This paper evaluates how the design and resource use of an air-cooled data center-to-greenhouse energy symbiosis, operating in Swedish conditions, is affected by the desired microclimate criteria within the facilities. The necessary data center power, electricity use, heat reuse, water use, and air changes were evaluated by using analytical solutions and constrained, nonlinear optimization modeling of the heat and mass transfers in MATLAB. An analytical design expression is presented, which returns the minimum data center power per unit greenhouse area, as well as a fitted model to predict the energy reuse. By evaluating multiple design/operation cases for four locations in Sweden, the design data center power per unit greenhouse area was estimated as 0.40-10 kW·m−2, with an energy reuse factor index of 0.02-0.13 and a water use effectiveness of 5·10−5-0.22 L·kWh−1. Warmer climates together with proper microclimate matches (both in terms of temperature and specific humidity between the facilities) required substantially smaller data centers and produced significantly higher energy reuse factors. Poor matches between the data center and greenhouse microclimates could increase the greenhouse heat demand by over 1000 kWh·m−2·year−1 due to excessive need for humidification.

The transition to sustainable transportation fuels requires investment in emerging biomass-to-liquid production pathways under uncertain market and policy conditions. This study applies a real options analysis framework to evaluate the economic viability and timing of investments in biomass- and power-to-liquid pathways by identifying conditions where an investor should invest, defer, or abandon investments. The analysis is conducted for Sweden, reflected by its large biomass base and well-developed forest industry and ambitious defossilization policies. Results indicate that large price gaps between feedstock and produced fuels are not by themselves sufficient to trigger investment; in volatile markets, investors may still defer because the option to wait has economic value. Thus, even at identical price levels across scenarios, outcomes range from commitment to inaction depending on volatility. Moreover, when investments do occur, they are consistently deferred until the final year of the investment window. While modest subsidies may suffice under stable price conditions, volatile markets with high drifts require significantly greater support to counteract the incentive to defer investments. Electricity cost structures and carbon pricing must be targeted to support the transition toward electrified fuel production pathways. The insights from this study can inform the design of policy instruments that align investor incentives with global transition goals.

Hydrogen production coupled with renewable energy sources (RES) is a promising solution to utilize otherwise curtailed electricity. Hydrogen is also seen as a potential solution in several hard-to-abate industries, such as the maritime industry. This opens the opportunity for hydrogen supply chains utilizing RES to supply hard-to-abate industries with hydrogen. These hydrogen supply chains utilize either electricity cables or hydrogen pipelines to transport energy. Previous studies show that the most cost-efficient means of transportation depends on both the distance and the amount of energy to be transported. In the context of offshore energy production, the problem is further expanded by the conditions of offshore infrastructure. To capture the effect of offshore conditions in the supply chain design, this paper presents a MILP model that minimizes the cost of a power-to-gas hydrogen supply chain, including the decision of where in the supply chain the electrolyzer should be located. The model is applied to a case in southern Sweden with renewable offshore wind supplying electricity to produce hydrogen as maritime fuel for a ferry. The results show that the relation between offshore and onshore distances, together with increased costs for offshore infrastructure, greatly influence the choice of transmission mode. Hence, this study found that a hybrid solution with offshore electricity transmission to the closest point onshore followed by onshore hydrogen transmission through pipelines to be the least cost option for energy transmission in the hydrogen supply chain.

Transitioning to biofuels is crucial for reducing greenhouse gas (GHG) emissions in transportation, but limited biomass availability requires maximizing carbon efficiency. This study evaluates Fischer-Tropsch liquid (FTL) production from biomass, focusing on the impact of partial electrification and carbon capture and storage (CCS) on efficiency and flexibility. Five configurations—ranging from a biomass-intensive base case to a fully electrified process—are simulated and assessed through techno-economic and GHG evaluations under fluctuating energy prices. Full electrification achieves the highest carbon efficiency, increasing carbon-to-liquid fuel conversion from 37 % to 91 %, but faces challenges due to high electricity demand (up to 2.5 MWh per MWh of fuel) and reliance on low-carbon grids. Partial electrification offers a cost-effective alternative, reducing production costs by up to 40 % compared to fully electrified cases, while maintaining a carbon efficiency of around 60 %. CCS enables net-negative emissions, though its viability hinges on sufficiently strong carbon pricing incentives. Compliance with sustainability mandates, such as Renewable Fuels of Non-Biological Origin (RFNBO) requirements, depends on access to decarbonized electricity. Overall, partially electrified BtL pathways enhance carbon utilization, reduce emissions, and offer resilience to market fluctuations. These pathways provide a promising balance of environmental and economic performance, outperforming both traditional BtL under high biomass prices and fully electrified e-fuels in terms of cost. Their advantages make them attractive from both investment and policy perspectives—especially in markets supported by stable electricity prices, carbon incentives, and sustainability-driven regulation.

