Recent Updates

The following items have been recently added or updated:

Some Almost Forgotten Solar History

Berkeley Lab’s “Utility-Scale Solar, 2021 Edition”

Electrification of transportation sector = More Renewable Energy Needed

Tucson Electric Power (TEP) to provide 70% of its energy from solar and wind by 2035

A link to a good article on What You Need to Know to make Sure Your Solar Rooftop is Properly Valued at Time of Sale: Is Solar Sexy When You Sell Your Home?

APS- Residential Battery Pilot Program

See the section "Some things to pay attention to in Arizona", click on the various tabs.

  • 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) The information below is somewhat dated, the incentives have been extended, but reduced.  See our more up to date article. 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:   26% Maximum Incentive:   Solar-electric systems 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


  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 (Select Tab)

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 Interesting Arizona Solar Stories

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Other Announcements

Interesting Technology Updates -Click on a title below

  • - A radical idea to get a high-renewable electric grid

    This is an interesting approach to optaining very high penetration of renewables such as photovoltaics and wind.  At present most large installations operate under Power Purchase Agreements (PPA) wherein the economics are based on a sell all output at predetermined prices. This contrasts with standalone systems wherein the system size Read More
  • - Breakthrough Batteries Powering the Era of Clean Electrification

    - Breakthrough Batteries Powering the Era of Clean Electrification Battery Storage Costs Drop Dramatically, Making Way to a New Era. A recent Rocky Mountain Institute (RMI) report continues to confirm that clean electrification through batteries is advancing at impressive rates. Very interesting report: Breakthrough Batteries- Powering the Era of Clean Electrification Read More
  • - Changes impacting photovoltaic (PV) installations in the 2020 National Electrical Code (NEC)

    - Changes impacting photovoltaic (PV) installations in the 2020 National Electrical Code (NEC) 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. Read More
  • - Arizona's Corporate Commission Eases Solar Restrictions

    KJZZ’s The Show had a good (October 31, 2019 - 1:57pm) article about new rules (2019) regarding the installation of battery-storage and renewable-energy systems, voted on by regulators in 2019.  Worth viewing.  KJZZ website link Read More
  • - Interesting Technology

    An assortment of links to interesting information   Semiconductor Nanowires Could Double the Efficiency of Silicon Solar Cells A p/n semiconductor junction is not the only way of converting sunshine into useful electrical energy.  Light consists of a flow of photons of various energy levels (colors).  See this article-Solar Cells.  Nanowires Read More
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General News

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.

Interesting Videos

Economics of Solar Swimming Pool Heating

Updated Feb. 16, 2014

Swimming pools are popular in Arizona with more being built each year. However, the cost of heating a pool can be an expensive proposition. To extend the swimming season beyond just the hot summer months, pools require a heating device to maintain comfortable swimming conditions.

Solar heating of swimming pools is an economical alternative in Arizona since it can extend the swimming season for outdoor pools significantly - by at least two months in both spring and fall - more if a pool cover is used. Thus the time pools can be used is at least doubled.

solar-pool-heating-economicsInitial costs of a solar installation are estimated in the $3,000 to $4,000 range for a typical home pool, which is similar to the cost of natural gas installations. However, the cost of heating pools with gas can run to several hundred dollars per month so that the payback period for solar units is very short (average 18 months).

Advantages of solar pool heaters extend beyond just economics in terms of payback. Solar pool heaters last significantly longer than gas or electric heaters. A solar pool heater last nearly twice as long as either gas or electric heaters.

As with a solar water heating system, it is important to consider local building codes and regulations before purchasing a system.

U.S Department of Energy (

Economics of Solar Hot Water

Updated Feb. 16, 2014

Solar energy can provide all normal domestic water needs. Backup may be required for cloudy days.

Initial investment is in the $4,000 - $7,000 range, though some systems, cost less. State tax credits (25% of the purchase price with a maximum of $1,000 per installation) and, federal tax credits (30%) and in some cases utility rebates, can reduce initial costs significantly. If conventional heaters need replacement, initial costs are further lowered by the cost of the conventional unit.

How much money you save versus a traditional water heater depends on a number of factors:

The amount of hot water you use Your system's performance Your geographic location and solar resource Available financing and incentives The cost of conventional fuels (natural gas, oil, and electricity) The cost of the fuel you use for your backup water heating system, if you have one.

On average, if you install a solar water heater, your water heating bills should drop 50%–80%.

Costs and payback periods for residential SWH systems with savings of 200 kWh/month
System cost After tax credits/rebates Electricity cost/kWh Electricity saving/month Payback period
$5000 $1540 11.2 cents per kWh $22.40 5.7 years


If you're building a new home or refinancing, the economics are even more attractive. Including the price of a solar water heater in a new 30-year mortgage usually amounts to between $13 and $20 per month. The federal income tax deduction for mortgage interest attributable to the solar system reduces that by about $3–$5 per month. So if your fuel savings are more than $15 per month, the solar investment is profitable immediately. On a monthly basis, you're saving more than you're paying.


