Search

[EN] Different Zero-Energy Building (ZEB)-related definitions considering its four main dimensions, such as zero energy, zero carbon, zero exergy and zero cost, have been proposed by different investigators. Among these, exergy-based definitions are relatively low in numbers. In this regard, the main objective of this present study is to propose net zero extended exergy buildings as a new concept, which combines extended exergy and net zero exergy building concepts and is a measure of the exergetic footprint. This concept setups a balance between extended exergy accounting of electricity from the grid and electricity generated in building. The proposed methodology is applied to a building available in the literature for heating and cooling seasons. Results show that 450Wp peak power and 44.181 kWh electrical energy must be obtained for meeting the electricity demand of the building. Another novel result is that the extended exergy accounting of the electricity generated by PV panels is bigger than the extended exergy of the electricity taken from the gird meaning that exergetic footprint of the electricity generated by PV panels is bigger. However, this result must be interpreted for the whole life time of the system.

[EN] This research presents a novel approach that analyzes the water requirements for hydrogen production associ- ated with a nationally adopted Green Hydrogen strategy. Green Hydrogen production is one of the most relevant technologies for massive renewable energy integration in transport systems, industries, or heating systems. European Union has launched a strategic roadmap for green hydrogen generation and integration in the energy chain. Spain aims to be one of the most important producers and exporters and has approved a Hydrogen Roadmap for next years, but no previous research has focused on the water requirements. This research finds that Spain’s Green Hydrogen Roadmap, and a similar European one, is based on electrolyzers’ peak capacity, and this causes a large uncertainty in real hydrogen production and associated water requirements. Spain represents a case study that can be a reference worldwide as it suffers from increasing droughts, has considerable tourist pressure, and is one of the most important producers of greens and fruits. This study proposes a methodology to quantify actual hydrogen production and associated water requirements and proves that current large-scale planning based on peak generation will produce a large uncertainty and could directly impact water supply security. One of the most relevant findings is that hydrogen production and water requirements must be included in these strategies to avoid future water supply tensions. An analysis of alternative water supply using desali- nated water analyzes its feasibility and the effects on final cost. The outcomes are an example to be applied in similar scenarios worldwide and prove the need for an integrated energy-water-food strategy to deploy green hydrogen systems.

[EN] Buildings are one of the most important energy consumers in modern economy countries. The massive use of electrical vehicles could help decarbonizing the economy by using electricity produced using renewable energy. Combined use of Vehicle to Grid (V2G), Vehicle to Home (V2H) and Vehicle to Building (V2B) is one of the strategies to increase the number of electrical vehicles, ensure a better coupling between energy generation and consumption, reducing peak demand and increasing global energy efficiency. This research presents a novel approach of combined use of V2H and V2B that can be applied in different scenarios such as when the building workers own EVs, company shared car fleets or leasing, among others. Recharged energy at workers homes during night hours is delivered in the building during daily working hours lowering peak demand, reducing carbon intensity and energy cost savings. The results show that the methodology is feasible and can be extended to other cases and greatly contribute to better energy efficiency, reduces peak demand in buildings and increase electric vehicles penetration in transport to workplaces.