• New Discovery Could Improve Organic Solar Cell Performance

    While there is a growing market for organic solar cells ­­– they contain materials that are cheaper, more abundant, and more environmentally friendly than those used in typical solar panels – they also tend to be less efficient in converting sunlight to electricity than conventional solar cells. Now, scientists who are members of the Center for Computational Study of Excited-State Phenomena in Energy Materials (C2SEPEM) a new Read More
  • 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 force the homeowners to remove Read More
  • Home Battery Systems

    Rooftop solar panels are common in Arizona thanks to abundant sunshine, but to get even more use from the technology, homeowners are beginning to pair them with large home batteries. Batteries allow homeowners to store their surplus electricity, rather than send it to the grid in exchange for credit from their electric company. 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 water or a heat-transfer fluid. 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 2009: $2,000Solar water heaters placed 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 in The idea of using 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 mv is the normal range Read More
  • 1 New Discovery Could Improve Organic Solar Cell Performance
  • 2 Know Your Rights
  • 3 Home Battery Systems
  • 4 Solar Hot Water
  • 5 Federal Residential Renewable Energy Tax Credit
  • 6 Solar Building Design in Arizona
  • 7 How Not to- Battery Connections

Blogs

  1. Solar Center Blog
Brian Czech
17 February 2019

What’s Really Green and What’s Really New

Ask Americans what the Green New Deal is all about, and you’ll get two basic answers. Most often you’ll hear, “It’s about moving to renewable energy in order to fight climate change.” You’ll also hear, from a camp further right, “It’s all about socialism!”

Lucy Mason
06 January 2018

Wishing you a wonderful and Happy New Year!

The year 2017 has gone by quickly, and AriSEIA has accomplished a full and active agenda to further solar and renewable energy in Arizona. 


Featured (Note- Articles below shift Left-Right)

Some things to pay attention to in Arizona

AriSeia 2019On Nov. 26th, an administrative law judge issued a recommendation that would be a huge setback for independent solar producers looking to add more solar to Arizona’s grid under PURPA. Click here to read AriSEIA’s statement.

It is vital that the Commissioners hear our comments against this terrible proposal.

Please call and email all five Commissioners with your comments. Click here to access contact information for the Commissioners. Everyone who is available should plan to attend the ACC meeting in person on Dec. 10th/Dec. 11th. The agenda currently says this item will not be heard before 1 p.m. on Dec. 10th. Click here to view the agenda, and stay tuned for more details.

Please share this call to action with your network. Thank you for your time and for taking action!


Seeking Arizona agriculture producers who are using small solar systems in their operations in Arizona

Dr. Bonnie Eberhardt Bobb, Executive Director of the Western Sustainable Agriculture Working Group, is looking for agriculture producers who are using small solar systems in their operations in Arizona who might be willing to help her with preparing ACC testimony, discussion with representatives, writing letters of support, signing petitions, etc. to further their goal of increased renewables in agriculture. She would love to hear from ag producers and listen to their stories of how solar has benefited their operations. Thank you so much. Please contact drbonnie2002@yahoo.com if you can assist.

Arizona Corporation Commission 

See our information on PROPOSED RULEMAKING REGARDING INTERCONNECTION OF DISTRIBUTED GENERATION FACILITIES PROPOSED RULEMAKING REGARDING INTERCONNECTION OF DISTRIBUTED GENERATION FACILITIES

During March 2019, SRP wrapped up their public pricing process at a final rate setting board hearing.

The board approved new rates for SRP customers, which will translate to a $1 to $4 decrease in monthly bills.
The board also voted to lower rates for solar customers, approve three new options for solar customers, and adopt a new battery/storage incentive.

https://www.azcentral.com/story/money/business/energy/2019/03/25/salt-river-project-decreases-rates-customers-but-solar-debate-rages/3245669002/.

APS announces 2018 ended with 16,479 applications and 14,818 installations: 

APS 2018 PV

Note: APS applications peak in August due to deadlines to freeze APS purchase rates for 10 years.

FRAUD ALERT

Attorney General Warns About Deceptive “Solar Initiative” Flyers

PHOENIX – Attorney General Mark Brnovich issued a warning today about deceptive flyers appearing on residences in the Phoenix area that promote a solar energy effort.

The flyers claim to be a “Public Notice” from the “Maricopa County Solar Initiative,” and claim that “Arizona and the Federal Government ITC (26 USC § 25D) are paying to have solar energy systems installed on qualified homes in this neighborhood.” The flyers tell consumers to call to schedule their “site audits.” Consumers who call are subjected to a solar sales pitch by a private company. In addition, the Maricopa County Solar Initiative’s website improperly uses a modified version of the county seal, but the “Solar Initiative” is linked to a private business and is not associated with the county. The “Solar Initiative” is also not registered to do business in Arizona.

