Requirements for BIPV Electronics

September 2018 Stefan Dewallef stefan.dewallef@soltech.be

Introduction Soltech

BIPV customized

BIPV standardized

Pro and contra micro-inverters

Micro-inverters vs optimizers

Requirements for inverters specific for BIPV modules

INTRODUCTION OF SOLTECH

company specialized in the production

of customized photovoltaic modules

created as spin-off of IMEC in 1989

high investment in research & development

total system engineering autonomous applications

grid connected BIPV

production of customized and

high quality solar panels

prototyping

project related customized modules

dedicated production runs

Located in Tienen, België

© Soltech

Off Grid Applications

© Soltech

Off Grid Applications

© Soltech

Keep the ‘classic’ functionalities

- watertight, insulation (thermal, acoustic)

- humidity regulation, mechanical aspects

- light comfort, safety,…

Add additional functions

- production of energy (electrical, heat)

- sensors

- communication

...

BIPV

We divided the BIPV-materials in two different types

Customized BIPV-modules for special projects

-> Actual commercial market high price high added value

Standardized building products -> Only way to come to market penetration reasonable cost high volume production possible

We believe that the building skin will have to be active

SOL SKY®

Facades

Pioneer projects

© Soltech

BIPV-projects

Customized projects

Project CEDUBO • Heusden-Zolder (Belgium) • Realization in 2001 • Area: 150m² • Power: 15kWp

© Soltech

Renovation old building Lightstreet

Bio Incubator - Tienen

Area: 463m² Power: 60kWp Realization 2012

© Soltech © IBA-Technics

Customized-projects

Shading elements

Carreau du Temple - Paris - France

Power: 28,56 kWp Area: 465 m² Realization: 2012 Partners: Ecotemis and Loison Owner: Ville de Paris Architect: Studio Milou

© Soltech

Customized-projects

City Mortsel - BE

Canopy

Power: 134,85 kWp Area: ±1300 m² Year of realization: 2012 Partner: AGC Glass Europe Final customer: City of Mortsel Architect: ABSCIS architecten

© Soltech

Customized-projects

OCMW Beersel - BE

Supply of Photovoltaic

sun Shade Louvers

Power: 18 kWp Year of realization: 2012 Partner: Colt International Final customer: Stad Beersel

© Soltech

© Colt International

Customized-projects

Project client Quenea

Ecole Marcel Pagnol

Area: 240m² Power: 19,7kWp Slope: 10° Cannes (FR) Realization: 2013

© Quenea

Customized-projects

EDF ENR Solaire

Power: 195 kWp

Solar area: 1350m² Year of realization: 2013 Partner: Energis (Rennes)

Customized-projects

Sonil

Shading elements Bellegarde sur Valserine et Vénissieux - 2013.

Customized-projects

Eau de Paris

Site Orly Power: 75,75 kWp Area: 630 m² Realization: 2012 Partner: Cegelec Paris Owner: Eau de Paris Architect: ALP CAR Architectes

© Soltech

Customized-projects

Facade of industrial area

MFO Erasmus Universiteit

Area: 285m² Power: 25,2kWp Realization: 2014 Rotterdam (NL)

© Soltech

Insulated glass Customized-projects

Jahra Court Complex - Kuwait

Area: 1525m² Power: 95kWp Realization: 2015 Partners: IQ-Tech - Clenergy Architect: Fentress

© Soltech

Shading elements

Customized-projects

Our experience

Often an intrinsically more expensive product

Cost reduction possible

Avoided cost materials that are replaced

Fast / easy mounting

Savings on mounting structure

BIPV-products

Product characteristics

Very detailed, far-reaching engineering

Production possible at large scale

Easy project-design without additional engineering

Standardized packages with installation that doesn’t need to be done by specialists - Plug & Play

Our challenges

Maintain the full functionality Esthetics Easy to install Cost in competition with

standard BIPV

Standardized building elements

© Solaroad

Positive

• Flat surface

• Esthetics

• Easy project integration - sides in traditionnal materials

Case I BIPV-product - Solar Slate

Costs • No mounting structure • Fast mounting • Avoided material and

mounting cost • No frame needed

© Eternit

Challenges

Panel size Volumes

Positive Flat surface

Esthetics

Long lifetime (glass/glass)

