutions to housing companies, with comparable operational focus on multi-family PV, metering, and energy supply — directly competing for the same housing-industry customers as Polarstern.
• Lichtblick: Hamburg-based renewable electricity and gas retailer competing head-to-head with Polarstern in the German green-energy retail market, including residential, B2B, and dynamic tariff offerings. Closely comparable on product breadth, customer base, and certification-led differentiation.
• Greenpeace Energy: German cooperative green energy retailer founded by Greenpeace, offering 100% renewable electricity and gas to residential and commercial customers. Closely comparable as a values-driven, certification-led direct competitor in the same German market segments as Polarstern.

Emerging players

• Zolar: Online solar platform connecting German homeowners to regional installers for rooftop PV and battery storage. Overlaps with Polarstern's Eigenstrom product line on customer acquisition and residential solar supply.
• Enerix: German franchise solar installer specializing in rooftop PV, battery storage, and EV charging for residential and commercial customers. Comparable to Polarstern's Gewerbesolar and Eigenstrom offerings on the distributed-generation side.
• 1Komma5°: Hamburg-based climate-tech company installing rooftop solar, heat pumps, and EV charging for homeowners, with its own energy-supply arm ('Heartbeat'). Comparable to Polarstern's Eigenstrom, Wärmepumpenstrom and Autostrom lines and a potential competitor for residential electrification customers.

Broad incumbents

• E.ON: Major European integrated utility with a large German retail business and growing renewable offerings. Comparable as the dominant incumbent in the German residential and SME energy supply market in which Polarstern competes.
• EnBW (with Yello): One of Germany's largest integrated utilities, with significant renewable generation assets and a discount retail brand (Yello) competing on price. Comparable as a broad incumbent offering green tariffs across all customer segments that Polarstern serves.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights6 records

Customer concentration

• YouTubeyoutube.com/user/polarsternenergie
• Facebookfacebook.com/PolarsternEnergie
• LinkedInlinkedin.com/company/polarstern-energie
• Instagraminstagram.com/polarstern_energie
• Pinterestpinterest.de/polarstern
• Xx.com/polarstern_nrgi

Compliance7 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles4 records

Subsidiaries1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Polarstern