Energy generation at home: Converting rainwater to green hydrogen in Malaysia

The tropical climate of Malaysia sets the stage for a unique solution that could hold the key to decarbonising homes.

Decarbonising homes and the promise of green hydrogen

In the quest to combat climate change, the imperative to decarbonise homes has never been more urgent. At the heart of this endeavour lies a groundbreaking solution: green hydrogen. Decarbonising homes involves reducing carbon emissions through cleaner energy sources, improved energy efficiency and sustainable practices. Generated from renewable sources like rainwater and solar power, green hydrogen emerges as a beacon of environmental responsibility and a sustainable energy option.

The fossil fuel predicament and the call for innovation

For over 150 years, fossil fuels have dominated the world's energy supply, contributing to about 80% of the present energy landscape, according to the Environmental and Energy Study Institute. Although it meets energy demands, the combustion of fossil fuels for electricity generation has taken a severe toll on the environment. The World Nuclear Institute states that over 40% of carbon dioxide emissions associated with energy production result from this combustion, exacerbating the global climate crisis.

The depletion of finite fossil fuel reserves also raises concerns about long-term energy security. The challenge to achieve net-zero carbon emissions by 2050 therefore presents formidable hurdles but also sparks innovation opportunities, as recognised by RICS (see Decarbonising the residential sector and RICS responds to UK government review of net zero strategy).

Green hydrogen as a catalyst for change

Green hydrogen, produced through water electrolysis using renewable energy sources, stands as a transformative force in the journey towards decarbonisation. Its application in the residential sector in particular could hold the key to addressing the pressing issue of carbon emissions.

The proposal to harness rainwater to produce green hydrogen in Malaysian homes, inspired by innovators like LogisGreen and researchers such as Archaya and colleagues, envisions a sustainable and decentralised energy future.

Solutions tailored to Malaysia’s climate

Characterised by abundant rainfall, the tropical climate of Malaysia sets the stage for a unique solution: rainwater-based power generation. The proposal introduces a tailored rainwater collection system for Malaysian residential houses, with a focus on utilising green hydrogen for electricity generation. The abundance of rainfall, with an annual mean precipitation of 3,085.5 millimetres, positions Malaysia as an ideal location for this innovative approach (see the Climate Change Knowledge Portal). Designed for pitched roofs and limited space, the system emphasises its viability in the context of Malaysian residential architecture.

A four-step journey: from raindrop to electricity

The proposed system (Figures 1 and 2) unfolds in four crucial steps, ensuring a seamless conversion of rainwater into electricity.

1. Rainwater collection: rainwater is efficiently gathered from rooftops, with the initial runoff being separated to ensure water quality.
2. Water purification: a water still is used to filter rainwater and ensure its purity.
3. Green hydrogen production: solar-powered electrolysis splits green hydrogen and oxygen from filtered pure water.
4. Electricity production: green hydrogen is used in fuel cells to generate electricity, ensuring a consistent energy supply even in the absence of sunlight.

What are the economic and environmental impacts?

Implementing this system in Malaysian homes could lead to substantial cost savings. With an estimated 40% reduction in monthly electricity costs, the potential for long-term economic benefits is significant. Moreover, the system offers environmental advantages, reducing fresh-water consumption and promoting environmental conservation.

Acknowledging challenges and opportunities

Considering that the presented system is currently a mock-up, it is essential to acknowledge potential challenges. Initial costs may be higher, but with the prospect of mass production, there is potential for significant cost reduction in the future. While solar power depends on sunlight, the green hydrogen system allows electricity production even when the sun isn't shining, contributing to a more reliable energy supply.

Benefits beyond energy production

The proposed solution extends beyond addressing decarbonisation challenges. It offers additional benefits, including:

• advancements in sustainable technologies, driving innovation in sustainable energy technologies and methods
• enhanced energy independence, reducing dependence on fossil fuel imports and promoting local green hydrogen-based electricity generation and
• economic opportunities, fostering growth in the renewable energy industry and developing local expertise in green hydrogen technologies.

Collaboration for a greener tomorrow

The proposed system aligns seamlessly with the World Built Environment Forum’s (WBEF) principles of addressing global challenges through collaborative efforts among stakeholders, policymakers and industry players. By tapping into Malaysia's abundant rainwater resources, this innovative solution has the potential to reshape the residential energy landscape, creating a model for other regions to follow.

A sustainable path forward

The convergence of rainwater and green hydrogen offers a sustainable solution for Malaysian homes. By adhering to the World Built Environment Forum principles of addressing global challenges, this proposal exemplifies the potential for collaborative efforts to shape a cleaner, greener and more sustainable future. The initiative aligns with WBEF's vision, heralding a new era of decentralised and environmentally responsible energy production in residential settings.

This article was written for WBEF by Jen Yee Long and Yap Jia Hui, showcasing their winning entry to the RICS Student Competition 2023. Ahead of COP28, RICS launched the global student competition, encouraging students from all over the world to share their ideas on accelerating the decarbonisation of the build environment within five themes: policy, technology, finance, society, and skills. Find out more below.