Enabling Flanders towards SustainableGeneration & Storage in an Urban Context

Jef Poortmans

• Why this project:

• LCOE of PV has reached “grid parity”

• Further reduction of LCOE requires focus on kWh’s, not only on Wp

• Requires study/improvement of PV-modules & PV-system integration

• PV-system + storage system is the name of the game

• The rebirth of DC

What is it about?

SolSThore

• Strong position in PV R&D • Global leader in PV-cell technology

• Presence in other parts of the PV value chain to be reinforced

• .. and is growing in battery research:• Material- and cell oriented R&D-activities in imec and

UHasselt

• Battery Management System R&D at VITO

• High potential in linking power device development-expertise to DC-application

SolSThore

Bringing the different expertise together ...

• Objective 1: Investment in SoA lab-infrastructure for PV-module, storage and DC-systems research • TF-PV module process technology lab (EnergyVille 2)

• Si-PV module process technology lab (EnergyVille 2)

• Battery material & process technology lab (EnergyVille 2)

• DC-nanogrid (EnergyVille 1)

• Outdoor & indoor PV-system measurement setup (EnergyVille 1)

• BIPV set-up (EnergyVille 2)

• Commercial PV-roof setup (EnergyVille 1)

• Objective 2: Build up human expertise in the related fields

• Objective 3: Build up demonstrators for credibility

SolSThore

High-level Objectives

• Activity 1: Innovative cell and module technology

• Activity 2: Towards safe and reliable highly performing local electrochemical storage based on Li-ion system

• Activity 3: Power electronics in a DC-nanogrid context

• Activity 4: Modelling and prediction of energy yield

• Activity 5: Demonstrators in BIPV and commercial roof

SolSThore

Project structure

Activity 1Innovative cell and module technology

Eszter Voroshazi

Technology seeds for world class innovation

Crystalline silicon PV module technology and characterisation

and their reliability testing &simulations

• Thin-film (perovskite) PV module technology

10

LET’S WEAVE

Bifacial cell and module tech’ for BIPV

• Woven cell interconnection technology for bifacial cells: from concept to 9-cell demonstration Optimised woven fabric combines encapsulation and

interconnection metallisation in one sheet

Optimised solder and lamination process

Proven <1% CtM current loss (while 1-3% with latest industrial technologies)

• Record performance busbarless and bifacial cells: 22.8% and 98% bifaciality Integration with SmartWire interconnection proven in

60-cell module

Optimised process to pass 200 thermal cycles < 5% loss

• Next: ICON project starting for industrial fabrication of the foils

For more: Poster in EV2 PV lab and live demo in EV2 entrance

glass

glass

woven fabric

cell

3 generations of real-life BIPV demonstrators

2016: 9-cell (10 pcs)

modules with industry

baseline technology

2017: 9-cell modules (12 pcs)

with imec cells and SmartWire

interconnection

2018: 60-cell (5 pcs) and 9-cell (12 pcs)

BIPV modules benchmarking of latest

ribbon and industrial and imec multi-wire

interconnection technologies For more: Activity 5 presentation and demo sites

• Potential induced degradation: in-depth insights on mechanism and its characterisation (up to 5000V)

• Thermo-mechanical stress modelling and measurement• multi-scale modelling of full-size

modules

• advanced adhesion and load measurement

Reliability testing and simulation expertise

Stress concentrations due

to the clamping method

PID

No PID

Increasing

voltage

Back-end thin-film PV module technology

• Record performance large area modules with traditional patterning: 10% on 10cm2

• One step patterning of the thin-film layer to form the module interconnection

Laser process replaces mechanical scribe: 10 x faster, improved accuracy and reduced line width

• Next: Novel materials and upscaling to 900 cm2

literature benchmark

imec/Solliance results in orange

Insulator and

conductive ink

materials selected

For more: Poster in EV2 PV lab

(BI)PV module prototyping and characterisation facilities

• cSi BIPV assembly line (1x1.6m2)• Automatic module assembly tool

• Laminator for glass/glass and curved modules

• TFPV assembly (30x30cm2)• Laser patterning

• Slot-die coating

• Vacuum evaporation/sputtering

• PV module performance and quality testing• Bifacial LED based solar simulator

• Spectral response and reflectivity

• Material characterisation tools

• Large area climate chambers

For more: Poster and visit in EV1 and EV2 labs

In the last 3 years...we have made record modules, started two modules lines, moved

teams and labs...and it is just the start of a new innovation roadmap.

