Tag Archives for " solar growth "

What are Thin Film Solar Panels?

What-are-thin-film-solar-panels

The details about thin film solar panels.

In recent years we have seen radical improvements in the underlying technology of solar panels and although you are familiar with the traditional-style solar panels in pictures and on rooftops, thin film solar panels are now making their way into the mainstream.  They are called ‘thin film’ because they are able to be produced in such a way that allows them to be flexible and coat materials other than the standard wafer boards. This allows for many more applications for solar power and can allow them to blend more seamlessly into your home’s aesthetics.

The Difference Between Traditional Solar Panels and Thin Film

The most obvious difference between the traditional silicon wafer solar panel and newer thin film varieties is the thickness. There are also currently gaps in solar capture efficiencies between first-generation silicon-based wafers and newer, second-generation methods that use different compounds. This comes down to the materials being used in the panels themselves.

Traditional panels often use crystalline silicon (c-Si) in their manufacture. This process has been around for years and has established itself to be reliable.  It should be mentioned that although c-Si is considered to have a high-efficiency rate in terms of energy production from installed systems, it is actually a relatively poor absorber of light. This means that the cells must be fairly thick and rigid in order to produce effectively.

Related: Comparing Solar Panel Types 

In contrast, thin film technologies employ different elements that allow the cells to be up to 350 times thinner than the traditional wafer. This material can then be layered over coated glass, metal, or plastic to create a solar cell, and allows for many different types of materials and objects to produce energy.

Main Types of Thin Film Solar Cells

There are two main goals for thin film solar cells today: to have the flexibility to attach it to a larger variety of building materials and to eventually achieve the same or higher efficiency than traditional silicon-based methods. All of these methods below offer some differences in pros and cons compared to the traditional-style panels. Their names usually derives from the type of material that is used for its semiconductor. Let’s take a look at four and see how the different technologies compare:

#1: Amorphous Silicon (a-Si)a-Si photovoltaic cell structure

a-Si photovoltaic cell structure.  Image by Alfred Hicks/NREL.gov

Amorphous Silicon is the oldest and most mature type of thin film to produce solar power. This is likely because silicon was already being used in its crystalline form to produce the more traditional panels and silicon’s electrical properties were well understood.

Pros:

  • Unlike crystalline silicon, the amorphous silicon version actually has a very high solar absorption rate which makes very thin layers of the material possible. This effectively reduced material costs and because it is relatively abundant, nontoxic, and inexpensive it quickly became the first thin film method to break into the mainstream.

Cons:

  • Because of its relatively low efficiency, however, you will mostly only see this method used in small-scale, flexible power packs and electronics.

#2: Cadmium Telluride (CdTe)

CdTe

CdTe photovoltaic cell structure.  Image by Alfred Hicks/NREL.gov

Solar technology based on cadmium telluride is now the second most popular PV technology in the world, sitting at around 5%. This is thanks to the fact that manufacturing of this process is cheaper and quicker than comparable silicon-based methods and recent leaps in efficiency have prompted more mainstream adoption.

Pros:

  • As mentioned before, CdTe is cheaper than silicon-based methods, but it is important to note that by 2014 the technology had the smallest overall carbon footprint and payback time from purchase. Although CdTe, as well as thin film cells in general, lag behind the traditional c-Si panels in terms of efficiency, they have been rapidly approaching that gold standard. As of 2015, a company called First Solar reached an average commercial module efficiency of 16.1%.
  • CdTe panels are also highly adaptable to hot, humid weather and low light when compared to traditional cells. This means that they work best in the areas with the most sun and are able to be used in areas that up until now were less than ideal.