Similar flyers previously appeared in Clark County, Nevada, this summer, and law enforcement officials there have warned that the “Clark County Solar Initiative” notices are deceptive.

Arizona Attorney General Mark Brnovich has aggressively prosecuted businesses masquerading as government agencies, including obtaining consent judgments against “Mandatory Poster Agency” and “Compliance Filings Service,” resulting in full restitution for Arizonans totaling hundreds of thousands of dollars.

A picture of the “Public Notice” is below:
A picture of the improperly modified county seal used by the “Solar Initiative” is below:

 If you believe you are a victim of consumer fraud, you can file a complaint online at the Arizona Attorney General’s website. You can also contact the Consumer Information and Complaints Unit in Phoenix at (602) 542-5763, in Tucson at (520) 628-6648, and outside of the metro areas at (800) 352-8431.

Source:https://www.azag.gov/press-release/attorney-general-mark-brnovich-warns-about-deceptive-solar-initiative-flyers

Also covered at: https://www.azcentral.com/story/news/local/arizona/2018/11/26/deceptive-flyers-circulate-arizona-promoting-solar-energy-effort/2115597002/


Interesting Technology Updates;

A look at some of the more significant changes under consideration for the 2020 National Electrical Code (NEC) that will affect future distributed generation systems (solar electric wind, etc.). Article 690, Solar Photovoltaic (PV) Systems and Article 705, being renamed Interconnected Electric Power Production Sources, are specific to distributed generation.

The referenced article below by IAEI, a membership driven, non-profit association promoting electrical safety, has a good summary of upcoming changes.

https://iaeimagazine.org/magazine/2019/09/10/pv-installations-for-the-2020-nec/

 

 

 

 


Events

No result.

Interesting Videos

The Challenge of Storing Energy

Introduction


All sources of energy have some level of intermittency, they are not always available when needed. The reliability range is wide, utility supplied electric or gas energy seldom fails while we know that the sun is not available to operate photovoltaic (PV) or thermal systems at night. Our needs for energy also vary from critical full time (example: network computer servers), to critical when needed (example: emergence lighting), to use it while it is available with no problem with loss of operation (example: cathodic protection systems).

Key to reliable power is redundancy, having multiple sources of power. For utilities this usually means multiple generating stations and multiple transmission paths to ensure delivery of power. For applications not connected to a reliable power grid, the alternate power source can be small emergency generators or battery backup.

Most renewable energy sources, solar and wind being the main sources, are intermittent by their very nature. If continuous power is required, they need to be backed up by energy storage or generators. The most common combination is PV power systems with batteries. In these systems the PV system is designed to provide enough energy to meet the energy needs and recharge the battery. As such the size is based the worst case during the year with safety factors added for year to year differences, longest expected periods of low sunshine, and the expected degradation of equipment as it ages. The result is rather high energy costs because at many times of the year the energy produced by the PV array exceeds needs and is not harvested.

More popular these days are PV systems that are utility connected and any excess energy is either banked with the utility (net metering) or sold to the utility (net billing). Since most of these utility connected systems generate energy only when the utility is functioning, there is also the ability to design the system to include energy storage. There are many options, see the AZSC separate article on (title and article needed covering AC vs DC coupled storage, demand reduction, backfeed limiting, etc. based on 2019 products).

There are many aspects to energy storage, size can range from very small (battery or capacitor) to very large (pumped hydro), many technologies, safety aspects, to name a few.  There is no easy way of describing this wide range of technologies, but we will start with some definitions.

 There are two basic terms for defining storage, Power and Energy:

Watt: A unit of Power, one Watt is the rate at which work is done when one ampere (A) of current flows through an electrical potential difference of one volt (V). Items like light bulbs are rated in watts. Power is the rate at which energy is generated or consumed and hence is measured in units (e.g. watts) that represent energy per unit time. Electrical demand is a power term, usually measured in kilo-Watts (kW).

Watt-hours: A unit of Energy, defined as power over a time interval. One watt of power for one hour is one Watt-Hour. Often used with the prefixes Mega for 1-million (mWh) and Kilo for 1-thousand (kWh).

 

The suitability of a storage technology is determined primarily by its power and energy capacity and the rate at which these can be stored and delivered. Other characteristics to consider are round-trip efficiency (how much energy is lost from charging and discharging), cycle life (how many times the technology can charge and discharge at a particular depth of discharge [e.g., 80% or 100%]), safety, and ramp rate (how fast the technology can respond to a command).

