Give me a counter argument to this article. Please!

[.jg.]

Are electric vehicles really so climate friendly?

For starters, the subtitle:
"EVs produce more CO2 than say diesel – it’s just they emit via the power plant not the exhaust pipe"
This only works if one makes the utterly daft and erroneous assumption that the extraction, refinement, storage and distribution of diesel (or petrol) is carbon free.
The article has cherry-picked data and glossed over inconvenient facts to arrive at the conclusion that it would be nice for the German automotive industry and the German economy if the EU's carbon targets were discarded. It is depressing but not entirely unexpected, given the author's background as an economist connected with the German government.

 

[Battpower]

90% of our heating is overnight, with the ASHP heating up a well-insulated concrete slab

Same here. Almost same set up! In fact, in winter months I am worried about maxing out the 100a supply fuse if any unplanned loads are switched on!

The biggest opportunity I see from EV's is that they potentially provide a huge place to dump energy from wind and solar. I'm not convinced that it will ever make much sense to use vehicle batteries to feed back into the grid. It is already hard enough to get enough energy into an EV without shortening battery life, without pulling more energy out of the battery for non-EV purposes.

Once you have a place to dump excess energy (which will take some time to evolve - but over-produced electricity when there is loads of excess capacity - will be cheap enough to make it worthwhile developing ways of charging cars at low cost - almost as a service to the generation process.

With devices like Zappi it becomes even more attractive to have solar panels on any suitable roof as you can be sure of making use of more self-generated energy.

Something has to kick-start EV charging infrastructure, and having viable EV's is a good starting point.

Also consider that Tesla is almost to EV's what Hoover once was to vacuum cleaners. That doesn't mean that Tesla is the only EV in town, by a long way. If you want efficiency, less absolute depreciation, arguably more eco friendly, then look for well designed smaller car. The Leaf and my preference - Zoe - have been holding their ground well in perhaps lower profile but equal or more significant markets.

Electric vehicles are so so much more flexible in terms of options for underlying energy than ICE so development of motors, whole power train, braking systems, comfort and safety that there is no argument I can see against them, even if they ended up being a stepping stone or partial solution.

 

[cassiopeia]

One other element in addition to all of the above is that with electric vehicles there is the possibility to make them greener after they are built. Stay with me on this one...
All the analysis I’ve seen is considering the existing mix of energy sources, and not considering that this may change over the lifetime of a vehicle. With ICE cars, once they are built they will never get any more efficient no matter what regulations are put into effect. In fact most ICE vehicles burn more fuel as they get older. Regulations about emissions affect the sale of NEW cars and it can take years to affect the overall consumption of the full fleet of vehicles. Meanwhile if you convert to electrics and move all their emissions to the power plants, then by making power generation more efficient or less emitting, ALL electric cars are affected, including those that were built years earlier. This means that there is at least the possibility of changing the emissions of EXISTING electric vehicles. So if a country suddenly makes it a priority to go 100% renewable, suddenly all their electric vehicles are completely clean, at least from a tailpipe standpoint.
Just one more argument for you.

 

[WannabeOwner]

Give me a comeback please!

Here's a couple of data points, if you are backed into a corner

Drive a modern Volvo on a gallon of diesel, or put that Diesel into a generator, charge your Tesla, and drive further. (Generator running at optimum REVs ... ICE having to handle emissions control over full range of REVs)

https://ww.electrek.co/2018/02/16/tesla-model-s-charged-diesel-generator/

Or this Fully Charged video about how much energy is consumed to make that gallon of Diesel / Petrol before it ever gets to be put into the ICE. Your Tesla will go further on the energy needed to make that gallon ... than an ICE can go ON that gallon

 

[Yev000]

This only works if

It doesn't work, period. even if you burn the same diesel at the power plant EV is still more efficient at converting that energy from electric to kinetic, transmission losses and all.

If you are going to buy a new car it makes zero sense to go ICE.

From wikipedia:
"Typical thermal efficiency for utility-scale electrical generators is around 37% for coal and oil-fired plants, and 56 – 60% (LEV) for combined-cycle gas-fired plants."

"most engines retain an average efficiency of about 18–20%" - unless you are in a formula one car....

So even with a transmission loss of ~10% and electric motor loss of 10% you are still looking at ~30% minimum (10% of 37% = 3.7 then another 10% of 34% = 3.4), from a coal power plant to moving your EV.

You can of course argue that there is more carbon in coal than diesel... But then you can counter that by saying in a coal power plant it's in a single location and much easier to trap and manage than in a car.

 

[LukeT]

... Looking at the price I pay for kWh for electricity vs gas, the electricity is 2x the price for E7, or 3.5x the price for daytime. So even without allowing for the gas boiler being less than 100% efficient, the heat pump only has to achieve a CoP of 2 for nighttime or 3.5 for daytime, which is quite plausibly achievable.

