It isn’t commonly known, or even advertised, that about U.S. workers are electrocuted every week.  This is the cause of 12% of all young worker workplace deaths.

It takes very little electrical energy to cause injury or death to the human body.  This can occur with as little as 100 milli-amperes of current.  This is only one-tenth of 1 amp of electrical current.  It is extremely important, therefore, that we are aware of the risks and dangers inherent with working on electrical systems, and this includes working on Solar Photovoltaic systems.

Solar PV panels are considered ‘low-voltage’ devices.  Consider, however, that although they are ‘low-voltage’ a single Solar PV panel can carry a voltage of 36 to 50 volts of Direct Current (D.C) at 5 to 7 amps.  Also consider what we stated above about potential injury or even death at just one-tenth of an amp.  Always remember, that as long as a Solar PV panel is facing the sun it is providing voltage.  Working with electric current is serious business.  Although we shouldn’t fear electric current, we must certainly respect it.

The degree of injury, and the risk of death, from electric shock depends on several factors including the amount of voltage contacted, how the current travels through the body, the person’s overall health and how quickly the shock victim is treated.  It is critically important, therefore, that you call 911 or other emergency number immediately when any of the following symptoms occur due to electric shock:

• Cardiac Arrest
• Heart rhythm problems (arrythmia)
• Respiratory failure
• Muscle pain and/or contractions
• Seizures
• Numbness and tingling
• Unconsciousness

Safety Tips When You Witness Electric Shock and When Waiting for Emergency Help:

It is an important aspect of on the job safety to make sure you are aware of the following when you work with electricity:

1. LOOK FIRST, but DON’T TOUCH.  The person may still be in contact with the voltage source where touching the victim may pass the electric current to you.
2. Turn off the voltage source if possible.  If not, move the source away from you and the victim using a non-conducting object such as a piece of wood, cardboard or plastic.
3. Immediately after removing the person from the voltage check for signs of circulation such as breating, coughing or movement, and call 911 Emergency Services.
4. If the person is not breathing, immediatley begin cardiopulmonary resuscitation (CPR).
5. Once you are able to restore breathing, try to prevent ‘traumatic shock’ by making sure the victim is lying down with the head slightly lower than the trunk and the legs slightly elevated.
6. Do not try to move the person to another location unless the person is in immediate danger.
7. CAUTION! Dont get near the high-voltage wires until the power is turned off.  Stay at least 20 feet away, or further if the wires are jumping and sparking.

On the Job Electrical Safety Tips

Over the years many people, probably in the thousands, have been injured or killed while working around electricity…even in the home.  The sad part is that in many of these cases these injuries and deaths have occurred even though the victims were aware of the risks and hazzards.  The problem is that people don’t always take the time to first eliminate the risks.  The following are safety tips you should ALWAYS take time to perform BEFORE you work on any electrical circuit.   Remember,  ordinary 120 volt household voltage is the most common source of fatal electrical accidents.

• Never use bare wire for exposed circuits or open construction with exposed connections
• Never work on electrical wiring with the conductors energized.  Remember, all Solar PV panels produce energy in the presence of sunlight even when they are not connected
• Always use a voltmeter or other tester to check for the presence of energy, even AFTER you turn off the circuit breaker.  Even the best intenioned electrician can sometimes turn off the wrong circuit breaker.
• Be aware that destructive transient (stray) voltages and currents from lightening and power line faults can reach PV equipment or other circuits you may be working on.  These transient voltages can come from such things as TV antennas, telephone and cable TV cables, or metallic roof structures.  A good rule to practice is to NEVER work on electrial circuits during bad or inclement weather.
• Always use protective mats and gloves when working in high-voltage environments such as power distribution stations, power transmission stations, and cell and PCS sites where antenna towers and power lines can be a source of transient voltages.
• Always keep a safe distance from energized electrical circuits
• Never “assume” that a circuit is at zero potential even after the switch is turned off.  Remeber, capacitors in a circuit can retain a charge for a long time period.
• Never rely on another person to turn off and lock-out a voltage source.  Always do this yourself and check for voltage presence AFTER you do so to verify the circuit is “dead” before you start working on it.
• If you must hold a voltage probe to take a measurement, a good safety practice is to keep one hand in your pocket to avoid hand-to-hand current flow through your body if you short circuit yourself across a voltage
• Never work alone.  Always make sure someone is nearby your work area, and make sure they know how to turn off or remove the power source safely in case you are electrocuted.  Also, make sure they know not to touch you until the power is turned off, and to call 911 emergency services in the case of electrocution.
• When you replace a fuse or a circuit breaker, replace ONLY with those having proper voltage and current ratings for their circuit.

