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[10ebbor10]

Lifetime carbon emissions cycle: Ie construction, use , fuel refinement, waste processing, all the stuff.

Capturing carbon emmissions only works with heavy polluters. Otherwise you're wasting more energy than doing good. Oh, and converting that back to hydrocarbons has been tested and works, but it's rather energy efficient.

The reason that conversion inefficiencies matter is that no energy source is carbon free. If you loose 50% of the energy, then you need to double production capacity, and as such also double emissions. At that point, Solar PV becomes a better alternative than Thermal solar.

[Descan]

Electricity isn't for everything, mostly because electricty has a terrible enegy density. You nee to convert it to, say, hydrogen fuel cells to use it in cars.
Efficiency is important because renewable energy isn't free—it costs the environment almost always. Better efficiency also means lower costs and thus more affordable plants.

Also,capturing carbons to convert to hydrocarbon isn't useful at all. If you're going to burn it anyways, why bother using expensive (energy-wise) processes for nothing, compared to getting your daily requirement of hydrocarbons from easier sources? O.o

Because those easier sources are becoming less easy as they run out while the hydrocarbon creation is becoming easier every year. Because hydrocarbon creation from the air or from (hopefully scrap) biomass is carbon-neutral or negative, either not adding carbon to the atmosphere when burned, or by taking carbon -out- of the atmosphere.

@Ebbor: I can sort of see the fuel refinement being carbon-positive, depending on where we get the carbon FROM (if we get it from, say, Limestone, carbon that's been locked away from the carbon cycle for eons, then that would add to the carbon-count of the atmosphere), but I'm not sure how use adds atmospheric carbon if you're just shining mirrors on a pipe to heat water that drives a turbine. Or what waste management would need to be done. Construction, at least for the first few, would definitely add carbon, but it's a one-time cost and in the future we would probably get the energy required for construction from OTHER solar towers and their fuel creation. I.E. no carbon added to the atmosphere that wasn't already in the cycle.

And I might be wrong, but wouldn't getting the energy from towers in unpopulated areas -to- populated areas VIA power lines cause an energy loss? I mean getting power from, say, Nevada to New York, or from the deep sahara to Cairo or London, that sounds like it would lead to a lot of inefficiency. Even a 50% loss to convert it to easily-transportable fuel would probably save, not to mention the construction or maintenance of power lines.

[Descan]

Sorry for the double-post, I just wanted to make sure this was seen:

Just to be clear, here's how I picture it. Energy production from entirely renewables. Hydro, geothermal, solar, etc. That energy is usable, but we don't currently have the infrastructure for it. We'd need battery powered cars, and not everyone can afford to switch to them. That's where hydro-carbon creation comes in. We use the renewable-sourced electricity to create fuels we CAN use in our current cars and trucks and buses and industries. That fuel is created from carbon and water, preferably carbon sources that were in the carbon cycle recently, such as actual atmospheric carbon or lawn-cuttings, agricultural chaff, etc.

When burned, you're not -adding- to the carbon cycle. You're only putting carbon back that's been there recently. The carbon count stays level for the next hundred years, or thousand, or however long. We have a renewable source of energy, the Sun, however we extract the energy from the Sun, or from nuclear/geothermal, so it's not a closed system. There's no "infinite energy!" going on here. And we have usable, and more importantly renewable, carbon-neutral fuel source, that we can just drop into cars as-is.

And since it's cleaner than fossil fuels, as it's ONLY the artificial hydrocarbon, not any sulfur or other pollutants, the only products are carbon dioxide and water.

[10ebbor10]

@Ebbor: I can sort of see the fuel refinement being carbon-positive, depending on where we get the carbon FROM (if we get it from, say, Limestone, carbon that's been locked away from the carbon cycle for eons, then that would add to the carbon-count of the atmosphere), but I'm not sure how use adds atmospheric carbon if you're just shining mirrors on a pipe to heat water that drives a turbine. Or what waste management would need to be done. Construction, at least for the first few, would definitely add carbon, but it's a one-time cost and in the future we would probably get the energy required for construction from OTHER solar towers and their fuel creation. I.E. no carbon added to the atmosphere that wasn't already in the cycle.

The cost is determined for today's situations. Ie construction costs and maintenance cost form the bulk of carbon emission for solar.  Still, you might go as energy green as you want, there's still a minimal carbon emmission due to the refining of the materials required to build the tower. Concrete is a big example of this.

