Like any industrial activity, solar cell and system manufacturing, installation, operation and decommissioning have an environmental impact.

The effects can be calculated using a Life Cycle Analysis (LCA). There is a growing literature base, but not everything is comparable, as some authors look only in the cell and module manufacturing, whereas others look at complete PV systems.

In general the environmental impact is given as g of CO2/kWh produced. As the output of a PV system depends on the available sunshine, it is obvious that the same system (assumed it is well designed and maintained) produces electricity with more CO2/kWh in a less sunny region then in a region with vast sunshine.

The National Renewable Energy Laboratory (NREL) runs a project on Life Cycle Assessment Harmonization (http://www.nrel.gov/analysis/sustain_lcah.html) to make the studies more comparable. This harmonised data were also used by the IPCC in its new Climate Change Report 2014 or the Special Report on Renewable Energy Sources and Climate Change Mitigation (2012).

It is important to note, that LCA results depend on the input data as well as a number of assumptions and therefore, are only a tool to compare in relative terms. In addition, manufacturing data depend on the location of the manufacturing plant as well as on the year, as the technology is continuously improved. Production data from 2005 or 2010 do no longer reflect the current state of the art, but might be valid for some older factories.

Last but not least, even if you have a product, with a very low environmental impact on the production side, an energy intensive installation process as well as poor operation and maintenance performance can significantly change the real environmental impact.

To my knowledge, Si is the most abundant element in earth therefore solar cells are eco-friendly.

Like any industrial activity, solar cell and system manufacturing, installation, operation and decommissioning have an environmental impact.

The effects can be calculated using a Life Cycle Analysis (LCA). There is a growing literature base, but not everything is comparable, as some authors look only in the cell and module manufacturing, whereas others look at complete PV systems.

In general the environmental impact is given as g of CO2/kWh produced. As the output of a PV system depends on the available sunshine, it is obvious that the same system (assumed it is well designed and maintained) produces electricity with more CO2/kWh in a less sunny region then in a region with vast sunshine.

The National Renewable Energy Laboratory (NREL) runs a project on Life Cycle Assessment Harmonization (http://www.nrel.gov/analysis/sustain_lcah.html) to make the studies more comparable. This harmonised data were also used by the IPCC in its new Climate Change Report 2014 or the Special Report on Renewable Energy Sources and Climate Change Mitigation (2012).

It is important to note, that LCA results depend on the input data as well as a number of assumptions and therefore, are only a tool to compare in relative terms. In addition, manufacturing data depend on the location of the manufacturing plant as well as on the year, as the technology is continuously improved. Production data from 2005 or 2010 do no longer reflect the current state of the art, but might be valid for some older factories.

Last but not least, even if you have a product, with a very low environmental impact on the production side, an energy intensive installation process as well as poor operation and maintenance performance can significantly change the real environmental impact.

There is another aspect of potential hazard which is related to less popular materials used in PV cells, like for example CdS and PbS thin film solar cells. From one point of view Pb and Cd toxicity (by itself) drows attention. What is frequently missed in such opinions is tha fact that both Pb and Cd, when bonded with S, are stable compounds. Its similar to this: while either Na or Cl is toxic (and poisonous for humans) by itself, when bonded one with another, NaCl is stable, tasty and salty. That is why stability analisys and improvement is very important among PV lines of investigation.

When producing ultra high purity Silicon for mono crystalline solar cells, Silicon dioxide is usually reacted with coke to give Silicon and CO2. However, it has been calculated that the amount of CO2 it will save over its lifetime is way higher than what is produced.

Also, in the case of amorphous silicon solar cells, SiH4 compounds called Silanes are produced which are harmful chemicals

Dear Ahmed,

there is one more disadvantage with every renewable energy, solar in particular.

People are so used to burn energy generated by fossil fuel that they don't care about things like ecological burden, efficiency or availability.

Now that renewable energy is discussed in the media a lot, everybody seems to have become an expert on the topic, starting an endless stream of talking about sideffects, disadvantages and drawbacks.

Most - if not all -  of the discussions about secondary effects reveal to be peanuts if you account for the similar effects in traditional energy generation.

Considering that no fuel is needed for the lifetime of a solar plant or wind farm, that no transportation of fuel is needed, no impact to the environment takes place after installation is complete, I think it is nitpicking to ask and search for the "dark side of solar power".

Without adding reliable facts or a comparison what the difference towards traditional energy generation is, discussions like these increase the FUD-factor (Fear, Uncertainty and Doubt) about solar power without spreading real knowledge.

To give an example:

Take energy generation by burning oil - very common in the US today - and ask for "indirect disadvantages".

Let's take a minor one, fuel transportation.

A single Helespond-Alhambra-Class Supercarrier bringing oil to the US consumes about half a million liters of crude oil for a single trip, bringing 5 Million liters of oil.

Fuel in these ships is crude oil, sulfur content is about 4g/l.

Diesel to drive cars has to be low on sulfur, less than 4mg/l is permitted.

