3 ms·

> That's about 70 GWh of overnight capacity that could have been used...Our grid excess capacity of 70 GWh means we can charge just under 11 million cars before

by ppf 5y ago

> That's about 70 GWh of overnight capacity that could have been used...Our grid excess capacity of 70 GWh means we can charge just under 11 million cars before we're using more than our current peak electricity demand. You've ignored all losses. Transmission and distribution losses, the latter of which are worse for low-voltage customers (ie, domestic use, and is over 10%), total around 15% for domestic use. As well as that, charger loss is around 15%. Adding all that up, a car that needs 20 miles at 333 Wh/mile needs 9kWh of generated supply power, or barely 8 million cars (assuming this power is actually available). There is also the obvious problem that there is no solar availabe at night, which makes up a relatively large percentage of the UK's energy mix (over 8GW right now, as I just looked). >The maximum delivered power in the last year was 47.275 GW How much of that peak power was from peaking plants, for example, the 1.8GW pumped hydro storage at Dinorwic? A huge part of the problems with EVs are related to unrealistic and misleading estimates. Please be careful with the maths.

leoedin 5y ago
The comment you're replying to was in response to the parent comment, who said "Its not even clear how we are supposed to produce the necessary amounts of electricity" You can argue about efficiencies (which it's true, should be taken into account) - but the point remains. The current grid already has very close to the capacity required for electric cars. Maybe we'll need to add a few power stations or interconnects, maybe we'll need to upgrade some local infrastructure here or there, but it's not like we're an order of magnitude off. There's currently close to 100 GW of installed capacity on the UK grid (https://www.statista.com/statistics/496283/total-electricity-generation-capacity-uk/ https://www.statista.com/statistics/496283/total-electricity...) - even if you completely stripped out all the variable-supply renewables like solar and wind, you'd still be left with a substantial margin. There's no solar overnight - true - but there's also very little solar on dark cloudy December days (when demand is often high) and the grid manages to deliver ~40GW peak then without issues. The pumped storage couldn't have been more than 2.8GW - because that's how much is installed. In fact, apparently overall demand has dropped year on year - the overall peak was 62 GW, in 2002. At least in the UK, National Grid (the grid operator) agrees - https://www.nationalgrid.com/stories/journey-to-net-zero/5-myths-about-electric-vehicles-busted https://www.nationalgrid.com/stories/journey-to-net-zero/5-m.... There's not an issue with overall capacity.
- ppf 5y ago
  No, it's not an order of magnitude, although I find it disingenuous to use the peak load from 20 years ago, when the UK National Grid has changed quite considerably since then, and has lost 16GW in production capacity [1] We're also apparently in the process of nuclear decomissioning, and I'm not sure where that lost power will come from. At the moment, we just ramp up gas-fired power stations to meet demand, so yes, we can just burn more gas to generate more power. In this scenario, transmission/distribution and charger losses wipe out a lot of the CO2 gains. We also haven't even touched on the idea of commercial EVs - I'm not sure of the figures, but I suspect that the energy requirements for making all vans, trucks, and lorries electrically powered will outstrip EV domestic usage (and, for that matter, should be more important from a CO2 reduction point of view). [1]https://en.wikipedia.org/wiki/List_of_power_stations_in_England https://en.wikipedia.org/wiki/List_of_power_stations_in_Engl...
  - leoedin 5y ago
    The 47 GW peak which would provide more than enough power for 30 million cars was this year. I gave the all-time peak as an example of how high it has been in the past - as a means of demonstrating that not only is charging cars within the scope of our current grid, but our current grid isn't even as heavily utilised as it was in the past - so it's unlikely to be burdensome to expand it back to those levels. I don't know to what extent the infrastructure itself has changed - but given National Grid themselves don't think it'll be a big issue, the grid itself is probably still capable of that 62GW (even if generating capacity is less). I haven't mentioned CO2 in my comments because that was not part of the original discussion. "Its not even clear how we are supposed to produce the necessary amounts of electricity" is patently false in the case of the UK. Maybe overall CO2 production would be less, maybe more - that's a different (though important) discussion. At least with electric vehicles there's a clear technological roadmap to 0 emissions - there's no credible roadmap for 0 emissions with internal combustion engines. Vans aren't likely to be vastly different from cars - eg the Ducato Electric claims 235 km on a 47 kWh battery - vs a Model 3's claimed 265 km on a 50 kWh battery. HGVs are much heavier vehicles though - the path for electrification for those is likely to be slower.

