Solar Panels 

When it comes to installing solar panels on your home or business, there are more choices now than ever before.  Chances are good that a manufacturer is making a solar panel that will be perfect for your application; the challenge is figuring out which one to use, the proper size, voltage output, etc.  There is no shortage of data out there, but real information is scattered about and confusing, so I built this guide based on the data I have collected for my own solar installation project.  I hope you find the guide useful.

Solar Panel Considerations

Solar panels are certainly in vogue today and it seems like everyone is building their version of the next great PV (Photovoltaic) module.  Prices range from $3 to $20 per watt and the panels come in so many configurations that it hurts to think about all the options.  Considerations include:

• Watts - Maybe the most commonly used measurement of a solar panel, “DC Watts” tells you how much power the panel is capable of generating. Solar panels for home and commercial applications currently range in wattage from 5 - 220 watts and these numbers continue to grow as panels become more efficient.
• Efficiency (Solar Panel’s ability to convert sun into power) - Some solar panels just put out more juice per square inch than others. They also may operate better in off-perfect conditions. For these reasons, it makes sense to pay attention to the efficiency rating when you go shopping for solar panels.
• Size - This is important if space is limited or confined to a certain shape. Solar panels take up a lot of space, so pay attention to the dimensions and work out the numbers to see how many square feet of space you will need. (length * width * number of panels)/144
• Voltage - Depending on your application, you may need to consider panels that have a voltage better suited to your system design. Common solar panels range from 12 - 60 volts.
• Warranty - You are making a huge investment so you want to pay attention to how the manufacturer backs up their products. As this industry is really starts to grow, many solar panel makers come and go. I would suggest sticking with a maker that is proven in the industry. We will look at several solar panel makers in just a minute, but you should expect to get a warranty of 20 - 30 years on most quality solar panels. It also pays to read the fine print to see what that warranty covers. Some only cover the complete failure of the panel; not depreciated production due to partial panel defect or failure.
• Application - There are rigid solar panels encased in glass and frames like we all have seen, but there is also new technology breaking into the market. Solar power producing panels are being designed into all sort of common items ranging from fabric to roof tiles. So if you need a new roof, you may consider using a product that not only keeps you dry, but also generates power.
• Weight - Usually weight is not a major consideration, but it may come into play if you are adding solar panels to a light weight structure. When in doubt, consult an engineer.

Solar Panel Manufacturers

There are literally hundreds of manufacturers that are designing and building solar panels.  Some focus on commercial application while others target specific regions like Europe or South America. Even when you weed out those panel builders that focus on a certain niche markets, there are still plenty choices for your home or business application.  Let’s take a look at some of the more common and readily available solar panel brands. 

Sharp Solar

Chances are good that you have owned or do own products from Sharp already, so you are familiar with their brand of electronics.  What you may not realize it that Sharp got into building solar panels in 1959 with their first solar cells being designed for the space program.  In the 80s Sharp brought you the solar calculator, and in 2004, their solar panels were used in the largest solar panel installation (FedEx 904 kW.)   In 2005 they gained 45% market share in the solar panel market, and have since taken on other large fixed installations such as Google’s behemoth 1.6 megawatt solar farm.

Sharp currently offers a line of individual solar panels ranging from 62 - 216 watts.  They also produce triangular panels for those applications where you want to maximize every inch of space.   Sharp is also trying to make the decision making process easy with their OnEnergy program.   This program consists of several preconfigured systems that include everything you need to install a solar panel system on your home or business.

Sanyo

In 1967, a company by the name of Solec started churning out solar panels.   In 1994, Solec joined with Sanyo to make a run at furthering solar technology.  Solec pioneered the development of major improvements in crystalline silicon photovoltaic (PV) technology, which is standard in nearly all high-power PV applications made today.

In 1997, SANYO introduced a product called HIT Power 21 (Heterojunction with Intrinsic thin layer). This product combines the single crystalline cell with amorphous silicon and solar panels that exceed 17.4% efficiency. They also produce solar panels that create power from both sides.  This increases power generation compared to conventional single-sided HIT panels at any angle and direction.  The rear of the solar panel generates electricity from ambient light that has passed through the panel or is reflected off surrounding surfaces.  The HIT panel also claims to have 10% better efficiency at higher temperatures than it’s standard crystalline silicon counterpart.   

 Sanyo is currently offering panels that range from 63 watts to 200 watts. 

BP Solar

Like many in the solar industry they bought their way in.  A company by the name of Solarex was formed in 1973 to commercialize terrestrial PV and initiate the polycrystalline process.  A few years later (1982), Solarex constructed a manufacturing plant in Frederick, MD, USA which is still one of the largest installations of building-integrated photovoltaics in the world.  The following year, Solarex was purchased by Amoco Oil Company.  In 1984, Solarex acquired Exxon’s solar power corporation.  In 1996, BP introduced their plug in the sun initiative which aimed to equip BP gas stations with solar panels.  Following this campaign, Solarex and BP merged to form BP Solarex which was later shortened to BP Solar.  Then in 2007, BP Solar announced a $97 million investment at North American HQ in Frederick, MD, allowing for space to enlarge manufacturing capacity to 400+ megawatt. Construction is slated for completion by the end of 2009.

BP Solar is making panels that range from 75 watts to 200 watts, but they are also offering integrated solutions that blend in with custom roofs.  Check out their Energy Tile and Integra roof systems for more details. 