Join us!

Thank you for the incredible effort of the team!

Activity 2Battery Technology

An HardyJeroen Büscher

Electrochemical energy storage

• Framework of decentralised energy generation & electric mobility

• Energy storage is crucial

• Enabling high penetration of renewable energy

Why?

EnergyVille electrochemical energy storage roadmap

Solid-state Li-ionSolid-state Na

Solid-state LiS

Pouch cellsElectrode coatings - A4 sheets - mesh current collectors

1-phase grid inv.3-phase grid inv.

DC nanogrid inv.Modular DC nanogrid inverter

Voltage balancing SoC balancing Battery reconfiguration

Model-based SoCModel based SoH

Insulation mon.Connectivity check

Li-air

Battery

Modules

Systems

Materials &Cell

technology

UpscalingAssembly (Cutting/stacking and Lamination)

mAh Ah

• Design battery labs

• Installation of pouch cell manufacturing line

• Platform process for solid state batteries• materials development: solid composite electrolytes over 1 mS/cm

• cell development: functional solid state batteries demonstrated

Results during EFRO 936 – SolSThore activities

Battery lab designFrom the drawing table to reality today

Installation of pouch cell manufacturing lineFrom tough selections into fully installed dry room today

Installation of pouch cell manufacturing lineFrom tough selections into fully installed dry room today

OxidesSulphidesPolymer PEO

Expensive large scale

production

Medium conductivity

Low stability to oxidation,

moisture, cathode materials

Very high conductivity

Low oxidation voltage

Limited thermal stability

Taken from Manthiram et al. doi:10.1038/natrevmats.2016.103

Solid composite electrolytes

Inexpensive

Compatible with current LIB

production methods

High conductivity

High oxidation voltage

Versatility

Platform process for solid state batteriesMaterials development: solid & composite electrolytes

SCE or ETG precursor

CC

Coating (AM/C/Binder)

Electrolyte+membrane

Compatibility to current

manufacturing lines

Platform process for solid state batteriesCell development: solid state batteries

EnergyVille electrochemical energy storage roadmap

Solid-state Li-ionSolid-state Na

Solid-state LiS

Pouch cellsElectrode coatings - A4 sheets - mesh current collectors

1-phase grid inv.3-phase grid inv.

DC nanogrid inv.Modular DC nanogrid inverter

Voltage balancing SoC balancing Battery reconfiguration

Model-based SoCModel based SoH

Insulation mon.Connectivity check

Li-air

Battery

Modules

Systems

Materials &Cell

technology

UpscalingAssembly (Cutting/stacking and Lamination)

mAh Ah

Results during EFRO 936 – SolSThore activities

• Extension battery Testing Lab

• Development of Battery Management System

• Tool to asses total cost of ownership

Battery Testing Lab

• Cell, module and system testers up to 1000VDC , 30kW

• Climate chambers for testing [-20⁰C, +55⁰C]

• Standardised and application specific tests with a focus on performance and ageing

• Testing of commercial and prototype batteries

• Risk analysis and system design review

State-of-the-art testing infrastructure at your service

• Ensured safe battery operation

• Optimised performance and lifetime

• Maximised usable battery capacity

• Improved lifetime prediction

• Benchmarking SoC estimation for Li-ion

• Better than competition• Especially in case of “solar cycles” and

when using old cells

Battery Management SystemsAdvanced technology in a modular concept

Time

Time

Total Cost of Ownership (TCO) tool

• Application specific guide for

• Storage technology choice and dimensioning

• Decision support

• CBA* of service delivery

*CBA = cost benefit analysis; **DPP = discounted payback period

Energy price

(€/kWh)

DPP**

Activity 3Development of power electronics

Johan Driesen

LVDC for smart citiesTowards more energy efficiency, distributed generation and internet-of-things

LVDC for smart citiesTowards more energy efficiency, distributed generation and internet-of-things

LVDC for smart citiesTowards more energy efficiency, distributed generation and internet-of-things

LVDC for smart citiesTowards more energy efficiency, distributed generation and internet-of-things

LVDC for smart cities

Three arguments: compatibility, power transfer capability and controllability

• Motivation for LVDC distribution systems• Compatibility with DC devices• Increased power transfer capability• Increased controllability

