Creation of Zero CO<sub>2</sub> Emissions Residential Buildings due to Operating and Embodied Energy Use on the Island of Crete, Greece

Abstract

The possibility of creating zero CO 2 emissions residential buildings due to life cycle energy use in the island of Crete, Greece has been examined. In a typical residential building located in Crete, Greece, its annual operating energy has been appraised at 170 KWh/m 2 and its embodied energy at 30 KWh/m 2 . Various locally available renewable energies including solar energy, solid biomass and low enthalpy geothermal energy with heat pumps have been considered for generating the required heat and offsetting the grid electricity used. Their technologies are mature, reliable and cost-effective. Offset of the annual grid electricity use in the building with solar-PV electricity is allowed according to the net metering regulation. For zero carbon emissions due to embodied energy of the building, generation of additional solar electricity injected into the grid is required. A mathematical model has been developed for sizing the required solar-PV system installed in the building in order to offset the grid electricity use. For a residential building in Crete, Greece with a covered area of 100 m 2 , the power of the additional solar-PV system has been estimated at 1.6 KWp and its cost at 2400 €. In the current work, it is indicated that the creation of a zero CO 2 emissions residential building due to life cycle energy use in Crete, Greece does not have major difficulties and it could be achieved relatively easily.

Comparison of the Applied Measures on the Simulated Scenarios for the Sustainable Building Construction through Carbon Footprint Emissions—Case Study of Building Construction in Serbia

“…The importance of improvement of energy efficiency through the reduction of operational energy was emphasized by Vourdoubas [17]. Certain activities are undertaken to increase the thickness of thermal insulation materials in thermal layers of a building which consequently results in the rise in the embodied energy, i.e., embodied carbon in a building.…”

“…That embodied carbon particularly is to be included in the calculation of the impact a building has on the environment [22]. The current European regulations give directions for the designers to design energy efficient buildings with zero net energy consumption [17], the goal of which is that by 2020 all public buildings are to be zero-energy buildings; however, the focus is on operational energy. The total carbon footprint from the construction sector is measured based on operational energy, which is the basis for forecasts and plans for the emission reductions on both local and global levels.…”

“…The total carbon footprint from the construction sector is measured based on operational energy, which is the basis for forecasts and plans for the emission reductions on both local and global levels. Vourdoubas [17] suggested that zero-energy buildings, despite their zero-energy consumption in exploitation phase, do impact the environment, which consequently comes from those higher demands and that a concept of zero CO 2 emission, from operational and embodied energy, has not been developed so far. The same author concluded that there are no regulations for zero-energy buildings.…”

“…The impact a building has on the environment starts with the exploitation of natural materials from the environment (cradle) followed by the production of construction materials, transportation, construction and continues through the building life span, its maintenance, replacement of components and at the end of the life cycle its demolition and recycling or generated waste. The total emissions of the building life cycle are the outcome of operational and embodied energy, as asserted by Vourdoubas [17].…”

“…EU Directives (Directive 2002/91/EC and Directive 2010/31/EU) [18,19] focus on the energy used in the operational phase (operational energy), while Vourdoubas [17] suggested that, along with operational energy, which is used during the building exploitation, embodied energy used during the construction of a building as well as during the production of the building materials, is usually not taken into consideration. Ibn-Mohammed et al [23], who also reviewed the current literature on the embodied energy in a building, stated that, for mitigating climate changes, buildings should be designed and constructed with the minimum effect on the environment.…”