A tank of cold: cleantech leapfrog to a more food secure world
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New report: Governments and NGOs must focus investment in developing economies on better refrigeration in order to alleviate world hunger
Food security - the 21st century challenge
As the world’s population moves towards 9.5 billion later this century, meeting future demand for food while responding to stresses placed on the food system, such as changing dietary preferences, climate change, resource competition, land-use tensions and soil nutrient degradation, will present significant challenges to engineers, as well as the public at large. Indeed, the way we farm, harvest, store, transport, process, distribute and consume food will be a major determinant in the outcome for our well-being in the 21st century.
Developing countries will need improved agricultural productivity to feed larger populations, and better connections between farmers and different market options to drive economic development. This is particularly important in sub-Saharan Africa and Asia, where the greatest growth in population is projected. In addition to meeting the food needs of an increased number of people, these countries will see the largest changes in their population demographics through urbanisation and increased affluence. The global middle class is expected to increase by about 3 billion by 2030, with much of this growth anticipated in the developing economies. The latter will require new food systems to be established that create more rural-urban supply chains, and will need to produce new types of food to meet changing consumer expectations. All of this will need to be achieved in nations that are anticipated to be simultaneously experiencing the most severe impacts of climate change.
The wastage opportunity
Work to increase yields from the full range of agricultural activity clearly has a role to play in meeting the 21st century’s food security challenge. However, working towards ensuring sustainable food security, not just increased production, is critically important. Engineers are consistently called upon to deliver more water and energy to satisfy a wide range of demands, including for food systems, and to help resolve land-use tensions. A valid question for the profession to ask therefore, is how much yield improvement is truly necessary and what alternative approaches might be more sustainable?
Much of the food produced for human consumption today does not actually reach a human stomach, as it is either ‘lost’ within the food supply system through spoilage, largely as a result of poor handling and inadequate infrastructure, or is discarded in the marketplace or home as ‘waste’ as a result of societal and consumerist behaviour. In both cases this wastage, which is estimated to be 30–50% of global production, is largely unnecessary and also represents waste of the associated water, energy and land used to produce this food. Tackling food waste requires cultural and societal change, whereas preventing produce losses is in most cases about the application of relatively basic engineering and management practice. Reducing food wastage provides an opportunity to help meet future growth in food demand while simultaneously relieving pressure on natural resources and mitigating the risks associated with environmental degradation.
Preventing perishable food losses - critical to development
In the developing economies of sub-Saharan Africa and Asia there are high levels of post-harvest food losses, and of particular concern is the loss of perishable produce, such as fruit, vegetables, fish, meat and dairy, which currently can reach as much as 50% annually. These countries will not only experience the largest population increases, but also the largest shifts in dietary preferences which, together with increasing demand for convenience foods, will increase perishable produce demand and drive greater resource consumption. When combined with the fact that they are located in warm areas and are anticipated to experience some of the most extreme impacts of global warming, it is critical to ensure that as much of the harvested produce as possible reaches its final marketplace. Cold is the key to tackling the loss of perishable produce. In this regard, it is estimated that around a quarter of total food wastage in developing countries could be eliminated if these countries adopted the same level of refrigeration equipment as that in developed economies. Establishing a continuous chain of temperature-controlled cold environments from the point of harvest to the marketplace and on into the home – a ‘cold chain’ – is required.
The first step in a cold chain is pre-cooling, chilling and/or freezing produce as close to the point of harvest as possible, to retain nutrients and add shelf life. Subsequent steps of cold storage and refrigerated transport continue the preservation process, boosting food safety and maintaining quality. Many mature established technologies are available to achieve all of this. The challenge is that in nearly all cases they rely on access to a reliable and affordable source of either electricity or diesel fuel, which are often lacking or virtually non-existent in developing countries, particularly in rural areas where energy security is a significant issue. In sub-Saharan Africa, 70% of the population has no access to electricity, and 80% of those are located in rural areas. In India about 350 million people are in rural off-grid villages.
The IEA predicts that by 2035 energy demand globally will increase by 40%, and 90% of this growth will be from non-OECD countries. Finding a sustainable solution to meet the energy security needs of cold chain technologies is therefore crucial to aid international development and help deliver a more food-secure world. This not only will lead to a reduction in post-harvest losses, but also has the potential to avoid additional harmful emissions of air pollutants.
A sustainable cold chain infrastructure
The Institution of Mechanical Engineers has identified a pressing need in developing countries to connect local farmers with higher-value market options locally, nationally and internationally through cold chains. The challenge for the engineering profession is to do that in a way which minimises food wastage, is sustainable and avoids harmful emissions and air pollutants. In other words, we need to help establish sustainable and resilient infrastructure, fit for purpose in the local context from the beginning. There are two elements that are important; firstly, projects need to be affordable; secondly they must be safe, reliable, easy to build, operate and maintain.
