By Eamonn Ryan
At a UNEP Cool Coalition webinar Vishnu Sasidharan of Pluss Advanced Technologies spoke on the role of phase-change materials (PCMs) in storing cold efficiently, especially where power is unreliable or off-grid.
These materials, embedded in cold rooms, maintain precise temperatures for hours without electricity. A PCM-equipped, solar-powered cold room in Rourkela, India, is now run by a women-led co-operative. It operates fully off-grid, reduces costs for local vendors and has slashed food spoilage rates.
As solar capacity expands, PCMs offer a low-cost, scalable solution for making 24/7 cooling accessible to rural communities.
Refrigerant transition reduces the hidden emissions
Anatoly Mikhailov of Danfoss addressed another critical piece of the puzzle: refrigerants. Traditional cooling systems often use synthetic refrigerants with high global warming potential (GWP). If leaked, these chemicals can cause significant environmental harm.
Danfoss is promoting the use of natural refrigerants such as CO₂ and ammonia – climate-friendly alternatives with ultra-low GWP. Combined with energy-efficient compressors, these systems can cut both emissions and energy bills, offering short payback periods, especially in rapidly urbanising economies. He also noted that cold rooms can act as thermal batteries – helping balance demand on renewable-powered grids by shifting cooling loads to when solar or wind power is available.
Lessons from the field
From GIZ Proklima, Guntram Glasbrenner emphasised that technology alone is not enough. GIZ’s work in Burkina Faso and Malawi has shown that without proper technician training, community buy-in and supportive policy frameworks, even the best equipment can become underutilised or abandoned.
GIZ’s approach pairs solar-powered cold storage with local capacity-building and sensor-based monitoring, especially in the health sector. In Malawi, cool boxes equipped with temperature sensors are linked to apps that track vaccine doses in real time – helping health workers better manage stock and reduce waste. In fact, vaccine wastage has dropped by over 50% in some regions thanks to these systems.
Siddhanta called for an urgent transition from isolated pilot projects to integrated, scalable solutions – supported by governments, financial institutions and the private sector.
“Cold chains are no longer background infrastructure. They’re at the frontline of food security, health equity and climate action,” he said.
To succeed, cold chain expansion must include:
- Integration with climate and food policies
- Adoption of natural refrigerants and clean energy
- Development of skills and standards
- Strong business models and finance mechanisms
As the climate crisis intensifies, cold chains are emerging as a lifeline – not just for preserving perishables, but for building resilience in the most vulnerable corners of our world. The message from the UNEP webinar was clear: we can no longer afford to overlook the cold chain. Instead, we must harness its potential as a climate solution, an equity tool and a pathway to a more sustainable future.