Due to increased share of fluctuating renewable energy sources in future decarbonized, electricity-driven energy systems, participating in the electricity markets yields the potential for industry to reduce its energy costs and emissions. A key enabling technology is thermal energy storage combined with power-to-heat technologies, allowing the industries to shift their energy demands to periods with low electricity prices. This paper presents an optimization-based method which helps to select and dimension the cost-optimal thermal energy storage technology for a given industrial steam process. The storage technologies considered in this work are latent heat thermal energy storage, Ruths steam storage, molten salt storage and sensible concrete storage. Due to their individual advantages and disadvantages, the applicability of these storage technologies strongly depends on the process requirements. The proposed method is based on mathematical programming and simplified transient simulations and is demonstrated using different scenarios for energy prices, i.e., various types of renewable energy generation, and varying heat demand, e.g., due to batch operation or non-continuous production.

The urgent need for CO${}_2$ reduction is calling upon the industry to contribute. However, changes within local energy supply systems including efficiency enhancement are bound to several economical and technical constraints, which results in interfering trade-offs that make it difficult to find the optimal investment option for CO${}_2$ mitigation. In this article, a new optimization model is presented that allows to optimize the design and operation of a supply and heat recovery system and production scheduling simultaneously. The model was used for retrofitting of a small brewery’s local energy system to identify decarbonization measures for eight potential future scenarios with different technical, economical and ecological boundary conditions. The results show that the proposed cost-optimized changes to the current energy system only slightly reduce carbon emissions if decarbonization is not enforced since the optimal solutions prioritize integration of photo voltaic (PV) modules that mainly substitute electricity purchase from grid, which is already assumed to be carbon free. However, enforcing decarbonization rates of 50% for the assumed future boundary conditions still results in cost savings compared to the current energy system. These systems contain heat pumps, thermal energy storages, electric boilers, and PV. Battery storages are only part of the optimal system configuration if low to moderate decarbonization rates below 50% are enforced. An analysis of marginal costs for units not considered in the optimal solutions shows that solar thermal collectors only require small decreases in collector cost to be selected by the solver.

Steel production is one of the biggest emitters of greenhouse gas in the industrial sector with about 8% of total global CO${}_2$ emissions. Although the majority of emissions can be attributed to primary steel production, there is also potential for reducing CO${}_2$ emissions in downstream steel processing. Large industrial furnaces, which are necessary for heating steel, are currently primarily fired with natural gas and by-product gases from primary steel production, offering great potential for heat recovery measures from exhaust gases. However, switching to alternative climate-neutral fuels could change this potential and thus jeopardize the economic viability of heat recovery measures. In the present work, it was therefore examined to what extent a change in energy sources in industrial furnaces affects the potential use of heat recovery in steel processing. For this purpose, an optimization model was used that takes into account heat recovery by means of direct heat transfer, heat pumps and heat distribution systems. Potential future changes in energy supply for industrial furnaces were examined using different storylines. Two different energy price scenarios were also considered to address uncertain developments in energy markets. The results show that heat recovery is a cost-effective and definitely recommendable measure. Switching to alternative fuels has little impact on the use of heat recovery. Electrification and thus the elimination of flue gas, on the other hand, greatly reduces the potential for heat recovery.

In the pharmaceutical industry, energy efficiency has played a minor role compared to other energy-intensive industries. However, there is a growing recognition of the need to address environmental concerns. With ambitious climate targets and the increasing demand for significant reductions in CO2 emissions, the pharmaceutical industry is now embracing the opportunity to enhance its sustainability practices. Mainly fossil fuels are used to provide process steam at moderate temperature levels at about 160-180°C and to a lesser extent to provide hot water or for on-site power production in CHPs. In this paper, the main processes with demands for process heat, such as media supply, cleaning, or air conditioning, are presented and possibilities for increasing efficiency, for switching to alternative heat supply and for using alternative process technologies are evaluated with respect to economics, but also regarding hurdles for implementation such as requirements for revalidation of production processes and possible necessity of re-approval of products. The present study highlights the potentials for decarbonization of the Austrian pharmaceutical industry using a generic but representative production site applying various measures that either reduce heating and cooling requirements or alter the temperature requirements for heat supply. It is shown that, at least for the example case, full decarbonization is technically feasibly without an increase in energy costs if efficiency measures are progressively used on demand level.