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CEM 162SP, Stewart Wadsworth, Intro to Solar PV Systems

Introduction To PV Systems

History of Solar

–For a more complete version visit

Introduction To PV Systems 1839 •  French scientist Edmond Becquerel discovers the photovoltaic effect

while experimenting with an electrolytic cell made up of two metal electrodes placed in an electricity-conducting solution; the electricity generation increases when exposed to light

1905 •  Albert Einstein publishes his paper on the photoelectric effect, along

with a paper on his theory of relativity.

1921 •  Albert Einstein wins the Nobel Prize for his theories explaining the

photoelectric effect; for details, see his 1904 technical paper on the subject.

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Introduction To PV Systems 1954 •  Photovoltaic technology is born in the United States when Daryl

Chapin, Calvin Fuller, and Gerald Pearson develop the silicon photovoltaic (or PV) cell at Bell Labs — the first solar cell capable of generating enough power from the sun to run everyday electrical equipment. Bell Telephone Laboratories then produces a silicon solar cell with 6% efficiency and later, 11% efficiency. See the

for more information.

1970 •  With help from Exxon Corporation, Dr. Elliot Berman designs a

significantly less costly solar cell, bringing the price down from $100 per watt to $20 per watt. Solar cells begin powering navigation warning lights and horns on offshore gas and oil rigs, lighthouses, and railroad crossings. Domestic solar applications are considered good alternatives in remote areas where utility-grid connections are too costly.

•  W = watt •  x 1,000 = kW kilowatt, over an hour = kWh •  x 1,000 = MW megawatt •  x 1,000 = GW giga watt •  x 1,000 = TW terawatt •  BTU = 1,055 Joules per BTU •  3,412 BTU’s per kWh •  1 joule = 1 watt per second •  QUAD = quadrition BTU’s •  See energy glossary at consumerenergycenter.org/glossary/index.html

Energy Basics

Energy Use

•  Avg. household in U.S. 888kWh •  California peak demand 58,000MW •  U.S. net summer capacity 995,000MW •  Global grid tied production 15TW •  Projected 2050 demand 50TW

http://www.eia.doe.gov/cneaf/electricity/epa/epat2p1.html

Industry Introduction / Technology Options / Starting Your Installation Business / Project Economics / Sales and Marketing / Resources for Next Steps

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Energy Sources

•  Approx. 3,300 utilities (diff type) •  Central power stations usually > 300MW

Industry Introduction / Technology Options / Starting Your Installation Business / Project Economics / Sales and Marketing / Resources for Next Steps

PV Industry Defined

• 

-  Distributed Generation (DG)

•  Residential/Commercial/Industrial/Municipal/Utility

•  On site kWh production for on site use

•  “Behind the meter”/Load Side

-  Centralized Generation (CSP)

•  Central production for far-away transmission

•  Generally > 20MW

-  Wholesale DG

•  1 to 20MW solar production with closer/shorter transmission needs.

Industry Introduction / Technology Options / Starting Your Installation Business / Project Economics / Sales and Marketing / Resources for Next Steps

View of PV in 2010 from Roger Little, CEO Spire Solar

•  Global market 8-10 GW per year •  6 major manufacturers over 1,000MW •  30 other manufacturers less than 1,000MW •  Module wholesale selling price $2.30/W •  Technology: 90% crystalline/10% thin film

Industry Introduction / Technology Options / Starting Your Installation Business / Project Economics / Sales and Marketing / Resources for Next Steps

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Market Research

• Solar incentive data – californiasolarstatistics.ca.gov – solarinstalldata.com – DSIREUSA.ORG - http://openpv.nrel.gov/visualization/index

• FindSolar.com – choose all installers

• EnergySourceGuides

• Conference/Events sponsors- SEIA and ASES

• Marketing in your region

NREL, http://www.solarinstalldata.com/resources-page.html

Introduction To PV Systems

PV Cells •  Convert solar radiation (Photons) into electricity •  PV systems use wafers, typically made of

crystalline silicon •  No moving parts, noise or emissions Definition: a Photovoltaic (PV) system is an

electrical system consisting of and array of one or more PV modules, conductors, electrical components, and one or more loads.

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Introduction To PV Systems

Modules Inverters

Racking

Introduction To PV Systems Utility Connected or Grid-tied systems are the most commonly found systems in

the market.

