• Know Your Rights

    Arizona law protects individual homeowners’ private property rights to solar access by dissolving any local covenant, restriction or condition attached to a property deed that restricts the use of solar energy. This law sustained a legal challenge in 2000. A Maricopa County Superior Court judge ruled in favor of homeowners in a lawsuit filed by their homeowners association seeking to Read more
  • Agua Caliente PV Power Plant Among World’s Largest

    The Agua Caliente solar farm near Yuma features First Solar’s thin-film cadmium-telluride (CdTe) solar modules. Located 65 miles east of the city of Yuma, Arizona, this plant is one of the world’s largest operational PV power plants with 290MW (AC) connected to the electricity grid. Read more
  • Solar Hot Water

    There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don't. The typical solar water heater is comprised of solar collectors and a well-insulated storage tank. The solar collector is a network of pipes that gathers the sun's energy, transforms its radiation into heat, and then transfers that heat to either Read more
  • Federal Residential Renewable Energy Tax Credit

    (Information provided by DSIRE - Last reviewed 02/19/2009) Incentive Type: Personal Tax Credit State: Federal Eligible Renewable/Other Technologies: Solar Water Heat, Photovoltaics, Wind, Fuel Cells, Geothermal Heat Pumps, Other Solar Electric Technologies Applicable Sectors: Residential Amount: 30% Maximum Incentive: Solar-electric systems placed in service before 2009: $2,000Solar-electric systems placed in service after 2008: no maximumSolar water heaters placed in service before Read more
  • Solar Building Design in Arizona

    The idea of using the sun to meet the energy needs in our buildings has been with us since the time of the Greeks, with some of the design manifestations even evident in the prehistoric structures of Arizona and the Southwest. There is a great historic tradition for Arizona buildings that utilize our most abundant resource, and the current increases Read more
  • How Not to- Battery Connections

    Photo shows the situation after a battery discharge test at 300 amps was terminated on a 1530 AH IBE battery string when one post melted. During the discharge test all cell voltages are logged. The sum of the cell voltages was 2.73 volts lower than the 48-volt string voltage. This is an average of 118 mv per inter-cell connection, 5-10 Read more
  • 1 Know Your Rights
  • 2 Agua Caliente PV Power Plant Among World’s Largest
  • 3 Solar Hot Water
  • 4 Federal Residential Renewable Energy Tax Credit
  • 5 Solar Building Design in Arizona
  • 6 How Not to- Battery Connections

Blogs

  1. Solar Center Blog
  2. Guest Blogs
Geoff Sutton
25 November 2017

In the desert south-west the intense sunshine and long summer days result in uncomfortable and even dangerously high temperatures for about four months.

Jim Arwood
28 December 2016

“A lie gets halfway around the world before the truth has a chance to get its pants on.”  --Winston Churchill


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Some things to pay attention to in Arizona

ASEA REBOOT

The Arizona Solar Energy Association (ASEA), State Chapter of the American Solar Energy Society ASES), will be holding meetings in a follow-up to the-long awaited updated ASES‚  Chapters handbook and directives.

ASES evolution, in response to some problematic economic and operational conditions, has resulted in a hearty and robust context for the present and the future. ASEA is now responding with an appropriate updating, through local and statewide discussion. 

Interim Chair, Andy Gerl, a past ASEA Chair and Board member, is making arrangements for Arizona solar advocates and supporters, members and non-members, to receive both an update re: ASES adaptation and changes, and to discuss solar in Arizona and the “reboot" of the ASEA  context, goals and objectives, within the context of varied renewable energy groups within the State, such as AriSEIA (the solar trade association); various sustainability groups; Green Building organizations; the recently formed solar hot water businesses non-profit entity; research and development at the universities; and others.

For more information about the ASEA Reboot discussions, contact Andy at andrew@blazingsolar.com  or 602-799-5942

APS Rate Case - Higher rates, solar changes now effective as of September 1st

APS customers had until August 31st to submit complete interconnection applications to APS in order to be grandfathered under earlier solar policy.  Basic rates have increased and net metering was eliminated, replaced by a fixed purchase rate that starts at $0.129 per kwhr and will decrease in the future.  Further details are posted in a link below.

