Thermal and PV SystemThermal and PV SystemLauren MasseriaLauren Masseria

Jenny BishopJenny BishopBryan PicardBryan Picard

Solar PhotovoltaicSolar Photovoltaic Photo=light Voltaic=electricityPhoto=light Voltaic=electricity

The conversion of solar The conversion of solar energy directly into electricityenergy directly into electricity

Brief HistoryBrief History

• Discovery credited to French physicist Discovery credited to French physicist Edmund Becquerel in 1839Edmund Becquerel in 1839– ‘‘Wet Cell’ BatteryWet Cell’ Battery

• 1883 the first PV cell was created1883 the first PV cell was created

• 1950 at the Bell Laboratory, New Jersey1950 at the Bell Laboratory, New Jersey– Research on silicon semiconductorsResearch on silicon semiconductors

• 1960’s-70’s Orbiting satellite usage1960’s-70’s Orbiting satellite usage

• 1970’s Rise in residential and commercial 1970’s Rise in residential and commercial usageusage– Energy crisisEnergy crisis

• 1980’s Consumer electronic devices1980’s Consumer electronic devices

Why Solar?Why Solar?

• ReliableReliable

• Long term cost benefitsLong term cost benefits

• Environmentally friendlyEnvironmentally friendly

• Remote Locations (grid unavailability)Remote Locations (grid unavailability)

• State, federal and private incentivesState, federal and private incentives

• Socially responsibleSocially responsible

• Positive public imagePositive public image

Panels & CellsPanels & Cells

• A cell consists of sliced up crystals, connected A cell consists of sliced up crystals, connected with wire, and placed in a modulewith wire, and placed in a module

• Life expectancy = over 30 yearsLife expectancy = over 30 years

• There is nothing exhausted in There is nothing exhausted in the silicon cells, and theoretically, the silicon cells, and theoretically, if well packaged and protected if well packaged and protected from moisture they could produce from moisture they could produce electricity indefinitely. electricity indefinitely.

• PV cells are a junction between two thin layers of PV cells are a junction between two thin layers of dissimilar semi-conduction materials known as ‘p’ and dissimilar semi-conduction materials known as ‘p’ and ‘n’ type semi conductors‘n’ type semi conductors

• Most cells made from silicon, a semiconductor, and Most cells made from silicon, a semiconductor, and the second most abundant element in the earth’s the second most abundant element in the earth’s crustcrust

• Sets up an electric field when joinedSets up an electric field when joined• Photons (sun energy) hit this electric field and transfer Photons (sun energy) hit this electric field and transfer

energy to the p and n semi conductors creating a energy to the p and n semi conductors creating a reverse electric field and an electric currentreverse electric field and an electric current

Types of CellsTypes of Cells

Three types of PV cellsThree types of PV cells

MonocrystallineMonocrystalline

PolycrystallinePolycrystalline

AmorphousAmorphous

MonocrystallineMonocrystalline

Silicon with a single crystal lattice Silicon with a single crystal lattice structure with no impurities and structure with no impurities and virtually no defectsvirtually no defects

most efficient at 16%most efficient at 16%– most expensivemost expensive– longest life spanlongest life span

PolycrystallinePolycrystalline

Consists of many small grains of Consists of many small grains of connected monocrystalline silicon connected monocrystalline silicon

– 15% efficiency15% efficiency– typically less expensivetypically less expensive

than monocrystallinethan monocrystalline

Amorphous / Thin FilmAmorphous / Thin Film

Silicon are much less ordered than in the Silicon are much less ordered than in the mono and polycrystalline cellsmono and polycrystalline cells

– 8% efficiency8% efficiency– least expensiveleast expensive– Most flexible models, ex rollsMost flexible models, ex rolls– Take the most space Take the most space – Are being phased outAre being phased out