And I might be wrong, but wouldn't getting the energy from towers in unpopulated areas -to- populated areas VIA power lines cause an energy loss? I mean getting power from, say, Nevada to New York, or from the deep sahara to Cairo or London, that sounds like it would lead to a lot of inefficiency. Even a 50% loss to convert it to easily-transportable fuel would probably save, not to mention the construction or maintenance of power lines.

Both would. However, it lowers the useability of the technology in favour of local power sources,.

Beside, if you transport it you need to maintain a fleet of ship's, or build pipelines. This also incurs energy losses, and in case of hydrogen, is quite dangerous. Meanwhile, progress is made on hyperconductive cabling.

Sorry for the double-post, I just wanted to make sure this was seen:

Just to be clear, here's how I picture it. Energy production from entirely renewables. Hydro, geothermal, solar, etc. That energy is usable, but we don't currently have the infrastructure for it. We'd need battery powered cars, and not everyone can afford to switch to them. That's where hydro-carbon creation comes in. We use the renewable-sourced electricity to create fuels we CAN use in our current cars and trucks and buses and industries. That fuel is created from carbon and water, preferably carbon sources that were in the carbon cycle recently, such as actual atmospheric carbon or lawn-cuttings, agricultural chaff, etc.

When burned, you're not -adding- to the carbon cycle. You're only putting carbon back that's been there recently. The carbon count stays level for the next hundred years, or thousand, or however long. We have a renewable source of energy, the Sun, however we extract the energy from the Sun, or from nuclear/geothermal, so it's not a closed system. There's no "infinite energy!" going on here. And we have usable, and more importantly renewable, carbon-neutral fuel source, that we can just drop into cars as-is.

And since it's cleaner than fossil fuels, as it's ONLY the artificial hydrocarbon, not any sulfur or other pollutants, the only products are carbon dioxide and water.

Sadly, we have neither the money, nor the resources, nor the political will to get both money and resources. We're quite some distance away from fully renewable energy, and actually, getting everyone to switch to electrical** is easier than replacing the production capacity of the whole world with renewable. ()

Also, rather than making hydrocarbons*, we can just use the hydrocarbons we have now, and capture some from the atmosphere. After all, stuffing things in the ground doesn't require 100% pure carbon dioxide.

*Which only works with a pure enough source of Co² (Ie, fossil fuel or chemical plant)
**Not that it'd do us any good till we go full carbon neutral power, but anyway.

[SalmonGod]

I like Iceland more all the time.

[Devling]

I am super sceptical about wikileaks in general.

[da_nang]

I like Iceland more all the time.

Took them long enough.

[SalmonGod]

I like Iceland more all the time.

Took them long enough.

Yet they're still miles ahead of the pack.

[Scoops Novel]

If you could wax eloquent SalmonGod?

[Dutchling]

If you could wax eloquent SalmonGod?

We're gonna wax SG? I'm in

[Reelya]

**Not that it'd do us any good till we go full carbon neutral power, but anyway.

It would do us some good to switch away from gasoline-powered cars: A centralized coal plant is more efficient than many small gas engines (and not all electricity is generated by coal, so the average CO2 per KWh is a bit lower), and is much easier to regulate and filter, and there's also the fact that you won't be pumping toxic emissions including carcinogenic compounds out the back of every vehicle in a residential area.

[Skyrunner]

**Not that it'd do us any good till we go full carbon neutral power, but anyway.

It would do us some good to switch away from gasoline-powered cars: A centralized coal plant is more efficient than many small gas engines (and not all electricity is generated by coal, so the average CO2 per KWh is a bit lower), and is much easier to regulate and filter, and there's also the fact that you won't be pumping toxic emissions including carcinogenic compounds out the back of every vehicle in a residential area.

That's probably a very good point.

Also, centralized power means you can take advantage of things like nuclear energy, which are much less polluting in terms of carbon, and take up quite a fraction of energy supply. Though you get radioactive waste...

[SalmonGod]

Student wrongly tied to Boston bombings found dead

[10ebbor10]

**Not that it'd do us any good till we go full carbon neutral power, but anyway.

It would do us some good to switch away from gasoline-powered cars: A centralized coal plant is more efficient than many small gas engines (and not all electricity is generated by coal, so the average CO2 per KWh is a bit lower), and is much easier to regulate and filter, and there's also the fact that you won't be pumping toxic emissions including carcinogenic compounds out the back of every vehicle in a residential area.

Electric cars are however twice as polluting to produce. 40% of that is the battery but still. And depending on powerplant and engine design, gasoline might be better. No sense in switching to electric so you can keep 40 year old coal plants in operation.

[Putnam]

The pollution over a lifetime of a gasoline-run car would be much more than the production of an electric one.