Quick APS Links:

News Release (Aug. 15, 2017)
Summary for Residential Customers
Summary for Business Customers
Solar Grandfathering Fact Sheet (also see the note below for additional information)

The Arizona Solar Center has put together an unofficial summary of the new APS rate schedules for new solar customers, click here.

On August 21st APS emailed the following information to Stakeholders (but it does not seem to be on the APS website):

Stakeholders,

The Arizona Corporation Commission (ACC) has approved a decision in our rate review, and we are happy to share some details with you affecting our solar customers. We appreciate your support in delivering this message to customers and will be glad to help you with any questions you may have. For your reference, attached are letters that were sent to customers regarding grandfathering. Other resources are available at aps.com/gosolar.

Grandfathering

  • Current solar customers that are interconnected to the APS grid will remain grandfathered for 20 years from the date of interconnection.
    • The grandfathering stays with the premise. Systems transferred to a new premise will require a new application, and the customer would no longer be eligible for EPR-6.
    • Over the terms of the grandfathering period, a customer may not increase the capacity of their grandfathered solar system by more than a total of 10% or 1 kW, whichever is greater.
  • Customers who submit a complete application by 11:59 p.m. August 31, 2017 will be eligible for grandfathering. The system would need to be installed and have AHJ approval by February 28, 2018 in order to qualify. A complete application includes all of the following:
    • Customer Application
    • Executed Contract
    • Disclaimer
    • Consumer Acknowledgement
    • Installer Application
    • Three Line Diagram
    • Site Plan

Public Meetings:

Green Building Lecture - Economic Value of Green: Knowledge is EmPOWERing

Scottsdale’s Green Building Lecture season kicks off with a panel of industry leaders on the economic value of green. 
 
These free programs run from 7 to 8:30 p.m. on the dates listed below at the Granite Reef Senior Center, 1700 N. Granite Reef Road. RSVPs are not needed.

Green Building Lecture Series

Solar Energy and Battery Storage Systems

Date: Thursday, Dec. 7

Time: 7 - 8:30 p.m.

This is an exciting time for renewables and on-site energy storage systems as solar continues to take off in the valley. Just this year, Scottsdale has had a record year with more than 500 residential solar electric installations and a growing number of battery storage system installs.  

ASU Senior Sustainability Scholar Paul Hirt will discuss the solar energy revolution, why solar is coming faster than anyone expected and how it will change our world. His current research includes a history of electric power, transition to renewable energy, and collaborative interdisciplinary research on water use, urban growth and sustainability.

Titan Solar Power Director of Business Development Jack Walker joins Hirt. He’ll discuss residential battery storage options for utility-connected solar photovoltaics systems. Walker is set to address homeowners’ concerns about time of use rates, controlling demand charges and having a backup system in the event of a utility grid failure. For some homeowners it’s about control over time of use rates, for others it may be about controlling demand charges while for others it may be about having a "back up" system in the event of utility grid failure.

For more information see the 'Next Lecture' section of this link: http://www.scottsdaleaz.gov/green-building-program

The  scheduled lecture series includes:

  • Feb. 1, 2018 – Living an Edible Landscape Life
  • April 5, 2018 – Building with earth and Mass in the Desert 
  • June 7, 2018 – Heating and Cooling with Ductless Mini-Splits

Further information on this worthwhile program

General News feed

Caution- News leads open in new windows. Warning- These news links are automatically generated by others such as Google News and are not reviewed by the Arizona Solar Center, Inc. We are not responsible for link content.

