grid-connected solar pv systems
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Grid-Connected Solar PV Systems. Shawn Murphy September 29, 2011. Outline. Solar Photovoltaics Electricity Generation, the CEC and PUC Silicon Solar Cell production Technical challenges of grid-tied solar Grid-tied issues Permitting and Rebates Net Metering Design issues - PowerPoint PPT PresentationTRANSCRIPT
Grid-Connected Solar PV SystemsShawn Murphy
September 29, 2011
Shawn Murphy, PE • ENGR10 Guest Speaker
Solar Photovoltaics◦ Electricity Generation, the CEC and PUC◦ Silicon Solar Cell production◦ Technical challenges of grid-tied solar◦ Grid-tied issues◦ Permitting and Rebates◦ Net Metering◦ Design issues
Solar Engineering as a Career◦ General class recommendations◦ Training on solar PV
Outline
Shawn Murphy, PE • ENGR10 Guest Speaker
Conventional Energy Generation
Shawn Murphy, PE • ENGR10 Guest Speaker
There is no good way to store electricity Batteries Peak energy is more expensive and more
polluting Energy produced during high demand
periods is more valuable
Electricity Storage
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
California Energy Commission Founded early 70’s CEC goals
◦ Generate power using alternative means◦ Generate power during peak hours
Public Utilities Commission Regulate public utilities like PG&E, SCE and
SDG&E Tells utilities what they can charge for electricity Decoupled utility profits from electricity
generation
The CEC and the PUC
Shawn Murphy, PE • ENGR10 Guest Speaker
Similar process as semiconductor manufacturing. Conventional silicon still dominates market
Solar Photovoltaic Panels
Shawn Murphy, PE • ENGR10 Guest Speaker
Poly or multicrystalline Silicon
Monocrystalline Silicon
Shawn Murphy, PE • ENGR10 Guest Speaker
Much simpler than battery-based system. Grid serves as free, infinitely-large, no-
maintenance battery System sizing not as crucial Can be designed to maximize yearly annual
electricity generation. Does not have to be optimized for winter production.
Can operate at much higher voltages, saving power losses.
On-Grid Solar
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
CEC goals◦ Generate power during peak hours◦ Generate power using alternative means
Grid connected solar photovoltaic◦ Maximum generation during sunny summer days◦ Distributed generation◦ Uses existing spaces◦ Very quick deployment
Grid Connected Solar PV Meets the state’s goals
Shawn Murphy, PE • ENGR10 Guest Speaker
Power Quality Safety Connection to Existing Equipment
Technical Issues with Grid-Connection
Shawn Murphy, PE • ENGR10 Guest Speaker
How do you keep track of the power? How much do you pay for the power? How do you take into account when the
power is produced? How do you determine the rebate amount? How do you incentivize grid-connected solar
at the proper amount over time? How often do you read the meter? Who inspects the system?
Grid Connected Solar
Shawn Murphy, PE • ENGR10 Guest Speaker
One single meter that spins forward and backwards.
Meter can take into account time of use rates
Annual true-up Minimum monthly meter fee, $4 to $13,
charged by utility
Net Metering & Interconnection
Shawn Murphy, PE • ENGR10 Guest Speaker
Tax Credits and deductions◦ 30% FITC◦ MACRS depreciation◦ Various state tax breaks
Renewable Energy Credits State Rebates California Solar Initiative
◦ Declining schedule – based on expected performance
Rebates and Incentives
Shawn Murphy, PE • ENGR10 Guest Speaker
Must know how much a customer is paying for electricity
How do you compare one-time cost of a solar system versus the value of lower electricity bills in future years?
Engineering economics◦ Payback◦ Net Present Value◦ Internal Rate of Return
Economic EvaluationSolar Offsets Electricity Use
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Shawn Murphy, PE • ENGR10 Guest Speaker
Engineering Economics Accounting Technical Writing Public Speaking Engineering Statistics Computer Drafting/ CAD
◦ Google Sketchup◦ Autocad◦ Solidworks◦ Pro-E
Recommended Classes
Shawn Murphy, PE • ENGR10 Guest Speaker
PG&E Energy Center Diablo Valley College Private classes
◦ Solar Living Institute◦ Solar Power International
Semicon – Intersolar SF July
More Solar resources