Other metrics to consider include specific energy and specific power. Specific energy is a measure of energy per unit mass of an energy storage system. Specific power is defined as the power per unit mass of an energy storage system. When specific power and energy are high, the weight of the energy storage system tends to be lower per kW/kWh. See the Figure below for a comparison of specific power and specific energy for each of the many of the energy storage technologies presently available. Optimal characteristics of energy storage technology include high specific energy and specific power, but these features are often costly and not necessary for every application.

 Comparison of Specific Power and Specific Energy

The above graphic covers battery technologies from the point of view of large scale energy storage.  It was extracted from a good report that is worth reading: ENERGY STORAGE TECHNOLOGIES WHITE PAPER by the Port of Long Beach

The basic physics of energy storage

There are three basic ways to store energy; electrochemical, mechanical and electrical.

Electrochemical methods basically change one element or compound into another wherein the process is reversible (the energy can later be recovered). Examples include breaking water into its components of hydrogen and oxygen (H₂O into H₂ and O₂) and lead-acid batteries (PbO₂ + Pb + 2H₂SO₄ into 2PbSO₄ + 2H₂0), more on these later. 

Mechanical methods utilize physical forces such as gravity (pumped hydro), angular momentum (flywheels), pressure (compressed air), and heat.

Electrical storage includes capacitors and inductors. Some energy storage combine elements of these ways.

https://pv-magazine-usa.com/2019/10/10/energy-storage-solutions-to-get-you-through-power-outtages/

Understanding your APS Connected Photovoltaic System- Net Metering

If you have a photovoltaic (PV) system connected to APS and do not have other monitoring of the PV system such as that provided by most inverter manufacturers, it is not easy to determine the solar production that corresponds with the monthly electric bill.  APS requires a solar production meter and this data is recorded and made available to the customer, but with a little difficulty.  The following example is based on the now grandfathered 'Net Metering' (rate rider EPR-6) wherein any excess PV production, measured in kilowatt-hours (kWh) is used to offset energy delivered by APS.  This method has been replaced by a system APS calls RCP, utility speak called 'Resource Comparison Proxy' (note that the APS website was developed by utility personnel using their view of the situation, not the customer view). The Solar Center intends to repeat the following procedure later with examples based on RCP.

Look at the recent example of an APS electric bill and see if you can determine the solar production:

APS web 6m

The APS bills show only that 186 kWh in this case was net metered.  The bill does not show the solar production that was directly used, to determine this one has to have an APS web account (free) and has to go online to learn more. There is a lot of data available.  Note the 'Meter reading' dates above, this will be used later to calculate the solar production. Using a browser such as you are using to view this article, go to https://www.aps.com/

There is presently a Capcha screen to prove that a person and not an automated computer is accessing the website.  Enter the requested data.  

APS web 1b

Enter your APS username/password then click login.  If you do not already have a username and password, click on 'register'. The following is typical.

APS web 1

Next select 'daily and hourly usage'.  Solar production is a subset of usage for some APS reason.

APS web 1a

There are four types of data available and a calendar to select the dates to view.  See the red instructions in the examples below.  In APS jargon 'received usage' is solar production. This screen shows the solar production graphically, good for seeing relative production that depends on the sunshine and to a lesser extent the air temperature. Clicking on the 'Day' tab will expand that day, otherwise a month (or the current month to date) is displayed.

APS web 2

This view shows the pattern of the energy drawn from APS.  Actual total usage at a specific time will be higher since PV system production will be used directly if there is enough usage at the specific instant.

APS web 3

 APS web 4

APS web 5

Note that on each of the above examples, there is a down arrow next to the 'for service at' section and that clicking on this down arrow shows a second service, the PV production Meter with an '*'. The address is blurred in this example. Select the line with the *.

APS web 11

The production data is displayed in two formats, a bar graph for the month, and a graphical format for the week.

Hal Jul 2019 PV

Hal Aug 2019 PV Hr

In order to get values for calculations, the monthly summary data needs to be downloaded as Excel files, usually for the two months that include the date range of the electric bill.  With the 'daily energy useage' tab selected, select the first month of the range (click on any date), then click on the 'download meter data' text link over the calendar.  This will download a file named 'Excel.xlsx' ( or Excel(y).xlsx where 'y' is a digit, added by your computer when 'Excel.xlsx' already exists).  A spreadsheet program is needed to open and view these files, Excel for example.  Select the 'daily energy usage' and 'delivered useage' tabs.  The Excel data will look like this:

APS web 8 The values for the billing date range, July 25 to August 23 in this example, need to be added.  This can be done with the spreadsheet program or manually.  In this example the sum is 711.5 kWh. This is not straight forward since the values shown are actually text and Excel can not directly add them.  Use the =value(cell) function in another column to convert the text to actual values.  Now that the actual solar production is known, the below  chart shows the relationship of these values.

