Dear Folks In our electrical system various fuels give a carbon footprint which can be measured as grams of carbon dioxide per kilowatt hour of electricity produced.

Here are some comparisons

Coal thermogeneration 960 to 1,500 grams of carbon dioxide per kilowatt

Oil 742 to 778 g CO2 per kilowatt hour

Gas 543 to 608 g CO2 per kwh

Photovoltais 21 to 50 g Co2 per KWH

Nuclear 34 to 66 g CO2 per KWh

Wind 7l9 to 23.7 g CO2 per KWH

A take home of this is coal thermogeneration represents a worse case scenario and among fossil fuels natural gas is substantially less.

In terms of carbon footprint Nuclear solar and wind are all very low.

My caution here is nuclear is very expensive and solar and wind but not hydro and geothermal are intermittent but much cheaper than nuclear and also nuclear is not renewable and the others are.

For small farming in India the milk animal can generate manure to produce farmstake energy by anaerobic decomposition and the manure processed can add to soil organic matter. Such a system lowers carbon footprint of the production practice but also can lead to adding to soil organic matter which can take enriched carbon dioxide in the air and let it be transferred to soil as a beneficial carbon rather than a climate issue.

In looking at the Carbon Budget the footprint is not only the cost of atmosperic emissions but also the positive footpring of the increasing of soil organic condition.

Soil organic matter improvement stabilizes the soil resource improves the ability to produce food and gives the food produced a higher quality.

Solar energy reduces greenhouse gas emissions primarily by displacing the need for electricity generation from fossil fuel sources, which are major contributors to greenhouse gas emissions.

Here's how solar energy contributes to the reduction of greenhouse gases:

The extent to which solar energy reduces the carbon footprint depends on various factors:

While it's challenging to provide a specific number for how much solar energy reduces the carbon footprint, studies and analyses have shown that solar power does result in significant emissions reductions over its lifetime. The actual reduction varies based on the factors mentioned above. The International Energy Agency (IEA) and other organizations continuously assess and model the environmental impacts of renewable energy technologies like solar to better understand their contributions to greenhouse gas mitigation.

Dr Paul Reed Hepperly and Dr Gaurav H Tandon thank you for your contribution to the discussion

Solar energy technologies and power plants do not produce air pollution or greenhouse gases when operating. Using solar energy can have a positive, indirect effect on the environment when solar energy replaces or reduces the use of other energy sources that have larger effects on the environment. Solar energy that is reflected back to space does not warm the earth. Certain gases in the atmosphere absorb energy, slowing or preventing the loss of heat to space. Those gases are known as “greenhouse gases.” They act like a blanket, making the earth warmer than it would otherwise be. By decreasing the use of fossil fuels, solar power helps reduce the amount of carbon dioxide and other greenhouse gases released into the atmosphere. Solar can replace about 80% of the energy needed to heat indoor spaces and water this reduction can help mitigate climate change in a meaningful way. Solar power produces no emissions during generation itself, and life-cycle assessments clearly demonstrate that it has a smaller carbon footprint from "cradle-to-grave" than fossil fuels. Renewable energy sources which are available in abundance all around us, provided by the sun, wind, water, waste, and heat from the Earth are replenished by nature and emit little to no greenhouse gases or pollutants into the air. The Sun's irradiance has its greatest effect on Earth's upper atmosphere, while the lower atmosphere insulates Earth from the increased heat. If the Sun were driving Earth's warming, one would expect to see that upper atmosphere getting increasingly hot. For a rooftop solar system with a 30-year life, the total emissions associated with generating 1 kWh of electricity add up to 41 grams of CO2 equivalents – roughly the mass of a medium-sized chicken egg. That's nearly 12 times lower than natural gas and 20 times lower than coal.Every kilowatt of green energy can reduce your carbon footprint by 3,000 pounds annually. So, even a 5KW solar plant can save approximately 15,000 pounds of CO2 every year, making huge contributions in protecting our environment from global warming and related issues. Solar panels emit around 50g of CO2 per kWh produced in its first few years of operation. By the third year of having solar panels, most solar panels become carbon neutral. This is still roughly 20 times less than the carbon output of coal-powered electricity sources.