This single ship on a single trip produces the same SO2 emissions as burning 5 Million liters of Diesel in cars.

Zero oil needs to be transported to power solar cells.

Which leads to a further hidden disadvantage for some people:

Installing solar panels will shift the monopoly of energy generation away from those companies that earn money on harvesting, transporting and selling fossil fuels, threatening their powerful position.

Dear Tola,

if Silan is a byproduct and it is at least Octasilan, this is not a drawback but an advantage.

Octasilan is a stable, liquid fuel with an energy density slightly higher than gasoline, reacting to heat far more efficient than oil-based fuels. Due to the different chain in reaction with, no carbon dioxide is generated making it a rather clean energy storage.

Drawback is, that crystalline parts result from the reaction, so Silan can't be used in typical piston-based combustion engines.

Dear Martin Schulz

in the last para addressed to Mr. Tola the drawback part, as I am a non technical person so would be happy if little bit more elaboration was possible

thanking you in advance

Dear Ahmed,

A Silan is a chemical substance which in structure is similar to Carbon-Hydrogens.

Instead of having CnH2n+2 you get Si to replace the C ending up in SinH2n+2.

For a long time, Trisilan Si3H8 was the longest chain that could be synthesized but it was so highly reactive that it started reacting even if only getting in touch with atmospheric air. The reaction is quite volatile.

Silan gets more stable the longer the chain gets and Octasilan Si8H18 is as stable as gasoline and liquid at room temperature.

A reaction can be triggered by igniting the stuff, similar to gasoline but the reacting partners and end products are different.

Silan reacts with the Oxygen of the air, reaction partners include SiO2 which is a white, crystalline and very hard substance known as sand.

For simplicity, take the Monosilan-reaction: SiH4+2O2-->SiO2+2H2O

In case you try using Octasilan to replace gasoline in a combustion engine, this would grind away your pistons and cylinders in no time.

Experiments considered using ceramic parts but the lifetime was insufficient.

It might be possible to operate turbines on this fuel though.

A Sterling-Engine would also be a viable option, so is steam production despite the fact, that the efficiency would return to

Similar questions have been asked many times before here at RG, use the searchox at the top of the page to find these questions + the answers.

For example:

https://www.researchgate.net/post/Is_it_environmentally_friendly_to_produce_and_recycle_PV_panels

https://www.researchgate.net/post/How_is_solar_power_bad_for_the_environment

https://www.researchgate.net/post/What_are_the_environmental_effects_of_solar_power_plant

For the rest: do an internet (literature) search for "solar energy systems life cycle analysis" and you will find a wealth of literature on the subject.

The immense atmospheric pollution due to the burning of fossil fuels in automobiles and power plants etc. arises from the emission of  SO2, CO, CO2... into atmosphere that  are usually ignored. For instance SO2 abundant  threshold is 40 ppm, while in polluted cities it may exceed 4000 ppm!

The green house effect of  CO2  can not be ignored too. CO affinity with Homogolobin is called silence death.

Conversely, no fuel is consumed by Solar cells and no waste is found during its electricity generation.

Si is a friendly element : glass is made of Si and can be recovered. No hazard  is assumed for mankind and nature.

Solar panels and other renewable energy sources exhibit no hazardous environmental impact regarding the polluting aspects of oil and other  fossil fuels.

Lot of Thanks to all of you who have helped me get a better understanding on the subject.

Dear All

I suggest you:

What are the Disadvantages of Solar Energy?

What follows is a list that is not in any particular order of importance.

High initial capital outlay. The initial cost of installing a solar energy system can be prohibitively high for some budgets. The cost of buying and installing solar panel arrays is a bit steep. Payback times may reach from ten to fifteen years before you can even break even with your initial investment.

Dubious reliability. It is obviously impossible to power your home with a solar array at night if you don’t have a system in which to store power. This means batteries at our present level of technology. So you will probably still need to draw electricity from the local utility grid.

Availability of sunlight. The position of your solar array is obviously of major importance in the generation of electricity. This means that some houses will not be ideally suited for conversion or for installing a solar energy system.

Polluting materials used in solar panels. The majority of photovoltaic panels are made from silicon and other metals that are potentially toxic like mercury, lead, and cadmium. This is the dirty secret of this “clean” technology.

The efficiency question. The current efficiency rate of most solar panels is just a mere forty percent. This means that sixty percent of the sun’s energy is wasted. There are some state of the art solar panels that can reach a maximum efficiency of eighty percent. There are continuing technological advances that increase efficiency and lower costs.

All the best

Hengky

@Hengky:

I found several versions of exactly the same text elsewhere on the web.

As an Associate Professor you should know that you should mention that the text is not your own and that you should mention your source when you cite.

Your source conveniently doesn't make a comparison with conventional power sources.

Fthenakis et al [1] do make such a comparison and come to the conclusion that  for all kinds of pollution PV systems score considerably better than conventional power systems

"For example the emissions of Cd from the life

cycle of CdTe PV are 90-300 times lower than those from

coal power plants with optimally functioning particulate

control devices."