MOST OF ALL…in ANY job…Always Think SAFETY!

By Burt Price, Executive Vice President, Ameri-Skills Technical Training

One of the greenest opportunities in years is brewing on community college campuses across America.  The U.S.A. has officially embarked on a mission to reduce its addiction to foreign oil and is now investing heavily in building a green economy.  The combination of President Obama’s Renewable Energy Programs along with new federal tax incentives, utility rebate programs, state community outreach programs and pending approvals of feed-in tariffs are creating a golden opportunity for community colleges to harness the power of students seeking clean green energy training courses.

 Federal Renewable Energy Programs

Leading the pack is President Obama who signed a massive $787 billion American Recovery and Reinvestment Act in February 2009, which provides up to $75 billion in formula-based education grants^[1], $61 billion on building renewable energy related programs^[2], and over $150 billion over the next ten years to create green jobs^[3].

Last October, the federal government also extended a 30% federal tax credit for residential customers and created a 30% tax grant for commercial customers to subsidize the costs of building solar and alternative energy power plants^[4].

 State Regulatory Energy Policies

In addition to federal money, many state regulatory and public utility commissions have passed Renewable Energy Standards that require utility companies to set up budgets for both renewable energy incentive/rebate programs and the community outreach programs needed to market them to the masses.^[5]

 Utility Rebates

Utility companies are required to allocate hundreds of millions of dollars for renewable energy rebates and incentive plans^[6] designed to help residential and commercial customers pay for the installation of their energy efficiency and renewable energy renovations.

 Utility Marketing Programs

Utilities are also required to fund large community outreach marketing programs to educate their customers on how to reduce their electricity usage through demand side management programs and how to increase the production of clean green power from systems that are powered by solar, wind, geothermal and other flavors of alternative energy.

 Economic Development, Feed-in Tariffs and State Marketing Programs

Governors and state legislatures are interested in renewable energy too because they understand the vital importance that these projects hold for stimulating economic development, creating new jobs and, at the same time, reducing the amount of carbon emissions being emitted into the earth’s atmosphere.

For example, Governor Schwarzenegger recently signed California Feed-in Tariff and Net Metering legislation that becomes effective Jan. 1, 2010^[7], which pays homeowners and businesses an above market price for electricity that is generated from solar systems above the amount the use.

Using feed-in tariff programs has made Spain and Germany the largest solar producing nations in the world.  Arizona, Arkansas, Florida, Hawaii, Michigan, Minnesota, Iowa, Indiana, New Mexico, New York, Oregon, and Washington State are currently evaluating the use of feed-in tariffs^[8].  As more states approve feed-in tariffs, investment will pour into these markets and a large number of alternative energy workers will be needed.

To remove other barriers-to-entry, the state of California has launched a very successful www.GoSolarCalifornia.com^[9] marketing campaign, which educates customers on the benefits of installing solar.  The program provides step-by-step instructions and literature for solar advocates on how to petition local government officials to remove the last standing hurdles in the way of rapid of solar deployments such as permit fees and home owner association rules.

 Golden Opportunity for Community Colleges

As the momentum grows for solar and other types of alternative energy programs, more and more residential and commercial customers will make the decision to add green power systems to their homes and buildings.  Unfortunately, the demand from consumers may soon outpace the number of experienced workers needed to build the coming wave of renewable energy projects.

For community colleges that can move quickly, augmenting their curriculum to include solar, wind and geothermal courses will be a sure way to attract students that want to become renewable energy entrepreneurs and green collar engineers.

