Engineering Photovoltaic Systems II

Application Flexibility of Solar Electricity

Original Presentation by J. M. Pearce, 2006 Email: profpearce@gmail.com

Outline Part II

• Distributed Energy Source– Roof Retrofits– BIPV – Tiles, Shingles– Facades– Parking and Sound Barriers

• Centralized PV• PV Systems for Transportation

– Cars, Boats, and Bikes

Photovoltaic Cells as Distributed Energy

Source

• Located near the consumer in order to eliminate transmission losses (which can be higher than 50% on some antiquated grids).

• Panels can be placed on roofs, built into roofs, building facades, carports, highway sound barriers, etc.

• Any surface which is exposed to sunlight is fair game.

Roof Retrofits• This house on right is

modular construction and includes 6 kW of PV modules.

• Below retrofits to schools

Building Integrated Photovoltaics or BIPV

The design and integration of PV technology into the building envelope, usually replacing conventional building materials:

• vertical facades, • replacing view glass, • spandrel glass, • or other facade material; • into semitransparent skylight systems; • into roofing systems, • replacing traditional roofing

materials;• into shading "eyebrows" over

windows; • or other building envelope systems.

Solar modules come in a variety of shapes, colors, sizes and can be integrated into any type of architecture.

• Advantages– Aesthetics– Reduce the cost of

the system (e.g. roof, awning, etc.)

Residential Rooftops

• Specifically designed for PV.

• This energy efficient home in Oxford generates more electricity than it uses. – Surplus electricity

is sold to the local utility company and to power an electric car

Roofing Tiles and Shingles• The PV shingle shown

here won Popular Science Magazine's grand award for What's new in Environmental Technology.

• PV shingles can replace common roofing shingles.

• PV shingles look much like ordinary roofing shingles, but they generate electricity.

• They were laid out and nailed to the roof using the same methods as are used to lay conventional shingles.

• Like their non-PV counterparts, these shingles overlap providing for water shedding capability.

Relaxing on Solar Shingles

• Bill Ball, president of the Stellar Sun Shop in Little Rock, Arkansas, is clearly comfortable with PV shingles on the rooftop of his shop.

The flexible shingles, rated at 17 watts each, are manufactured by United Solar Systems Corp.

Peal and Stick Solar Cells

• Thin film amorphous silicon solar cells which can be deposited on plastic or steel (right) are extremely versatile

• The panels on the right can be stuck directly to standard standing seam metal roofs

Standing-Seam PV

• Buildings with standing-seam metal roofs can use solar module material referred to as "thin films" that can be rolled out inside the standing seams. Roof-integrated PV panels were installed on the south-facing roof of the BigHorn Home Improvement Center in Silverthorne, Colorado.

Semi-Transparent Solar PV

These panels have amorphous silicon deposited on glass and are semi-transparent – they can be used both as tinted glass but also as a project screen backdrop.

Putting it all Together

The Boston Edison “Impact 2000” home incorporated – a 4-kWp utility-

connected photovoltaic array in the original construction

– all electric appliances,

– solar electric water heating, and

– both passive and active space heating.

Commercial Rooftops

Large rooftops are ideal

locations for PV

PowerGuard sloped tiles, 150 Wp per tile, shown on customer's roof

PV at Lowe's• Lowe’s executives

determined that clean, reliable distributed solar generation offers many benefits both to its retail operations and to the surrounding community.

• Lowe’s is extremely committed to reducing greenhouse gas emissions, while promoting and selling energy efficient home improvement products.

• Lowe’s sought a cost-effective solution to reduce the operating costs associated with providing reliable electricity supply at its West Hills store.

Could Wal-Mart be far behind?

• Wal-Mart McKinneyLocation: TXOperator: Wal-MartConfiguration: 59 kWp PVOperation: 2005System supplier: RWE Schott

• This pilot installation for Wal-Mart has 5,500sqft of crystalline and thin film PV in five separate locations. 

Solar Powered Hotels• Hawaii’s Mauna

Lani Bay Hotel• This sprawling hotel

had acres of roof space, making it the perfect host for a photovoltaic system.

• They installed a PowerGuard (R) system of insulating PV roofing tiles that covers 10,000 ft2 and generates 75kWs.

• The hotel will be spared hundreds and thousands of dollars in utility bills.

4 Times Square - BIPV

• The building’s most advanced feature is the photovoltaic skin, a system that uses thin-film PV panels to replace traditional glass cladding material.

• The PV curtain wall extends from the 35th to the 48th floor on the south and east walls of the building, making it a highly visible part of the midtown New York skyline.

Solar Skylights and Cladding

PV Facades

• Scheidegger Building with photovoltaic facade near Bern in Switzerland. Courtesy of Atlantis Solar Systeme AG

• Austria• Swtizerland

Building Facades

Building Facades• 73 kW system and generates ~ 55 000 kW-

hrs of electricity per year in Sunderland, UK. • This 3500 m2 solar office building at the

Doxford International Business Park near Sunderland in the UK incorporates 646 m2 of photovoltaic modules.

Facades

• Solar cells can be made in different colors

• Glass façades on office buildings, winter gardens or sunroofs on automobiles will become energy suppliers with the transparent solar cell.

