Sustainable Energy Systems Sustainable Energy Systems EngineeringEngineering

Peter GevorkianPeter Gevorkian

Ch 3: Solar Power Generation Ch 3: Solar Power Generation Project ImplementationProject Implementation

Brevard Community CollegeBrevard Community College

ETP1401ETP1401

Bruce HesherBruce Hesher

Designing a Typical residential Designing a Typical residential Solar Power SystemSolar Power System

The first step (after conservation The first step (after conservation and weatherization) in designing a and weatherization) in designing a system is to determine the system is to determine the electrical needs (load). The steps electrical needs (load). The steps listed on listed on p70p70 are one way. Another are one way. Another is to look at the electrical bills for a is to look at the electrical bills for a year year ANDAND do an energy survey at do an energy survey at the utility providers website.the utility providers website.

System Type SelectionSystem Type Selection

Utility Interactive (Grid-Tied)Utility Interactive (Grid-Tied): Most common type for : Most common type for residential. Only works when sun is up. Uses the grid residential. Only works when sun is up. Uses the grid to store energy. Used to lower the electric bill. Least to store energy. Used to lower the electric bill. Least expensive, lowest maintenance, shortest payback.expensive, lowest maintenance, shortest payback.

Stand-aloneStand-alone: Provides power when grid is down. : Provides power when grid is down. Uses batteries to store energy. Has high cost and Uses batteries to store energy. Has high cost and maintenance. maintenance.

Bi-ModalBi-Modal: has features of both Grid-Tied and Stand-: has features of both Grid-Tied and Stand-alone. More equipment but provides power when alone. More equipment but provides power when utility is out. Most expensive. utility is out. Most expensive.

Utility Interactive: Utility Interactive: StringString or or Micro-inverterMicro-inverter

• MPPTMPPT down to individual module level. down to individual module level.• No No DCDC wiring, fuse combiner box, or DC breaker. wiring, fuse combiner box, or DC breaker.• Micro-inverters do not “dummy down” modules.Micro-inverters do not “dummy down” modules.• Higher inverter/system efficiencies. (96% vs 85%)Higher inverter/system efficiencies. (96% vs 85%)• Can use different modules.Can use different modules.• Can be expandedCan be expanded

• Work with crystalline (Work with crystalline (cSicSi) or thin film modules.) or thin film modules.• Easier to later upgrade to system with storage.Easier to later upgrade to system with storage.

Pros of Micro-inverters:Pros of Micro-inverters:

Pros of String inverters:Pros of String inverters:

PV Estimator SpreadsheetPV Estimator Spreadsheet(Get from Angel)(Get from Angel)

Click on each cell with a red triangle for details.

Wiring Diagram of a Grid-tied, Wiring Diagram of a Grid-tied, One String systemOne String system

Typical Solar Power System Typical Solar Power System Design for a Single Residential Design for a Single Residential

UnitUnit

(Wiring diagram micro-inverter based (Wiring diagram micro-inverter based system)system)

Example Site DrawingExample Site Drawing

A sealed site drawing from a licensed civil engineer is A sealed site drawing from a licensed civil engineer is usually required to pull a permit.usually required to pull a permit.

Residential Equipment LocationResidential Equipment Location• Array needs to be 3’ from edges (gutter & eves).Array needs to be 3’ from edges (gutter & eves).• AC disconnect needs to line-of-site within 30’ of meter.AC disconnect needs to line-of-site within 30’ of meter.

Assembling the ArrayAssembling the Array

Unirac (www.unirac.com) is a major manufacturer of Unirac (www.unirac.com) is a major manufacturer of mounting rails. They have videos on their website.mounting rails. They have videos on their website.

Enphase (www.enphase.com) is the predominant Enphase (www.enphase.com) is the predominant manufacturer of micro-inverter power conditioning units manufacturer of micro-inverter power conditioning units ((PCUPCUs). They have many excellent installation videos!s). They have many excellent installation videos!

notenote: Many equipment manufacturers also have on-line : Many equipment manufacturers also have on-line tools to assist with ordering the correct equipment and with tools to assist with ordering the correct equipment and with the materials (drawings and product certifications) needed the materials (drawings and product certifications) needed to pull a permit.to pull a permit.

PV Equipment PV Equipment ShoppingShopping

The spreadsheet shows prices found on-line Sep The spreadsheet shows prices found on-line Sep 2010. 2010.

Some good shopping sites are:Some good shopping sites are:

www.ecobusinesslinks.comwww.ecobusinesslinks.com

http://http://sunelec.comsunelec.com// www.altestore.comwww.altestore.com/store//store/

In a commercial In a commercial environment, all equipment environment, all equipment sold in Florida must be sold in Florida must be FSECFSEC approved!approved! Quality, service, and price vary. Please buy American

Software Design Software Design ToolsTools

PV WattsPV Watts: On-line tool for estimating system : On-line tool for estimating system

output and financial payback.output and financial payback.

http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/ http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/

RoofRayRoofRay: On-line tool used to guage if a site suitable for PV. : On-line tool used to guage if a site suitable for PV. http://www.roofray.com/ http://www.roofray.com/

PV EstimatorPV Estimator: (prior slide): (prior slide)

Many equipment manufacturers have on-line design tools Many equipment manufacturers have on-line design tools for use with their equipment.for use with their equipment.

HOMERHOMER: Energy Modeling Software for Hybrid : Energy Modeling Software for Hybrid Renewable Energy Systems. Renewable Energy Systems. http://www.homerenergy.com/ http://www.homerenergy.com/

Solar Assistant / Solar PathfinderSolar Assistant / Solar Pathfinder: Site shading analysis. : Site shading analysis.

http://www.solarpathfinder.com/ http://www.solarpathfinder.com/

PV Industry Periodicals & Web Sites:PV Industry Periodicals & Web Sites:

Home Power magazine: http://homepower.com/home/ Home Power magazine: http://homepower.com/home/

Solar Pro magazine: http://solarprofessional.com/home/ Solar Pro magazine: http://solarprofessional.com/home/

www.renewableenergyworld.com www.renewableenergyworld.com