Picking Solar Panels – Finding the Best Solar Panels

Last Update: August 23, 2018

The Earth receives more energy from the Sun in one hour than the whole World uses in a whole year.  Time to tap into that. Solar power is used to power everything from calculators to Coast Guard buoys to highway signs to the International Space Station.

You have read Are Solar Panels for me? and Solar Panel Installation – Planning and are ready for more details. Photovoltaic Solar panels were invented at Bell Labs in 1953. They have evolved over the years and several different types of solar panels exist, and choosing between then is confusing.  No one vendor will have access to all products, so you will have to do some shopping around to find the best solar panels.

After speaking with some industry veterans, the following companies were recommended. They reiterated that most US and Canada made panels are good.

• Sunpower (Sold only by Authorized dealers)
• Panasonic
• LG
• Hyundai
• Shell

The main criteria is efficiency, how fast the efficiency falls off, and long term reliability.  There are many cheaper solar panels from Asian companies that may not have long track records. Be careful being tempted with cheaper panels that may fail sooner than expected.

Monocrystalline or Polycrystalline Panels

These solar panels are made either from single crystal cells or stringing ribbon of multiple crystals. They are the classic version of solar panels and are rated for good efficiency, around 12-13% power conversion, and a Long lifespan, possibly 30 years+?  Sunpower has a model with a very high 22% efficiency.  Monocrystalline panels are less efficient in hotter climates and work best in unobstructed sun.

Polycrystalline panels are the most popular today.

Do not spend too much time overthinking this, Most people judge panels on:

• Cost
• Efficiency
• Warranty
• Track record

Most older solar panel’s power will drop by to the lowest one in a string if even one cell on the panel is partially shaded. Micro inverters in each panel help mitigate this.

Micro Inverters are made by:

• Enphase
• Power One
• Enecsys

Temperatures typically above 75 degrees F cause most solar panel power generation to decrease.

Solar panel suppliers include:

• Sharp
• Hitachi
• Mitsubishi
• Kyocera
• LG
• Panasonic
• SolarWorld (German company with USA factory)
• SunTech
• Sunpower
• bp solar
• Mitsubishi electric
• Evergreen solar

Often time, the brand of panel you purchase is dictated by the solar company you use. Sometime they will have a special on one brand, or an older model, which makes picking a particular solar panel more attractive.

Thin Film Panels

Less efficient than the Crystal Panels, but they much thinner and easier to make.  Less efficient than monocrystalline, at 10-12% efficiency. They work better when you have slight shading and are not affected by hot weather as much as monocrystalline. Major Drawback of performance degradation over time.  Possible lifespans of 10 years. Suppliers include: Nanosolar, Unisolar

Hybrid Panels

Hybrids of single crystalline silicon surrounded by ultra-thin amorphous silicon layers.  Produces 10% or more electricity  (kWh) than conventional crystalline silicon solar panels at the same temperature. Good efficiency levels of 16%. Hybrid Solar Panel Suppliers include: Sanyo

Solar Panel Quality Control

With the falling prices of solar panels, companies are being squeezed for profits. Recent audits have found that some solar panel manufacturers have been cutting corners. Defect rates have been averaging 8% on unshipped panels, while some have defect rates as high as 20%. These companies are fighting to stay in business. When considering a solar electric power system purchase, be sure to understand the warranty and the manufacturer’s reputation.

Warranty and our Old Solar Electric Panels

How long do solar panels really last? 25 years? How reliable are they?

There are some answers for our system. First the Solar Panels:

• Original Installation Date: 2004
• Solar Panels: Schott North America ASE 300/50
• Number of Panels: 16 300 Watt panels
• Power output warranty: Ten Percent (10%) during the first ten (10) years and (ii) twenty percent (20%) during the first twenty (20) years
• Schott stopped selling solar panels: 2012
• One panel failed 2017 (13-years old)
• One panel failed 2018 (14-years old)
• Schott replaced the two dead solar panels in 2018!

Our Power Inverters

• Model: 2 SMA Sunny Boy 2500U-SBD Inverters
• One inverter failed 2018

Are you thinking about adding solar?

Posted on January 1st, 2019
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