School administrators that take a “wait-and-see” approach may find that the number of qualified instructors needed to teach classes will be insufficient to meet the marketplace demand.  Accordingly, Community colleges need to work swiftly to find training materials and develop expert “hands-on” training programs that will teach students the right set of skills to perform quality installations.

The good news is there are numerous Workforce Investment Act funding^[10], job training grants^[11], and educational stimulus money available to fund the development of renewable energy training programs^[12] .

 Alternative Energy Job Training Guidelines

One company that can help community colleges meet the demand for alternative energy training programs is Ameri-Skills (www.ameriskillstech).  Ameri-Skills has been working closely with ETA, International to develop a set of Alternative Energy Job Training Guidelines^[13].  These job training guidelines specify a framework of requirements that alternative energy programs need to meet in order for their students to be able to perform well in the alternative energy marketplace.  (www.eta-i.org)

ETA’s staff works closely with school administrators to help them implement Ameri-Skills alternative energy curriculum and streamline installation practices through real world “hands-on” training classes.

 Continuing Education Workforce Programs

Working alone, it may take a community college up to 12-18 months to implement an alternative energy program.  In the meantime, many students in their community simply will not be able to wait to obtain the training they need in order to enter the booming alternative energy business.

Ameri-Skills makes it easy for a community college’s continuing education faculty to provide popular solar PV, solar thermal and wind training programs that can provide students affordable ETA entry-level certifications.

Providing alternative energy workforce training programs is an excellent way for community colleges to become an established leader for renewable energy training in their communities and for school administrators to gain inside knowledge and experience on the renewable energy industry.

Most community colleges will need to begin holding one-week training courses at least once a month.  The classes include four days of classroom training, an ETA Certification Test and eight hours of “hands-on” instruction.  Students that pass the class will receive an entry-level installer certification, which shows prospective employers that they are qualified with sufficient knowledge to begin a career in the renewable energy sector.

ETA has developed more than 50 different training certification programs and has more than 900 certified administrators in the field.  Over the past 31 years they have issued more than 100,000 certifications and have successfully placed students in thousands of businesses, branches of the federal government and the U.S. Armed Forces^[14].

 # # #

 Burt Price, Executive Vice President of Ameri-Skills.  Mr. Price manages Ameri-Skills’ business development for the company’s alternative energy training programs for universities, community colleges and vocational schools across North America.  Interested colleges can visit the company’s website or call him directly at (800) 710-7595 to learn more about building an alternative energy training program for their community.

^[1] http://www.ed.gov/policy/gen/leg/recovery/index.html

^[2] http://apps1.eere.energy.gov/news/doe.cfm

^[3] http://www.barackobama.com/pdf/factsheet_energy_speech_080308.pdf

^[4] http://www.dsireusa.org/documents/SummaryMaps/TaxIncentives_Map.ppt

^[5] http://www.dsireusa.org/documents/SummaryMaps/Rebate_map.ppt

^[6] http://www.dsireusa.org/

^[7] http://apps1.eere.energy.gov/news/news_detail.cfm/news_id=11592

^[8] http://www.wind-works.org/FeedLaws/USA/StatesProvincesConsideringFeed-inTariffs.html

^[9] http://www.gosolarcalifornia.org/

^[10] http://www.doleta.gov/USWORKFORCE/

^[11] http://www.doleta.gov/business/Community-BasedJobTrainingGrants.cfm

^[12] http://www.ed.gov/policy/gen/leg/recovery/index.html

^[13] http://www.eta-i.org/

^[14] http://www.eta-i.org/ETA%20Companies%20Who.pdf

Batteries

Technically, a battery is any device that can store energy.  But what we typically refer to when we think “battery” is an electrochemical device that converts chemical energy into electricity through a galvanic cell.  A galvanic cell is a device consisting of two electrodes of different metals that we call anode and cathode, and an electrolyte chemical (usually acid) solution.  When we connect two or more of these galvanic cells in a series connection we call this a battery.  For example, the left side of the graphic below shows a single cell of a multi-cell battery connected in series inside of a casing.

