Looks like the party is over....

[JamesPa]

39 minutes ago, Beelbeebub said:

A bit off topic but I don't think people have range anxiety. 

 

They have refueling anxiety.

That's very perceptive! Also spot on and a better description.

[Michael_S]

2 hours ago, MrPotts said:

I think a scop of 4+ is needed to breakeven the cost of gas v's electricity.

Depends a bit how efficient you think a gas boiler is in terms of KWH of gas per kwh of heat.

[Michael_S]

2 hours ago, MrPotts said:

I think a scop of 4+ is needed to breakeven the cost of gas v's electricity.

Depends a bit how efficient you think a gas boiler is in terms of KWH of gas per kwh of heat.

[SteamyTea]

3 hours ago, sharpener said:

And as you say a petrol fill-up only takes 5 mins.

I filled up today, well put 30 litres in.

The car in front of me was already filling up, was ten minutes before they came back to the car (with coffees), then 4 minutes before they pulled away.

I filled up in 3 minutes (pay at pump).

So a total of 17 minutes.

Now a 150 kW charger could probably pump in 40 kWh in that time, so about 160 miles.

 

3 hours ago, MikeSharp01 said:

the elephant in the room problem is that we don't have enough electricity to move

I looked at this a few years back, worked out that we could charge 3.5 million cars without any changes (apart from charging points), and 7.5 million cars with minor changes, but all without adding capacity or infrastructure.

I posted it up here somewhere.

[MikeSharp01]

7 minutes ago, SteamyTea said:

3.5 million cars without any changes (apart from charging points), and 7.5 million cars with minor changes

Yes but there are 35 million cars registered in the UK!

[SteamyTea]

10 minutes ago, MikeSharp01 said:

Yes but there are 35 million cars registered in the UK!

We are not going to wake up tomorrow with nothing but EVs in all our drives.

2021 there were about 190k, 2022 270k, 2023 315k, 2024 382k and 2025 (TD) 386k.

So still going to take a while.

[SteamyTea]

6 minutes ago, SteamyTea said:

We are not going to wake up tomorrow with nothing but EVs in all our drives.

2021 there were about 190k, 2022 270k, 2023 315k, 2024 382k and 2025 (TD) 386k.

So still going to take a while.

(the numbers are new registrations, there are about 1.7m BEVs)

 

Edited 13 hours ago by SteamyTea

[marshian]

16 hours ago, HughF said:

Even if we do, it’s far more efficient to burn it in a CCGT, transmit the energy to the home as electricity, then run a heat pump with that electricity than it is to pipe the gas and then burn it in the home.

 

Breakeven point for efficiency is a scop of 2.8 iirc.

 

Is that considering the utterly dreadful efficiency of 50-60% of a CCGT - I get your point about transmission issues (and losses) for gas supply but I'm running a gas boiler at 97.5% efficiency on CH and 89% on HW

 

What about the electricity transmission losses?

[Crofter]

If fiddling with the cost of electricity/gas is part of this, the progressive approach would be to reduce standing charges, which have become inflated in recent years.

[Andehh]

15 hours ago, MrPotts said:

I think a scop of 4+ is needed to breakeven the cost of gas v's electricity.

We run a COP of about 3 atm (heavy users of hot water), but with off peak leccy at 7.5p being 90% of our ASHP energy usage, we're making significant savings vs gas. We also then run the dish washer etc during that off peak rate.

 

Then we don't pay a gas standing charge which is the icing on the cake. 

 

With this setup, even a COP of 2, we would work out cheaper then gas I recon. 

[Beelbeebub]

13 hours ago, sharpener said:

 

Yes, my first 4-wheeled vehicle was a s/h Viva van, the tank only held 7 gals which was good for just 200 miles.

 

Which going to the Fringe meant one stop between London and Edinburgh and I knew where all the Jet stations were. 

 

And as you say a petrol fill-up only takes 5 mins.

 

ln contrast the EV takes at least 10 for a useful addition to the range and the best part of an hour from empty to full. I have had my fair share of charging points being ICEd in, and having to detour via 3 charging stations late at night before I found one that would accept normal c/cards. That's certainly anxiety-inducing. So it's very handy to be able to get from Cambridge to Romsey and back on one charge.

This illustrates my point very well. 

 

You need the range to go there and back on one charge because you're anxious about the trouble of trying to charge away from home. 

 

Which isn't a.worry with ice cars.

 

Imagine if petrol stations were really rare and had very slow pumps, 30mins to fill

 

Your 200mile can would be pretty stressful. Everyone would want huge tanks, which would take even longer to fill etc. 

 

Some of the new generation of Chinese LFP batteries can charge at 10C, ie they can fill in 6 minutes (assuming you have a powerful enough charger). In practice it's a hit linger because of charge curves but people don't usually fill 0-100, it's 20-90 or something. 

 

For a 100kwh battery that's a 1MW charger! 

 

But for a 30 kwh battery ,which could do 120 miles, you only need 300kw, which are not impractical.

 

My longest daily trip is London and back 150mi each way. I do it a few times a year. 

 

Currently easy on one tank. 

 

If I had an electric 150m range would be doable *if* I could guarentee an easy fill up at the other end. Otherwise I need 300 miles (plus reserve) 

[Beelbeebub]

8 hours ago, marshian said:

 

Is that considering the utterly dreadful efficiency of 50-60% of a CCGT - I get your point about transmission issues (and losses) for gas supply but I'm running a gas boiler at 97.5% efficiency on CH and 89% on HW

 

What about the electricity transmission losses?

The 250% figure is for kwh delivered at your house (including transmission losses) assuming a 100% efficency boiler. 

 

Ie volume of gas burned in a ccgt plant is 2.5x the volume of gas burned in a gas boiler to deliver 1kwh of heat in your living room. 

 

So, as long as your heatpump can achive a Cop of 2.5 or better you will burn less gas in the power plant than you would in your boiler. 

 

2.5 is pretty achievable in all but the most ham fisted installation. 

 

If we snapped our fingers and swapped every domestic gas heating system with a heatpump and created enough ccgt plants to power them, our national gas demand would fall. 

 

[JamesPa]

8 hours ago, marshian said:

 

Is that considering the utterly dreadful efficiency of 50-60% of a CCGT - I get your point about transmission issues (and losses) for gas supply but I'm running a gas boiler at 97.5% efficiency on CH and 89% on HW

 

What about the electricity transmission losses?

Transmission losses and power station efficiency etc are all accounted for on the published figures for carbon intensity of fuels, which are updated annually.

 

The carbon footprint from UK domestic electricity per kWh is about 10% less than that of domestic gas, furthermore it's falling as we move to renewables.  That means that a heat pump with a cop of 3 causes less than one third the carbon emissions (actually it's a bit better still than that because most has boilers are set up by the heating industry in a way that makes them less than 100% efficient).  

 

This stuff is well established and the carbon case for heat pumps irrefutable.