For many developing communities in sub-Saharan Africa and Asia, renewable energy resources are available in abundance and the key to unlocking sustainable cold chains is to develop technology that can either utilise these directly, such as cooling through solar-driven absorption, or to power existing or new technologies through electricity generation. In many cases the costs of installing small-scale renewable infrastructure are already about the same or lower than those involved for establishing connections to a largescale centralised electricity grid. This economic reality, combined with the substantial engineering resource needed to create a grid, means that local off-grid or micro-grid-based solutions are an attractive option.
However, in many cases the utilisation of renewable energy for power generation requires energy storage technology in order to mitigate the intermittent and seasonal nature of some of these resources, such as sun and wind. This report proposes a range of energy storage solutions that meet the criteria for use in the context of a developing economy, and are either commercially available today, or in development and close to market. One contender in this regard is cryogenic energy storage.
Using cryogenic energy storage can not only facilitate reliable electricity supply, but through the provision of direct cooling it enables a holistic systems level approach to be established. It would also avoid the use of traditional refrigerants in chilling equipment, which have environmental and health issues. The cheapest form of cryogenic energy storage is based on the use of liquid air, which involves the liquefaction of atmospheric air. Once liquefied, in addition to providing on-demand power and cooling for pre-cooling, chilling, freezing and cold storage, liquid air can deliver the energy required to drive a simple cryogenic piston engine that can form the basis of a zero-emissions refrigeration unit for transport vehicles. This is a particularly useful application, as the traditional diesel-fuelled unit not only suffers from energy security issues, due to its reliance on diesel, but also leads to environmental degradation through emissions of air-polluting nitrogen oxides and particulate matter, as well as greenhouse gases.
This report shows how by locating a cryogenic energy storage facility at an agricultural ‘hub’ in a rural location, effectively establishing a local ‘tank of cold’, sustainable power and cooling can be provided to drive all three cold chain steps. Additionally, this tank of cold could help improve a broad range of local services essential to an agricultural community. These include community electricity through micro-grid application, smallscale fertiliser production, refrigeration for vaccine storage and distribution, and cooling for value aded food processing. It also shows how existing cryogenic infrastructure in more industrialised developing economies can be utilised to begin the process of building a sustainable cold chain.
What needs to be done?
There is much work to be done by engineers to provide affordable, safe, reliable, easy to operate and maintain, clean technologies for cold chains in developing economies. In particular the profession must focus on delivering appropriate energy storage technologies for use in off-grid and microgrid applications, tackle issues of equipment and plant scaling to enable a range of smaller facilities to be deployed in distributed configurations, and offer alternative technologies for the delivery of both power and cooling in rural and urban settings. Beyond the engineering however, empowering communities to implement cold chain infrastructure through access to appropriate finance mechanisms is the most critical need.
Investments in cold chains are already taking place in more industrialised developing nations, such as India’s planned five-year US$15 billion commitment, and some Chinese cities subsidising up to 40% of cold store building costs. But there needs to be a concerted effort by governments of developing economies to introduce policy initiatives that offer support to clean technologies and distributed solutions, which build on existing aspirations for electricity access and energy security, ensure that the regulatory frameworks can support such investments and deployments, and encourage inward investment with a focus on adopting technology that is sustainable. The African Union has declared 2014 the Year of Agriculture and Food Security, and publication of this report provides a clear vision of a route to help deliver on these actions.
Cold chains are an essential component in establishing an efficient food supply chain, but the current deployment model is unsustainable in the developing world where in many cases energy security is completely absent. The Institution of Mechanical Engineers therefore makes the following key recommendations:
1. Governments of newly emerging and rapidly industrialising economies must prioritise support investment in cold chain infrastructure to improve food security, underpin development and help alleviate poverty. Providing farmers with opportunities to access higher-value market options for their produce is widely recognised as a key route to moving individuals and communities out of subsistence and poverty towards higher-level economic activity and increased well-being. For perishable produce, cold chain infrastructure is essential to ensuring that as much product as possible reaches the marketplace. Beyond this, encouraging and incentivising developments that are based on sustainable solutions, including renewable energy and clean technologies, offer opportunities for affordable routes to energy security and reduced environmental risk.
2. Donor country governments and development NGOs must support and incentivise aid recipients to develop sustainable cold chains using renewable energy and waste cold. Increasingly overseas aid from donor governments and NGOs is being allocated to development projects that help individuals and communities become more self-sufficient and resilient. A sustainable cold chain solution based on renewable energy, clean technologies and waste cold recycling should be encouraged and incentivised.
3. The UK engineering community should come together to define in detail the potential opportunities a joined-up cold economy presents for the developed and developing world. The UK has a substantial heritage in the industrial gases and broader cryogenics sectors. As a leader in the field of the industrial application of cold, as well as in renewable energy utilisation, clean technologies and energy systems integration for efficient resource use, the nation is well placed to lead on work to tackle the technical challenge of equipment scaling and explore the environmental and societal benefits of establishing cold-chain economies.
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