• Energy Research

Powering refrigerated warehouses by renewable energy sources (RES) turns from an extravagancy to a routine. RES intermittency requires suitable energy storage for both off-grid and on-grid applications. Cryogenic energy storage, integrated synergistically with RES and large refrigerated warehouses, is a promising environmentally friendly technology (addressed by the EU CryoHub project). Hence, studies were carried out to identify where large energy-intensive refrigerated warehouses are situated across Europe and how much power they consume. By employing diverse instruments and data sources, some 1049 warehouses were established, while 503 energy intensive ones were mapped and further co-located with 3200 solar PV and 11700 onshore wind parks to discover the best areas for RES integration across EU28. As compared with similar international surveys, the CryoHub statistics covers simultaneously warehouse capacity, geographical location and energy data, which permit a comprehensive analysis and strategic planning in both food refrigeration and energy sectors. International audience

© 2016 Elsevier LtdBackground Independence from fossil fuels, energy diversification, decarbonisation and energy efficiency are key prerequisites to make a national, regional or continental economy competitive in the global marketplace. As Europe is about to generate 20% of its energy demand from Renewable Energy Sources (RES) by 2020, adequate RES integration and renewable energy storage throughout the entire food cold chain must properly be addressed. Scope and approach Refrigerated warehouses for chilled and frozen foods are large energy consumers and account for a significant portion of the global energy demand. Nevertheless, the opportunity for RES integration in the energy supply of large food storage facilities is often neglected. In situ power generation using RES permits capture of a large portion of virtually free energy, thereby reducing dramatically the running costs and carbon footprint, while enhancing the economic competitiveness. In that context, there exist promising engineering solutions to exploit various renewables in the food preservation sector, in combination with the emerging sustainability-enhancing technology of Cryogenic Energy Storage (CES). Key findings and conclusions Substantial research endeavours are driven by the noble objective to turn the Europe's Energy Union into the world's number one in renewable energies. Integrating RES, in synchrony with CES development and proper control, is capable of both strengthening the food refrigeration sector and improving dramatically the power grid balance and energy system sustainability. Hence, this article aims to familiarise stakeholders of the European and global food preservation industry with state-of-the-art knowledge, know-how, opportunities and professional achievements in the concerned field.

New refrigeration system configurations and other innovating technologies in retail supermarkets need to beconsidered to reduce energy use and greenhouse gas emissions. In supermarkets, there is a strong interactionbetween the refrigerated display cases, supermarket structure, internal machinery, customers, and the store’sHVAC system. The impact of these interactions on the energy and carbon emissions of a medium sized supermarket in Paris was modelled using EnergyPlus™. The results were calibrated against a typical UK store and validated against the Paris store. The effects of applying the technologies identified to have the greatest potential to reduce carbon emissions (changing the refrigerant to R-744, switching from gas to electrical heating and adding doors to chilled cabinets) were modelled. The impact of climate change on ambient temperature and the impact of changes to the grid conversion factor were predicted for the store in Paris from 2020 to 2050.

The European Green Deal is a political milestone aiming to promote a carbon-neutral economy in the European Union. Decarbonizing the complex food sector requires the unified interaction among effective climate policies, economic instruments, and initiatives involving multiple stakeholders. Despite increasing efforts to highlight the importance of innovations and finance to achieve sustainable food supply chains (FSC), comprehensive information about related opportunities and barriers to mitigating emissions in the food sector is still under-explored. To cover this gap, this paper applies an existing industrial policy framework under the lens of the EU FSC to identify potential strategies that should help achieve the needed financial means and innovation actions, as well as to gauge political alignment across FSC stages. Methodologically, the pillars proposed in the framework are linked to multi-stakeholders’ initiatives engaged in achieving net-zero emissions. The paper highlights three main implications of the identified interlinkages. First, political directionality related to the food sector should be more comprehensively tailored to account for the specificities of all stages of the FSC. Second, research and development projects shall likewise cover all stages, instead of emphasizing only food production and agricultural systems. Finally, multiple stakeholders are crucial as promoters of technology and innovation towards a green economy. Nevertheless, initiatives should be integrated into political discussions in order to promote civil awareness, sustainable food and services demand, aligned to political guidelines.

Cold storage warehouses (CSWs) are large energy consumers and account for a significant portion of the global energy demand. CSWs are ideally suited for solar renewable energy, as they generally have large flat roofs and their peak demand can coincide with the sun shining. A challenge with fluctuating renewables is their variability,which means generation may not coincide with demand. Liquid air energy storage (LAES) is a technology that stores electrical energy as a cryogenic liquid. This paper presents two strategies for using LAES at CSWs, firstly to shift the import of energy from peak to off-peak tariffs and secondly to store on site renewable energy when there is a surplus and use when not. The financial viability of these strategies is then investigated taking into account the capital cost of the LAES and the money that can be saved due to the differences in tariffs at different times.

Cold storage rooms consume considerable amounts of energy. Within cold storage facilities 60-70% of the electrical energy may be used for refrigeration. Therefore cold store users have considerable incentive to reduce energy consumption. The performance of a large number of cold stores has never been compared in detail across a range of locations. With government targets to reduce energy and emissions of greenhouse gasses (GHG), the need to benchmark and understand potential energy and GHG reductions is of great interest to end users. As part of a large project on cold store energy performance, internet based surveys were developed and data collected to determine energy usage in different cold store types, sizes and configurations. Mathematical models were developed to assist end users to reduce energy consumption and to identify how much energy a store should use in different usages and configurations. The information previously collected on cold store energy performance has previously been presented (Evans, et al., 2014a). Since that time the original data set has been increased by 46% to a total of 758 stores. This enables further analysis of the data. The work compares energy usage of cold stores in different parts of the World (countries, continents and according to temperature zone). The energy use of the cold stores is compared to theoretical energy use figures generated from a mathematical model.

Two benchmarking surveys were created to collect data on the performance of chilled, frozen and mixed (chilled and frozen stores operated from a single refrigeration system) food cold stores with the aim of identifying the major factors influencing energy consumption. The volume of the cold store was found to have the greatest relationship with energy use with none of the other factors collected having any significant impact on energy use. For chilled cold stores, 93% of the variation in energy was related to store volume. For frozen stores, 56% and for mixed stores, 67% of the variation in energy consumption was related to store volume. The results also demonstrated the large variability in performance of cold stores. This was investigated using a mathematical model to predict energy use under typical cold store construction, usage and efficiency scenarios. The model demonstrated that store shape factor (which had a major impact on surface area of the stores), usage and to a lesser degree ambient temperature all had an impact on energy consumption. The work provides an initial basis to compare energy performance of cold stores and indicates the areas where considerable energy saving are achievable in food cold stores. © 2013 Elsevier B.V.