19 th International Conference on Renewable Energies and Power Quality (ICREPQ’21) Almeria (Spain), 28 th to 30 th July 2021 Renewable Energy and Power Quality Journal (RE&PQJ) ISSN 2172-038 X, Volume No.19, September 2021 Reducing the carbon footprint of Whisky production through the use of a battery and heat storage alongside renewable generation Wolf-Gerrit Früh 1 , Jamie Hillis 2 , Sandy Gataora 3 , Dawn Maskell 4 1 Institute of Mechanical, Process and Energy Engineering, School of Engineering & Physical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland (UK), e-mail: w.g.fruh@hw.ac.uk 2 Sunamp Ltd., 1 Satellite Park, Macmerry, East Lothian, EH33 1RY, e-mail: Jamie.Hillis@sunamp.com 3 Sunamp Ltd., 1 Satellite Park, Macmerry, East Lothian, EH33 1RY, e-mail: sandy.gataora@sunamp.com 4 International Centre for Brewing & Distilling, School of Engineering & Physical Sciences, Heriot-Watt University, Riccarton, Edinburgh, Scotland (UK), e-mail: D.L.Maskell@hw.ac.uk Abstract. This paper presents an analysis of providing a typical distillery with low carbon energy through the combination of local wind energy, solar PV, electricity storage and heat storage. The aim of this is to increase the sustainability of the energy- intensive whisky industry. Using hourly local renewable resource data and typical distillery consumption information, the local energy generation is balanced against the demand at the time of use. This followed by load shifting using a battery and heat storage. Results show that significant carbon savings can be achieved by a carefully designed portfolio of hybrid generation, battery storage and heat storage. Key words. Hybrid System, Wind Energy, Solar PV, Heat storage. 1. Introduction The Whisky industry is one of the main industries in Scotland and is one of the energy intensive industries, where the heat demand for the production process alone requires typically 60 MJ or 17 kWh per litre alcohol (pLA). This is complemented by a similar amount of energy for the other parts of the distilleries’ operation. With a typical annual output of a billion (10 9 ) litres of whisky from around 130 distilleries in Scotland, this constituted around 20% of the UK’s total food and drink export in 2019 [1]. With a typical alcohol content of 40%ABV (alcohol by volume), this production equates to 400 million litres of alcohol or 6700 GWh of heat consumption or 13 000 to 14 000 GWh of total energy consumption by the industry, which is about 10% of Scotland’s total energy consumption [2]. Currently much of this heat demand is met by raising steam by electric heating or by burning fossil fuels but there is a drive to reduce the carbon footprint of the industry. For example, the UK Government has recently launched a ‘Green Distilleries’ competition [3] for Research and Development. This paper evaluates the opportunities provided by combining local low-carbon electricity generation in the form of solar PV and/or wind energy with suitable heat and electricity storage to maximise the local exploitation of the low-carbon energy sources while being able to shift electric demand and heat load from times of high demand and low generation to times of availability of electricity. Even though this analysis is applied to a very specific application, the method and results are applicable for a wide range of energy-intensive industries. While the size of the stills used by distilleries varies greatly, from around 2 000 to 20 000 litres, the standard batch process is common to the vast majority; after the initial heating of the ‘wort’ (germinated and ground barley in water) to 72°C to initiate fermentation, and the consequent fermentation to ‘wash’ with a typical alcohol concentration of about 8%ABV. The first distillation stage in the ‘wash still’ distils this wash, which has a boiling temperature of around 92°C and results in a ‘low wine’ with an alcohol content of about 20%ABV. The second distillation in the ‘spirit still’ then completes the distillation process (other varieties such as Irish whiskey uses three distillation stages). Given the temperature requirements for the distillation, any thermal storage has to store and provide heat at temperatures above 100°C. Technologies which could provide this are either steam accumulators [4] or phase change material (PCM) energy storage devices [5], also known as ‘heat batteries’. The aim of this paper is to explore how much low-carbon on-site generation and heat demand management can improve the environmental credentials of a distillery. This https://doi.org/10.24084/repqj19.310 429 RE&PQJ, Volume No.19, September 2021