Good ventilation concept

Case II BIPV-product - Aerspire Energy Roof

Costs 60 cells-panel > cost optimum Easy mounting structure Fast mounting Avoided material and cost No frame needed

© Aerspire

Case III BIPV-product – noise barrier Positive

• Esthetics • Functional element -> cost mounting

structure is necessary anyway • Fast mounting, large area available

• Bifacial -> high performance

Challenges

• Project engineering • Simulations energy production

UNIQUE! Noise absorbing transparent materials Collaboration with

Case III BIPV-product – noise barrier

Cell inclination Orientation kWh/kWp/y Ref.

Standard 35° South 959 1

Standard 90° South 668 0,70

Bifacial 90° North + South 827 0,86

Bifacial 90° East + West 888 0,93

Bifacial 90° SE + NW or SW + NE

870 0,91

Very rough first simulation for Brussels, bifacial ratio 90%, no shading

On a yearly base almost as good as standard modules in perfect conditions Orientation is for bifacial vertical not critical at all!

© zh aw

Energy production better distributed over the day. Higher valorization of the energy possible!

Energy production over the year Distribution over the day

2

- Shading (MPPT at module level) - More and more BIPV

- ‘Best areas’ already installed

- Mixed installations possible (orientation/tilt/shading)

- Every ‘window’ can be different

- Easier cabling - No system design needed

- No specific knowledge installers needed (roofers)

- Safety - Installer electrocution risk

- Fire

- Less risk to initiate fire

- Less risks for intervention in case of fire

- New regulations will force decoupling at module level

- Less risk for induced currents due to ‘loops’ of the cables

PRO Arguments pro and contra micro-inverters

2

- Cheaper modules? - No need for high voltage tests

- Backsheet

- Side clearance

- Connection box

- Connectors

- Individual monitoring - During installation

- Easy detection of serial numbers

- Functionnality of individual modules

- Monitoring during lifetime

- Information at module level

PRO Arguments pro and contra micro-inverters

2

- Maintenance - Intervention can be planned without system breakdown

- Direct view on fault location

- Easier taking out or putting in of modules

- No need for (complicated) system redesign

- Other data from the building skin can be integrated - Light/temperature/sun

-> usefull for central energy management

- HVAC

- light

PRO

Arguments pro and contra micro-inverters

2

- Price - More components

- Islanding protection at module level

- Compensated by scaling effect?

Actually micro: 0,40 EURO/W

string: 0,15 EURO/W

central: 0,10 EURO/W

- Efficiency - Small device

- more cable losses? (230 or 400VAC vs 300 to max.1500VDC)

- Lifetime - Saving on components

- Temperature - Modules in less controled areas

CONTRA

Arguments pro and contra micro-inverters

2

- Interventions always on the roof?

- Too much data - Client knows too much

- Central data management

- Data transmission is a weak link - Reliability (down times?)

- Communication lines and/or signal polution

CONTRA

Arguments pro and contra micro-inverters

Microinverters vs optimizers • Optimizers:

• More flexible

• More reliable • Cost-effective (inherently less expensive) • No geographic range (different requirements grids)

Easier to comply to grid requirements (darkstart, harmonics, power control, active/reactive,...) • Robust, very efficient, cheap central inverter

• Very often larger input range • Total eff. higher • Less heat dissipation at module level

• Microinverters: • Easier to install • Safety argument (not true?)

• Best suited for small installations • Independent from central risk

Requirements for electronics specific for BIPV modules

• Voltage – current (- Power) • 100% customized BIPV: can be anything

• Standardized:

Very often multiplications of 20 to 22 cells

• Because the diodes that have to be integrated

• Optimization in terms of cost when developping these modules

• Bifacial cells can make it even more complicated

• Temperature resistance (if installed in the PV-area) • Solar panels go sometimes up to more then 85°C in BIPV

• Size inverter (if installed in the PV-area)

• For PV-tiles -> thickness!

• Integration in profiles of the façade could be an option

• Cooling by aluminum contact

• Could be Accessible from the inside

-> longer shape required