"Green" energy

[305561744]

Chemically speaking, how are other alternative energy sources better than fossil fuels and the like? Does it have to do with the energy requirement in harvesting it, or the energy released upon its use?

[Autumn Jackson Dis 1J]

Alternate fuels like methane and ethanol generally produce less CO and hydrocarbons. They do produce CO2 still, but methane and ethanol are renewable, so this helps as well. Similarly, biodiesel oils have more energy density, getting more energy per amount, and are renewable, but they have the tendency to solidify at lower temperatures, making it hard for some devices to use it.

[Anthony Tam]

This section is in Focus 4D of the textbook (in box 4D.1). This box talks about 4 different alternative fuels that all have their pros and cons. They are not necessarily "better" (in terms of being more efficient, except for biodiesel), but they are renewable sources of fuel unlike fossil fuels. Hope this helps!

[Olivia Peony Dis 2A]

I think sometimes it could be because the byproduct is less harmful (or produce less byproduct), also the energy source is renewable, which makers it more sustainable. Larger energy density is also beneficial because it reduces the amount of fuel we need to use. But again there are pros and cons so definitely check the textbook as Anthony mentioned.

Olivia Peony Dis 2A

[005801694]

Hi! Common alternative fuels include hydrogen, ethanol, methane and biodiesel. The oxygenation of ethanol reduces the emission of carbon monoxide and hydrocarbons by ensuring complete combustion. Biodiesel is diesel fuel that comes from renewable, biological sources. Diesel engines are more efficient than gasoline engines because the fuel has a higher energy density (enthalpy of combustion per liter).

[elenadworak]

Yah from an environmental standpoint, renewable energy sources are much better because they don't diminish resources from the earth. Geothermal power is good but still harms the earth, wind and slower power are the best because they are constantly renewable. Chemically speaking, some emit harmful things to the atmosphere while other energy sources emit nothing harmful.

[405566265]

Windmills are a great source of renewable energy!

[Ashley Gonzalez Dis 2A]

Fossil fuels are nonrenewable so there is a finite amount but renewable resources are better in regards to sustainability and how they generate more energy and produce fewer emissions (carbon dioxide) than fossil fuels.

[005502505]

Coming from an environmental science major, a lot of which fuels are considered "green" have to do with how the energy is released. Burning, as is needed for the release of coal/oil energy, produces methane, a greenhouse gas, which leads to global warming. Cleaner energy sources, such as wind and water power, may be harvested in a less harmful way (through kinetic energy of motion).

[Emily Vargas 2I]

I would think that this is because, unlike fossil fuels, green energy sources release less carbon emissions. To add on to that these sources are renewable and demand less harvesting wise over the long terms. If you consider the process for continuously gathering fossil fuels and compare that to the one instance it takes to build a windmill for instance, the difference in terms of impact is less so for the windmill.

[Sofi Ghasemzadeh 2G]

Alternate fuels, while they produce CO2, emit a much smaller quantity of CO. Additionally, they are renewable, and hence, more sustainable and overall better for the environment.

[Moselle Stieler 3A]

In terms of vehicles, would electric be better than gas as they are rechargeable? I wonder about the batteries and the production and consequent inevitable disposal of them. Which would be better long term do you think?

[Hritika Chaturvedi 3L]

Other alternative energy sources are better than fossil fuels mainly because of their lower environmental impact and reduced greenhouse gas emissions. They often have lower energy requirements during harvesting and produce less pollution when used. Examples include solar, wind, and hydroelectric power.

[005925345]

Alternative energy sources, at this point in time, basically means any energy source that isn't fossil fuels (coal, oil, natural gas, substances derived from them, etc.). This means that anything from nuclear, renewables (solar/wind/hydro), hydrogen, or even burning garbage could be considered to be an alternative energy source. As you can see, there's a lot of variety in this single "umbrella" word.

You would have to look at a lifecycle assessment of an energy source to evaluate how clean and sustainable it is, and you'd have to consider how and where it would be used (not to mention cost). Various types of pollution can be generated at different stages of using an energy source, and it's a matter of accounting for all of these environmental impacts before we can truly declare an energy source to be "green". I've see methane be considered to be "green" because it can be reproduced easily by biological processes (and is thus renewable), but methane is a much more potent greenhouse gas than carbon dioxide- any leakage of it can easily make methane not green! That's also not to mention what it requires- often, methane comes from landfills or oil wells.

It takes a lot of research to discover the shortcomings of these alternative energy sources- I prefer being a skeptic to anything that isn't proven. Speaking from what I've read, the cleanest and most proven energy sources are solar, wind, and nuclear, but they all have their niches and applications. I would encourage that you do some research on a website like carbonbrief.org or to read some research papers if you're interested.