Water heating is more troublesome as the high target temperature gives poor CoP and/or needs resistive supplementary heat. Still, water heating has a useful side-benefit of giving easy storage (so you should be working with the E7 figure), and even if you decide to do it with just resistive heating (CoP=1) that is therefore more expensive per unit than gas, you can now scrap your gas boiler and offset the standing charge and maintenance costs against the higher cost of the electric option.

So I think it's fairly cost neutral.

However, for domestic heating the real win would be from better insulation so you don't need to buy the energy in the first place; if only someone could crack the politics of making this happen, particularly for rented accommodation where landlords currently have little incentive to make improvements.

Need to consider the upfront cost as well as the running costs though. At which point they are more expensive than gas. That's not to say I'm not right behind heat pumps, having installed one at home, work in an office with them and am about to install another.

Just insulate houses properly. Passive House / EnerPHit needs virtually no heat (nor aircon) input. The top-up needed is trivial to achieve
using electricity. The PEAK heating requirement (i.e. outside temperature well below 0C) for an average sized 3-bed house is 1kW - that's for the whole house)

Much better to insulate than carry on chucking heating energy at the building, year after year, particularly if the fuel is imported and distorts the balance of payments.

This is the big one. A kwh saved far outweighs one used but sourced from renewables.

 

[Bernard_S]

Another good reason to stop buying Chinese products.

Climate change: China coal surge threatens Paris targets;
While the rest of the world has cut coal-based electricity over the past 18 months, China has added enough to power 31 million homes.

China coal surge threatens Paris climate targets

 

[Glan gluaisne]

Need to consider the upfront cost as well as the running costs though. At which point they are more expensive than gas. That's not to say I'm not right behind heat pumps, having installed one at home, work in an office with them and am about to install another.

The last replacement gas boiler we had installed cost a bit over £2k. No work was done on the heating system, it was just a swap of an old gas boiler for a new one.

When I built our house I bought a brand new Glowworm branded (in reality a Carrier) 6 kW ASHP for £1,700 delivered, including VAT. It cost me another £300 to install it.

I suspect that the reality is that there's not much cost difference between a gas boiler and an ASHP, once the over-charging due to subsidy schemes is taken out of the equation. I did get a quote to supply and installer an ASHP here, under the RHI scheme. The price was £6k... In return for paying £4k more for the thing, we would have received about £84 a year for 7 years in RHI payments, so it was a no-brainer to ignore an MCS install and just buy and fit the thing. Took me about half a day to do the full ASHP installation, from bolting it to the concrete base to running the commissioning checks.

 

[Battpower]

so it was a no-brainer to ignore an MCS install and just buy and fit the thing.

Same here (again!)

Started off looking at ground source, but it looked like a total ponsi scheme for installers and suppliers of kit. I did 8kw ashp for and the 2.5kw input power runs nicely off a 10kwh battery charged overnight or by PV in summer.

Still got some insulating to do. Gotta have air to breath and ventilation, and doors to come in and out of....

Loading up a concrete floor slab is a great way to spread the benefit of low-cost energy. I will be in for about 20k for my whole energy system, but with net energy costs inc 14k miles at around 1200 gbp pa and 8-900 back in FIT it wont take long to earn back the 20k. 8 years if you consider just the car fuel element. After 5 years, batteries & PV still doing same as day 1.

 

[Alex987854]

TBH If you are claiming climate change green credentials as your main justification for buying a Tesla you'd better be a vegetarian or I am calling BS and saying that that may not be your primary motivation...

Need to add not travelling by air to that, and considering the carbon impact of all your food. I've been a vegetarian for 30+ years, but environmental reasons are more of a happy coincidence.

 

[rotor2k]

A couple of questions about the heat pump:

1) the brief research I've done suggests that they aren't as powerful as a gas boiler, so you need an extremely well insulated house, or you need an electric boiler to supplement the heat pump on really cold days
2) if all you're doing is heating a massive concrete slab, what happens if the next day is mild, doesn't that mean your house is now too hot? In other words, how does it handle the natural variability (10+ degrees from one day to another?) of the weather?

If the answer to both my questions is that you need an extremely well insulated house with a massive concrete slab then it's not very useful for 90% of existing UK houses...

 

[Glan gluaisne]

The answer, in our case, is that we have:

...an extremely well insulated house with a massive concrete slab...

Our maximum heating requirement when the temperature outside is -10°C, with no one at home, and no incidental heat gain, is about 1.6 kW. Most of the time the house needs virtually no heating, as we get enough heat from the two of us, plus a bit of incidental heat gain from appliances etc, to keep it warm.

 

[Adopado]

If the answer to both my questions is that you need an extremely well insulated house with a massive concrete slab then it's not very useful for 90% of existing UK houses...

