Strategies for the design of Net zero energy balance buildings

1. Sustentabilidade energética e metabolismo urbano Strategies for the design of Net zero energy balance buildings Vítor Leal Lisboa, 07 de Julho de 2010 10 !

2. NZEB – The concept • A building which is bidirectionally connected to the energy grids [/electric grid]. • Which incorporates local microgeneration equipments such that • On an annual basis the amount of energy that it injects in the grid(s) is at least equal to the one that it draws from them.

3. Policy Context • UK decided in 2007 that they would become mandatory for after 2016. Others followed. • EU EPBD recast published on the 18th June 2010 calls requires (article 9) that • (a) by 31 December 2020, all new buildings are nearly zero- energy buildings; and • (b) after 31 December 2018, new buildings occupied and owned by public authorities are nearly zero-energy buildings. Challenges to Policy/Economy and Research

4. Challenges for Portugal (1) • Definition and reference conditions adapted to the local conditions • Definition of “energy from renewable resources produced nearby” • Conversion factors to primary energy of the different carriers representative of Portuguese reality; • Typical values for the building life-cycle to be considered in the economic studies.

5. Strategies on how to achieve net-zero performance | the extremes: • Design as usual (high consumption) and then install [a lot of] micro(?)generation to offset the consumption. • Design for the lowest possible consumption and then [few] microgeneration will be needed to reach net-zero balance. Note that from the environmental point of view both approaches seem to be [apart from the use of materials] equally good ! The problem thus becomes one of Costs / Economy

6. Optimal zone Cost [Initial or life-cycle] + Eficiency + Microgeneration

7. Furthermore, the scope of technologies that can be employed [Energy services @ building and micro-generation to offset the consumption] is large and “ever-growing”.

8. Challenges for Portugal (2) 2. Identify for each specific building which are the combinations of ENVELOPE + ENERGY SERVICES + MICROGENERATION Technologies That are in the most cost/economic effective area. Need to develop tools to assist in choosing efficient / cost effective design, which may help to: 1. Correctly assess the building performance; 3. Assist the Policy and Market forces to identify the clusters of technologies with most potential in Portugal and foster / support its development.

9. Other research issues raised by NZEBs: • Potential contribution to the Energy balance of Portugal and comparison with other investment alternatives in EE&RE • Impact / interaction on Electric Grids; • Modern technologies of biomass for heating; • Local offset / microgeneration vs. off-site Renewables. • Potential contribution of Smartmetering to Energy Efficiency. • Design of incentives to promote the measure.

10. Some ongoing Research work ongoing within the MPP in this area: • Maria Kapsalaki:Carbon Neutral Buildings Design in Respect to Climate and Resource Diversity • Gonçalo Cardoso:Building integrated micro-generation solutions for a sustainable built environment • Isabel Azevedo:A study of NZEB from an energy systems perspective • Ariovaldo Carvalho: Retrofitting opportunities for buildings in historical centers: balancing energy efficiency, sustainability and comfort. • Pedro Gonçalves: Exergy Systems Analysis for High Performance Buildings

11. Slide plataforma Maria Kapsalaki

12. THANK YOU

13. EXTRAS

15. 15 Comparative Analysis

16. Comparative Analysis 16