Cons:

  • One possible disadvantage of the CdTe method lies in the very materials used to manufacture them. Cadmium, by itself, is a very toxic substance that can accumulate in the food chain much like Mercury. Early results show that cadmium can leach from the compound over time in landfills and CdTe itself has shown toxic effects when inhaled by test rats. Fortunately, proper handling and disposal methods will negate much of the potential concern.
  • As such, many agencies and laboratories are actively searching for alternatives that are safe for the environment while also being efficient. Current manufacturers are also searching for ways to reuse or recycle these materials as a way to help solve the issues concerning the environment.

#3: Copper Indium Gallium Diselenide (CIGS)

CIGS

CIGS photovoltaic cell structure.  Image by Alfred Hicks/NREL.gov

This type of solar cell is another popular type of semiconductor used to create thin film applications. The CIGS method is currently more popular in Europe and Japan, but there are manufacturers all over the world making use of this technique to take advantage of its environmentally safe materials and peak efficiency potential.

Pros:

  • CIGS have the benefit of being environmentally friendly in terms of materials used which is a boon for manufacturers looking for a long-term benefit to the planet. The materials used also allow it to have the highest potential efficiency of any of the thin-film technologies as well as a great resistance to heat. There is also a great potential for long-life applications due to the lack of significant degradation over time.
  • The methods used also allow for extremely thin sizes of less than one micrometer to be used in creating devices. This means that there are even more potential applications for this technology such as building materials, cars, and airplanes.

Cons:

  • CIGS technology has yet to reach or surpass the traditional silicon-based panels, but it has made great leaps forward in recent years. Although the record for lab-based efficiency is over 20%, real-world applications still fall in the mid-teens.

#4: New Copper Zinc Tin Sulphur (CZTS) Method

CZTS photovoltaic cell structure

CZTS photovoltaic cell structure.  Image by Alfred Hicks/NREL.gov

In an ongoing effort to find solar technology that is both environmentally friendly as well as manufactured using abundant materials, the CZTS method was discovered. This method is very similar to CIGS in terms of properties and methods of fabrication, but its efficiency is still very low.

Pros:

  • As mentioned before, CZTS is made up of the earth-abundant elements copper, zinc, tin, and sulfoselenide. This means that the compound is both environmentally friendly and could ultimately become quite cheap because of the material cost. The tellurium and indium found in the CdTe and CIGS models are extremely rare, for instance.

Cons:

  • CZTS is still in the early stages of development and in order to be more commercially viable, higher efficiencies are required. The technology current taps out at around 7.6%. It would need to hit around 20% efficiency before it could become competitive among its peers.

Conclusion

We trust this information has helped shed light on what exactly are thin film solar panels and how they are shaping the current landscape of solar energy production.

As these technologies mature, they will make their way into competitive products available for purchase. Already there are alternative methods of solar production, such as solar roof tiles, that allow customers to have a more aesthetically pleasing look while still saving money on their energy bills. Watch this space to see what innovative and new trends will be developed.

Photos courtesy of NREL.gov

Solar Energy vs Coal: A Comprehensive Comparison

solar energy vs coal

How does solar energy stack up vs coal for electricity generation?

In 2015, the United States used about 3,724,500 million kWh of electricity.

Most of us don’t have enough context to realize how big this number actually is, so here are some facts: First off, the US is the 2nd biggest user of electricity in the world (just behind Canada). Secondly, think about what exactly this number includes: all the electricity used in millions of homes across the US for air conditioning, lights, refrigerators, stoves, hot water, and all our devices, as well as factories, office buildings, data centers, agricultural applications, government offices, recreation centers, football fields, streetlights, and about a billion other things we don’t even think about on a daily basis.

With so much electricity being used and created every day, as a country we need to constantly assess if all this electricity is being created in the most responsible way, both monetarily and environmentally.Continue reading

Solar Panels For Sale: A Third-World Perspective

If you live in a developed country, installing solar panels on your rooftop involves selecting a solar power company from a growing list of providers and setting up an appointment.

But this is far from the case for third-world countries.

Even if you’re only researching the theoretical principles of solar energy, it’s hard not to come across an ad shouting Solar Panels for Sale! when scouring the Internet, along with statistics and facts on how much solar energy can save you in the long run.