Crikey, I'd be staggered if anything like 10% of houses are at passive house standards or likely to be in the near future. Definitely agree that's what we should be aiming for but it's a longterm project.

 

[WannabeOwner]

Gotta have air to breath and ventilation,

Passive House is pretty much hermetically sealed. But then uses Mechanical Ventilation with Heat Recovery. So the exhaust air passes through a heat exchanger and warms the incoming air. No draughts in the rooms, plus the ducted air gets into all corners, by design. I've lived in old houses where the wind came straight through ... plenty of fresh air but we still had rooms with damp - if not mushrooms growing on the walls then some damp-smell, or some spores, enough to make the immune system have to work harder, along with the body having to combat the cold temperatures in some rooms. And condensation on the inside of the windows on cold mornings. All terrible for health.

Passive House is like night-and-day to that. They have air changes on a par with draughty houses - no shortage of fresh air - all filtered to remove both dust and pollen.

 

[ACarneiro]

The answer, in our case, is that we have:



Our maximum heating requirement when the temperature outside is -10°C, with no one at home, and no incidental heat gain, is about 1.6 kW. Most of the time the house needs virtually no heating, as we get enough heat from the two of us, plus a bit of incidental heat gain from appliances etc, to keep it warm.

Is it not like an oven in the summer?

 

[WannabeOwner]

what happens if the next day is mild, doesn't that mean your house is now too hot?

For me the water going through my slab is only a couple of degrees above ambient. In really cold weather I could turn up the water temperature a degree or two ... but by the time I get around to it the cold snap has finished. The last seriously cold snap we had, that went on a week, and I still failed to turn up the water temperature, my logs showed that the lowest overnight temperatures were 0.5C lower than usual ... not enough to notice, as the room temperature doesn't change by more than about 1C

It needs so little heat that you put very little it ... and then insulation keep that heat ni, and the cold out. The weather takes ages to actually make a difference. Summer heatwave its a good week before we start noticing temperatures climbing to the point where we think about doing something about it - e.g. opening the windows at night to let cool air in (although the ventilation does that automatically, bypassing the heat exchanger, if house > 22C and outside < 20C)

likely to be in the near future

Why? Adds 7% to the cost of a new building. Minimal maintenance, no almost no heating costs for the lifetime oo the building. The things that is surprising is that government hasn't mandated it. Neither wife nor I have had a winter cough or cold in the 6 years since we moved into our. In shirt sleeves in the house all winter. Can't imagine living in anything different now.

Is it not like an oven in the summer?

The Insulation keeps the heat out in Summer. Passive House typically has roof overhang to South to share "high" Summer sun out, but allow low Winter sun / heat in. if you install a reversible heat pump you are on the same PEAK 1kw-ish in Summer, for cooling, as in Winter for heating. Works well if you have PV for the juice.

 

[WannabeOwner]

I posted a graph in this thread of temperature cycle (inside and out) in September / October in this thread. no heating at all used then and temperature didn't move more than 1C day/night

 

[Glan gluaisne]

Having lived in a 1980's built bungalow for a few years whilst we were building our passive house, albeit a bungalow that had been significantly improved (cavity wall insulation, 300mm of loft insulation, reasonably good double glazing, etc) I can say that the most significant difference between the new house and our old one is the massively improved air quality.

The MVHR changes all the air in the house about once every 2 1/2 hours, with the fresh air coming in through an F7 pollen filter and then being warmed by the waste exhaust air. The house always seems very fresh, with no lingering smells from cooking etc. The relatively high continuous ventilation rate also means that the bathrooms dry out after use within a short time, and any damp towels etc dry very quickly. We have no internal condensation, although finding that the outside pane of the triple glazing tends to attract condensation and ice on the outer face was a bit novel.

In terms of cost, I don't believe our build cost any more than it would if we'd built the house to just meet building regs. The fabric of the house is a relatively small part of the overall build cost; a lot of it went on kitchen, bathrooms, oak joinery etc.

 

[EinSV]

Auke Hoekstra, a professor from the Netherlands, has debunked this on several occasions.

More details in the link here: AukeHoekstra on Twitter

He also has a published paper on the topic here: The Underestimated Potential of Battery Electric Vehicles to Reduce Emissions - ScienceDirect

 

[Glan gluaisne]

Is it not like an oven in the summer?

No, as the insulation works both ways, and keeps the heat out in summer, just as well as it keeps the heat in during the winter. The key is ensuring the house structure has a long decrement delay, so it takes longer for heat to travel from outside to in (or vice versa) than the length of the hottest/coldest part of the day. The decrement delay of our walls and roof is around 8 to 12 hours, so heat from the sun beating down on them doesn't have enough time to reach the interior before the sun's moved around to shine on a different surface. At night the heat that made it part-way through the walls/roof moves outwards again as the air cools.