Thermal desalination lost the water industry to reverse osmosis on one number: boiling seawater takes about ten times more energy than pushing it through a membrane. So why is one of the 20 teams left in the XPRIZE Water Scarcity competition still betting on heat?

Desolenator is a Dutch water tech company that desalinates with heat instead of pressure, running on solar energy and industrial waste heat rather than grid electricity. Its hybrid panel harvests electricity and thermal energy from the same sunlight, recovers the latent heat of its own steam, and can run to zero liquid discharge, leaving salt instead of brine. Four patents, and a scale-up from 25 to 100, then 1,000 cubic metres a day.

William Janssen built the first proof of principle in his living room and kept the distilled water in his freezer as proof. He won 100,000 euros at Climate Launchpad, was picked up by the Dubai Future Accelerator and Dubai Electricity and Water Authority, and delivered plants in Dubai and Abu Dhabi. Desolenator is chaired by Paddy Padmanathan, who led ACWA Power for 18 years and made it the world's largest desalination company.

🌶️ KEY SPICES 🌶️

🌡️ Why thermal desalination's ten-times energy penalty disappears when the heat is "chaleur fatale", the waste heat industry pays to throw away

🔌 How a phone call about data centre cooling became patent number four: one heat pump worked from BOTH sides, lifting 50°C exhaust to the 70°C a distiller needs

🌱 Why farmers around Al Ain are salting the aquifer they irrigate from, and how zero liquid discharge breaks that loop

📉 Paddy Padmanathan on the cost curve he signed himself: $2.50 per cubic metre in 2005, $0.46 on his last ACWA Power contract in 2023, and why it still isn't solved

🏆 What William answers when asked point blank whether Desolenator wins the XPRIZE: two words no founder is supposed to say

🥜 IN A NUTSHELL 🥜

What is thermal desalination, and how does it differ from reverse osmosis?

Thermal desalination makes fresh water by evaporating seawater and condensing the steam, the way rain works, while reverse osmosis pushes seawater through a fine membrane under pressure. Reverse osmosis uses roughly ten times less energy and won the municipal market, but it needs electricity, while thermal desalination runs on the low-grade heat industry already wastes.

Can solar energy power desalination?

Yes. Desolenator's panels harvest electricity and heat from the same sunlight and buffer both, which is how its Dubai plant hit the benchmark set by Dubai Electricity and Water Authority: 10 cubic metres a day, 20 hours a day, year-round.

What is zero liquid discharge, and why does it matter for water scarcity?

Zero liquid discharge recovers all the water from a stream and leaves solid salt instead of brine. It matters where brine has nowhere to go: around Al Ain, farmers desalinate saline groundwater and flush the concentrate back into the aquifer, making it saltier each year.

Is thermal desalination a good water investment in 2026?

It depends on scale and free heat. Desolenator draws its own fence at 100 million litres a day, above which membranes win. Its CapEx runs higher than conventional quotes and its OpEx dramatically lower, so the economics favour industrial sites with waste heat or land for solar, and buyers needing zero liquid discharge.

#️⃣ Mentioned Links #️⃣

Desolenator - desolenator.com

Why Elon Musk's Desalination Vision is Failing - watch on YouTube

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See how the Northumbrian Water Innovation Festival brings together creative minds in Newcastle for collaborative problem solving.

Watch the energy of this unique event.

This episode takes you inside the Northumbrian Water Innovation Festival to show how large groups tackle industry challenges through structured collaboration.

You will see firsthand how participants move from concept to practical solutions using specific frameworks like sprint tents and the Crystal Ball method.

Whether you are interested in corporate innovation or local Newcastle events, this footage highlights the collaborative process in action.

It is designed for professionals and curious viewers who want to observe how collaborative problem-solving works in a real-world setting, moving beyond traditional meeting rooms to open, creative environments.

If you enjoyed seeing how an Innovation Festival operates, subscribe for weekly industry event recaps, and let us know in the comments if you prefer structured workshops or free-form brainstorming sessions.

#️⃣ All the Links Mentioned in this Video #️⃣

Design Thinking with Lea im Obersteg: https://dww.show/who/lea-im-obersteg/

🎙️ Subscribe and Listen to the Don't Waste Water Podcast HERE 🎙️

Podcast Channel: @dwwpodcast

Main Channel: @AntoineWalterDWW

Smartlink: https://smartlink.ausha.co/dont-waste-water

Website: https://dww.show/podcast/

🙋 QUESTION: What would you like me to cover next?