Our Twitter Feed

azsolarcenter "A lie gets halfway around the world before the truth has a chance to get its pants on.” --Winston... https://t.co/YZUiXLzsKz
azsolarcenter The Sun Day Blog: The future is not what it used to be. In the aftermath of the 2016 election, the question has... https://t.co/lSR5RFewJm
azsolarcenter Novermber 5, 2016 -- APS, pro-solar group together spend $6 million on Arizona Corporation Commission races: The... https://t.co/5xyq4EsoFm
azsolarcenter November 3, 2016 Solar Battles Playing Out On Arizona Ballot This Election: It may not be at the top of the... https://t.co/uYSRxv97YR
azsolarcenter November 4, 2016: Utility spends $3.5 million to keep Arizona Corporation Commission all-GOP: The state’s largest... https://t.co/imqk6z2sDU
azsolarcenter October 25, 2016: 42 States (and DC) try to screw with solar The 50 States of Solar Policy Report by the NC... https://t.co/JBYTzpf2ui
azsolarcenter October 24, 2016 -- Future of independent solar energy at stake in Corporation Commission raceL The long-term... https://t.co/D6jy4I5Ci0
azsolarcenter October 13, 2016 -- State policy matters: It is very easy to get distracted by the dog-and-pony show of this... https://t.co/MH7mEMg9MC
azsolarcenter October 16, 2016: Arizona Corporation Commission DebateL Five candidates running for three open seats on the... https://t.co/tm0XLl6CqG
azsolarcenter My Sun Day blog is posted to the Arizona Solar Center. https://t.co/vRrxwSSQpw
azsolarcenter There is No Plan(et) B: Climate change is no longer an issue that our politicians can kick down the road for... https://t.co/KHZzajZc9K
azsolarcenter High Noon: Nearly 40 years ago, President Carter proclaimed the dawn of the solar age. If President Carter was... https://t.co/JmZSHlmBUI
azsolarcenter High Noon: Nearly 40 years ago, President Carter proclaimed the dawn of the solar age. If President Carter was... https://t.co/rBgkaWKDs6
azsolarcenter High Noon: Nearly 40 years ago, President Carter proclaimed the dawn of the solar age. If President Carter was... https://t.co/RzXaQACpPR
azsolarcenter High Noon: Nearly 40 years ago, President Carter proclaimed the dawn of the solar age. If President Carter was... https://t.co/t1fKNTPwIB
azsolarcenter High Noon: Nearly 40 years ago, President Carter proclaimed the dawn of the solar age. If President Carter was... https://t.co/dWEKk3QR6H
azsolarcenter High Noon: Nearly 40 years ago, President Carter proclaimed the dawn of the solar age. If President Carter was... https://t.co/y4vhOpjfh1
azsolarcenter September 29, 2016: To cover a utility's fixed costs, are demand charges or time-of-use (TOU) rates superior?... https://t.co/RgneQWNKyM
azsolarcenter September 25, 2016: Arizona Public Service not only rejected an Arizona Corporation commissioner’s request to... https://t.co/iip6RwoOOS
azsolarcenter September 22, 2016: The Salt River Project (SRP) board of directors has agreed to purchase energy produced by... https://t.co/xYegEuiI43
azsolarcenter September 18, 2016: UniSource Energy officials have shelved plans to use of land surroundingMohave Community... https://t.co/eXmHxo03wQ
azsolarcenter September 13, 2016: The city of Sedona spent about 90 minutes at its September 13 council meeting discussing... https://t.co/LHV2QcsvYt
azsolarcenter September 15, 2016: New solar research projects at Arizona State University will receive $3.75 million in funding... https://t.co/N20NYLWxGy
azsolarcenter September 25, 2016: The parable of the frog and boiling water is hundreds of years old. It has been used... https://t.co/O5PYqvxIJg

Fundamentals of Photovoltaic Systems

 

The basic element of a photovoltaic system is the solar cell. Modern solar cells are made in sizes up to about 6 inches square and are most often made from silicon, a semiconductor.

The photovoltaic effect occurs when sunlight shines on the silicon, freeing electrons and generating an electric current. The electricity is collected and transported by metal contacts on the top and bottom of the cell. The current flows through a wire to provide electricity. 

A single cell produces only about 0.45 volts. It takes 36 cells connected in series to generate the voltage required for charging a 12-volt battery. The power produced in full sunlight is a function of the size of the solar cell and the efficiency (always getting higher as the technology improves).  These cells are usually mounted (laminated with a clear plactic) behind a tempered glass sheet with the cells wired together to form a photovoltaic module (also called a” panel” or “flat-plate collector”). For instance, the most popular design in 2016 is to use 60 cells, each about 6" square, to produce 230 to 310 watts (depending on efficiency) from modules that are about 39" x 66".  The rear of the module is sealed with plastic or glass for protection, long life requires a moisture tight assembly. The modules connected together for one system form an “array.”  Large systems will have these photovoltaic modules connected physically and electrically in "sub-arrays". 

Single cells produce little power and are not often used individually.  They can be found, however, in some items such as small yard lights.    Arrays, depending on the number of panels used, can provide all the electricity for a home or even create a huge generating station.