UPS System

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Introduction To PV Systems Location:

•  PV system array will typically be mounted on a rooftop or nearby on the ground.

Electrical components:

•  Inverters and DC and AC disconnects •  These inverters or charge controllers condition DC power from the array

and either direct it to DC loads or convert it to AC grid power. •  Inverters convert DC electricity into AC electricity, regulates voltage and

matches the frequency (60Hz) of the Utility.

Load:

•  A load is a device that consumes electricity, such as TVs, refrigerators, light bulbs, etc.

Introduction To PV Systems To the left, an inverter Fronius IG, and to the left a 600V DC disconnect

Introduction To PV Systems

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Introduction To PV Systems Advantages:

•  Supplies clean green energy •  When loads are located far from the grid, an off-grid PV

system is a great application to supplying power for those loads

•  PV systems are flexible, reliable and last a long time with minimal maintenance

•  Provide energy independence •  Conventionally produced electricity is expected to get

more expensive over time –as it has happened over the past 30 years.

Introduction To PV Systems Disadvantages: •  High initial cost to install •  Customers understanding of the technology and benefits •  Political obstacles from existing generating industries

and utilities •  Net-metering agreements or feed in tariff laws by utility •  Solar access laws •  Present funding issues •  AHJ (authorities having jurisdiction) or HOA’s

Introduction To PV Systems Electricity Distribution

Definitions: •  Utility: a company that produces and/or distributes

electricity – PG&E, SCE, SDG&E •  Grid: utility’s network of conductors, substations and

equipment that distributes electricity from its central generation point to the consumer

•  Distributed generation: is a system in which many smaller power-generating systems create electrical power near the point of consumption. Examples of these systems are PV systems, wind turbines, engine generators, etc.

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Introduction To PV Systems

Introduction To PV Systems

Introduction To PV Systems

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Introduction To PV Systems Value Chain of Solar Industry

More Value Chain

Introduction To PV Systems

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Introduction To PV Systems PV Installers:

•  They need to understand and comply with building and electrical codes standards -National Electric Code

•  Obtain permits and approvals from local building and utility authorities as required

•  Know their capabilities and limitations, and seek outside expertise as required

•  Select and size systems and equipment to meet performance expectations

•  Recommends well engineered, quality components •  Ensures equipment is properly labeled and safety hazards are

identified •  Locates and orients array to maximize performance and accessibility •  Mounts array with strong, weather-sealed attachments •  Utility interconnection and rebate applications

Introduction To PV Systems PV Installers:

•  Uses accepted utility-interconnection practices and obtains utility approval as required

•  Completes work in a timely manner while practicing safe and orderly work habits

•  Completes inspections, commissioning and acceptance test

•  Provides owner/operator with appropriate documentation, instructions and training

•  Provides follow-up service for completed work as required and documents data accordingly each time a system is serviced/ inspected.

Introduction To PV Systems Standards:

•  National Association of Certified Electrical Practitioners: •  The NABCEP PV installer certification is a voluntary certification that

provides a set of national standards by which PV installers with skills and experience can distinguish themselves from their competition. Certification provides a measure of protection to the public by giving them a credential for judging the competency of practitioners

National Electric Code:

•  NEC determines the minimum standard for the safe installation of electrical wiring and equipment in the United States. The authority having jurisdiction –i.e. building department and other regulatory agencies- will help contractors to interpret the regulations therein and will enforce the compliance of them

•  As solar installers, Article 690 will be of particular interest to us

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Introduction To PV Systems

Introduction To PV Systems Government Policies:

•  Individuals can make a great difference when it comes to passing legislation that supports solar. It is a recommended practice to follow these events and participate in the decision making process as much as possible

Incentives:

•  There are several types of incentives available in the market. Californians can take advantage of:

•  The California Solar Initiative program- EPBB or PBI rebates •  The Federal Tax Credits (30%) available for residential and

commercial systems •  Other programs supported by cities and counties •  Federal grants for commercial systems

Introduction To PV Systems

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Introduction To PV Systems

Introduction To PV Systems

Introduction To PV Systems

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Introduction To PV Systems

Introduction To PV Systems

Concentrated PV – Sol Focus

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Introduction To PV Systems

Introduction To PV Systems

Periodicals

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U.S Solar Organizations