Innovation

PureGreen’s innovation is a compact, easy-to-install water-saving adapter, available for both showers and sinks, which significantly reduces water and energy use, without sacrificing comfort. By applying the Venturi principle to mix air into the water stream, it maintains the sensation of a strong flow while using much less hot water. Their adapter functions as a “vortex-style nozzle” that is installed between the shower arm and the hose. It draws in air through a small side opening and mixes it with the water. This process increases the water’s surface area and creates a wide, aerated spray, which delivers the same shower sensation while reducing the water consumption. The installation process is simple and tool-free, as it requires only a few twists to attach. This makes it an effective tool for lowering household energy demand and conserving natural resources. Despite limited marketing resources, PureGreen has reached over one million households, largely through strategic media exposure, proving that simple, scalable innovations can drive real environmental impact.

The product contributes to multiple UN Sustainable Development goals, including SDG 6 (Clean Water and Sanitation) and SDG 7 (Affordable and Clean Energy), SDG 12 (Responsible Consumption and Production), SDG 13 (Climate Action), and it also aligns with SDG 11 (Sustainable Cities and Communities).

SDG 6 - Clean Water and Sanitation. PureGreen helps households to dramatically reduce water usage in the shower, which is the most water-intensive part of daily life. Even small-scale adoption generates a significant collective impact. By making water conservation easy and accessible, the adapter directly supports the global efforts towards ensuring water availability and sustainable management for all.

SDG 7- Affordable and Clean Energy. Showering accounts for up to 20% of household energy consumption in Germany due to the need to heat water. PureGreen’s adapter cuts this consumption by reducing hot water usage without affecting the quality of the user’s experience. On average, a single device can lower a household’s overall energy consumption by up to 10%. This directly advances energy efficiency in residential settings, which is a key component of SDG 7.

SDG 12 - Responsible Consumption and Production. The adapter encourages a more efficient use of existing household infrastructure and supports a shift towards more mindful consumption. By reducing water and energy use without requiring new appliances or behavioral changes, it empowers consumers to lower their environmental impact in a simple, cost-effective way.

SDG 13 - Climate Action. Heating water is a significant source of household carbon emissions. By reducing the energy required for this process, PureGreen’s innovation can contribute to high levels of CO2 savings. With one million units already in use, the climate benefits are real and repeatable.

SDG 11 - Sustainable Cities and Communities. In urban areas, the widespread use of PureGreen’s adapters can ease pressure on municipal water and energy systems, which helps cities to operate more efficiently. By lowering the demand at the household level, the innovation can support a more efficient infrastructure use and help cities build resilience against potential resource scarcity.

Inspiration

The idea for PureGreen began with a long shower and a polar bear. When founder Alexander Schulze moved into a new house in 2015, he noticed a quirky water meter in the shower. On its screen, a small polar bear stood atop an ice floe that slowly shrank the longer the water ran. As Alexander enjoyed his usual hot shower, he watched the bear sink beneath the surface. The image stuck with him. “I’m a passionate, long, hot-shower aficionado,...but that bear made me realize how much energy and water I was wasting just to feel comfortable.” The insight hit: hot water is more than water, it’s also energy and lots of it. As a tech-driven problem solver, he explored how to reduce water and energy use without sacrificing comfort. He tested existing restrictors but found they made showers weak and unpleasant. Then the breakthrough came: using the Venturi principle to mix in air and maintain water pressure, just like how planes achieve lift. From this blend of personal awareness, engineering curiosity and a desire for impact, PureGreen was born.

Overall impact

To date, PureGreen has sold over one million units in Germany, each capable of saving up to 10% of a household’s annual energy use. Assuming continuous use, this results in substantial environmental and financial savings across the country. Even conservative estimates suggest that one million adapters could save between 10–20 million cubic meters of water and over 100,000 tons of CO₂ annually. The savings are not limited to a one-time effect; each year the device is used, it continues to conserve valuable resources. As he puts it, “One million households at roughly 10% saved energy is a serious impact. That makes me very proud.” According to Alexander, the most common feedback from customers is their surprise that such a small device can generate such a significant impact.

The innovation has also sparked international interest, particularly in water-stressed regions like South Africa, where communities face frequent shortages. Organizations there have approached PureGreen as a simple, effective way to alleviate water scarcity. Trials are also underway aboard cruise ships, such as the AIDA Cruises fleet, where desalinated water must be heated for thousands of daily showers. With approximately 100 ships and 200,000 showers involved, the savings potential is immense, especially since hotel and cruise guests tend to shower longer than at home. 

Business benefit

This innovation addresses a pressing global challenge on a household level: the sustainable use of water and energy in daily life. By reducing consumption without compromising comfort, it offers a practical and appealing solution for individuals who want to make a meaningful environmental impact. PureGreen has built a sustainable business around a low-cost, high-impact product. After initial sales through local retailers and online platforms, the company gained significant traction in 2021 when Alexander Schulze and his Co-founder Karsten Gaedke, Karsten Gaedke, pitched the water-saving device on the pitching competition show ‘Die Höhle der Löwen’ (translated to the ‘Lions Den’), the German version of Shark Tank. He received offers from two investors and ultimately partnered with Ralf Dümmel. This collaboration, combined with national media exposure, enabled PureGreen to scale up manufacturing and expand its distribution network. The company has successfully leveraged both online and direct-to-consumer channels. Listings on Amazon and Otto, sales through discounters like Lidl and their own website, along with the TV show’s appearance, have not only driven sales but also functioned as powerful marketing tools, crucial for a product that relies heavily on awareness. Internally, PureGreen remains a small and agile team of four. The company prioritizes reinvestment and ongoing product development over aggressive expansion, maintaining a clear focus on sustainable growth. 

In terms of competition, major bathroom fixture brands have since replicated the concept, but often in far more expensive, less adaptable formats (e.g. €100+ new shower heads). PureGreen’s device fits onto existing infrastructure, saving cost and reducing waste.

Social and environmental benefit

PureGreen’s innovation delivers meaningful benefits for both society and the environment, starting at the household level. By reducing hot water usage, the adapter allows consumers to lower their energy and water bills while contributing to more sustainable resource use. Alexander highlights this “win-win” effect: users save money and the planet benefits from reduced consumption. Widespread adoption can ease pressure on municipal water and energy infrastructure, helping cities reduce operational costs and preserve clean water for critical uses like agriculture and sanitation. Every liter saved in a shower is a liter that remains in reservoirs, an increasingly vital consideration as water scarcity becomes more widespread. In fact, global projections suggest that by 2025 (this year!), nearly half the world’s population will live in areas facing water stress. On a global scale, the ethical dimension becomes clear: the daily shower habits of industrialized nations use more water than some countries can access in weeks. PureGreen’s adapter helps reduce such inequalities through simple conservation. Environmentally, the impact includes lower carbon emissions and less strain on wastewater treatment systems, leading to fewer pollutants entering natural waterways. Socially, users report increased awareness of their daily consumption habits. The simplicity of the solution makes sustainability feel achievable, even for those without access to advanced green technologies.

By aligning individual action with multiple of the UN Sustainable Development Goals, PureGreen proves that environmental impact does not require sacrifice, just a smarter design. In a world facing complex climate and resource challenges, it offers a meaningful reminder that change often begins at home, with small steps that scale.

Interview

Alexander Schulze, Founder