Design and operation optimization of Renewable-Integrated greenhouse energy Systems: Implications of climate and carbon policies in the Netherlands and Spain

• An energy hub is designed to fulfill the greenhouse’s electrical, heating, and cooling demands. • A MILP optimization model minimizes the annual cost of greenhouse operations in Spain and the Netherlands. • Spain demonstrates 58% lower annual costs and 71% lower CO 2 emissions compared to the Netherlands. • Carbon tax increases are critical for effective emissions reduction in the Netherlands. • Lettuce is identified as the most cost-effective and environmentally sustainable crop in both regions. Greenhouse agriculture is highly energy-intensive, requiring significant heating, cooling, and electricity that lead to high costs and carbon emissions. Developing sustainable energy solutions tailored to local conditions is therefore essential. This study aims to design and optimize an integrated energy hub for greenhouses, minimizing the total annual cost while meeting all energy demands. A mixed-integer linear programming (MILP) model is applied to two European locations with contrasting climates: the Netherlands and Spain. The analysis further considers environmental policies, alternative crop cultivation schemes, and variations in renewable technology costs. Results indicate that the Netherlands incurs about 40% higher annual costs and 141.7% more CO 2 emissions compared to Spain. This gap is driven by Spain’s higher solar irradiance, which enables greater use of solar collectors and photovoltaic systems. Under carbon taxation, Spain achieves up to 80% emission reduction, while the Netherlands reaches only 37%. Achieving a 20% reduction requires a carbon tax of €94/ton CO 2 in Spain but €777/ton CO 2 in the Netherlands. Crop analysis shows that lettuce cultivation results in the lowest costs and emissions in both countries, suggesting that the Netherlands could specialize in lettuce while importing more resource-intensive crops, such as tomatoes, from Spain. These findings demonstrate the importance of region-specific energy strategies and policies to achieve economically viable and environmentally sustainable greenhouse agriculture.