Which electric car to buy?

[andyinluton]

why can't we have electric heaters why we got to have heat pumps ?

An air source heat pump is a type of electric heater, in ideal conditions its far more efficient than a normal electric fire.

 

[Velma's Dad]

why can't we have electric heaters why we got to have heat pumps ?

And to add a little to Andy's answer - a heat pump boosts up the low-grade heat contained in the outside air (air source heat pump) or under the ground (ground source). So you get out in heat energy to warm your house a multiple of the electrical energy you put in from the grid.

 

[starbug]

An air source heat pump is a type of electric heater, in ideal conditions its far more efficient than a normal electric fire.

we had a quote for heat pump and it was 25000 . a quote for electric rads was 3000.

 

[Velma's Dad]

we had a quote for heat pump and it was 25000 . a quote for electric rads was 3000.

Sure. The heat pump has a high capital cost. Over time it will however cost considerably less in electricity than direct electric rads will. But it will take maybe 20+ years to recover the extra costs, which is why various government schemes are intended to incentivise people to put in hear pumps.

£25,000 sounds a lot for an air source heat pump though, unless you have a huge house or one that's very poorly insulated.

 

[Amarillo]

An air source heat pump is a type of electric heater, in ideal conditions its far more efficient than a normal electric fire.

I think I read that for every watt of input you get three watts of heat.

 

[GrumpyGranddad]

Who needs an electric car when you have a bike for transporting the kids and long loads?

Great fun

 

[GrannyJen]

I investigated a heat pump for my house. The quote, including government subsidy, meant that my extra electricity costs would be offset by savings in gas for my CH boiler. However the grants ran for only seven years after which the differentials all went south.

The other two things, you need to plonk it against the house somewhere which takes both space and installation and secondly you need a hot water tank, you are stuffed if like me you have a combi boiler for the simple reason there is nowhere to put a tank.

In anticipation of power cuts, and possibly gas cuts, Both caravan and Camper now have enough of everything to be able to live in them for several days.

 

[starbug]

Sure. The heat pump has a high capital cost. Over time it will however cost considerably less in electricity than direct electric rads will. But it will take maybe 20+ years to recover the extra costs, which is why various government schemes are intended to incentivise people to put in hear pumps.

£25,000 sounds a lot for an air source heat pump though, unless you have a huge house or one that's very poorly insulated.

both. im not sure if any of us will be able to afford electric in 20 years.

 

[starbug]

I investigated a heat pump for my house. The quote, including government subsidy, meant that my extra electricity costs would be offset by savings in gas for my CH boiler. However the grants ran for only seven years after which the differentials all went south.

The other two things, you need to plonk it against the house somewhere which takes both space and installation and secondly you need a hot water tank, you are stuffed if like me you have a combi boiler for the simple reason there is nowhere to put a tank.

In anticipation of power cuts, and possibly gas cuts, Both caravan and Camper now have enough of everything to be able to live in them for several days.

sounds like a good idea .

 

[Amarillo]

I investigated a heat pump for my house. The quote, including government subsidy, meant that my extra electricity costs would be offset by savings in gas for my CH boiler. However the grants ran for only seven years after which the differentials all went south.

The other two things, you need to plonk it against the house somewhere which takes both space and installation and secondly you need a hot water tank, you are stuffed if like me you have a combi boiler for the simple reason there is nowhere to put a tank.

In anticipation of power cuts, and possibly gas cuts, Both caravan and Camper now have enough of everything to be able to live in them for several days.

Does the technology exist for people in costal areas, or by rivers, lakes, etc., to have water source heat pumps.

If so, you could have large water source heat pumps supplying several properties.

 

[GrannyJen]

Does the technology exist for people in costal areas, or by rivers, lakes, etc., to have water source heat pumps.

If so, you could have large water source heat pumps supplying several properties.

No idea Tom, are you anticipating a failure of the Thames Barrage in the near future? Greenwich by the sea?

 

[Amarillo]

No idea Tom, are you anticipating a failure of the Thames Barrage in the near future? Greenwich by the sea?

I was thinking of you in Littlehampton. A community water source heat pump installed just offshore supplying low carbon heating and hot water to Littlehamptonians.

I know little about the transfer of heat from air, soil or water, but it would make sense, in my ignorance, if it is easier to extract heat from water. And the sea is a more consistent temperature year round than air.

