WHAT IS THE DIFFERENCE?

Monocrystalline vs Polycrystalline Photovoltaic Cells

You may have heard the terms monocrystalline and polycrystalline used to describe photovoltaic cells, but what does that mean and how does it affect a cell’s performance?

Basic Anatomy of a PV cell

A lump of pure silicon

The main ingredient in most photovoltaic cells is silicon – the same element that makes computer chips possible.  Silicon is the second most abundant element in the Earth’s crust, but unfortunately it is normally found in the form of silica – you might know it as sand.

Various methods exist to extract the pure silicon, but the most common is carbothermic reduction, where the silica is heated to 1700°C in the presence of carbon.  As the silicon cools it forms crystals.

The speed at which the silicon cools is one of the critical factors that determine the crystal size: the slower the silicon cools, the larger the crystals.  With care the silicon can be extracted as one large crystal.  As you might imagine, that’s more difficult, which means it’s more expensive.

The difference between monocrystalline vs polycrystalline solar cells is simply that one is produced from a single crystal of silicon and the other is produced from a piece of silicon consisting of many crystals.

Practical Differences

So what is the impact on cell performance?

Since polycrystalline cells contain many crystals, they have a less perfect surface than monocrystalline cells.  This means that they absorb slightly less solar energy and produce slightly less electricity per square foot. On the plus side, the process of creating the silicon for a polycrystalline cell is much simpler, so these cells are generally cheaper per square foot.

On balance, the cost of monocrystalline vs polycrystalline based panels per Watt of power output works out about the same, but the polycrystalline panels will be slightly larger than equivalent monocrystalline panels.  This is generally not a problem unless you have a very limited area available for the installation, in which case you will want to maximise the power output per square foot.

Monocrystalline and polycrystalline can also look different.  Monocrystalline cells will usually have a perfectly uniform appearance, but polycrystalline cells will appear “grainy” – think of how a granite worktop looks and you’ll get the idea.  From a distance this will not be noticeable, so if they are going on your roof this is unlikely to worry you.

 So which should I choose?

At the end of the day, unless you are very space constrained, your choice of panel will probably be dictated by factors other than whether they are made up of mono or polycrystalline cells.

The price per Watt is an important factor, and that is largely unaffected by the choice of monocrystalline versus polycrystalline cells.  In some circumstances, the area available for the installation may be a factor that pushes you to go for monocrystalline cells.

But the most important thing is to make sure that you choose a reputable installer and manufacturer.  Your panels will most likely give you many years of trouble free operation, but for your own peace of mind you will probably want to choose a manufacturer that is likely to be around for long enough to honor the terms of the guarantee – which may be up to 25 years!

Please contact Electrical Systems and Services, Inc should you have any questions or would like to schedule a site survey to see the potential your home or business could have with a solar system installed.

QUESTIONS TO ASK ABOUT SOLAR......

5 Questions to Ask Before Purchasing a Solar Electric System

There are a nerve-wracking number of solar manufacturers and installers out there, so Electrical Systems and Services, Inc. came up with the 5 most important questions to ask before making the decision to install solar modules on your roof.

1. “How many systems has your company installed?”
Due to the recent spike in solar panel installations, and the decrease in other construction-related businesses, many roofers, fencers, and builders are attempting to start solar installation companies with no solar experience and without proper solar installation knowledge. Look for a reputable installer with an NABCEP certification as Electrical Systems and Services does.

2. “Is the warranty on my solar panels 25 years?”
Most solar panels on the market are high-quality and will have a guaranteed output of not less than 90% after 10 years and no less than 80% after 25 years. Any brand panel should have this warranty, whether it’s made in China, Germany, or America.

3. “Is the warranty on your labor 10 years or longer?”
Some states require installers to warranty their labor for 10 years in order for the system to be eligible for state rebates. Any good installer should have no problem including this.

4. “How many kilowatt-hours will the system produce the first year?”
This is arguably the most important factor in comparing solar electric systems (other than price, of course). If you have solar panels warranted for 25 years, and labor guaranteed for 10, then the brand of solar panel – whether Canadian Solar, SunPower, Suntech, Helios or any other – doesn’t matter. The only thing that matters is how much energy they are expected to produce in a year. Many times the cheaper, “less efficient” solar panels will produce more energy in a year at a better price than the pricier, “more efficient” solar panels. When warranties are the same, output is the money-maker, not brand or efficiency.

5. “How much will it cost? (…after parts, labor, installation and rebates)?”
Don’t compare the cost of the panels exclusively, or the labor exclusively. Compare the bottom-line cost after rebates. Whoever can give you the most output (kWh/year) at the best price, is the company you should chose. This is what Electrical Systems and Services, Inc. calls ‘solar value’.

