1. Strategies for the design of Net zero energy balance buildings
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. Challenges to Policy/Economy and Research
Policy Context
UK decided in 2007 that they would become mandatory for after 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. The problem thus becomes one of Costs / Economy
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. [Initial or life-cycle]
Optimal zone
Cost
[Initial or life-cycle]
+ Eficiency
+ Microgeneration

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

8. Challenges for Portugal (2)
Need to develop tools to assist in choosing efficient / cost effective design, which may help to:
1. Correctly assess the building performance;
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.
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. Comparative Analysis 15 Case Study Location Climate HDD (b18)
Solar radiation horizontal (KWh/m2.yr)
Floor Area (m2)
Wall U-value (W/m2.K)
Roof U-value (W/m2.K)
Glazing U-value (W/m2.K)
Building Ventilation
Heating Needs (KWh/m2.yr)
Electricity Needs (KWh/m2.yr)
PV installed per building floor area(W/m2)
Eco-Terra
Quebec
4966
3 591
234
0.16
0.125
0.8
mech 37 33 12
Solar Harvest
Colorado
3322
4 619
426
0.17
0.09
1.1
nat+mech 7 23 21
Tanno
Weiz
3260
3 044
120
0.11 15 39 5
Crossway Eco
Kent
2866
2 757
285
0.12
0.7 34 11
Solar Plus Haus
Hessen
2865
2 575
212 -
12.6 2
Mariolopoulos
Athens
1112
4 565
1267
0.25
0.26
1.0
nat 4 29
PVRES
Florida
534
4 590
225
0.57
0.19 31 18

16. 16
Comparative Analysis