SolarSpring

What SolarSpring does

SolarSpring GmbH was a German water technology company, founded in 2009 and headquartered in Freiburg, that developed and produced membrane-based water treatment systems. Its core technology was modular membrane distillation using waste heat to desalinate seawater and treat industrial wastewater — a thermal desalination approach distinct from conventional reverse osmosis. The company also offered ultrafiltration products for water treatment applications and positioned itself as a technology provider for brine resource recovery and microbial desalination. It participated in two notable European research collaborations: the SALTEAU project (funded by a 351,800 euro EU LIFE programme grant, focused on alternative water resource infrastructure with six European partners) and the RoKKa project (funded by the Baden-Württemberg Ministry for the Environment, with Fraunhofer IGB and multiple universities, testing recovery of phosphorus, nitrogen, and formate from wastewater at municipal treatment plants in Erbach and Neu-Ulm).

SolarSpring's business model combined hardware sales of membrane distillation and ultrafiltration systems with revenue from collaborative research and development services. It operated as a B2B technology provider serving industrial water treatment clients, municipalities, and research institutions, with a primarily direct enterprise field-sales motion for large-scale systems. The company's horizontal segmentation spanned industrial desalination, municipal wastewater resource recovery, and research partnerships.

In 2024, SolarSpring GmbH entered insolvency proceedings. Aquastill, a leader in modular membrane distillation, acquired the membrane distillation assets out of liquidation, while Wolf Water Solutions continued distribution of the Ultra Filtration product line. The company's operating status is recorded as closed, marking the end of SolarSpring as an independent entity.

Name

SolarSpring

Legal name

SolarSpring GmbH

Website

https://solarspring.de

Company type

Private

Founded year

2009

Operating status

Closed

Headcount range

11–50 employees

Short description

SolarSpring GmbH was a German water technology company developing membrane distillation systems for sustainable thermal desalination of seawater and industrial wastewater, serving industrial clients, municipalities, and research institutions before its 2024 insolvency and asset acquisition by Aquastill.

Ownership category

akta.pro rank

Product category

Industrial Water Treatment Equipment

NAICS

Water Supply and Irrigation Systems (22131), Sewage Treatment Facilities (22132)

SIC

Water Supply (4941)

akta.pro primary industry

Thermal Desalination (MSF/MED) Plants & Operations (EUANAFAC)

akta.pro secondary industries

Membranes, Consumables & Chemicals (Elements, Antiscalants, Cleaning) (EUANAFAJ), Advanced Treatment & Purification Utilities (MF/UF, RO, AOP, UV) (EUANAGAD), Industrial Water Reuse Utilities (ZLD/MLD & Process Water Recycling) (EUANAGAG)

Keywords

• Membrane distillation systems
• Water desalination equipment
• Industrial water treatment
• Wastewater treatment solutions
• Ultrafiltration products

Headquarters

HQ city

Freiburg

HQ country

Germany

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Operations, Personnel, Supply Chain

Revenue model

1. Water Treatment Equipment Sales: Sale of membrane distillation and ultrafiltration equipment and systems for water treatment and desalination
2. Research and Development Services: Research collaboration and technology provision in collaborative R&D projects with academic and industrial partners

Go-to-market motion2 records

Distribution channels2 records

Marketing channels1 record

Core offering

SolarSpring GmbH developed and produced modular membrane distillation systems for sustainable thermal desalination of seawater and industrial wastewater using waste heat as an energy source. The company also offered ultrafiltration products for water treatment applications and served as a technology provider for brine resource recovery and microbial desalination in collaborative research projects.

Product overview

SolarSpring GmbH was a water technology company that developed and provided membrane-based water treatment solutions, operating as a dual-product company. Its primary offerings included modular membrane distillation technology (branded under Aquastill following acquisition) for sustainable thermal desalination of seawater and industrial wastewater using waste heat, and ultrafiltration products for water treatment applications. Following SolarSpring GmbH's insolvency, Aquastill acquired the membrane distillation assets, while Ultra Filtration products continue to be available through Wolf Water Solutions. The company also served as a technology provider for brine resource recovery in the EU-funded SALTEAU project.

Differentiator

Problem solved

Functional benefit

Products and services

• Membrane Distillation Technology Modular membrane distillation technology that uses waste heat as an energy source for sustainable thermal desalination of seawater and industrial wastewater. Developed and sold by SolarSpring GmbH; assets now continued under the Aquastill brand following acquisition.
• Ultra Filtration Products Ultrafiltration products for water treatment applications. Following SolarSpring's insolvency, these products continue to be distributed by Wolf Water Solutions for industrial and municipal water treatment buyers.

Quantifiable outcome

• Recovery of phosphorus and nitrogen from wastewater for fertiliser production
• +1 more outcomes

Named customers1 record

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Ten partnerships are on record, tiered core and minor.

