Solar Hydrogen: Renewable Powered Electrolysis

Photo of a solar farm generating hydrogen
There are two primary ways to generate solar hydrogen: hydrogen produced from solar energy. The first is via a photochemical process, using solar energy directly to split water. The second is solar powered electrolysis, which uses solar cells to generate electricity and power electrolysers.

While the photochemical process is appealing due to its direct hydrogen production, it must still undergo significant innovation to reach scalability. Solar powered electrolysis, on the other hand, uses already established technologies and can therefore more immediately be used to provide certain geographies with the opportunity to produce large amounts of green hydrogen.

Current solar hydrogen capabilities

A 2023 research paper analyzing the advancements and challenges in photovoltaic-based hydrogen production highlights key barriers such as safety, production, storage, utilization, commercialization, weather variability, and cooling of photovoltaic cells. The paper reports that the highest solar-to-hydrogen conversion efficiency achieved so far is 30%.

Generally, these 30% systems rely solely on electrical energy and suffer from low efficiency due to significant heat losses. One solution is hybrid photovoltaic-thermal systems which convert solar energy into both electricity and useable heat, improving process efficiencies up to 80%.

In both systems, excess energy can be stored as hydrogen and used at some point in the future instead of going to waste. Hybrid systems have the added bonus of producing heat that can be fed into electrolysis processes (which are more efficient at higher temperatures) – or used to heat buildings. Other methods such as photoelectrocatalytic hydrogen production via water splitting

Existing solar hydrogen projects

Manilla Community Solar array – New South Wales

A $2.3 million grant was awarded in 2020 to a project in rural New South Wales for a 4.5 MW solar array and a 2 MW solar hydrogen storage system. The installation will also be one of the first commercial scale projects to use solid-state hydrogen storage in the form of sodium borohydride (NaBH4). This “H2Store battery” technology was developed by the University of New South Wales and the cost is comparable to existing chemical battery storage technology.

First Solar & Nel Hydrogen

The American solar systems manufacturer First Solar partnered with Norway’s Nel Hydrogen to develop a power plant that produces solar-generated hydrogen and low-cost electricity. Initially, they used proton exchange membrane (PEM) electrolysis systems but faced equipment challenges. The ball-type rotameters that Nel Hydrogen had traditionally used lacked the necessary precision, so they switched to Alicat mass flow meters to test their S, H, and C PEM electrolysers.

BP, Iberdrola, & Enagás

BP teamed up with Iberdrola and Enagás installed a photovoltaic powered, 20 MW electrolyser that will allow them to transition from grey hydrogen consumption to green.

Soto Solar España

Independent producer Soto Solar España plans to develop a 1 GW photovoltaic park with a 100 MW electrolyser by 2024.

Baofeng Energy

The Chinese coal mining company Baofeng Energy announced in 2021 plans for two 100 MW solar power generators to power electrolysis as part of their efforts to half CO2 emissions by 2030. The project was finished approximately in December of 2021, and is claimed by Baofeng Energy to be the world’s largest solar hydrogen generation project.

Sinopec & Longi

The oil firm Sinopec had previously partnered with the solar technology manufacturer Longi to work on the company’s decarbonization efforts by developing green hydrogen production infrastructure back in 2021. In 2025, Sinopec announced a $690 million dollar hydrogen venture capital fund to invest in hydrogen energy startups.

H2B2

Starting in 2018, the California Energy Commission issued a solicitation to create renewable hydrogen generation facilities across the state. The SoHyCal project, presented by the hydrogen processing company H2B2, touts itself as the largest operational green hydrogen production plant in North America, powered entirely by renewable energy.