NABCEP CERTIFICATION FOR RJ DATT

North American Board of Certified Energy Practitioners

RJ Datt of Electrical Systems and Services, Inc. has successfully satisfied the requirements and standards for the Certified Solar PV Installer in credentials established by the NABCEP Board of Directors.

This is a great honor and achievement, as it means RJ is one of very few Certified Solar PV Installers in SouthEast Wisconsin.

PV Installer Certification

The NABCEP PV installer certification is a voluntary certification that provides a set of national standards by which PV installers with skills and experience can distinguish themselves from their competition. Certification provides a measure of protection to the public by giving them a credential for judging the competency of practitioners. It is not intended to prevent qualified individuals from installing PV systems nor to replace state licensure requirements.

The target candidate for NABCEP certification is the person responsible for the system installation (e.g., contractor, foreman, supervisor, or journeyman).

The NABCEP PV Installer certification has been developed in accordance with the certification field’s best practices. NABCEP is a member of the Institute for Credentialing Excellence (I.C.E.) and has endeavored to follow the requirements of ISO/IEC Standard 17024: General Requirements for Bodies Operating Certification Systems of Persons.

NABCEP’s PV Installer Certification is North America’s only renewable energy personnel certification that has been ANSI accredited to the internationally recognized ISO/IEC 17024 standard.

Congratulations to RJ on this great accomplishment!

T12 LIGHTING PHASE-OUT JULY 1, 2012

What should I be prepared for?

• Manufacturers will be phasing out their production

of T12 lamps and ballasts

• Progressively less availability of T12 lamps and

ballasts

• Increased cost of T12 lamps and ballasts due to

demand vs. limited supply

• To keep up with federal regulations of energy

efficiency, manufacturers’ technology and production

will be focused on T8 and T5 systems

What T12 Lamps are affected by this

phase out?

• T12 4-ft. & 2-ft U-lamps with medium bi-pin bases

   - Majority of F40 and F34T12 lamps and all FB40

and FB34T12 U-lamps

   - 4-ft. requires 3560 lumens @ 40W and 3030

lumens @ 34W to pass @ 89 LPW

   - 2-ft. U-lamps require 3360 lumens @ 40W and

2856 @ 34W to pass @ 84 LPW

• T12 8-ft. Slimline with single pin bases

   - All 75W F96T12 lamps

   - All 60W F96T12/ES except for the 800 Series

• T12 8-ft. 800mA HO with RDC bases

   - All 110W F96T12 HO lamps 

   - All 95W F96T12/ES/HO lamps

Did you know?

Approximately 30 percent of all fluorescent lamps sold

in the U.S. are still T12 technology. As a result of the

T12 phase out, 70 percent of all T12 fluorescent lamps

sold in the U.S. will be phased out come July 2012.

FAQ's

1. Why are T12 fluorescents systems being 

phased out?

Answer: T12 lamps and magnetic ballasts are 

considered outdated compared to the far more energy 

efficient T8 and T5 fluorescent technologies now 

available. The Department of Energy’s objective is to 

remove less efficient T12 fluorescent systems from the 

market, and thus increase lighting energy efficiency for 

organizations. 

2. What type of energy savings can I expect 

for upgrading?

Answer: Managers of facilities can select from several 

upgrade scenarios which could result in energy savings 

as high as 45 percent, with attractive 1-3 year simple 

paybacks to the building owner. 

3. Why are Energy Efficiency Fund incentives only 

offered for a limited time on T12 upgrades?

Answer: Once the DOE mandate becomes effective, 

it will become common practice to remove less efficient 

T12 systems; therefore, retrofitting T12 systems will be 

the customer’s only option for maintaining their old, 

inefficient lighting system.  Energy Efficiency Fund 

incentive programs will likely not support commercial 

and industrial T12 system retrofits in the future.

4. Are there some T12 systems that will continue to 

be manufactured?

Answer: Yes.  The following will continue to be manufactured:

• T-12 ballasts designed to dim fixtures more than 

50 percent of their full light output

• T-12 ballasts driving 8-foot, high-output fixtures 

designed for outdoor advertising

• T-12 ballasts designed and labeled for use in 

residential applications

5. Should I gradually change out my T12 magnetic 

ballast system or should I change it all at once?

Answer: In order to take advantage of the Energy 

Efficiency Fund’s 50 percent upgrade incentive, a 

project must upgrade the lighting system as a whole, 

not as individual fixture upgrades.