⏰ TIME CODES ⏰

00:00 The Northumbrian Water Innovation Festival

03:55 Inside Tent 15

04:32 Design Sprint Crash Course

06:13 South Bend Smart Sewer Origin

09:18 UK Spill Crisis Context

11:25 Power of Ten Ambition

13:30 Reality Check and Tease

14:27 Beetroot Break

15:21 Adoption Workshop Takeaways

20:39 Why Tents Work

21:23 NUAR Billion Dollar Story

24:55 Festival Scale and Impact

28:50 Wrap Up and Reflections

30:31 Free Tool

About this Podcast:

Welcome to the (don't) Waste Water podcast, the leading podcast for water industry professionals, investors, and entrepreneurs seeking deep insights into water tech innovation, investment trends, and strategic moves in the sector. Host Antoine Walter blends his technical expertise with sharp business acumen to deliver weekly episodes featuring candid conversations with C-suite executives, detailed analysis of major water industry developments, and practical insights for water tech startups and seasoned players alike.

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How did HG Ventures quietly become one of the most active water tech investors on the planet, without even calling itself a water VC?

HG Ventures is the corporate venture capital arm of The Heritage Group, a 100-year-old, family-owned Indianapolis conglomerate active in asphalt, quarries, environmental services and specialty chemicals. With $350M in assets, the fund deploys around $50M a year across 41 portfolio companies and 7 sectors, and ranks 5th globally in water tech by deal count despite water being only 18% of its thesis.

Ginger Rothrock holds a PhD in chemistry from UNC Chapel Hill, co-founded the NASDAQ-listed pharmaceutical company Liquidia, was promoted to Managing Director of HG Ventures in December 2025, and is a Global Corporate Venturing Rising Star and Kauffman Fellow with deep expertise in industrial water, industrial wastewater treatment, and corporate venture capital in cleantech.

🌶️ KEY SPICES 🌶️

🏗️ How a 100-year-old asphalt-and-quarries empire ended up running one of the most active water tech portfolios on the planet

🧪 Why a PhD chemist with 75 R&D scientists down the hallway puts technology last, and storytelling first, when she evaluates water tech founders

💧 How HG Ventures built its industrial wastewater treatment, industrial water reuse and zero liquid discharge thesis from the inside out

⚡ Why a 4-person investment team and a 2-month decision cycle out-deal-flow every other corporate venture capital fund in the water industry

🎯 Why Ginger Rothrock calls the water industry "inevitable", and how HG Ventures is positioning for the next decade of water tech exits

🥜 IN A NUTSHELL 🥜

Who are the biggest water tech investors and venture capital firms in 2026?

The most active water tech investors by deal count are Burnt Island Ventures, Echo River Capital, PureTerra Ventures, Emerald Technology Ventures, and HG Ventures, the corporate venture capital arm of The Heritage Group, ranked 5th globally despite water being only 18% of its thesis.

What is corporate venture capital (CVC) and how does it differ from traditional venture capital?

Corporate venture capital is venture investing from inside a corporation rather than from an independent fund, which means a CVC like HG Ventures can hold portfolio companies for a decade or more without the LP pressure that kills the average CVC at year four.

How do you pitch a venture capital firm to fund a water tech startup?

Most water tech VCs filter pitches on whether the fund can actually help you commercially, whether you understand the market problem (especially who your real competition is), and whether you can tell a clear story under five minutes, and most water tech founders lose by leading with the technology.

Is the water industry a good long-term investment in 2026?

Yes, water tech venture capital deal counts have quadrupled since 2018, but capital flows mostly through specialist venture capital, corporate venture capital and private equity rather than the public market, because most water stocks underperformed in the 2020s.

What is industrial water reuse, and what is zero liquid discharge?

Industrial water reuse is treating a facility's wastewater on-site and recycling it back into the process, while zero liquid discharge is the extreme version where 100% of the water is recovered, and both are accelerating because of rising freshwater costs, tightening discharge regulations and corporate ESG targets.

#️⃣ Mentioned Links #️⃣

HG Ventures — hgventures.com

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