Market opportunities and future outlook

Photo of industrial smokestacks emitting pollutants
The global push towards decarbonization has triggered increasing investments in PV hydrogen projects, with many countries and corporations seeking to reduce reliance on fossil fuels and bring down the dollar cost per kW. Analysts predict that green hydrogen demand could rise dramatically by 2030, driven by heavy industry, transportation, and grid balancing needs. Major economies including the European Union, the United States, China, and Australia are rolling out policies, subsidies, and research funding to accelerate adoption. As technologies mature and costs continue to decline, solar hydrogen could transform not only the energy landscape but also create new market opportunities in renewable chemicals, synthetic fuels, and distributed energy storage.

Applications

Converting solar energy into hydrogen requires systems that operate reliably under varying conditions while maintaining high efficiency and safety. Alicat’s precision mass flow and pressure instruments have supported a variety of solar hydrogen projects in achieving these goals.

One research laboratory needed an on-site solution to blend natural gas and hydrogen in precise ratios before feeding the mixture to a gas turbine. The hydrogen was produced by a PEM electrolyzer powered by 30 kW of solar panels. To ensure consistent flow and mixing, they used the FusionFlow MXM all-in-one gas blender, delivering a stable output at 40 PSI and 150 SLPM to match the turbine’s requirements.

In another project, Alicat liquid flow controllers were used to deliver deionized water through prototype equipment prior to field deployment. Additionally, Alicat MC-Series mass flow controllers helped deposit polymorphous and doped polymorphous silicon for developing solar cell prototypes.

With reliable flow and pressure control, Alicat instruments continue to enable clean energy innovations worldwide.

 

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Green future

Using solar energy to power electrolysis offers an alternative pathway for sunny regions to produce energy sustainably. Green hydrogen production like this reduces dependence on fossil fuels and encourages innovation in solar and electrolysis technologies, helping to meet the energy needs of large populations. In the short term, individual projects and plants have a minimal impact on the overall energy market. However, by expanding the capacity for solar hydrogen generation, we can build a stronger foundation for a cleaner, more resilient energy system.

Enabling Liquid Hydrogen Fuel Systems in Maritime Innovation

Alicat MCRQ Mass Flow Controllers Support TU Delft Hydro Motion Team’s Hydrogen Boat for the Monaco Energy Boat Challenge

Empowering Discovery on Water

The transition to sustainable energy in the maritime sector demands more than ambition, it requires precision. That is why Alicat Scientific is proud to support the TU Delft Hydro Motion Team as a Bronze Partner in their groundbreaking 2025 campaign: to design, build, test and race Mira, a liquid hydrogen-powered boat at the Monaco Energy Boat Challenge.

Equipping this innovative project with our MCRQ mass flow controllers enables the team to manage hydrogen fuel delivery safely and accurately, helping them prove that liquid hydrogen can power the next generation of clean marine propulsion.

Mira at the official reveal, Hydro Motion Team’s 2025 liquid hydrogen-powered boat.

Figure 1: Mira at the official reveal. Hydro Motion Team’s 2025 liquid hydrogen-powered boat.

The Challenge: Making Hydrogen Work for Maritime Transport

The goal of the TU Delft Hydro Motion Team is as ambitious as it is inspiring: to design, build, test, and race a fully functioning boat powered by liquid hydrogen, all within one year, and to compete at the Monaco Energy Boat Challenge 2025. But beyond the competition itself, the team’s mission reaches further. By proving that a boat can operate successfully on liquid hydrogen, they aim to spark broader innovation across the maritime sector and demonstrate hydrogen’s potential as a clean, scalable alternative to fossil fuels.

This project builds on the team’s past successes with compressed hydrogen, already a proven, zero-emission marine fuel. But as the team pushes for longer range and greater onboard efficiency, storage volume and energy density become the next major challenges. To solve this, the team chose to work with liquid hydrogen. With a volumetric energy density three times higher than compressed hydrogen at 350 bar, liquid hydrogen offers a powerful solution for saving space and extending endurance, key requirements in performance vessels.