So the use of solar power will reduce also heavy metal pollution, not just CHG emissions.

[1] Fthenakis, Vasilis M., Hyung Chul Kim, and Erik Alsema. "Emissions from photovoltaic life cycles." Environmental science & technology 42.6 (2008): 2168-2174.

Dear Martin,

Thanks for the correction and enlightenment. However, I think there have been cases where some of  these silanes (gas) have been reported to cause accidents and/or explosions when released

Dear Jethro: Thank you for remind me, and herewith  I quote another from Green (2015).

1. Initial Cost : The initial cost of purchasing and installing solar panels always become the first disadvantage when the subject of comes up. Although subsidy programs, tax initiatives and rebate incentives are given by government to promote the use of solar panels we are still way behind in making full and efficient use of solar energy. As new technologies emerge, the cost of solar panels is likely to decrease and then we can see an increase in the use of solar cells to generate electricity.

2. Location : The location of solar panels is of major importance in the generation of electricity. Areas which remains mostly cloudy and foggy will produce electricity but at a reduced rate and may require more panels to generate enough electricity for your home. Houses which are covered by trees, landscapes or other buildings may not be suitable enough to produce solar power.

3. Pollution : Most of the photovoltaic panels are made up of silicon and other toxic metals like mercury, lead and cadmium. Pollution in the environment can also degrade the quality and efficiency of photovoltaic cells. New innovative technologies can overcome the worst of these effects.

4. Inefficiency : Since not all the light from the sun is absorbed by the solar panels therefore most solar panels have a 40% efficiency rate which means 60% of the sunlight gets wasted and is not harnessed. New emerging technologies however have increased the rate of efficiency of solar panels from 40 to 80% and on the downside have increased the cost of solar panels as well.

5. Reliability : Unlike other renewable source which can also be operated during night, solar panels prove to be useless during night which means you have to depend on the local utility grid to draw power in the night. Else you can buy solar batteries to store excess power which you can later utilize in the night.

6. Installation area : For home users, a solar energy installation may not require huge space but for big companies, a large area is required for the system to be efficient in providing a source of electricity.

Kindly suggest  me @Jethro? I appreciate that. and I can learn more from you.

Thank you.

All the best

Hengky

I conclude that the development of solar cell and the other renewable energy sources are crucial to rescue the environment from ever increasing pollution of fossil fuels.

I am agree with @Parviz that  the development of solar cell and the other renewable energy sources are crucial to rescue the environment in the near future

Dear Jethro,

Just for the nitpicking :-)

"For example the emissions of Cd from the life

cycle of CdTe PV are 90-300 times lower than those from

coal power plants with optimally functioning particulate

control devices."

So if the amount of Cd generated by coal power p.u. is "1", than 90-300 times this low would result in an increase and in turn make solar more pollutant than coal, right?

Or did you mean it will be 90-1 to 300-1 that of coal?

Nothing can get smaller if multiplied by a factor >1.

Just to make you think :-)

Keep smiling!

@Martin:

1) It is a quote, the wording is not my own

2) "90-300 times LOWER" implies 90^-1 to 300^-1 times the emissions of coal power plants.

3) Still smiling ;-)

@Hengky:

"Green 2015" does not really help readers to find the original source. Since we are not writing a scientific article here, a simple link would suffice. Like this:

http://www.conserve-energy-future.com/Disadvantages_SolarEnergy.php

Regarding the list: I find it a bit of a strange mixture:

Points 1,2 , 5 and 6 are formulated as disadvantages for some potential investors. 3 and 4 are formulated as general problems. Points 5 and 6 are only relevant if your aim is to be self-sufficient in your electricity production.

I already addressed point 3.

Regarding point 4. I find it a bit weird to see solar cell inefficiency as a problem on its own. Sunlight comes for free, and does not pollute. Efficiency of course does influence the cost per kWh and the pollution per kWh. However, these points are already in the list, so point 4  seems to be added just to fluff up the list.

Point 1, 5 and 6 could of course be generalised.

1) Solar power was very expensive just a few years ago. But cost have come down tremendously and are still falling.

5) Without cheap storage, the variability of the solar resource limits the amount of solar power that can be integrated into the grid. However, more is possible than most people expect intuitively. In their report, "the power of transformation" [1], the IEA comes to the conclusion that with existing technology 45% of solar and wind power can be integrated into the grid at acceptable cost.

6) The area needed to provide all the earth's energy needs with solar power is only a minute fraction of the earth surface. So there is not really a problem here.

[1] http://www.iea.org/newsroomandevents/pressreleases/2014/february/any-country-can-reach-high-shares-of-wind-solar-power-cost-effectively-study-shows.html

http://www.iea.org/bookshop/465-The_Power_of_Transformation

P.S. Please, don't be offended by my Dutch directness. This is just one of those cultural differences.