heating with pv façade in a passive house...south facade b system of case a plus shower drain-water...

Georgios Dermentzis, Fabian Ochs,

Aleksandra Ksiezyk, Elisa Venturi, Mara

Magni, Hannes Gstrein

University of Innsbruck

[email protected]

Heating with PV Façade in a Passive House

Outline

• Building and concept

• Method and results

• Primary energy evaluation

01.10.2018 2Georgios Dermentzis University of Innsbruck

Building & Concept

• MFH in Innsbruck, Austria

for temporary assisted

living environment

• Passive House

(9 kWh/m2a)

• 14 flats (~35 m2 each) +

common areas

• PV on the south façade

27.3 kWp

• Electric radiators for

space heating

• Electric boilers for DHW

• Mechanical ventilation with

heat recovery


Building construction

01.10.2018Georgios Dermentzis University of Innsbruck

4

IIG – Innsbrucker Immobiliengesellschaft

Construction through prefabricated

concrete elements

Concept


5

Installed decentralized system:

Direct electric heating & DHW

Almost no pipes

Centralized system

2- or 4-pipe distribution

system

E-boilerElectric

radiators

Central

storage

DHWDHW

Radiators

PV

Batteries

Grid

Heat

pump

Motivation

Investigate a direct electric system in combination with

PV on the façade

• keep the investments costs low

• minimize the installation effort

• eliminate the distribution losses

• increase the share of on-site renewable energy

production using the available space in the façade


Method

Calculation tool: PHPP

1. Compare the PV algorithm in PHPP vs

Matlab/Simulink

2. Perform a parametric study in PHPPInstalled decentralized system vs centralized heat

pump systems by comparing:

a. Final energy (here electricity)

b. Primary energy (PE) using:

i. annual PE factors

ii. monthly PE factors


7

Parametric study

Case System description PV

A Direct electric system with PV in the South façade27.3 kWp –

South facade

BSystem of case A plus shower drain-water heat

recovery27.3 kWp –

South facade

C System of case A plus PV in the East and West façade57.9 kWp –

South, East & West facade

DReference centralized air-source heat pump (4-pipe

distribution system)-

EReference centralized groundwater-source heat

pump (4-pipe distribution system)-


CaseABC

CaseDE

Parametric study - PV on the facades

Area [m2]

FaçadeFaçade without

windowsPV

Coveringpercentage

South 374 285 211 74%

East 184 144 104 72%

West 242 215 133 62%


Triangle

shape ->

no PV

PV yield - PHPP vs Matlab/Simulink

0

3

6

9

12

15

0 3 6 9 12 15

PH

PP

-P

V [

kW

h/(

mP

V2∙m

on)]

MATLAB/Simulink - PV [kWh/(mPV

2∙mon)]

South

East-south

West-north

7%

-7%


Annual values

Difference PHPP

Matlab/Simulink

South

façade

South, east

& west

façades

Solar radiation -1% -3%

BIPV yield 1% -1%

Good agreement between the tools

Monthly electricity balance

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

1 2 3 4 5 6 7 8 9 10 11 12

Ele

ctr

icit

y [

kW

h/(

m2∙m

on)]

Time [mon]

Heating DHW Auxiliary Appliances PV

Direct electric sys. Ground-water

heat pump

South facade


South, East &

West facade

Annual electricity balance

0

5

10

15

20

25

30

35

40

45

50

A B C D E

Ele

ctr

icity [kW

h/(

m2∙a)]

Heating DHW Auxiliary Appliances PV


Highest

productionLowest

consumption

Primary energy factors


0.0

0.5

1.0

1.5

2.0

2.5

3.0

1 2 3 4 5 6 7 8 9 10 11 12

PE

facto

rs

Time [mon]

Monthly factors Annual factors

Primary energy results

40%

60%

80%

100%

120%

140%

160%

Annualmethod

Monthlymethod

rela

tive P

E to

case A

(annual m

eth

od

) [-

] PE total A

B

C

D

E


• The most beneficial:

Case C (dir. Electricity

with PV on the South,

West and East façade)

• Monthly instead of

annual PE factors:– In cases with PV the PE

increases more than in

cases with HP

Because PV have low

contribution during the

heating period

Conclusions

Concept of a Passive House building using direct electricity for heating and

DHW combined with PV on the façade

• The direct electricity systems combined with PV have similar or better

(in case of PV on the South, West and East façade, assuming shadings

losses of 10%) performance to heat pump systems without PV, because

PV can cover the additional electricity required.

• Monthly instead of annual PE factors leads different ranking of the

investigated concepts, since renewables have low contribution in winter,

when demand is high.

– E.g.: In case E (ground-water heat pump), in order to have the same PE as

case A (reference), a PV system of 3.7 kWp is required using annual PE factors

and 1.5 kWp using monthly PE factors.


Outlook

• In-situ detailed monitoringo Energy performance

o Comfort conditions

• Dynamic simulations o Calculate the part of PV electricity that is used directly

o Investigate grid interaction (load in winter, PV in summer)

o Investigate electric storage


Thank you

for your attention

[email protected]

heating with pv façade in a passive house...south facade b system of case a plus shower drain-water...

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