Please contact Electrical Systems and Services, Inc. with any questions or for a FREE evaluation and proposal for your lighting upgrade needs.

SOLAR MYTHS AND FACTS

MYTH #1: There are no jobs created by the solar industry

FACT:Today, the solar industry employs more than 100,000 Americans, double the amount of solar workers in 2009. They work at more than 5,000 companies, the vast majority being small businesses, in all 50 states. The industry grew by 69 percent in the past year, making it one of the fastest growing sectors in the U.S. economy.

MYTH #2: Solar only works in states like California.

FACT:Solar energy works in all 50 states. Germany has more installed solar capacity than any other country and it receives roughly the same amount of sunshine as Alaska. Less than one-third of the photovoltaic (PV) capacity installed in the U.S. in the second quarter of 2011 was installed in California. In fact, more PV was installed on commercial buildings in New Jersey than in California during that quarter.

MYTH #3: The market for solar energy is very small.

FACT:The U.S. solar energy market is big and growing fast. In 2010 alone, $6 billion worth of finished solar energy systems were installed in the U.S. The U.S. solar energy market grew 69 percent in the second quarter of 2011, helping aid our economic recovery. In fact, many analysts project that the U.S. will become the largest solar market in the world in the next few years.

MYTH #4: Solar energy is too expensive for widespread usage.

FACT:Solar energy is already cost effective in many locations across America. The price of solar modules has dropped 30 percent since the beginning of 2010 as the industry scales up and companies innovate with new products and manufacturing techniques. Also, new financing options allow homeowners and businesses to start saving money on their utility bills as soon as they turn on their solar systems.

MYTH #5: If solar power really worked, it wouldn’t need government support.

FACT:The U.S. decided long ago to support energy sources since energy drives our economy. Every major energy source and technology has benefited from federal government R&D support and incentives of various types. This is true of the oil, natural gas, hydroelectric, nuclear and biofuels industries—all of which continue to receive government support today.

MYTH #6: Solar products are all made in China.

FACT:The U.S. was a significant net exporter of solar products in 2010, including to China. Total U.S. exports of solar energy products was $5.6 billion, with net exports totaling $2 billion. Of the $6 billion in direct value created by U.S. solar installations in 2010, more than $4.4 billion, or 75 percent of the value, accrued to the United States.

MYTH #7: Solar devices require more energy to manufacture than they produce in their lifetime.

FACT:Studies have conclusively demonstrated that energy payback for photovoltaic (PV) energy is now less than three years. Given that PV module warranties are generally in excess of 20 years, a PV system will produce far more energy over its lifetime than was consumed to manufacture it. Technological progress is reducing the energy consumption of PV manufacturing further. Energy output and input ratios for concentrating solar power (CSP) and solar water heating equipment are also favorable.

MYTH #8: Solar energy needs a technological revolution to go mainstream.

FACT:Solar technologies available today already provide enough electricity to power 630,000 American homes. Solar panel prices have fallen 30 percent in the past year and a half. No scientific breakthroughs are required for solar energy to power America. Solar is 

Gateway Technical Institute adds 3 Windspire wind turbines

For those of you that have driven or walked around the Racine Gateway Campus you have probably noticed the newly installed Windspire wind turbines. ESS installed the three units and they are now producing electricity for the campus. The units are located on the east side of the building and are very easy to see.

Just another way Gateway is looking to improve the look of the campus for the students and to help offset  the rising energy costs.



DREAM WITH THE WIND

Why Small Wind?


For homeowners, farmers, small businesses, and public facilities, a wind turbine is a smart investment that will lower your monthly expenses, increase your net worth, and help support manufacturing jobs. At the same time it will help clean the air, slow climate change, and move us towards energy independence.

For remote sites without grid power, a wind turbine can significantly lower operating costs over a diesel generator and provide sustainable power where the power grid cannot reach.

Electrical Systems and Services, Inc. is an authorized dealer of Bergey Wind Turbines




Why Bergey?

Bergey Windpower is the oldest and most experienced manufacturer of residential-sized wind turbines in the world.

Thirty years ago Bergey pioneered the radically-simple “Bergey design” that has proven to provide the best reliability, performance, service life, and value of all of the hundreds of competitive products that have come and gone in that time. With only three moving parts and no scheduled maintenance necessary, the Bergey 10 kW has compiled a service record that no other wind turbine can match. We back it up with the longest warranty in the industry.

There are now many new small wind products on the market. Though sometimes heavily promoted, these new entrants lack the track record that provides confidence as a sound investment. Over the years Bergey wind turbines have often replaced unsuccessful competitive products. The bottom line is that wind turbines are a big investment, and Bergey is the wise choice.