With so much attention these days on solar panel manufacturers, it is appropriate to focus the first part of this 5 part series on the main driver of a solar electric (PV) system. This article will focus on the territories or the United States we are most familiar with like; Minnesota, Wisconsin, Louisiana, North Carolina, and Illinois and how the solar panels produce power in them.
Consumers are often confused by misleading marketing strategies on Efficiency, Company Strength, Performance Warranties, Durability, and Real World Output. Our extensive product procurement process takes all of these it to consideration and are outlined in our professional opinion based on intense experience and diverse national experience with many of the industry leading manufactures.
Solar Panel Efficiency- Panel efficiency is often the most misinterpreted item when it comes to comparing solar panels. Efficiency from solar manufacturers is almost always on their data sheets and it should never be used as a leading indicator against power production in real world circumstances. With a large gamut in efficiency ratings the only thing to consider when comparing efficiency is how much space it will take up to generate the overall power.
Efficiency on panels is so much more different then efficiency for instance on a water heater, refrigerator, or an air conditioner. Rather than indicating how a appliances uses energy, and because a solar panel doesn’t use energy, it is a reference to its ability to convert all of the suns energy on a scale of 1,000 watts per meter squared. So a higher efficient panel simply takes up a slightly less area to produce the same power, a 10% efficient solar panel vs. a 20% efficient solar panel rated at 200 watts simple means the 20% panel takes up half the space of a 10% module to produce the very same 200 watts.
Your core solar panel module floats around a panel efficiency (not cell efficiency, which is always slightly higher) of 15%, this area of rating provides the best bang for your buck or your fastest return on investment with maximum overall durability.
I often get asked about record breaking efficiency and "why shouldn’t I wait until the technology gets better". This is often misleading as what makes the news is the efficiency that we see hitting satellites and are financial unreasonable on an investment standpoint. There are some technologies that have been making some waves for quite some time now like, printed cells, new manufacturing process, etc. I am here to tell you what we have now with Polycrystalline modules is a durable product that is very much so perfected and will be here now and into the future as the core panel product.
The last item as it refers to efficiency is specific to the 2 core types of modules, Polycrystalline and Monocrystalline. Poly is taking over the mass market as it is a more stable product than Mono, as Mono, though slightly higher in efficiency out of the box, so to speak, suffers from a 1st year power output cliff that puts its efficiency after being in the field, very quickly to that of a Poly. Mono’s often cost slightly more as with all the very high efficient modules, so much so sometimes that a customer’s Return on Investment is put as far further out as 2-5 years longer with no additional power output benefits, making a 15-16% efficient Polycrystalline module the best selection for 95% of all solar projects.
Manufacture Strength- With what seems like monthly headlines of “Another Manufacturer goes out of Business”, it may seem daunting to how the actual solar market doing? It's doing Great! With almost every manufacturer as of the end of 2012 operating there businesses in the red to jockey for position as the leader in a market, trying to be here to stay, you the consumer and any well-built solar panel contractor is reaping the benefits. With that said manufacturer strength can seem daunting, and selecting a manufacture here to back there warranty is often a blind toss up, but there are some indicators to ensure the best educated guess (as of 2012 that is what it is shaping up to be, a guess).
I personally spend many hours a year qualifying these manufactures and often rely on many sources to establish an overall picture of company strength. As of the entire year of 2012 USA solar panel manufactures seem to taking the biggest hits in competing with companies in Asia and Europe. We have seen many US manufactures close their doors this year and retraction out of the US by European manufacturers.
Solar Panel Warranties- Warranties of panels have pretty much fell into a standard 10 year free from defects and a production warranty guaranteed out 25 years. At 25 years the solar panel manufacture guarantees an 80% power output as compared to its nameplate rating. So a 250 watt panel at year 25 is guaranteed to have a power output of 200 watts. Most solar panel manufacturers have a 2 tier output guarantee during these 25 years, 90% from 0-10 years and 80% from 11-25 years meaning any large drop would still be warrantied vs. a linear warranty that gradually goes down ensuring there is no large power production loss in any given year, this is the best warranty on the market at this time.
Product Durability- Most of the major brands on the market have very similar manufacturing processes that are related to product durability. I have spoken to customers that have had panels up since the 1980’s and they have survived many hails storms and terrible weather conditions in MN and WI weathers as well as the hot and Humid Baton Rouge, LA summers.
Most panel manufacturers are rated to survive at minimum 1” hail stone at 55 MPH at a 90 degree angle, making it debatable how much larger would they survive. I have personally been installing systems since 2006 and have never replaced one single module for hail or warranty issues making them a very robust product. Some manufacturers offer better framing allowing for a more diverse installation options, helping improve installation aesthetics, which at Able Energy Co. we weight very heavily.
Practical Power Output- I saved the most independently important topic for last. Every solar panel system installed throughout the United States relies on one thing, power output to pay for its self and save its owner money. Whether you are in Minnesota, Wisconsin, Illinois, Louisiana, North Carolina, New Mexico, Arizona, or Hawaii, power production is the name of the game and this is the largest distinguishing factor in solar panels. In evaluating a solar panels “Real Output” vs. “a lab number” or a flash test we rely on one source, which also happens to be the go to for the entire industry throughout the World, Photon Laboratories.
Photon Laboratories is the go-to source for a non-biased independent real world testing. In short, Photon takes voluntarily submitted modules from manufacturers and tests them in a field for one year, tracking each panels actual power output. The results have been a great breath of fresh air to installers and consumers everywhere on what they can actually expect out of each manufacturer that has submitted. We have seen some of the manufacturers doing a little cheating by submitting a module that is either no longer in production or haven’t had plans to large scale manufacture in an attempt to gain exposure. And being Photon does an excellent job of indicating these modules, it is very evident which models are still in production and which ones are not.
Our Selection(s)- So at Able Energy Co. we take selecting our modules as a balance between all of the above sections weighing each one of them quite heavily. If we are bias more one way than another it is towards energy production as it is the sole thing that pays for its self. In consideration of price as a ratio in reference to all of the above as well, in finding out which panel offers the best “Value”, our favorite word at Able Energy Co.
Each of our projects and customers has their goals and expectations and we offer a brand that fits into the selection process on the top of the list. We are not beholden to anyone manufacture making our selection as unbiased as it can get.
The information and views expressed in this blog post are solely those of the author and not necessarily those of RenewableEnergyWorld.com or the companies that advertise on this Web site and other publications. This blog was posted directly by the author and was not reviewed for accuracy, spelling or grammar.
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