The transition of energy systems requires policy frameworks and instruments to make both energy suppliers and consumers contribute to the common goal of emission reductions and to fairly allocate costs and benefits among market actors and the government. Assuming that market actors – suppliers and consumers adhering to their economic interests – would benefit from cooperating to mitigate emissions, this study applies a game theory-based approach to investigate the interaction between a local electricity supplier and a group of heating consumers not connected to district heating. Selected policy instruments are tested, and their consequences are analyzed in the context of a representative Nordic municipality. The results show that the auction-based Contract for Difference policy instrument is the most suitable one in the studied Nordic context to achieve significant levels of CO2 emissions reduction. It creates a higher level of strategic interaction between the actors, that would be lacking otherwise, under the form of transfer payments from consumers to supplier, and avoids costs to the general taxpayer. While this is sufficient to promote the investments in renewables by the supplier, additional subsidy policies are required to enable the heating consumers to invest in more capital-intensive energy efficiency measures or biomass heating.

The reduction of anthropogenic emissions of greenhouse gases requires decreasing the overall consumption of primary energy. Thus, waste heat recovery at medium-to-high temperature is an opportunity for generating electricity while reducing the need for primary resources. Recently, supercritical carbon dioxide power cycles (S-CO2) are emerging as a promising solution. However, a method lacks to simultaneously optimize their layout and design parameters, without relying on superstructures defined a priori. To this end, this paper suggests a novel extension of the superstructure free SYNTHSEP methodology, a bottom-up approach for the optimal synthesis and design of thermodynamic cycles, to handle also super- and transcritical cycles. An Evolutionary Algorithm combining elementary cycles makes it possible to define optimal S-CO2 configurations without limiting the search space of the optimization problem. The objective consists in finding the S-CO2 topology and design parameters that maximize the mechanical power extractable from waste heat streams in the temperature range from 200 to 700 °C, typical of the industrial sector. Results demonstrate the capability of the method to find optimal cycle layouts for any given waste heat temperature, and to achieve, at the same conditions, cycle efficiencies up to 5 % higher in relative terms than the best ones in the literature.

This paper examines the opportunities to reuse excess heat from direct free air-cooled data centres without incorporating heat pumps to upgrade the heat. The operation of a data centre in northern Sweden, Luleå, was simulated for a year. It was established that heat losses through the thermal envelope and from the humidification of the cooling airflow influenced the momentary energy reuse factor, iERF, with up to 7%. However, for the annual energy reuse factor, ERF, the heat losses could be neglected since they annually contributed to an error of less than 1%. It was shown that the ideal heat reuse temperature in Luleå was 13, 17, and 18 °C with an exhaust temperature of 30, 40 and 50 °C. The resulting ERF was 0.50, 0.59 and 0.66, meaning that a higher exhaust temperature resulted in potentially higher heat reuse. It could also be seen that raising the exhaust temperature lowered the power usage effectiveness, PUE, due to more efficient cooling. Using heat reuse applications with different heat reuse temperatures closer to the monthly average instead of an ideal heat reuse temperature for the whole year improved the ERF further. The improvement was 11–31% where a lower exhaust temperature meant a higher relative improvement.

Gasification is a promising pathway for converting biomass residues into renewable transportation fuels and chemicals needed to comply with the ambitious Swedish environmental targets. The paper investigates the integration of a molten carbonate electrolysis cell (MCEC) in biofuel production pathway from sawmill byproducts, to improve the performance of gas cleaning and conditioning steps prior to the final conversion of syngas into liquid biofuels. The energy, material, and economic performance of process configurations with different gasification technologies are simulated and compared. The results provide relevant information to develop the engineering of gas-to-liquid transportation fuels utilizing renewable electricity. The MCEC replaces the water-gas shift step of a conventional syngas conditioning process and enables increased product throughput by as much as 15%–31%. Depending on the process configuration and steam-methane reforming technology, biofuels can be produced to the cost range 140–155 €/MWh in the short-term.

A common approach to energy system optimization is to minimize overall costs at system level, regardless of the actors actually bearing those costs. This paper presents an approach inspired by Nash game theory concepts, in which the actors involved in an energy system determine their optimal strategies according to their own economic interests (profit functions) in a non-cooperative or in a cooperative way. A simple case study, considering an electric utility and individual heating consumers in the municipal energy system of a small town in northern Sweden, shows the differences between the two approaches. The game theory approach is able to represent more realistic interactions among the actors of an energy system, fair in fulfilling their conflicting economic interests, and, therefore, a more suitable tool for decision makers evaluating the impacts of policy instruments.