APS web 9

The calculation of Home useage is (Solar Production) + (Purchased from APS) - (Sold or net metered to APS).

 

Understanding your APS Connected Photovoltaic System

If you have a photovoltaic (PV) system connected to APS and do not have other monitoring of the PV system such as that provided by most inverter manufacturers, it is not easy to determine the solar production that corresponds with the monthly electric bill.  APS requires a solar production meter and this data is recorded and made available to the customer, but with a little effort.  The following example is based on the system APS calls RCP, utility speak called 'Resource Comparison Proxy' (note that the APS website was developed by utility personnel using their view of the situation, not the customer view). Under RCP APS purchases all excess PV output at a fixed rate. Some APS customers with older PV systems use the now grandfathered 'Net Metering' (rate rider EPR-6) wherein any excess PV production, measured in kilowatt-hours (kWh) is used to offset energy delivered by APS. For either Net Metering or RCP, the APS bills show only the measurements made by the bi-directional billing meter.  A summary of APS rates is available on our website at: Summary of APS Solar Rate Plans- 2019

Look at the recent example of an APS electric bill and see if you can determine the solar production (not shown):

CaldBill1

This APS bill shows that 229 kWh in this case was sold to APS under the RCP rate.  The bill does not show the solar production that was directly used; to determine this, one has to have an APS web account (free) and has to go online to learn more. There is a lot of data available.  Note the 'Meter reading' dates above, this will be used later to calculate the matching solar production. Using a browser such as you are using to view this article, go to https://www.aps.com/

The APS website was recently updated.  The top of the page has a Log In.    

APS Web 1

APS Web 3

Enter your APS username/password then click login.  If you do not already have a username and password, click on 'register'. The following is typical.

APS Web 2

Next select the tab 'Billing and Payment', then click on 'View your billing and usage'.  Be patient, this may take a minute or so while the APS website loads your data.

APS Web 4

 

This is a very useful page. There are really two related pages, 'Energy from APS' and 'Energy to APS'. The above is 'Energy from APS'.  Further detail is available by positioning the cursor over a specific date, this produces a pop-up with details:

APS Web 5 

 In this pop-up: 

Total Produced = PV energy generated

Total Delivered is energy from APS

and the On-peak and Off-peak components

are shown.

Selecting the 'Energy to APS'  tab shows the solar components:

APS Web 6

APS Web 7 

 In this pop-up: 

Total Produced = PV energy generated

Total received is the daily excess energy sold to APS (if RCP) or net Metered to APS.

 

Each of these pages has a 'Create Report' button. 

APS Web 8

There are 3 options:

Download graph data: This will provide daily values

Billing and usage data:

Peak usage data: 

The 'Download graph data' option downloads a file named downloadGraphView (y).xls wherein the 'y' is used if there are subsequent downloads.  These files have a header and 35 days of data.  If prior data is needed, simply select an earlier month. Typically the data will look like this (two months illustrated):

(Note: Windows 10 identifies these files "The file format and extension of 'downloadGraphView (2).xls' don't match. The file could be corrupted or unsafe. Unless you trust its source, don't open it. Do you want to open it anyway?".  Seems that the actual format is not .xls, but Excel loads the files.

APS Web 9

 

The values for the billing date range, July 25 to August 23 in this example, need to be added.  This can be done with the spreadsheet program or manually.  In this example the sum is 711.5 kWh. This is not straight forward since the values shown are actually text and Excel can not directly add them.  Use the =value(cell) function in another column to convert the text to actual values.  Now that the actual solar production is known, the below  chart shows the relationship of these values.

Cald 11

The calculation of Home useage is (Solar Production) + (Purchased from APS) - (Sold or net metered to APS).

Phoenix Solar Requirements- 2019

The City of Phoenix as adopted an Citywide Interpretation concerning New Solar PV Live Loads on Existing Building Roof Structures.

The sub-title is: Adding a new solar Photovoltaic (PV) panel system to an existing building's roof structure where the existing building is not undergoing a change of occupancy.


Basically an interpretation of the 2018 IEBC 303, 502.4, 503.3, 806.2 code. Designers of PV systems ahould review the Interpretation at:

https://www.phoenix.gov/pddsite/Documents/TRT/dsd_trt_pdf_00844.pdf

There is also Interpretation covering Solar Panel Connections:

https://www.phoenix.gov/pddsite/Documents/TRT/dsd_trt_pdf_00702.pdf

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

    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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