Renewable Energy Integration and Zero Energy Buildings

Abstract

Renewable energy is the energy that makes use of the continuous natural processes for its production and renews itself in a shorter time than the depletion rate of the resources it uses for production. The types of renewable energies include geothermal energy, wind energy, solar energy, hydroelectric, hydrogen, wave and biomass energy. Zero energy buildings (ZEB or nZEB) are highly energy efficient buildings with zero net energy consumption, meaning that the total amount of energy used by the building on an annual basis is equal to the amount of renewable energy created on the site or by renewable energy sources offsite, using technologies such as heat pumps, high efficiency windows and insulation, and solar panels. This definition is also used by the European Parliament Building Energy Performance Directive (EPBD) [Directive (EU) 2010/31/EU]. The directive enforces the buildings built after December 31, 2020 to be zero-energy buildings (ZEB) or nearly zero energy buildings (nZEB). They should be cooled or heated according to their purpose by renewable sources. The purpose of calculating energy performance in buildings is to determine the annual total energy demand given in net primary energy corresponding to energy for heating, cooling, ventilation, hot water and lighting. Therefore, high-energy consuming buildings should be supported with renewable energy. For residential buildings, most Member States aim to have a primary energy use of no higher than 50 kWh/(m² y). In our country, the energy performance of buildings is determined using the calculation method within the scope of the National Energy Performance of Buildings Method and using BEP-TR software. The method followed in this study is based on BEP-TR software and calculations. The Turkish Standards Institute study method (TSE/TSI) begins with the determination of the reference specifications for each building type, using the data. The share of renewable energies in the total energy supply is required for the net zero energy building concept, taking into account active systems such as photovoltaic panels, hot water collectors and heat pumps. As a result, net zero energy buildings, supported by renewable energy, have begun to be implemented in Turkey. The location of the buildings, the number and density of the building occupants provide a useful flexibility to reduce the performance deficiencies that may be experienced due to the design features and to achieve the nZEB targets. The European Union took the first step with the Energy Performance in Buildings Directive (2002/91/EC), EPBD. The directive, which was revised in 2010 (2010/31/EU), introduced concepts such as “reference building”, “optimum cost” and “nearly zero energy buildings”. The last revision of EPBD was approved in 2018. The new revision includes the strengthening of indoor environment quality, proper maintenance and effective inspection and setting more ambitious energy efficiency targets in line with the opinions of the stakeholders and REHVA. Encouraging the use of information and communication technology (ICT) and smart technologies (smart meters, building automation and control systems) to ensure efficient operation of buildings, energy storage and the definition of “smart readiness indicator” that shows how ready the buildings are for compliance with the distribution network, requests the renovation of existing and old buildings. The European Commission proposed a revision of the directive (COM (2021) 802 final) in 2021. It upgrades the existing regulatory framework to reflect higher ambitions and more pressure on climate and social action, while providing EU countries with the flexibility needed to take into account the differences in the building stock across Europe. Digitalization is a good opportunity to increase the share of various renewable energy sources to meet the demand for heating and cooling. Approximately 19% of Europe's heating and cooling consumption is met by renewable energy (mostly solid biomass) (EEA 2018). Renewable energy technologies used to heat and cool buildings can be placed in individual units of small capacity or in DHC, district heating and cooling systems with larger capacities. Digitization, by optimizing implementation, planning and business models, reduces the total cost of decarbonization by connecting heat and cooling device manufacturers, users, local stakeholders and energy markets. It is a driving force for smart buildings, smart communities, smart cities, local energy and district heating and cooling (DHC). In many buildings today, control is limited to at most one room thermostat. Even though thermostats are programmable, many building occupants do not know their existence or do not know how to do it. The benefits of digitization for heating and cooling, even the existence of technologies, are little known. However, heating and cooling are vital for comfort at home and at work. Using devices that analyze and process large amounts of data, digital technologies provide a new data layer that can be energetically and socially utilized, helping to better manage the building energy system and increase energy efficiency. For example, when digitization and electrification are used together, direct communication between the building and the main grid can be achieved, and both generation and demand sides can be optimized through some innovative approaches. “Internet of Things” solutions create greater interaction between HVAC systems and building occupants; consumers can become more aware of energy waste and make their own energy choices more consciously. Advanced HVAC technologies are actually ready for this environment; the main challenge is to show that they are economically and financially sustainable through cost–benefit analysis.