Modules or arrays are sometimes mounted on tracking systems, which follow the sun across the sky.  These devices help maximize electricity production because sunlight shines directly on the PV modules throughout the day.  Single-axis trackers move as the sun changes position from the east to west.  Two-axis trackers not only follow the suns east to west movement, but also allow for its apparent change in attitude with different seasons. Trackers can increase the energy production of a photovoltaic system by nearly 40 percent, but the tracking equipment costs more than a simple fixed mounting.

Electricity storage is a critical component of many PV systems. If power is needed at night or on cloudy days, solar-generated electricity can be stored in batteries.  It is even possible to have large PV-powered homes, for example, it is not uncommon to find banks of 50 or more batteries.  These battery banks usually store sufficient electricity to power the home through one or two cloudy days and nights.  However, it is generally more cost effective operate larger photovoltaic systems inter-actively with the local electric utility.

All photovoltaic, cells produce direct current (dc) electricity.  That electricity can be used immediately if the PV cell is connected to a device designed for dc power – many refrigerators in recreational vehicles, for example. However most homes and appliances are designed to operate on alternating current (ac) electricity provided by utility companies.  For applications, an inverter, which changes dc electricity to ac must be added to the PV system.

If a system uses batteries, charge controllers are also important components.  These devices protect batteries from excessive charge when the modules produce more electricity than the batteries can store.  They also keep batteries from releasing electricity if their charge is too low.  Without charge controllers, batteries suffer extreme wear-and-tear and become less effective, and last a shorter amount of time.

Insert links from Art 141 Photovoltaics (PV) - Introduction

Solar Electric (PV)

Photovoltaics (PV) covers the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry.

Solar electric has been a gaining strength for a number of years.  In the beginning, early adopters turned to solar for the independence or its environmental benefits: solar homeowners could live beyond the utility lines, and solar was a non-polluting resource.

The earliest adopters were almost exclusively people that lived beyond the reach of the utility lines.  Solar generated electricity and battery storage allowed people to live where ever they wanted. Land was cheaper beyond the power lines and even with the expense of solar, this made economic sense too many people looking to escape urban living. But, the numbers of people living off grid was still a small number.

Environmental concern represented the second wave of solar adopters – as people concerned about the impact their electrical demand was having on the planet turned to solar to lessen their carbon footprint.

According to a 2011 report on renewable energy sources and climate change mitigation, the International Panel on Climate Change calculated the life-cycle global warming emissions associated with renewable energy—including manufacturing, installation, operation and maintenance, and dismantling and decommissioning—as minimal [1].

These findings were repeated in other research and data collected and reported on in peer studies over the past decade and helped fuel the environmental argument for solar energy.

The Union of Concerned Scientists compared the carbon dioxide emissions equivalent per kilowatt-hour for coal and renewable energy resources.

It is no surprise that coal is ranked the most polluting electricity generating resource and renewables the least. Coal emits more than 20 times as much carbon dioxide equivalent per kilowatt-hour of generation compared to the life-cycle carbon emissions for solar PV. The comparison between coal and wind is even greater. Coal emits 71 times more carbon dioxide than wind for each kilowatt-hour of electricity generated [2].

In addition, a study by the U.S. Department of Energy's National Renewable Energy Laboratory explored the feasibility and environmental impacts associated with generating 80 percent of the country’s electricity from renewable sources by 2050 and found that global warming emissions from electricity production could be reduced by more than 80 percent [3].

The healthy alternative extended beyond the concern for the planet, the third wave of solar adopters included people looking for healthy alternatives for humankind.

This wave looked to generating electricity from renewable energy rather than fossil fuels because of the  significant public health benefits.  From reduced premature mortality to lost workdays associated with breathing illnesses, the economic impact of fossil fuels on overall healthcare costs has been estimated at between $361.7 and $886.5 billion [4].

The last wave came was the during the Great Recession of the late 2000s and early 2010s. Solar PV offered the opportunity to re-tool America and create significant jobs as a result.

In 2009, the Union of Concerned Scientists conducted an analysis of the economic benefits of a 25 percent renewable energy standard by 2025; it found that such a policy would create more than three times as many jobs as producing an equivalent amount of electricity from fossil fuels, resulting in a benefit of 202,000 new jobs in 2025 [5].

For the past two or three decades, the reasons for adopting solar have been growing stronger every day.  The tipping point is cost-parity and that day is not far off, and in some cases, it has already been realized.

