residential implementation issues

1. Residential Implementation of Photovoltaic Systems ByChris Hinton & Patrick Patterson

Off-Grid & Grid Tied

Mounting Techniques

Inverters

System Sizing & Design

PV Modules

Future of PVs

Placement & Orientation

Energy Storage

Charge controllers

Off-grid

Grid-tied

Power for remote systems

Cost-prohibitive utility line extensions

Net Metering

Local incentives promote grid-tied systems exclusively

Reduce peak power demand on utility

Energy use & auditing

Energy efficiency measures

Energy requirements for PV

Begin with precise load calculations

Reduce load requirements through efficiency measures

Estimate energy production potential from solar insolation data

Select PV hardware to match load requirements

Examine previous power bills

Implement energy efficiency first

Estimate production potential from solar insolation data

Choose % of load to match

Select PV hardware for utility interconnection

Implications of shading

The sun path

Azimuth

Tilt angle

Seasonal sun path variations

Solar pathfinder tool

Obstacles to sunlight can be traced and predicted for different times of the year

Standard PV module azimuth rule:

(Orientation) = (True South)

Note: In Portland, true South is about

19 east of magnetic South

Standard PV module tilt rule:

(Angle from horizontal) =

(Geographic Latitude)

Home Power Magazine # 93, pgs. 24-28

Placement and orientation often depend upon system priority:

Off-grid systems should maximize energy production

Grid-tied systems often maximize aesthetics characteristics

Home Power Magazine # 93, pg. 26

Home Power Magazine # 93, pgs. 10, 11

PV cooling

Wind resistance

Structural Stability

Code compliance

PV Orientation

Aesthetics

Visibility (visible installations may increase public awareness of renewable energy)

Off-grid storage needs

Grid-tied energy storage

Cost and Efficiency Considerations

Calculate storage requirements from:

Climate (periods of cloudy weather?)

Critical loads (what do youneed to power?)

Capacity should last 4 21 days

Batteries should not be discharged more than 50% 70% or battery life is shortened

Install batteries in safe, climate-controlled, ventilated location (not in your living room)

Most Grid-tied systems do not use batteries

Rather the utility grid is treated as a 100% efficient, unlimited capacity battery (except during outages)

Batteries may be added for additional storage flexibility

Batteries add significant cost to a PV system

Charging batteries significantly reduces system efficiency: 20% energy losses are typical during battery charging

PV Modules

Inverters & Charge Controllers

Mounting Hardware

Balance of System Components

Cell types(in decreasing order of price and efficiency)

Monocrystalline

Polycrystalline

Amorphous (thin-film)

Performance

IV curves

Maximum power rating

efficiency

Aesthetics

BP Solar: BP 5170http://www.bpsolar.com/ContentDocuments/84/BP%205170S.pdf

Shell Solar: SP150-PChttp://www.shell.com/static/shellsolar/downloads/products/us/ShellSP150-PC_USv1.pdf

Evergreen Solar: EC-110http://www.evergreensolar.com/egsolar1/pdf/ec100series13.pdf

Kyocera: KC120-1http://www.kyocerasolar.com/pdf/specsheets/kc120_1.pdf

Sharp: NT-S5E1Uhttp://www.sharpusa.com/files/sol_dow_185WSS.pdf

Output types

True sine wave

Modified sine wave

Input requirements

12VDC, 24VDC, 48VDC

String inverters

PV Modules wired accordingly

Monitoring and data logging capabilities

Non-islanding inverters for Grid-tie applications

Purpose safe battery charging

Series

Stand-alone units

Integrated (into inverter)

Home Power Magazine # 94, pgs. 24, 26

Outback Power Systems

http://www.outbackpower.com/

SMA America

http://www.sma-america.com/

Xantrex

http://www.xantrex.com/products/index.asp

Two Seas Mounting Structures

http://www.2seas.com/matrix_ground_roof_a_r.htm

Ground/Roof

Flush Mount

Multi-Tier

Low Profile

Unirac

http://www.unirac.com/

Large Array PV Module Mounting System

Solarmount (ground/roof)

Tracker 200 (2-module tracking rack)

DC disconnects

AC Disconnects

Fuses/Breakers

Grounding hardware

Lightning Arrestors

Combiner Boxes

Off Grid Living

Grid-tied with batteries and monitoring

Off Grid PV & Wind Hybrid System

Grid-tied system with unbelievable payback

Carefully designed residential PV systems provide their owners with clean, reliable power, and promote interest in renewable energy sources

Hydrogen as Energy Storage

Building-integrated materials

Expanded use of solar energy for water purification, water heating, space heating (air-to-air heat exchangers), as well as electricity production

Bell, John (2000).Questions from the Field[Internet] Available from: [Accessed July 2003]

Bisbee, D. (2002) Off the Grid: Starting SmallHome Power Magazine , No 92, December/January, pp. 22-23.

BP Solar (2003). BPSolar Home Page[Internet] Available from: [Accessed July 2003]

Chadderdon, M. and Chadderdon, J. (2003) The Chadderdon Photovoltaic Story.Home Power Magazine , No 93, February/March pp. 10-18.

Energy Trust (2003).Solar Electric for Homes and Businesses[Internet] Available from: [Accessed July 2003]

McCoy, C. and Reising, C. (2002) Still Saying "Yes" to SunshineHome Power Magazine , No 89, June/July, pp. 10-19.

National Renewable Energy Lab (2003).Photographic Information Exchange[Internet] Available from: [Accessed July 2003]

OutBack Power Systems (2003).OutBack Power Systems Home Page[Internet] Available from: [Accessed July 2003]

Perez, R. and Drake, J. (1997) Where and How to Mount PV Modules.Home Power Magazine , No 57, February/March, pp. 32-37.

RV Power Products (2003).RV Power Products Home Page[Internet] Available from: [Accessed July 2003]

Schaeffer, J. ed. (2001)Solar Living Source Book: The Complete Guide To Renewable Energy Technologies & Sustainable Living . 11th ed. USA,

Chelsea Green Publishing Company.

Simons, B. (2003) PV Done Right - Grid Tie, Battery Backup, and System Monitoring.Home Power Magazine , No 94, April/May, pp. 22-27.

SMA-America (2003).SMA-America Home Page[Internet] Available from: [Accessed July 2003]

Solar Depot (2003).Solar Depot Home Page[Internet] Available from: [Accessed July 2003]

Solatron Technologies (2003).Xantrex XS12205[Internet] Available from: [Accessed July 2003]

Two Seas Metalworks (2003). TwoSeas Metalworks Home Page[Internet] Available from: [Accessed July 2003]

UniRac (2003).Unirac Home Page[Internet] Available from: [Accessed July 2003]

Webster, D. (2003) Getting Off the Lifetime Utility Payment Plan.Home Power Magazine , No 95, June/July, pp. 22-28.

Xantrex (2003).Products[Internet] Available from: [Accessed July 2003]

Yewdall, Z. (2003) PV Orientation.Home Power Magazine , No 93, February/March, pp. 24-28.