Cold Chains: Connecting farmers in developing economies to market options through energy storage

The developing economies of the world are largely located in geographical regions that have abundant renewable energy resources, be they solar, wind, hydro or in some cases geothermal, yet paradoxically at the individual and rural community level, access to energy is often a very real issue. In sub-Saharan Africa for example, 70% of the population has no access to electricity, with 80% of those being in rural areas, and where grid access does exist it is often unreliable. Similarly, in Southern Asia 400 million (≈30%) of India’s 1.2 billion population are not connected to an electricity grid and 350 million of them are to be found in rural areas. Yet India has circa 4-7kWh per m2 per day of solar radiation across 3 million km2 and around 300 sunny days per year (small scale solar with photovoltaic technology is viable at around 4kWh per m2 per day and larger installations at about 5), as well as good wind resources and fast-flowing rivers from the Himalayas for hydro electricity generation.

In the absence of reliable grid supplies, citizens resort to burning kerosene for light and biomass for cooking, risking their health, while businesses and farmers resort to using diesel generator sets to power electrical equipment such as irrigation pumps. Diesel is however often vulnerable to supply shortages and volatile pricing in the rural areas of developing economies; and the energy security risks in relation to diesel can only get worse for these communities in future as international competition for fuel increases, particularly amongst non-OECD countries. The utilisation of renewable energy sources, either in standalone off-grid applications or in combination with local micro-grids, is therefore recognized as a potential route for rural farming communities to develop, as well as an opportunity to tackle the health issues associated with kerosene and biomass dependence. For example, the Indian Government aims to replace around 8 million existing diesel fuelled groundwater pumps, used by farmers for irrigation, with solar powered alternatives.

India has good renewable energy resources including high solar irradiance and fast-flowing rivers from the Himalayas for hydro-electric generation. Image: wikimedia user: heavyrunner
Historically, no country has significantly reduced the poverty of its population without achieving a higher level of agricultural productivity and successfully connecting farmers to market options (for example, it is estimated that growth in agriculture is 11 times more effective at reducing poverty in sub-Saharan Africa than growth in other primary industry sectors). Such a shift is urgently and critically needed in sub-Saharan Africa and Asia, where the greatest increases in population numbers are projected to occur over the next half century. In addition to the pressing need to meet the food needs of a growing number of additional people, these countries will see the largest changes in their population demographics through urbanisation and increased affluence.

The latter will require new food systems to be established that create more rural-urban supply chains and produce new types of food product to meet changing consumer expectations. Of particular relevance here is the loss of perishable produce such as fruit, vegetables, fish, meat and dairy in the warm sub-tropical, tropical and equatorial countries of the world. These developing countries already experience high levels of post-harvest losses, ranging between 10% and 50% annually for perishable produce, and are anticipated to experience some of the most extreme impacts of global warming, making it critical to ensure that as much of the food harvested in these regions as possible reaches its intended final marketplace.

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 what is required in order to avoid produce spoilage and to connect farmers with higher value market options in distant urban centres or overseas. In this way farm incomes can be increased, enabling farmers to invest in agriculture and thereby drive economic development forward.

A mix of technologies including storage and solar could transform the way rural communities live and work, according to Dr Tim Fox. Image: wikimedia user: USAID Africa Bureau
The first and in many cases critical step in a cold chain is that of pre-chilling or freezing produce as close to the point of harvest as possible, as soon as possible, so as 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, and many mature established technologies are available to achieve all of these functions. The challenge is that in nearly all cases they rely on access to a reliable and affordable source of either electricity, for pre-chilling/freezing and cold storage, or diesel fuel for transport refrigeration.

The key to unlocking the non-transport cold chain components in developing communities is to harness their abundant renewable energy resources for use either directly, such as in technology that provides cooling through solar driven absorption, or to generate power for technologies that need electricity. The latter can clearly be at the small scale, such as in the novel technology examples of solar-powered fridges which already exist, but in order to meet emerging demand the solutions will need to be at much larger scale, and in the first instance could utilise conventional cold chain technology in off-grid or micro-grid application. However, cold chains need ‘24-7-365’ reliable energy supply so in many such cases using renewables for power generation will require energy storage technology as an enabler, in order to mitigate the intermittent and seasonal nature of some sources, such as solar and wind. It is important to understand though, from an engineering perspective, that not all energy storage technologies will meet the criteria for use in the context of a developing economy. The Institution of Mechanical Engineers recently reported that flow batteries, pumped heat electrical storage and cryogenic energy storage have particular suitability in this regard.

Although many of the required solutions are already available, a major challenge to moving forward is making people aware of the falling prices of renewable energy, both in capital cost and operational costs. The cost for photovoltaic solar modules have come down dramatically in recent years and the low operating costs of these technologies mean they are in many cases cheap enough to compete with oil, kerosene, diesel and Liquified Natural Gas (LNG) in developing economies; but they are still not perceived as such. The fact is that in many cases the cost of installing technologies for electricity generation from renewable energy sources have already reached cost parity or below in developing countries, relative to the traditional approach of bringing power to rural customers through a large-scale transmission and distribution grid based on centralised generation facilities. Educating the finance and business community to understand the different financial model associated with renewable technologies (i.e. financing is capital cost intensive and operating cost light, rather than the opposite which is the traditional fossil-fuel based model) and getting greater private sector enagement in delivering projects and making public-private partnership work effectively is a key hurdle.

India's new government needs to add energy storage in addition to its "clear focus" on solar and other renewables, says Dr Tim Fox. Image: Wikimedia user: saravask
The Institution has identified a pressing need in developing countries to connect local farmers with higher value market options both locally, nationally and internationally through sustainable cold chains; both renewables and energy storage are essential to making that happen. To encourage development, governments need to focus on barrier removal and creating enabling policy frameworks that encourage inward investment and entrepreneurship. This should include considering tax breaks and import tariff strategies, the provision of basic infrastructure needed to support renewables deployment, the removal of unnecessary regulatory burdens and creating subsidies and incentives that recognise the different financial model associated with renewable technologies.

The recently announced India Union Budget 2014-15 showed a clear focus on solar for electricity generation as a driver for taking renewable energy forward in the nation, but Mr Modi's new government also needs to apply the lessons learnt from his time as Chief Minister in Gujaret for the design of national policies which will incentivise small decentralized solar applications as well as larger, grid connected photovoltaics. And additionally, of-course, there needs to be a focus on energy storage as an enabling technology, both for micro-grid and grid level applications. There are however signs that the Government is beginning to recognize this need, with the recent announcements of the Power Grid Corporation of India and Ministry of New and Renewable Energy on energy storage demonstration projects.