с учетом жизненного цикла данной технологии и уровня использования установленных мощностей они глобально не решают проблем декарбонизации Данные технологии целесообразны на удаленных изолированных территориях с высокой солнечной инсталляцией

Dr I V Petrov thank you for your contribution to the discussion

In terms of the how it reduces greenhouse gases, it happens during the usage of the solar panels. They are producing electricity without burning anything, without emitting any gases.

In terms of the how much it reduces the emission of such gases, this is a lot more complicated question. It depends at what you are looking at, the direct or indirect emissions?

The direct emissions are the one created while producing electricity. One panel produces 250 watts usually, when at full usage (sun is shining).

According to the EPA (https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator#results), 1 kilo watt hour produces 0.709 kilogramme of gas, so 1 panel can save 0.177 kg of greenhouse gas per hour. A typical house will have 6 to 8 solar panels, so you can estimate about 1 kg per hour of gas saved during daytime, when the sun is shining.

If the sun is not shining, the solar panel still produces electricity but not at 100% productivity, so the savings are less.

Now, the issue is the indirect emissions, theses are the one created to mine the components making the solar panels, to transport the minerals to factory and to produce the solar panels, to transport the panels to your house, to sell them to you, to install them (https://8billiontrees.com/solar-panels/carbon-footprint-solar-panel/)

It is difficult to estimate all of these and to know how long it takes to offset these emissions by using the solar panel, so estimates vary a lot from 3 years according to the solar panel industry to 20 years according to some environmental activists.

The life span of a panel is 20 years, so here you go!

Finally, there is the issue of what to do with the panel after 20 years!

These are not recyclable right now, so they get destroyed and go to landfill, more greenhouse gas emissions!

I think the main point here is that there is no pure negative greenhouse gas emission power production, there will always have some to produce power, and the idea of offsetting these emissions is ridiculous, all that means is that you displace it to other countries that are mining and the ones that are producing these panels. Because the emission is invisible, then people think it does not happen, just like for the electric cars.

Is it better than burning coal? Absolutely.

Is this better than wind power, I believe so as it is more reliable, predictable source of power and has less impact. But then the sea and the tides are the largest and the most predictable source of untapped power, and little is done to harvest it!

Dr Fabrice Teyssedou thank you for your contribution to the discussion

Solar energy technologies and power plants do not produce air pollution or greenhouse gases when operating. Using solar energy can have a positive, indirect effect on the environment when solar energy replaces or reduces the use of other energy sources that have larger effects on the environment. As a renewable source of power, solar energy has an important role in reducing greenhouse gas emissions and mitigating climate change, which is critical to protecting humans, wildlife, and ecosystems. Every kilowatt of green energy can reduce your carbon footprint by 3,000 pounds annually. So, even a 5KW solar plant can save approximately 15,000 pounds of CO2 every year, making huge contributions in protecting our environment from global warming and related issues. Solar panels emit around 50g of CO2 per kWh produced in its first few years of operation. By the third year of having solar panels, most solar panels become carbon neutral. This is still roughly 20 times less than the carbon output of coal-powered electricity sources. Solar energy systems can generate electricity in any climate. One of the disadvantages of solar energy is that it's subject to temporary weather disruption. Cloudy days reduce the amount of electricity you produce. Cold, however, doesn't affect productivity. There are four main types of low-carbon energy: wind, solar, hydro or nuclear power. The first three are renewable, which means these are good for the environment – as natural resources are used to produce electricity. Wind, nuclear, tidal, hydropower, geothermal, solar, and wave energy have the lowest carbon footprint. Per kWh produced, the energy sources emit between 11 and 48 gCO2 on a life-cycle basis. Solar energy technologies and power plants do not produce air pollution or greenhouse gases when operating. Using solar energy can have a positive, indirect effect on the environment when solar energy replaces or reduces the use of other energy sources that have larger effects on the environment. Solar power produces no emissions during generation itself, and life-cycle assessments clearly demonstrate that it has a smaller carbon footprint from "cradle-to-grave" than fossil fuels. By decreasing the use of fossil fuels, solar power helps reduce the amount of carbon dioxide and other greenhouse gases released into the atmosphere. Solar can replace about 80% of the energy needed to heat indoor spaces and water this reduction can help mitigate climate change in a meaningful way.