Water-smart cooling

The webinar, held in late July, explored the rising need for cooling in a world where resources are challenged and an estimated 14% of the food produced for human consumption is lost before it even reaches the consumers due to gaps in the cold chain.

Sustainable Cold Chain Expert at UNEP Cool Coalition, Angshuman Siddhanta, believes the food loss due to inadequate cold chains would be enough to feed one billion people globally.

In describing how important the cold chain is from farm gate to end user; he used the lychee (or litchi) as an example. The fruit has a shelf life of two to three days without cold storage, but with cold storage can last for up to three weeks.

“If you look at the resource use efficiency, each kilogram of lychee requires almost 1,800L of water to produce,” he said. “And if we waste and lose 100 metric tons, we’re losing 180 million litres of water.”

Dr Beatrice Ekesa-Onyango, Lead Global Technical Specialist, Nutrition at International Fund for Agricultural Development (IFAD) said having “cold gaps” in cooling systems also directly caused nutrition gaps.

She said 144 million tons of food is lost annually just in the nations of Africa. If people can’t access fresh food, they turn to processed goods – and therefore miss out on the nutritional value of fresh food.

“The transition from production to consumption is filled with risks that directly undermine our work, if we want to make sure that the food that is produced is able to translate to better diets and better nutrition outcome,” she said.

No universal solution

According to Larissa Nogueira, Team Lead, Energy Planning at the International Renewable Energy Agency (IRENA), cooling accounts for approximately 10% of global final electricity demand – and there are expectations that cooling capacity will triple by 2050.

So, how can demand flexibility be organised so that critical systems are supported in peak times?

Professor of Mechanical Engineering and Chair of Advanced Energy and Sustainability at Northumbria University, Dr Muhammad Wakil Shahzad, believes we need to look for alternative solutions that can produce cooling.

“Technology is not the only solution to reduce or to provide the cooling,” he said.

He said we need to reduce cooling demand overall with better building designs, better ventilation and passive solutions.

“We have to look for the alternative solutions that can produce cooling with minimal energy and with the lowest water footprint,” he said.

“There is no universal cooling solution.”

He said the technologies that might be applicable for India may not be good for Australia or the USA. It depends on which technology is the best solution for the local environment.

“We have to look at cooling as a whole system,” he said. “Conventionally we consider cooling as an end user for the energy, but we have to look at systems where we can integrate renewable energy and also water reutilisation (or grey water utilisation) within the cooling sector.

“We have to select the cooling system that can produce the best cooling with the lowest water, energy and environmental footprint.”

Issues in the cold chain

Siddhanta believes water harvesting plays a key role in using water resourcefully.

“If we lose one kilo of produce in the farm gate we are already losing 400L of water,” he said.

Energy efficiency should be a top priority, however looking at cooling as a systems approach means not just putting in the best energy efficiency technology but also considering the operational efficiency.

Dr Shahzad said there should be two parameters with every air conditioning system.

“They should show that how much is water consumed and how much is energy consumed,” he said.

“This is where the government can put the bar, and if any technology is below that bar it is not implementable in terms of sustainability or resilience.

“If we consider cooling as a whole system it will cover everything within that system, rather considering it as an end user.”

He suggested recovering condensate in humid environments, for example.

“In the Middle East most of the water is coming from desalination systems,” he said. “So in that environment the raw water or the grey water coming from the different industries can be used for the cooling systems.”

He explained it’s a two-layer system – government and industry bodies need to create the legislature to guide the cooling providers, and the providers need to ensure the water and energy is coming from renewable sources.

The question of cash

Siddhanta said that in India, when the government bought in defined policies and subsidies, it helped attract investors to sustainable projects.

“[When] the push comes from the policy side in a state or a national level, the investors are more encouraged to actually come in … because they know the government has a road map – a plan at state level, at national level,” he said.

“It has to be linked. And that’s actually what I think encourages investors.”

More information and the recording of the webinar is available here.

Feature image courtesy of Atul Somani from Pixabay.

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