Stand-Alone Photovoltaic Systems.pdf

Issued by Sandia National Laboratories operated for the United States

Department of Energy by Sandia Corporation

NOTICE: This report was prepared as an account of work sponsored by

an agency of the United States Government. Neither the United States

Government nor any agency thereof, nor any of their employees, nor any of

their contractors, subcontractors, or their employees, makes any warranty,

express or implied, or assumes any legal liability or responsibility for the

accuracy, completeness, or usefulness of any information, apparatus, prod-

uct, or process disclosed, or represents that its use would not infringe

privately owned rights. Reference herein to any specific commercial

product, process, or service by trade name, trademark, manufacturer, or

otherwise, does not necessarily constitute or imply its endorsement, recom-

mendation, or favoring by the United States Government, any agency

thereof or any of their contractors or subcontractors. The views and

opinions expressed herein do not necessarily state or reflect those of the

United States Government, any agency thereof or any of their contractors

or subcontractors.

The hardware available for use in photovoltaic systems will vary from

country to country. The reader is urged to make comparisons between

competitors’ products before buying any photovoltaic systems hardware.

The use of a specific manufacturer’s product in these design examples is not

intended as an endorsement.

Printed in the United States of America

Available from

National Technical Information Service

U.S. Department of Commerce

5285 Port Royal Road

Springfield, VA 22161

NTIS price codes

Printed copy: A12

Microfiche copy: A01

SAND87-7023

Distribution

UNLIMITED RELEASE

Category

Updated March 1995

UC-270

ABSTRACT

This document presents recommended design practices for stand-alone

photovoltaic (PV) systems. Sixteen specific examples of PV systems, designed for

different applications, are presented. These include warning signals, lighting,

refrigeration, communications, residential, water pumping, remote sensing, and

cathodic protection. Each example presents a system sizing technique that can be

completed using the worksheets provided. The calculations are simple and

straight-forward. In addition to sizing calculations, each example includes infor-

mation about available hardware, wire sizes, and a line-drawing to illustrate

installation techniques. However, the focus of this document is the presentation of

a consistent system sizing technique.

Stand-alone PV systems operate reliably and are the best option for many

remote applications around the world. Obtaining reliable long-term performance

from a PV system requires:

• consistent sizing calculations,

• knowledge of hardware availability and performance,

• use of good engineering practices when installing equipment, and

• developing and following a complete operation and maintenance plan.

These issues and others are discussed in this handbook.

Abstract

iii

FOREWORD

This popular handbook presents a consistent method for sizing PV

systems. Over 25,000 copies have been distributed worldwide since it was

first published in 1988. It was written by systems engineers with hands-on

experience with PV system design, installation, and operation. It has been

updated several times to stay current with the latest hardware and engineer-

ing techniques. This version reflects recent field experience with component

reliabilities and system lifetime.

The selection and proper installion of appropriately-sized components

directly affects system reliability, lifetime, and initial cost. The designs

presented here represent real applications and illustrate some of the trade-

offs necessary in system design and component selection. The example

systems are adequate for the application, and the initial cost is reasonable.

Using more batteries and increasing PV array size may extend the life and

reliability of a PV system designed for a specific application but will increase

the initial cost. It’s a trade-off.

This Handbook includes many details on system hardware, installa-

tion, and operation. However, exhaustive coverage of all issues is not

intended. The information on operating and maintaining (O&M) a PV

system is intentionally brief because Sandia National Laboratories publishes

a companion document titled Maintenance and Operation of Stand-Alone

Photovoltaic Systems. Likewise, the electrical drawings may not show all

components required by the National Electrical Code (NEC). Information on

applying the NEC to PV systems is discussed in the document Stand-Alone

Photovoltaic Systems and the National Electrical Code. Both documents are noted

in Recommended Reading, page 86, and are available from the PV Design

Assistance Center at Sandia National Laboratories.

Brand names for components used in the representative systems were

available commercially in the United States in 1994. Use of a specific product

does not constitute an endorsement of that product by Sandia National

Laboratories or the United States Government, nor indicate that it is the only

(or best) option. Each reader is encouraged to compare component perfor-

mance and cost from known vendors. The number of equipment dealers is

increasing throughout the world. Most dealers have experience with system

design and installation using compatible components. The PV system

vendors in your country are your best information resource.

Foreword

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika: