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Comment by olivermarks | Hacker News Reader

How these taxis will consume energy: electricity generation in the UK comes from three main sources – gas, coal-fired power stations and nuclear. A small but growing proportion of electricity is supplied by renewables. Gas accounted for 46 % of electricity supplied in 2008.

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>UK comes from three main sources – gas, coal-fired power stations and nuclear. A small but growing proportion of electricity is supplied by renewables.

That's not really true anymore. Wind power supplies double that of coal in the UK. It's gas, nuclear and wind with coal coming in 4th. Check out http://www.gridwatch.templar.co.uk/ for live figures.

You also have to think about when they will be consuming electricity, which will primarily be at night (taking a reasonable guess here) where the balance of wind and nuclear is even higher.

UK just started to build a new mega nuclear block: https://en.wikipedia.org/wiki/Hinkley_Point_C_nuclear_power_... .

It's not perfect but burning gas emits less CO2 than burning petrol or diesel. It also keeps all the pollutants out of the city, so public health should increase.

Keeping the pollution out of London is the best part. By European standards, the city is very polluted, and the old taxis are disproportionately responsible.

Buses are also a big contributor, although these are gradually being replaced too.

Buses in London have been updated to Euro IV standard, and most are Euro V or better. Of course, they are larger vehicles, and pollute in proportion, but at least they don't park in long lines and idle their engines for hours...

http://content.tfl.gov.uk/bus-fleet-audit-130117.pdf

Indeed, I've taken a 100% electric bus (route 507) and it was very good. No rumbling, polluting diesel engine.

Note there are significant losses in gas turbines, electricity transmission and battery storage. If you burn the gas near to where it's needed then you avoid most of those losses.

.. but larger turbines are more efficient than vehicle engines. I think Derek MacKay has some numbers on vehicle vs centralised generator, but can't find it right now.

(CNG has been an option for vehicles for ages, but for some reason never quite took off?)

Good point. There will also be an optimal efficiency speed and power level for a given internal combustion engine, which is more likely to be achievable in hybrid cars where the engine powers a generator and is therefore decoupled from providing direct power to the transmission.

yes but it's a move that allows for clean power generation in the future while reducing pollution in the city now

Ah, the good old "long tailpipe" fallacy occurs again to someone.

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