What's the deal with natural gas? It doesn't seem "renewable"; isn't it extracted just like petrol? Is it just that it burns cleaner? Doesn't burning it still produce carbon dioxide?
Another factor is that natural gas turbines can be turned on and off more quickly than coal fired plants. This is because a gas turbine is literally burning the gas in the turbine, it's akin to a jet engine on an airplane you can throttle up and down. A coal fired power plant is really a boiler that creates steam, and then the steam is fed through a turbine. Heating up all the water to make steam actually takes a long time.
In an era of renewable energy sources (solar, wind) that fluctuate more unpredictably, having that "dispatchability" is really valuable.
Typically coal and nuclear power plants are "base" load stations, providing always-on capacity. It's not always possible to vary their output to match demand, so typically (natural) gas power plants are used to match the remaining variable load. The start up/shut down cycle for these plants is far less costly.
Really interesting to see.
Britain also has the interesting culture of tea drinking in the evenings - almost all using electric kettles. I believe the grid uses hydro stations to cover the load of this. Typically peaks during breaks and/or after popular TV shows in the evening.
Even if it takes an hour to cool down, since daily and weekly patterns are generally known, can't they reduce or stop the coal supply an hour in advance?
In a world with more renewable energy, perhaps coal plants can be designed with smaller boilers, to strike a different tradeoff?
NG also is easier to transport (pipelines rather than hauling it with vehicles or boats) and does not cause the release of radioactive particles (which coal does do).
The other side of it is that unburned coal doesn't leak into the air as a potent greenhouse gas the way methane does.
To be clear, burning coal concentrates the uranium and thorium that naturally occur in coal by a factor of about 10. There is still only a very small amount. Living within the stack shadow (~1km) of a coal fired plant only increases your exposure to background radiation by about 5%
Of course, assuming you aren't accounting emission due to the operation itself.
A gas stove is natural gas, and they exhaust right into the house. You'd never do that with coal.
SMR is already being done at large scale for H2 production (IIRC we would only have to scale it up by 100x), but currently the CO2 is mainly released back to the atmosphere. If instead one would store the CO2 permanently underground in old gas reservoirs and saline aquifers, NG would give us a mostly clean energy source. I really hope we will see this happen, but it depends a lot on government action...
http://www.chemicalprocessing.com/articles/2015/researchers-...
The carbon comes off as powder, which is easier to sequester than CO2 because you can just throw it in the bin.
More seriously, i don't actually know. I think of tin as being quite cheap. Note that it's a catalyst in this reaction, so you don't need a giant supply of it.
[1] http://www.cornishpastyassociation.co.uk/about-the-pasty/his...
It's also more economical. Something like a coal or nuclear plant produces power whether you need it or not.
From point of view of greenhouse gas emissions, the impact is quite large because methane produced by biological decomposition is a potent greenhouse gas, so having more of it burned in power plants is definitely good.
The idea is that surplus electricity from renewable energy is used to create hydrogen which is added to the natural gas grid and burned later in gas turbines when the demand exceeds the supply of renewables. A significant amount of hydrogen can be mixed in with natural gas without issues.
For the longer term, people are also working on generating methane (CH4), which is the main component of natural gas, from electricity and CO2. Burning that would be carbon neutral as well.
Gas can be extracted from renewable sources too, and that gas works in the same infrastructure so hopefully biogas will displace more of the NG production in the future.