 

[GrannyJen]

I was thinking of you in Littlehampton. A community water source heat pump installed just offshore supplying low carbon heating and hot water to Littlehamptonians.

I know little about the transfer of heat from air, soil or water, but it would make sense, in my ignorance, if it is easier to extract heat from water. And the sea is a more consistent temperature year round than air.

Southern water here. The worst polluters of tidal shores anywhere!!

Seriously, it would be a major effort and we can't even get two neighbours to agree on a choice of solar panel....

 

[Velma's Dad]

I think I read that for every watt of input you get three watts of heat.

That's a reasonable rule of thumb (I got quotes a year or so ago) although from my own research I think the actual ratio achieved is very dependent on the precise set up and there's a lack of recent real-world test data for domestic installations in the UK, versus in France, Scandinavia etc, and a lot depends on the competence of the engineer who configures and commissions your system. Ground source is supposed to give a higher efficiency than air source, but for a considerably higher capital cost of course.

As a non-expert it's a bit of a minefield. Certainly even with the govt's new scheme (basically a £5k grant) the economics are poor in the short term (unless you're currently using bottled gas or oil for heating), but of course are highly sensitive to assumptions about future energy pricing, particularly the differential between gas and electric costs per kWh. If you're prepared to shell out a big sum as a gift to the planet and future generations (Swedish teenagers maybe?) then obviously it just depends how deep your pockets are.

 

[Velma's Dad]

Does the technology exist for people in costal areas, or by rivers, lakes, etc., to have water source heat pumps.

If so, you could have large water source heat pumps supplying several properties.

Certainly for rivers/streams, yes. Eg the company we got HP quotes from does them: https://www.oxonenergy.com/water-source-heat-pump

They look like potentially quite high efficiency versus air/ground source.

None of this is new tech of course. I'm told Mrs VD studied various heat pumps for her physics degree in (ahem!) about 1985.

 

[GrannyJen]

Coincidentally I was looking at the practicalities of this the other day, as a family member has just installed a large ground-based PV array with battery storage on their farm in Scotland.

The most popular home battery at the moment is the Tesla Powerwall. They aren't cheap at about £10k per unit installed but can hold 13.5 kWh which is a couple of day's leccy for a medium sized house (not including space heating/HW of course). However, if used with solar panels, you won't want to designate that whole 13.5 kWh as 'reserve' because then you'd have no working storage for the panels, while sod's law says the grid power will go off after a long winter's night when the PVs have been dark.

Another thing I learnt about PVs was that they usually need to be set up so they disconnect if the grid power goes down, to avoid sending current the 'wrong way' into the grid which would be a hazard for repair workers. To have the PVs available in grid outages you have to be able to 'island' the property which I gather is considerably more complex/expensive to set up. I'm not sure if the Powerwalls can do that out of the box, maybe they can.

I have no doubt that home battery storage is going to be a biggish thing but I can see it's a tad more complicated than sometimes made out - even though eminently solvable.

Something I am looking at.

As you may have noticed I have a huge south-facing roof in probably one of the sunniest parts of the UK. I can get 20 panels on there but the generation would mostly be when I don't need it and, unlike 10 years ago when I last had Solar panels, the feed-back tariffs are miserly.

 

[clarinetbcn]

I have two air heat pumps in my flat. During the summer they run backwards and provide air conditioning. Total cost of installation 3400 euros. Their electric consumption is 100% covered by my solar installation. The excess I generate during the day covers the amount I use from the network at night, even though I buy electricity from the network retail and my excess is compensated at wholesale. No batteries needed. My local green energy cooperative uses excess energy from installations like mine during the day to pump water to higher lakes, and during the night drains the water to lower lakes to generate electricity. The system is based on one in Germany that I visited two years ago, when it was celebrating its 100th anniversary. All the talk of this not being possible is bullsh1t, the technology has been around for decades. Too bad those in regions currently without power were deceived into not having electric cars. If they had had reliable info, they would now be powering their heat pumps from their car batteries.

 

[clarinetbcn]

we had a quote for heat pump and it was 25000 . a quote for electric rads was 3000.

You need to look for another supplier. Air heat pumps are basically air conditioners which can run backwards in the winter, and have a slightly higher price than the same air conditioning equipment without the reverse function. These are ideal for flats. If you have a house, it’s worth it to look into ground heat pumps, which are even more efficient, but at a higher cost.

