April 21, 2010 1 ESCI 61- PV Cells Modules and Arrays April 21- Week 3 Agenda 3:30-4:00- PV Current Events / Possible Guest Speaker 4:00-4:45- Group Research What are the different types of PV solar cells? Explain how they work How many PV modules were manufactured in 2009? Advantages and disadvantages Cost Efficiency 4:45-5:00- Break 5:00-5:15- Group Presentation 5:15-6:10 Lecture- PV Cells, Modules and Arrays Please note: Homework # 1 will be assigned next week- Due on May 5.
April 21, 2010 2 ESCI 61 Introduction to PV Technology Lecture #3 PV Cells, Modules and Arrays Bill Roeder Founder, VP Marketing Solar Power Assets, LLC
April 21, 2010 3
April 21, 2010 4 So how to we capture this great source of energy?
April 21, 2010 5 Solar cells have been around for awhile
April 21, 2010 6 Boron, Silicon, Phosphorous
April 21, 2010 7
Solar Cells producing electricity Solar Industry Revenues* 2008- $30B 2018- $81B Source: Clean Edge *Includes Modules, components and Installation 1MW of Solar Energy Powers 750-1000 homes
April 21, 2010 9 Short Video- Introduction to Solar Photovoltaic http://www.youtube.com/watch?v=2mctsv2f36a
April 21, 2010 10 Cell: Semiconductor device that converts sunlight into Direct Current (DC) electricity Modules: Consists of PV cell circuits sealed in environmentally protective laminate. They are the building block of a PV system Array: The complete power generating module consisting of any number of PV modules or panels Panel: Include one or more PV modules assembled in a pre-wired, field installable unit.
April 21, 2010 11 Animation http://www.noutilitybill.com
April 21, 2010 12 Types of PV module materials Monocrystalline PV Polycrystalline PV Amorphous Silicon Thin Film (Cadmium Telluride & CIGS)
April 21, 2010 14 Local Solar Innovators SolFocus- Mountain View, Ca. Solfocus has developed an innovative reflective optic system which includes a primary mirror to capture sunlight and secondary mirror and non-imaging optic to concentrate it at 500 suns onto high-efficiency solar cells. http://www.solfocus.com/en/
April 21, 2010 15 Local Solar Innovators Solyndra- Fremont, Ca. Solyndra designs, manufactures and sells solar photovoltaic (PV) systems comprised of panels and mounting hardware for low-slope commercial rooftops. The Solyndra system is designed to enhance PV performance on commercial rooftops by converting more of the sunlight that strikes the total rooftop area into electricity. www.solyndra.com
April 21, 2010 16 Local Solar Innovators Nanosolar- San Jose, Ca. On a product level, our solar cells are light-weight, bendable, easily interconnected, easily adjusted in size, and capable of supporting up to 25 Amps of current per cell. These are each attributes that lend themselves to creating products with unique advantages and benefits and delivering application-specific customer value. http://www.nanosolar.com
April 21, 2010 17 Modules Sizes and Shapes Modules are available in several sizes and shapes, including squares, rectangles, triangles, flexible units, and shingles.
April 21, 2010 18 Leading PV manufacturers* Source: Photon International 2009 *Total Production= 12.3GW; Top 10 = 45% of total production
April 21, 2010 19 Short Video How Panels are Manufactured http://www.youtube.com/watch?v=qyeynly6pj8& feature=related
April 21, 2010 20 Cell Efficiency Efficiency is a measure of how effectively a PV device converts solar power to electrical power.
April 21, 2010 21 PV Materials Efficiencies Various PV materials and technologies produce different efficiencies.
April 21, 2010 23 PV material efficiency
April 21, 2010 24 Junction Box A junction box on the back of a module provides a protected location for electrical connections and diodes.
April 21, 2010 25 Electrical Connections MC connectors
April 21, 2010 26 What about cost? Source: Tracking the Sun II: The installed costs of Photovoltaic in the US from 1998-2008- Lawrence Berkeley National Laboratory Other = Labor, permits, mounting hardware, profit
April 21, 2010 27 Goal = Grid Parity My personal bet is that it will be sooner than 2015! Factors: Improved economy/ higher cost of fossil fuel Continued innovation and cost improvements in PV
April 21, 2010 28 I-V Curve An I-V curve illustrates the electrical output profile of a PV cell, module, or array.
April 21, 2010 29 Open-Circuit Voltage (Voc) Open-circuit voltage is easily measured with test instruments.
April 21, 2010 30 Short-Circuit Current (Isc) Using in-line and clamp-on ammeters are two methods of measuring shortcircuit current.
April 21, 2010 31 Temperature Response Increasing cell temperature decreases voltage, slightly increases current, and results in a net loss of power.
April 21, 2010 32 Series Connections PV cells or modules are typically connected in series strings to build voltage.
April 21, 2010 33 Parallel Connections Strings of PV cells or modules may be connected in parallel to build current.
April 21, 2010 34 Building an Array Modules are added in series to form strings or panels, which are then combined in parallel to form arrays.
April 21, 2010 35 Short Video- Wiring in Series and Parallel http://www.youtube.com/watch?v=n86ehrgrj wq&feature=playlist&p=fd3bc7240ac84a5c &playnext_from=pl&playnext=1&index=8
April 21, 2010 36 STC vs PTC Standard Test Conditions (STC) 1,000 W/m2 AM1.5 solar spectral irradiance distribution 25 C cell or module temperature PVUSA Test Conditions (PTC) 1,000 W/m2 20 C ambient temperature 1m/s wind speed Silicon PV power varies by about -0.5% per C PV module temperature is about 50 C under PTC Module PTC power rating is about 88% of the PV module nameplate rating
April 21, 2010 37 CEC Rating http://www.gosolarcalifornia.ca.gov/equipment/
April 21, 2010 38 Next Week- 4/28 PV System Components and Configurations