by ppf 5y ago

leoedin 5y ago

The comment you're replying to was in response to the parent comment, who said "Its not even clear how we are supposed to produce the necessary amounts of electricity" You can argue about efficiencies (which it's true, should be taken into account) - but the point remains. The current grid already has very close to the capacity required for electric cars. Maybe we'll need to add a few power stations or interconnects, maybe we'll need to upgrade some local infrastructure here or there, but it's not like we're an order of magnitude off. There's currently close to 100 GW of installed capacity on the UK grid (https://www.statista.com/statistics/496283/total-electricity-generation-capacity-uk/ https://www.statista.com/statistics/496283/total-electricity...) - even if you completely stripped out all the variable-supply renewables like solar and wind, you'd still be left with a substantial margin. There's no solar overnight - true - but there's also very little solar on dark cloudy December days (when demand is often high) and the grid manages to deliver ~40GW peak then without issues. The pumped storage couldn't have been more than 2.8GW - because that's how much is installed. In fact, apparently overall demand has dropped year on year - the overall peak was 62 GW, in 2002. At least in the UK, National Grid (the grid operator) agrees - https://www.nationalgrid.com/stories/journey-to-net-zero/5-myths-about-electric-vehicles-busted https://www.nationalgrid.com/stories/journey-to-net-zero/5-m.... There's not an issue with overall capacity.

ppf 5y ago
No, it's not an order of magnitude, although I find it disingenuous to use the peak load from 20 years ago, when the UK National Grid has changed quite considerably since then, and has lost 16GW in production capacity [1] We're also apparently in the process of nuclear decomissioning, and I'm not sure where that lost power will come from. At the moment, we just ramp up gas-fired power stations to meet demand, so yes, we can just burn more gas to generate more power. In this scenario, transmission/distribution and charger losses wipe out a lot of the CO2 gains. We also haven't even touched on the idea of commercial EVs - I'm not sure of the figures, but I suspect that the energy requirements for making all vans, trucks, and lorries electrically powered will outstrip EV domestic usage (and, for that matter, should be more important from a CO2 reduction point of view). [1]https://en.wikipedia.org/wiki/List_of_power_stations_in_England https://en.wikipedia.org/wiki/List_of_power_stations_in_Engl...
- leoedin 5y ago
  The 47 GW peak which would provide more than enough power for 30 million cars was this year. I gave the all-time peak as an example of how high it has been in the past - as a means of demonstrating that not only is charging cars within the scope of our current grid, but our current grid isn't even as heavily utilised as it was in the past - so it's unlikely to be burdensome to expand it back to those levels. I don't know to what extent the infrastructure itself has changed - but given National Grid themselves don't think it'll be a big issue, the grid itself is probably still capable of that 62GW (even if generating capacity is less). I haven't mentioned CO2 in my comments because that was not part of the original discussion. "Its not even clear how we are supposed to produce the necessary amounts of electricity" is patently false in the case of the UK. Maybe overall CO2 production would be less, maybe more - that's a different (though important) discussion. At least with electric vehicles there's a clear technological roadmap to 0 emissions - there's no credible roadmap for 0 emissions with internal combustion engines. Vans aren't likely to be vastly different from cars - eg the Ducato Electric claims 235 km on a 47 kWh battery - vs a Model 3's claimed 265 km on a 50 kWh battery. HGVs are much heavier vehicles though - the path for electrification for those is likely to be slower.