• The use of the transparent, dark blue solar cells allows a beautiful play of light and shadow.

• The standard product lets a tenth of the light pass through and has a 10 % efficiency rate.

Solar Cube

The 20kW cube stands 135 feet tall on top of the Discovery Science Center in Santa Ana

Solar Olympics• The 1996 Olympic

Games in Atlanta featured a very unique PV system.

• The Natatorium (swimming and diving facility) that houses a large PV array for powering the facility also features a canopy system at the entrance to the building.

• The modules were made especially for the swimming facility with a clear backing to allow light to pass through.

Solar PV as Shading

Centralized PV

Prescott AirportLocation: AZ

Operator: Arizona Public Service

Configuration: 1,450 kWp

SGS SolarLocation: AZ

Operator: Tucson Electric Power Co

Configuration: 3,200 kWp

Pros and Cons of Centralized PV

•Advantages– Economy of scale– Single location for maintenance– You can put a fence around it

• Disadvantages– All eggs in one basket –

natural/terrorist disaster– Transmission losses– Land cost

Rem: Distributed vs Centralized

Hysperia PV Power Station.

Solar Concentrators

• These 20-kW Solar Systems dishes dwarf visitors in Alice Springs, Australia.

• The concentrators use an array of mirrors to focus sunlight onto high-efficiency solar cells.

• Four supports hold the cells in front of the mirrors

• The supports also supply cooling water and electrical connections

Centralized Wind-Solar Hybrid System

• In hybrid energy systems more than a single source of energy supplies the electricity.

• Wind and Solar compliment one another

Hybrid PV-Diesel Systems

• Unique to the project is the introduction of a new generation of hybrid power processing equipment.

• This new 115 kW PV/hybrid energy system

Art and PV

• Located among the rolling hills of Northern California, these solar electric sunflowers elegantly combine art and technology.

• Each sunflower produces 1 kW of solar electricity and consists of four 240 Wp polycrystalline PV modules custom made with yellow back-skins and yellow frames.

• The custom PV modules are attached to a two-axis-tracking mechanism and mounted on custom-painted green poles producing a field of 36 kW solar electric sunflowers.

• The sunflowers wake up each day and follow the sun's path from sunrise to sunset, increasing solar harvest over a fixed array by 25%.

• This system produces enough energy for approximately eight to ten homes and was an ideal engineering solution for the steep hillside site.

PV Systems for Transportation

• PV will be most applicable to transportation if it can be stored

–Batteries– Electrolysis of water to produce hydrogen

Solar Car Racing• Car #195, Cal

State University/Long Beach, at the start line of Sunrayce 1995

Sunrayce is a biennial solar-powered car race for colleges and universities in North America. Students design, build and then race their car 1,250 km from Indianapolis, IN, to Colo. Springs, CO.

Can Cars be Solar Powered?

• From July 15th to the 25th, 2001, 2300 miles of solar “raycing” challenged teams from around the world.

• High tech and high efficiency solar cars crossed the Great Plains, climbed the Rocky Mountains, and dashed over the Great American Desert to the finish line in Southern California

More Solar Cars• This solar

powered race car was built in Philadelphia, Pennsylvania, by students at Drexel University during the 1989-1990 school year.

• Car #43, University of Missouri/ Columbia, on the road in Sunrayce 1995

PV Covered ParkingElectric or hybrid electric vehicles can recharge their batteries at PV power stations such as this one at the University of S. Florida.

Covered parking in California provides shading and makes electricity

PV Integrated into Highway Sound

Barriers• Solar Panels on Sound

Barriers• This solar power, in

proposed system, could give EVs essentially unlimited range on freeways that supply in-transit power.

• Highway sound barrier above planted slope, with integrated PV panels,  in Austria. 

• An upcoming project in Holland will use PVs,  installed on railway right-of-way,  to power an entire electric rail system.

Solar Powered Bikes and Gold Carts!

Team #2, from Green Mountain High School in Lakewood, CO won the women's division of the solar bike race

• These golf carts are powered by photovoltaic modules from Shell Solar

Solar Electric for Boats

300-watt system powers on-board communications and lighting, an application that has been in use for 15 years

Solar Boats• On board, the solar modules

create a fascinating play of light, shadow, and transparency.

• The largest solar boat in the world began operating on the Alster River in Hamburg on May 23, 2000.

• This boat can hold up to 120 passengers for excursions and charter tours

The boat can hold up to 120 passengers for excursions and charter tours. The "Alster Sun" reaches a speed of 5 kmph just from solar power.If it has to go faster, the rest of the energy comes from batteries.

Solar Powered Fun!

• Catamaran “Sol 10”: direct current powering from 550 to 1600 watts.

• No drivers license needed, unsinkable, and easy to use.

Solar Photovoltaics is the Future

Acknowledgements

• This is the third in a series of presentations created for the solar energy community to assist in the dissemination of information about solar photovoltaics.

• This work was supported from a grant from the Pennsylvania State System of Higher Education.

• The author would like to acknowledge assistance in collecting information for this presentation from Heather Zielonka.