For instance, pulling up directories that list solar companies in each U.S. state is as easy as saying 1-2-3. Americans are offered tax reduction incentives, on top of getting closer to their goal of saving money and slashing their electricity bills.

To boot, even the environmentally conscious individual can feel good about purchasing and installing solar panels, knowing he is contributing, even minimally, to the reduction of carbon dioxide emission into the atmosphere.

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Recycling Solar Panels: It’s Time to Think Ahead!

recycling solar panels

Recycling solar panels: is it something we should start thinking about?

Solar has a useful life of half a century, and is such a new industry that we’ve yet to see much end-of-life recycling, but it is a responsibility that must be addressed as time goes on.

The very few first solar panels were manufactured in the 1970s, and for the most part, these very early solar pioneers have not yet dismantled their old solar arrays that are still producing after 45 years.

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Nationwide HVDC Grid: Cheapest Way to Radically Cut CO2 Emissions?

HVDCA Grid wind

According to a peer-reviewed paper just published at Nature Climate Change; “Future cost-competitive electricity systems and their impact on U.S. CO2 emissions” – the cheapest way to radically cut greenhouse gas emissions from generating electricity by 2030, would be a high-voltage direct current (HVDC) grid connecting America’s prime renewable resources to 256 electricity markets.

The study concludes that electricity prices could remain flat if the US could site projects for maximum generation – unconstrained by the current lack of a national HVDC grid – connecting the best carbon-free resources to load centers.

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Why Silver Prices Will Rise: Solar

silver solar

For every gigawatt of solar power installed, 80 metric tons of silver is required

Silver has long been viewed as an investment in its own right as an inflation hedge.It is also widely used in the manufacture of semiconductors, batteries, various nanotechnology applications, jewelery, photography, and in making solar photovoltaic cells.

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How Renewables Deplete the Capacity Factor of Fossil Fuels

solar storage

Capacity factor is how many hours an energy source operates. Here’s why that’s going down for fossil energy: It’s the renewables.

Fossil fuels normally run around the clock by combusting carbon like gas or coal – assuming you will be able to keep shipping a steady stream of gas or coal by pipeline or rail to the power plant and keep on throwing fuel on the fire, of course.

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Hawaii Aiming for 100 Percent Renewable Energy by 2045

honolulu

We already know how dedicated Hawaii is to clean energy. Solar energy is thriving! In fact, so many people want solar that many have had to wait for solar companies to catch up to them. Now, it’s doubling down on renewable energy sources in a tremendous way. Recently, Hawaii’s Legislature approved more than 100 bills, including a bill that requires Hawaii to reach 100 percent renewable energy by 2045. This means that all electricity provided by the electric companies will have to come from renewable sources like solar and wind. If it becomes law, it would make Hawaii the first state in the U.S. to commit to a 100 percent renewable energy goal.

Meeting Hawaii’s Renewable Energy Goal

According to Civil Beat, approximately 22 percent of the state’s energy came from renewable sources last year. While getting to 100 percent renewable is going to take some time, Hawaii is already well on its way. “It’s going to save everybody money, it’s going to put less carbon in the air, it’s going to boost jobs in our local energy industry,” said Rep. Chris Lee.

In addition to overall energy goals, the Legislature also passed a bill to make the University of Hawaii system the first in the nation with a goal of being 100 percent renewable, plus generating all their own power by 2035.Continue reading

Colorado CPUC Says No to Distributed, Community Solar

The Colorado Public Utilities Commission, in a decision reminiscent of the mythological Zeus’s thunderbolt, said no to Xcel Energy’s proposal to use its Solar Connect program to establish community solar projects.

Community solar, also known as distributed solar, is a program whereby utility company ratepayers can opt into solar power by investing in a “farm” of solar panels (often on public land) which sends electricity back into the grid for common use.Continue reading