During the ongoing transition towards cleaner energy production to tackle climate change, it is important to identify economically viable solutions. While Renewable Energy Sources (RES) offer clean energy, they cannot consistently meet energy demand. Therefore, energy storage technologies are necessary, particularly for thermal demand where thermal energy storage is the most sustainable, efficient, and cost-effective solution. In this study, a combination of RES, thermal storage, and electrical resistors converting electrical energy into thermal energy is proposed to hypothetically meet the energy requirements of a sludge drying facility. The implementation feasibility of such a setup is assessed, by using commercially available software tools but also developing a new methodology. This methodology calculates the efficient dimensioning of the initial setup (RES and storage technology), based on the hourly energy demand and RES production. Two main technical scenarios were identified. At the end, the most energy efficient scenario was chosen. The economic benefits were extracted, using the setup and the dimensioning proposed from this scenario. The future step of this assessment is to evaluate the environmental profitability of this setup, under the third sustainability development pillar.