 

[andyinluton]

Too bad those in regions currently without power were deceived into not having electric cars. If they had had reliable info, they would now be powering their heat pumps from their car batteries.

@clarinetbcn as you seem to be the expert on heating my Scottish holiday cottage......

Name me one affordable electric car that I could buy today, that comes with a handy plug that would would run my house for the nine days that the power has been off?

Don't forget, Ive got no way of charging it up & I still need to use it to get to the nearest shop, being in one of the isolated areas where the power is down, thats a 60 mile round trip.

I didn't buy any batteries for the house as some bloke on an Internet forum persuaded me I didn't need any, just buy solar panels & what you sell back to the grid pays for the stuff you use thats what he said!

Funny though I found when the sun rises at 10.30 and sets at 3pm ( but disappears behind a mountain at 1pm) I didn't generate enough energy to make the dial on the meter move , let alone any excess. I think the couple of inches of snow on the panels might have had an effect.

Of course even if the electric was working, no one told me that by the time it gets down to -10 Air source heat pumps are so inefficient that an old fashioned fan heater would be cheaper to run. If it gets down to -15 it will stop working completely.

I think I will stick to my £500 generator & a bit of stored petrol, along with my log burner.

 

[clarinetbcn]

@clarinetbcn as you seem to be the expert on heating my Scottish holiday cottage......

Name me one affordable electric car that I could buy today, that comes with a handy plug that would would run my house for the nine days that the power has been off?

Don't forget, Ive got no way of charging it up & I still need to use it to get to the nearest shop, being in one of the isolated areas where the power is down, thats a 60 mile round trip.

I didn't buy any batteries for the house as some bloke on an Internet forum persuaded me I didn't need any, just buy solar panels & what you sell back to the grid pays for the stuff you use thats what he said!

Funny though I found when the sun rises at 10.30 and sets at 3pm ( but disappears behind a mountain at 1pm) I didn't generate enough energy to make the dial on the meter move , let alone any excess. I think the couple of inches of snow on the panels might have had an effect.

Of course even if the electric was working, no one told me that by the time it gets down to -10 Air source heat pumps are so inefficient that an old fashioned fan heater would be cheaper to run. If it gets down to -15 it will stop working completely.

I think I will stick to my £500 generator & a bit of stored petrol, along with my log burner.

In your case if no one informed you about earth heat pumps, it sounds like you got bad advice.

About 80% of my system’s generation is between 10am and 3pm. I had specialized engineers design my system, recommending the number and position of panels based on the analysis of light patterns throughout the day. It pays to get professional advice.

Re: plug, see post 372 for what was available from a Nissan Leaf in 2017. You don’t even need imagination, just a little bit of self interest to see what bidirectional charging options are available on models available today.

The secret is to be motivated. Then the information jumps out at you. If you suffer from “Future shock,” and are convinced that there is no solution available, no amount of advice will help you.

 

[vmaxkiddy]

Thanks, that answers it. I guessed it might have a lot of intelligence built in. I assume most Powerwall buyers will also use one (or more) plugged-in EVs as part of their backup storage regime, so you could 'rob' power from one of your cars to power your microwave etc while the grid's down, if you needed to. Or power up a car to make a getaway. Quite cute.

[EDIT] Oops, looks like it actually can't 'shunt' power back in from a car, Tesla or otherwise. Less cute.

The Hyundai Ioniq 5 has car to grid capability.

Seven random things you can power with the Hyundai Ioniq 5

New EV can harvest battery charge to juice up a fridge. And that got us thinking…

www.topgear.com

 

[andyinluton]

In your case if no one informed you about earth heat pumps, it sounds like you got bad advice.

About 80% of my system’s generation is between 10am and 3pm.

Ground source heat pumps are not financially viable where the ground is predominantly rock.

Unfortunately I’ve yet to find a designer that can move the position of the sun!

Just because it works in Spain doesn’t mean it works everywhere.

 

[reserves]

So, does anyone know what Electric Car I should buy….?

 

[Amarillo]

Ground source heat pumps are not financially viable where the ground is predominantly rock.

Unfortunately I’ve yet to find a designer that can move the position of the sun!

Just because it works in Spain doesn’t mean it works everywhere.

But Scotland, especially the highlands, would be perfect for pumped water storage as @clarinetbcn alluded to earlier.

 

[Amarillo]

So, does anyone know what Electric Car I should buy….?

Citroen Ami