• Motivation for bipolar LVDC [1-4]• Increased power transfer capability• Two voltage levels available• Conduction losses are reduced• Potentially more reliable• But: voltage balancing converters required

[1] G. Van den Broeck, S. De Breucker, J. Beerten, M. Dalla Vecchia, and J. Driesen, “Analysis of Three-Level Converters with Voltage Balancing Capability in Bipolar DC Distribution Networks,” in International Conference on DC Microgrids, 2017, 8 pages.[2] H. Kakigano, Y. Miura, and T. Ise, “Low-voltage bipolar-type DC microgrid for super high quality distribution,” IEEE Trans. Power Electron., vol. 25, no. 12, pp. 3066–3075, Dec. 2010.[3] J. Lago, J. Moia, and M. Heldwein, “Evaluation of power converters to implement bipolar DC active distribution networks—DC-DC converters,” in Energy Conversion Congress and Exposition (ECCE), 2011, pp. 985–990.[4] T. Dragicevic, X. Lu, J. Vasquez, and J. Guerrero, “DC Microgrids–Part II: A Review of Power Architectures, Applications and Standardization Issues,” IEEE Trans. Power Electron., vol. 8993, no. 99, pp. 1–1, 2015.

Towards LVDC in commercial buildings

Bottom-up evolution of LVDC power systems• Fixed, high-power loads first

• PV installations, including BIPV installations

• Electric vehicle charging stations• HVAC systems (already inverter-driven)• Elevator drives (already inverter-driven)• Simplify the power conversion steps

(read: cost reduction)

• From a DC back-bone• Power LED lighting• Power office spaces

• Interconnect multiple LVDC commercial buildings

Source: AEG PS

Source: SMA AG

LVDC test facility

A ±500V bipolar DC test grid developed in the SolSThore project

Lab infrastructure100 kW ±500V DC test grid

Unipolar and bipolar configurationTN-S grounding or IT groundingReconfigurable

Power flow monitoringVoltage measurementsPower electronic converter testingCommunication interfacesConnected to other labs

Rooftop PV test siteBattery laboratoryEV Parking

TestsVoltage stability - power sharingProtection systemsEquipment interoperabilityEfficiency assessment

LVDC test facility: example set-up

Power electronic building blocks

• Smart AC/DC grid coupling

• Unbalance compensation on AC side

• Bipolar supply on DC side

• Solar converter

• DC/DC converter architecture• Non-isolated / isolated

• Design for reliability

• GaN-based circuits

• DC grid management

• Balancing/protection

• Conversion to LV busses (e.g. 48 V, USB-C)

Place of the DC-DC converter in the BIPV concept

Design specifications - Electrical

• Input voltage: 10 – 50 V

• Input current: max 10 A

• Output power: max 300 W

• Output voltage: 380 V (DC)

• DC bus gets stabilised by central inverter

• Unipolar

• MPPT

• Modularity

• Communication with central inverter

• General design

• Low component count

• Simple and robust

• Limit temperature rise

• Redundancy

• Use components that are rated up to 125°C

• For cooling

• Only passive is a viable option

• Temperature sensors?

• For switches

• Limit internal temperature (die)

• Soft switching?

• Use GaN

• For capacitors

• No electrolytic capacitors

• Limit current ripple

• Limit max voltage

Consequences of the required lifetime

455/06/2018

Comparison of Si vs. GaN in circuits:boost converter• Two PCB prototypes have been developed

• (a) employs Si MOSFETs

• (b) employs GaN HEMTs and is three times more compact

115x250x30

mm³

(b)

(a)

55x175x30 mm³

465/06/2018

Comparison of Si vs. GaN in circuits:isolated flyback converter

Si Mosfets, bulky transformer with undesired resonances GaN HEMTs: improved density

• Energy transition at building level: need to rethink the whole internal electricity system

• DC nanogrids allow efficient, affordable, safe integration of BIPV, storage, smart loads

• Living lab meeting safety standards constructed at EnergyVille

• Power converter development using GaN technology

• In EnergyVille, Imec + KU Leuven = full chain research in power electronics : components – circuits – systems - applications

Conclusions

Activity 4Modelling and Forecasting PV Energy Yield

Hans Goverde(Georgi Yordanov)

SolSThore – Activity 4

Trias Politica

515/06/2018

SolsThore – Activity 4Trias Policita PV Energy Yieldica

Indoor

Characterisation Characterisation

Outdoor

Modelling

Physical-

E-yield estimation

Measurement design

• Development of dedicated characterisation

tools and measurements

SolSThore – Activity 4Indoor characterisation

290

300

310

320

330

340

350

360

0 1000 2000 3000

Cel

l tem

per

atu

re [

K]