PV System Batteries

In a stand-alone off-grid system, batteries store energy created by the Solar PV panels to use later at night where utility grid power or other energy source power is not available.  In an off-grid PV system, batteries are typically the second most expensive component of the system.   Therefore, the type and care of off-grid PV System batteries is critically important to the long-term cost-effective operation of the system.

A battery’s capacity for holding energy is rated in amp-hours, 1 amp of current delivered for 1 hour = 1 amp-hour.

Also, battery capacity is typically listed in amp hours at a given voltage.  For example, a battery rated at 100 amp hours (20 hour reference) will deliver 5 amp hours for 20 hours before being discharged.  Note that manufacturer’s typically rate storage batteries using a 20-hour rate.

Another way to rate batteries is by their charge “cycles”, where a “cycle” is one complete discharge and recharge of the battery.   These ratings apply to batteries as either “shallow” cycle or “deep” cycle.   Shallow-cycle batteries, such as those used in automobiles, are designed to deliver several hundred amperes of current for just a few seconds, i.e., a high charge, in order to turn the starter to start the car.  Once started, the car’s alternator takes over and the battery is quickly recharged.   Shallow charge batteries, therefore, are used in applications where a large charging current is needed for a very short time.

Conversely,” deep-cycle” batteries are designed for long-term energy storage where only a few amperes of current are need for hundreds of hours between charges.   This is typically what is required for an off-grid PV system and, therefore, deep-cycle batteries are best suited for stand-alone PV power systems.

Keep in mind that these two types of batteries are designed for different applications and should never be interchanged.

Also keep in mind that battery cycle of a battery depends the depth of discharge for a given battery, where this can have a major affect on the lifetime of the battery.  Depth of discharge (DOD), also called “state of charge” of a battery is a measure of how much a battery is discharged (DOD) or how much energy remains in the battery (State of Charge).  It is important to remember that batteries should never be discharged beyond their rated DOD.  Discharging a battery below its DOD rating can cause damage to a battery which will affect its life time.  This can also lead to over-charging a battery to bring it back up to full charge, which can cause boiling of the electrolyte and further damaging the battery.

The following is a list of basic rules to follow to help you extend the life of your batteries in your Off-Grid PV System.

1. Always install and/or replace batteries in sets as batteries like to be together in the same group.  If you have 8 batteries in your system, avoid replacing just one or two batteries.  Try to install them all at the same time, and replace them all at the same time.  (However, it is also a good practice to rotate two batteries at a time in your set with fresh batteries as long as you rotate through the entire battery array at even time intervals).
2. Always check your battery connections; avoid battery post corrosion.
3. Try to keep the battery enclosure temperature somewhere between 50-90°F.  This will help extend the life of the battery as well as its efficiency.
4. Once they are installed, try to avoid moving or disturbing your batteries as much as possible.
5. Use a hydrometer to test the electrolyte level of each and every battery cell at least 2-3 times each year.   Recording these levels readings can help with changing trends to determine when to replace your batteries.

Roofers and Solar Installers don’t always talk the same language when it comes to explaining roof angle.  Solar Installers are always told to install panels at an angle – given in degrees (usually based on latitude position).  Roofers, on the other hand, use construction terms to define a roof angle. A  roofer describe this angle as “pitch”. For example a “5:12 Pitch”  means for every 12” of run there is a 5’ rise.  A Solar Installer can easily find the pitch of an existing roof  using a simple L-Square and a small level.

Hold the level against the L-Square and make sure the bubble is level. The “run” should be at the 12” mark. Check the rise. In this case we can see that there is 5 inches or rise for the 12 inches of run.  As you can see, we have created a triangle between the L-Square and the roof.

Since the purpose of this article is to get to the answer, we will avoid deep trigonometric functions and other math terms that make grown men weep – or slip into a coma while standing on a ladder. All we are looking for is angle “a”, as shown in the right triangle below.

We are looking for angle (a)

Now, your calculator must have an inverse tangent function. Sometimes these are labeled atan, arctan, or tan^-1 button. Often you must hit the 2^nd function key of the tan button to get the inverse function. Also, make sure your calculator is set up to give answers in degrees instead of radians.