But storing and using liquid hydrogen introduces challenges. The fuel must be kept at -253°C, requiring insulated cryogenic tanks. The team addresses this with a custom double-walled, vacuum-insulated carbon-fibber tank system, limiting heat ingress to just 7 watts, equivalent to a small LED bulb. To avoid wasting energy, waste heat from the fuel cell is used to bring hydrogen up to the required ~20°C operating temperature before reaching the fuel cell.

These trade-offs (boil-off rates, tank volume, storage weight, and onboard vaporization) are exactly the kinds of real-world constraints this project is designed to explore. And while Mira is a compact, foiling boat, the broader engineering question remains: could a system like this scale to larger vessels, such as ferries? That is the kind of thinking Alicat is excited to support with partners who are pushing the boundaries of what is possible.

The Role of Alicat: Flow Control After Vaporization

In Mira’s hydrogen system, hydrogen is stored as a cryogenic liquid. Before reaching the fuel cell, it passes through a vaporizer, transitioning into gas at ambient temperature. This phase is critical: delivering gas at the right pressure and flow requires stable regulation, fast feedback, and precise control.

Simplified diagram of the Hydro Motion Team’s hydrogen system.

Figure 2: Simplified diagram of the Hydro Motion Team’s hydrogen system.

To meet this need, the team integrated the Alicat MCRQ mass flow controller immediately downstream of the vaporizer. This device manages the mass flow of hydrogen gas into the fuel cell and enables:

  • Delivers stable and precise feed pressure to the fuel cell.
  • Measures hydrogen consumption through real-time mass flow monitoring
  • Monitors pressure and temperature to help prevent fuel cell issues like dehydration or fuel starvation.
  • Supports test validation and real-world performance optimization.

Compact, ATEX Zone 2 certified, and designed for fast system response, the MCRQ integrates easily into the tight constraints of a race-ready vessel. Its role is vital during system development, helping the team collect data, tune parameters, and prepare for race-day performance. In short, it helps translate bold hydrogen engineering into operational reliability.

Alicat’s MCRQ unit mounted inside the Hydro Motion Team’s hydrogen control system.

Figure 3:  Alicat’s MCRQ unit mounted inside the Hydro Motion Team’s hydrogen control system.

Why the MCRQ Was Selected

The Hydro Motion Team, together with our application engineers, selected the Alicat MCRQ series for its proven capability in low-flow hydrogen gas applications, offering a powerful combination of precision, speed, and safety. Key features that influenced the decision include:

  • Flow range of 0–1.5 g/s, which translates to ±0.01 g/s uncertainty at a nominal 1 g/s flow, small enough to maintain consistent fuel cell output.
  • 4–20 mA analog output, chosen specifically for its high-speed update rates (kHz range)
  • ATEX Zone 2 IIC certification, requiring minimal additional safety infrastructure.
  • Upstream valve position, enabling precise regulation of downstream feed pressure, supporting target values like the ~2.5 bar commonly seen in fuel cell stacks.
  • ±1.0% accuracy of reading (or ±0.2% of full scale)

Together, these features provide the team with a robust, compact, and responsive solution, a key enabler of real-world testing and a step toward scalable, clean hydrogen propulsion.

Competition Progress and What Comes Next

The TU Delft team unveiled the boat, Mira, earlier this year and is now deep into the testing phase, preparing for the Monaco Energy Boat Challenge 2025.

As testing progresses, the team continues optimizing the integration between hydrogen storage, vaporization, and control systems. Alicat’s instrumentation plays a central role in capturing this performance data for analysis and refinement.

This partnership represents more than a technical contribution. It reflects our belief that sustainable innovation thrives where education, engineering, and real-world experimentation meet.

By supporting the Hydro Motion Team and their work on Mira, Alicat contributes to:

  • Advancing liquid hydrogen fuel systems in marine transport
  • Empowering hands-on engineering education
  • Promoting practical low-emission propulsion technologies

We are honoured to be part of this project and proud to know that our instruments are helping to steer the future of clean maritime energy.

Together, we are not just measuring hydrogen. We are helping to Fuel the Future.

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