Economics of Photovoltaics

Updated November 27, 2019


PV arrays can be used to generate electric power for many end-uses including utility-scale PV projects, or in distributed applications such as homes, cabins, businesses, telecommunication equipment, lighting, and other electrical equipment.

The economics of utility-scale PV projects (solar farms) is difficult to discern given the small and diverse sample of projects and the proprietary nature of third-party contracts. However, the economics of distributed PV systems is well-known. The financial-side of distributed PV is determined by the capital and operating costs and will vary according to the type of PV power system; off-grid and grid connected.

Off Grid PV

Off-grid PV systems in Arizona are cost competitive with electric utilities in situations requiring utility line extension at high-cost (generally for extensions of over 0.5 miles, charged to the customer), and in situations requiring low amounts of power (irrigation control equipment, small lights, etc.) for which the minimum utility charges exceed the amortized cost of the PV system.

Like solar in general, the capital (initial) costs of off-grid PV systems have been falling in recent years; they currently are between $1 and $3 per peak watt of the PV module, less if rebates and tax credits are available. Storage batteries with related charge controllers cost about the same, but until newer battery technology is in volumn production, costs are rising.  Off-grid systems are typically combined with energy efficiency measures to make sure the solar electricity is not going to waste. When designing an off-grid system a quick-rule to follow is that for every dollar spent on energy efficiency measures will save $5 or more on solar generating equipment.

A small house (or larger house with extensive energy efficiency improvements) with a low usage can function with an off-grid PV system as small as 2 kW (peak), thus would call for a capital outlay of $10,000 to $16,000 (before any incentives). Assuming a 20-year simple amortization, this would be equivalent to about 10-20 cents per kWh. Such a unit can supply power for many appliances (refrigerators-freezers, computers, televisions, consumer electronics, etc.) and many lighting systems. It will not provide power for air conditioning or other large energy consuming appliances like clothes dryers or electric ovens. Comparable costs for alternatively home generated power vary but are typically significantly more than the solar alternative.

PV power costs for uses that do not require batteries, such as agricultural water pumping and pool pumps, are substantially lower than off-grid residential systems that include batteries.

Grid Connected PV

While solar has a ways to go to compete with conventional power plant generation costs at 4-6 cents/kWh, it is much closer to grid-parity when compared to the cost of electricity charged to residential, commercial and industrial consumers. This is especially relevant because when the PV is sited at the consumers' premises, then the customer is comparing the cost of PV electricity to the cost of the utility retail power, not to the cost of power generation.

Grid connected PV systems can be of two types, customer-owned or third-party owned (leased).

Leasing a solar electricity system is similar to leasing a car with the biggest exception being the contract terms are much longer in length for solar (typically 15 to 20 years). However, like a car lease, you pay a monthly fee to use the system over a specified period of time. The property owner benefits from the electricity produced by the system. Ideally, the cost of the monthly lease payment is less than the cost of the utility supplied-electricity that is offset by the solar system.

A customer-owned system is not cost-effective compared to utility electric power, but when combined with other considerations become more attractive and economical. Government subsidies, tax rebates/exemptions, the time of day value of summertime PV power, the enhanced value of "Green" power to a utility, etc. can and have made PV systems practical in Arizona.

Net Metering

The value of a PV system's electricity will depend on how much you pay your utility for electricity and how much your utility will pay you for any excess that you generate. The average cost of electricity from Arizona utilities is displayed on the chart below. Net metering is the mechanism by which Arizona utilities pay customers for any excess solar electricity they generate. The Arizona Corporation Commission allows for a kilowatt-hour (kWh) credit at the utility's retail rate for each solar kWh not used by the customer and fed back into the grid. The net metering described in this paragraph and the next paragraph is no longer offered by most Arizona utilities, but existing net metering customers are grandfathered.  At the end of each month any net excess solar generation is carried over to the customer's next bill. Any remaining credits on the customer's last monthly bill on an annual basis will be paid to the customer, via check or billing credit, at the utility's avoided cost payment.

This net metering arrangement was implemented as a way to help encourage PV system interconnection. It allows system-owners to offset some of the costs of purchased electric power by selling surplus electric power back to the utility. In an Off-Grid situation this excess power is typically stored in a battery bank for later use, but in a grid connected system with net metering, the excess power can be "sold" to the utility for use by other customers, and is generally an offset to the purchased power (such as night-time use).

Net metering rules differ among Arizona electric utilities. It is necessary to check with the utility serving a specific address to determine what rules apply for net metering customers in their service territory. See the article on Arizona Electric Utility Information for more detailed information.


For the last several years Lawrence Berkeley National Laboratory (LBNL) has published an annual 'Tracking the Sun' report that summarizes installed prices and other trends among grid-connected, distributed solar photovoltaic (PV) systems in the United States. The 2019 report is now available: Tracking the Sun 2019.



  • 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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