To calculate the angle of a 5:12 roof enter;

tan^-1 (5/12) = 22.619 degrees

This works with any roof rise. For example;

tan^-1 (1/12) =    4.763  degrees

tan^-1 (2/12) =    9.462  degrees

tan^-1 (3/12) =   14.036 degrees

tan^-1 (4/12) =   18.434 degrees

tan^-1 (5/12) =   22.619 degrees

tan^-1 (6/12) =   26.565 degrees

tan^-1 (7/12) =   30.256 degrees

tan^-1 (8/12) =   33.690 degrees

tan^-1 (9/12) =   36.869 degrees

tan^-1 (10/12) = 39.805 degrees

tan^-1 (11/12) = 42.510 degrees

tan^-1 (12/12) = 45         degrees

Tom Cawley – PV Installation Instructor

Hundreds, or even thousands, of people have been killed or injured while working around power lines, or even when working on common household electrical circuits. In fact, ordinary 120 volt house circuits are the most common source of fatal electrical accidents. Therefore, to help you with ‘Safe Job Performance’, we offer the following safety tips for working on Solar PV Installation. However, keep in mind that if you are not an electrician, the best tip we can offer is to always consult a qualified licensed electrician. If you are an electrician, these tips are reminders as to how to stay safe.

1. NEVER use bare wire for exposed circuits or open construction with exposed connections
2. NEVER work on electrical wiring with the conductors energized. Remember that all Solar PV Panels produce energy in the presence of sunlight, even when they are not connected to a circuit.
3. ALWAYS use a volt-meter or other voltage tester, to check for the presence of voltage. This ensure the circuit is “dead” even after you turn off the switch or circuit breaker. It is VERY IMPORTANT that YOU personally turn off the switch or the circuit breaker and tag it before you check for the presence of voltage with a meter. DO NOT rely on someone else turning it off for you.
4. BE AWARE that destructive “transient” (stray) voltages and currents from lightening and power line faults can reach PV equipment you may be working on. These transient energy sources can come from outside antennas, telephone and CableTV cables, or metallic roof structures. Never work on electrical circuits during bad or inclement weather.
5. ALWAYS use protective mats and gloves when working in high-voltage environments such as power distribution stations, power transmission stations, cell sites, and PCS sites where antenna towers and power lines can be a source of transient voltages.
6. ALWAYS keep a safe distance from energized electrical circuits.
7. NEVER assume that a circuit is zero potential even after the switch is turned off. Capacitors in a circuit can retain a voltage charge for a long period of time.
8. If you must hold a voltage probe to take a measurement, a good safety practice is to keep the other hand in your pocket to avoid touching a ground point with it and causing hand-to-hand current flow though your body.
9. NEVER work alone. Always make sure someone is in the room with you and be sure they know how to safely turn off the power. If they grab hold of you while you are energized and the power still on, they will be shocked as well.
10. ALWAYS replace fuses and circuit breakers with only with replacements having proper ratings.

Up to now, there existed only one option for any kind of acknowledgement of entry level knowledge of Solar Photovoltaic basics. This option was the NABCEP Entry-Level Certificate of Knowledge.

Today, this no longer holds true. Thanks to the Electronics Technician Association (ETA), you now have another option. Today you can now earn an “ACCREDITED CERTIFICATION” as an Entry-Level Solar PV Installer. ETA is a worldwide and highly respected entity that has provided over 100,000 technical certifications in the fields of electronics, fiber optics and others since 1978. ETA is accredited by the International Accreditation Council (ICAC) which audits ETA’s certification programs on a 5 year schedule. This assures quality solar training by qualified instructors because in order to offer an ETA certification not only does the course and materials need to be reviewed and approved, but the instructor must also be certified to teach the material and to proctor the exam. The ICAC audits make sure this happens. Then, to make sure the certification competencies are complete, ETA certification requires a hands-on component where each student must complete specific skills tasks, in addition to passing a written exam, in order to earn the Entry Level Installer Certification.

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