Time under 1000 W/m2 irradiance [s]

Thin white

Thick white backsheet

Thick white

(2x 2mm glass)

(4mm glass)

(2x 3.2mm glass)

Reduced time constant thin vs. thick

290

300

310

320

330

340

350

360

0 1000 2000 3000

Cel

l tem

per

atu

re [

K]

Time under 1000 W/m2 irradiance [s]

Thin white

Thin black

Thick white

Thick black

Reduced time constant thin vs. thick

independent on white/black

Reduced temperature white vs. black

SolSThore – Activity 4Outdoor measurement

0

0,2

0,4

0,6

0,8

1

1,2

thin white thick white thin black thick black

No

rmal

ized

En

ergy

p

rod

uct

ion

Energy production – Measured [kWh]

+2.3%+5.3% +1.1%

SolSThore – Activity 4Energy yield Simulations

0

0,5

1

1,5

Thin White ThickWhite

Thin Black Thick BlackNo

rmal

ised

ener

gy

pro

du

ctio

n

Energy Production - prediction [kWh]

+1.3%+2.6%+5.1%

0

0,2

0,4

0,6

0,8

1

1,2

thin white thick white thin black thick black

No

rmal

ised

Ener

gy

pro

du

ctio

n

Energy production – Measured [kWh]+2.3%+5.3% +1.1%

SolSThore – Activity 4Summary

E-yield estimation

Measurement design

Custom-made

measurement

equipment and

methods

Beyond state-of-

the-art outdoor

PV module

characterisation

setup

Validated

physics-based

energy yield

prediction

framework

Indoor

Characterisation

Modelling

Physical-

Characterisation

Outdoor

Activity 5PV System Demonstrators

Kris Baert

SolSthore Activity 5 : PV system integration

• PV integration in facades

• Commercial roof PV connected to a bipolar DC grid -> see

• poster : Low Voltage DC grid (EV-1, 2F, Home Lab)

• demo : rooftop PV installation (EV-1)

• Grid compliance testing by Real-Time Grid Emulator-> see

• Poster : Grid Compliance Testing of DC/AC PV Inverter (EV-1, Matrix Lab, 0F)

The case for integration of PV in facades of high-rise buildings

2020 NZEB directives => enhanced use of PV on buildings

• rooftop area for PV often scarce

• aesthetics suited for office-buildings

• high facade engineering capacity

• benign to the local grid (congestion !)• generation close to consumption

• in sync with airco load

• East – South – West facades => flatter day profile

• seasonal profile

• façade cost Euro/m2 marginally increased and compensated by enhanced “greening”

Heron Tower London

595/06/2018

The case for PV in ‘’curtain walls”

North Galaxy, Brussels

• Industrially pre-fabricated

• Semi-standardized dimensions

• Millions of m2 / year of facades installed

• multi-GW /yr. production opportunities for PV for facade-integration

605/06/2018

=> See Demo “Curtain wall BIPV” in Matrix Lab (0F)

Prototype: PV in curtain wall

PV module

Glass

Ventilation

holes

Thermal and electrical performance

Impact of black vs. white

backsheet in PV module:

- on operating temperature

- on energy yield

Impact of ventilation :

- on operating temperature

- on energy yield

Curtain wall BIPV element

feeding into DC Nanogrid

• Temperature distibution

• Energy yield

• DC/DC converter effic

=> See Poster “BIPV set-ups” in Matrix Lab (EV-1, 0F)

62

Modelling of BIPV solutions: Modellica IDEAS

Key features

• Object-oriented modelling

tool

• Open source library of

building components

• Clear and organized

documentation

Simulation examples

• BIPV configurations

• shading effects @cell level

=> See poster ‘’ Incorporation

of Façade-Integrated PV

models (Hygrothermal,

Electrical) in IDEAS ” in

Matrix lab (EV-1, 0F)

63

Simulations and measurements of BIPV curtain wall

What’s next ?

• Frame integration of EnergyVille’s DC/DC converter

• Develop, test and model otherfacade-BIPV building solutions

• for non-office buildings

• for integration in solar shades

• …

See demo : Facade-BIPV panels on East –South- West of EnergyVille-2 (2F)