Evergreen Solar

Massachusetts based Evergreen Solar makes solar panels, but what sets them apart is that they make all the components that make up their panels in house.  This gives them ultimate quality control, so it’s no wonder that their solar panels are some of the highest quality in the industry.  And they strive to be completely “green” throughout their manufacturing process. 

Currently, the Spruce Line features solar panels ranging up to 195W and are designed for residential or commercial applications. These solar panels offer superior performance while providing the utmost in installation flexibility.

 Kyocera Solar

Starting in 1976, Kyocera has been in the Solar panel business from almost the beginning.   But it wasn’t until 1983 that it started marketing solar products in the United States.   In 1988, Kyocera lead by example and installed a 50 kilowatt solar system on its headquarters in San Diego.  Their panels were the highest efficiency panels in production and the success of their design propelled them to be the largest solar panel manufacturer in the world by 1998.  Last year (2007,) Kyocera announced that they plan to expand their production capacity to 500 megawatts.

Like Sharp, Kyocera is offering packaged systems that are ready to be tied to the grid and provide all the necessary power.  The MyGen grid-tie photovoltaic (PV) power system consists of photovoltaic modules, a direct current to alternating current (DC-to-AC) power conversion device, DC wiring and protection, AC wiring and protection, lightning protection, component mounting and mechanical support.

If a package is not your gig, then you can choose from panels ranging from 135 watts to 205 watts.

Mitsubishi Solar

Another child of the 70s, Mitsubishi began exploring solar technology in the mid 1970s, but didn’t produce a residential solar panel until 1997.  After that, it was one design success after another until they captured the highest conversion cell efficiency rating (18 percent) in 2007.

Mitsubishi tends to have some of the most economical panels on the market.  They currently produce panels that range from 175 watts to 195 watts and module efficiency rating from 12.7 to 13.7 percent.     

Sun Power Solar

Sun Power Solar offers a wide variety of products to suit the most complicated installation.  Unlike a plain solar panel manufacturer, Sun Power make panels, sun trackers, inverters, solar roof tiles, and performance feedback tools.  Maybe one of the coolest products is a website that allows you to monitor your system performance and your energy usage. What better way to keep tabs on the vacation home or a rental property?

Another innovation by sun power is to add an all black skin to their panels.  Now your solar array will look seamless and uniform with their all black option.  Panels range in wattage between 205 and 215 watts and are backed by a 25 year warranty.

High Efficiency

If you took the time to read through the bios on the manufacturers, you may notice a trend: they all seem to be competing for the top spot in efficiency.  But what is efficiency and why does it matter?  In simple terms, solar panel efficiency refers to the panel’s ability to convert sunlight into power.  The higher the percentage, the more power the panel extracts from the sunlight.  There are several reasons you should consider the efficiency of a panel in addition to its wattage, size, color, etc.

1. Higher efficiency panels produce more power.
2. They can be smaller and produce the same power as their less efficient counterparts
3. In many cases, high efficiency panels can still produce power in off-peak sunlight.

Some panels  like the Sanyo HIT solar panel also claims to have 10% better efficiency at higher temperatures than its standard crystalline silicon counterpart.

Ultimately you should be looking for panels in the 14 - 20 percent efficiency range.  If the manufacturer doesn’t list or can’t tell you their efficiency rating on the panels, keep looking.  I have a cheap 15 watt solar panel for camping that I thought was a great buy at $60.  Turns out that I can only get about .75 amps out of it under perfect conditions.  A friend of mine has a small Kyocera 8 watt panel that is 1/3 the size, but produces more power. Therefore, my friend’s panel is better than two times more efficient at converting sunlight into power.

Special Application (Tiles, cloth, etc)

As we said earlier, some manufacturers are breaking the traditional solar panel mold and are creating solar panel that blend in and in some cases serve a function other than just producing power.  This type of solar panel technology is just starting to break onto the scene, so prices are higher than traditional solar panels.  However, in some cases the installation is so easy, you can save a bundle if you are having your panels professionally installed.  Check out the following links to non-traditional solar panel manufacturers:

Power Film - Thin film

Uni-Solar - flexible panels

Premier Power - Roof Shingles

SRS Building energy - Great tile systems that mimic a real tile roof.

Installing Solar Panels - calculations and considerations

There are tons of calculators online that will help you determine what you need to go solar.  Many of the solar module manufacturers are getting into the mix by offering calculators and pre built packages like the ones from Sharp and Kyocera that we discussed above.  Here are a couple more that I though were pretty good:

BP Solar - Simple calculator that does not require a lot of data to give you an estimate.  Plug in your zip code, average power bill, and the size of the system you are considering and it will tell you a system cost, monthly and annual power savings, and environmental impact stats.   It’s simple, but I’m not sure it’s very accurate.  I would need to spend $30,000 after rebates and tax incentives to reduce mu power bill by 49%.  At that rate, it would take 30 years to pay for itself. 

Find Solar - More comprehensive calculator that factors in granular power expense, utility provider, rebates and incentives and the percentage of power that you wish to offset. 

Conclusion

Solar is trying to take center stage in the race for alternative energy. I think we will all benefit from the results.  As more manufacturers pump out solar panels, the price will fall and the power output will grow. Take your time and think through you decision.  After all, you will be spending tens of thousands of dollars on a full solar panel system and will be living with it for 30 or more years.  No matter how handy you are, consult with a professional installer.  Their insight will be invaluable in determining if your goals can be achieved given your limitations in money, space, and sun exposure.   They will also give you confidence in your plan and also might be able to help with local utilities that don’t want to play nice.  

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