References:

1.      Intergovernmental Panel on Climate Change (IPCC). 2011. IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation.

2.      Union of Concerned Scientists (UCS). 2009.

3.      National Renewable Energy Laboratory (NREL). 2012. Renewable Electricity Futures Study. Volume 1, pg. 210.

4.      Machol, Rizk. 2013. Economic value of U.S. fossil fuel electricity health impacts. Environment International 52 75–80.

5.      Environmental Protection Agency. 2010. Assessing the Multiple Benefits of Clean Energy: A Resource for States. Chapter 5.

 

For more information, follow the topics below.

Links about larger scale photovoltaic systems:

Some interesting uses of PV:

In Hot Water - Experiences of Solar Hot Water in Arizona

Summary of Presentation given at the World Renewable Energy Forum (WREF)/ASES Conference in Denver, CO in  May 2012
(Full presentation is available for download below.)

During a utility (APS and SRP) funded 2010 Pilot Study to assess SDHW installations for assuring compliance for RECs, it was determined that there was an extremely high rate of failure in meeting basic national guidelines (SRCC), and now with over thousands of audits executed since the Pilot study, there is critical information that needs to be shared with the various solar arenas in Arizona - utilities; governmental code and inspections departments; State licensing agencies; the solar equipment industry; and the design and construction industry; as well as outside Arizona - the nationally growing trade education element; utilities; state and local governmental agencies; and trade organizations in other states.

With the implementation of permanent programs by both Salt River Project (SRP) and Arizona Public Service (APS), the AzSC, acting as a 3rd party neutral resource, has executed over 3000 audits. The findings of this effort are significant, not only for Arizona but also for the larger community - nationally and possibly internationally - for both the solar industry and for the consumer.

The Forum established by the AzSC is intended to share Arizona's experience in various contexts with participation of Daniel Peter Aiello and Geoff Sutton of the AzSC, and Joel Dickinson of Salt River Project. The presentation describes lessons learned, and significant issues discovered that impact the ongoing viability of this technology for government, industry, and the consumer.

The presentation comes from different contexts:

  • The utility experience and viewpoint of lessons learned, issues discovered, and actions taken (and planned) within the context of meeting utility incentives programs requirements.
  • Lessons learned in the trenches, and issues found in the quality of work and industry practice.
  • Conditions and issues involved with the numerous "players" in this arena including the utilities, and those outside the utility context - Registrar of Contractors (ROC), solar equipment organizations and trade associations, building departments and the inspections systems, and the design/construction community.

Full presentation available for download here (7.97 MB PDF).

Handbook of Secondary Storage Batteries and Charge Regulators in Photovoltaic Systems

Photo courtesy NREL

Solar photovoltaic systems often require battery subsystems to store reserve electrical energy for times of zero insolation. This handbook is designed to help the system designer make optimum choices of battery type, battery size and charge control circuits. Handbook of Secondary Storage Batteries and Charge Regulators in PV Systems.

NOTE: All files are PDF format

Complete Handbook (4,337kb)

The following files are divided into sections for easier viewing and download if necessary:


Prepared by: Exide Management and Technology Company, 19 West College Avenue, P.O. Box 336 Yardley, Pennsylvania 19067. Work Performed for The U.S. Department of Energy, Sandia National Laboratories, Albuquerque, New Mexico 87185 Under Contract No. 13-2202. Originally Printed August 1981; Updated 2003 by AzSC Board Members Lane Garrett and Bill Kaszeta.

About

  • Welcome to the Arizona Solar Center

     This is your source for solar and renewable energy information in Arizona. Explore various technologies, including photovoltaics, solar water heating, solar architecture, solar cooking and wind power. Keep up to date on the latest industry news. Follow relevant lectures, expositions and tours. Whether you are a homeowner looking to become more energy efficient, a student learning the science behind the technologies or an industry professional, you will find valuable information here.
  • About The Arizona Solar Center

    Arizona Solar Center Mission- The mission of the Arizona Solar Center is to enhance the utilization of renewable energy, educate Arizona's residents on solar technology developments, support commerce and industry in the development of solar and other sustainable technologies and coordinate these efforts throughout the state of Arizona. About the Arizona Solar Center- The Arizona Solar Center (AzSC) provides a broad-based understanding of solar energy, especially as it pertains to Arizona. Registered Read More
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