• Fraunhofer IGBcoreStrategic or Co-development Partner · 30 April 2026Collaboration in RoKKa research project funded by Baden-Württemberg Ministry for the Environment, Climate Protection and the Energy Sector. Project tests recovery of raw materials from wastewater at treatment plants in Erbach and Neu-Ulm, Germany.
• University of StuttgartcoreStrategic or Co-development Partner · 30 April 2026Collaborating in RoKKa research project to transform conventional sewage plants into biorefineries extracting phosphorus and nitrogen for fertilisers.
• University of KasselcoreStrategic or Co-development Partner · 30 April 2026Collaborating in RoKKa research project to transform conventional sewage plants into biorefineries extracting phosphorus and nitrogen for fertilisers.
• Technical University of KaiserslauterncoreStrategic or Co-development Partner · 30 April 2026Collaborating in RoKKa research project to transform conventional sewage plants into biorefineries extracting phosphorus and nitrogen for fertilisers.
• Deukum GmbHminorStrategic or Co-development Partner · 30 April 2026Collaborating in RoKKa research project to transform conventional sewage plants into biorefineries.
• Nanoscience for life GmbHminorStrategic or Co-development Partner · 30 April 2026Collaborating in RoKKa research project to transform conventional sewage plants into biorefineries.
• Umwelttechnik BW GmbHminorStrategic or Co-development Partner · 30 April 2026Collaborating in RoKKa research project to transform conventional sewage plants into biorefineries.
• AquastillcoreOEM/ Whitelabel/ Licensing Partner · 1 October 2024Aquastill, one of the leaders in modular membrane distillation technology, acquired the membrane distillation assets of SolarSpring following insolvency proceedings. Aquastill is committed to further development of Membrane Distillation as a Sustainable Thermal Desalination technology.
• Wolf Water SolutionsminorChannel Partner/ Reseller/ Distributor · 1 October 2024Following SolarSpring insolvency, Wolf Water Solutions serves as the contact for Ultra Filtration products, continuing distribution of these products.
• SALTEAU Project ConsortiumcoreStrategic or Co-development Partner · 26 February 2024SolarSpring received a 351,800 euro grant from the EU LIFE programme for participation in the SALTEAU project. The project aims to develop new infrastructure to utilize alternative water resources effectively. SolarSpring serves as technology provider for brine resource recovery. Project involves six European partners focusing on microbial desalination and membrane processes.

Scale indicators3 records

Recent moves6 records

Expansion highlights4 records

Broad incumbents

• Pentair: Pentair is a major water treatment equipment provider offering filtration, ultrafiltration, and desalination solutions globally. Comparable as a broader water treatment incumbent with overlapping ultrafiltration product lines to SolarSpring's UF business.
• IDE Technologies: IDE Technologies is a major desalination technology provider offering thermal and membrane-based solutions, including MED and reverse osmosis. Comparable as a broader desalination incumbent that competes for the same industrial and municipal customers as SolarSpring targeted.
• Suez Water Technologies & Solutions: Suez is a global water treatment and wastewater treatment giant offering membrane filtration, desalination, and resource recovery solutions. Comparable as a broad incumbent covering the full water treatment value chain that SolarSpring targeted, including industrial water reuse and brine management.
• Veolia (Sidem): Through its Sidem division, Veolia is a global leader in thermal desalination (MSF/MED) plants. It is comparable to SolarSpring as a broad incumbent in the thermal desalination space, though at significantly larger industrial scale.
• Toray Industries: Toray is a global leader in reverse osmosis and nanofiltration membrane manufacturing. Comparable as a broader membrane-based water treatment incumbent whose RO technology competes directly against SolarSpring's thermal membrane distillation for industrial and municipal water applications.

Direct peers

• Hyflux: Hyflux is a Singapore-based water treatment and desalination specialist offering membrane-based solutions including ultrafiltration and RO. Comparable as a peer in the membrane-based desalination and water reuse space, particularly for industrial applications.
• Aquastill: Aquastill is a Netherlands-based leader in modular membrane distillation technology using waste heat for desalination — directly comparable to SolarSpring's core technology. Notably, Aquastill acquired SolarSpring's membrane distillation assets out of liquidation, making it both a peer and successor operator.

Emerging players

• Saltworks Technologies: Saltworks Technologies specializes in thermal desalination and brine treatment using membrane distillation and evaporation technologies. Highly comparable as a focused specialist in the same thermal desalination / membrane distillation niche as SolarSpring.
• Energy Recovery Inc: Energy Recovery provides energy recovery devices and pressure exchanger technology for desalination. Comparable as an adjacent technology provider in the desalination value chain, targeting the same energy-efficiency challenges that membrane distillation attempts to solve through waste heat.

Others

• Fraunhofer IGB: Fraunhofer IGB is a German applied research institute collaborating with SolarSpring on the RoKKa project for wastewater resource recovery. Comparable as an R&D ecosystem partner rather than a direct competitor, but adjacent to the membrane distillation and biorefinery space.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat2 records

Key risks6 records

Key highlights6 records

Customer concentration

• Xx.com/solar_spring

Revenue estimate

Valuation estimate

Number of profiles

Funding overview

Funding rounds2 records

Investors2 records

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 SolarSpring