Impact on carbon footprint of upgrading to "green-er" equipment.

Discussion in 'Eco Talk' started by Boca2, Oct 16, 2021.

  1. Boca2

    Boca2 Member

    We are being encouraged to replace items with more energy efficient items and hence a benefit in carbon footprint.

    I have concerns that such replacement, in order to reduce the ongoing carbon footprint, may fail to account for the carbon footprint to manufacture the new item.

    E.g. if I replace my 6 year old diesel car by a fully electric one.... is my carbon footprint improved?.
    E.g. replacing oil boiler by heat-pump.. ditto?
    E.g. replacing halogen downlighters by LED

    For each purchase decision, there will be a number of factors to consider.

    What surprises me is that there seems to be an assumption that replacing with green-er options is always better.

    Has anyone seen any discussion on this point?
  2. CGN

    CGN Screwfix Select

    People go along with the narrative, mainly due to ‘doing the right thing’ however, as you point out, only see the ‘destination’.

    A lot of the technology is still on ‘the catwalk’ IMO and as well intentioned as it may be, I don’t buy into it. It will force people to a point where their only option is to lease expensive vehicles, to have inferior heating systems and be paying an absolute premium in energy costs.
    longboat and Boca2 like this.
  3. Jimbo

    Jimbo Screwfix Select

    It’s referred to as embedded carbon and yes government pays great attention to this. There is a very complex set of carbon accounting rules around everything in government now.

    The carbon payback on eg heat pumps is short. The energy mix in the electricity supply has changed dramatically in the past decade and this is well documented and freely available. Current heat pumps will return 4kW heat for every 1kW electricity, giving them a carbon intensity of about 70g per kWhr with the current mix. Compared to oil, which is over 250g at point of use, for a home with a heating demand of 16,000 kWhr pa then the carbon saving is approaching 3 tonnes per year, every year (even more when including the embedded carbon cost of supplying the oil).

    For cars, the supply of new cars into the market needs to be shifted towards electric as the transition needs to happen more quickly. Obviously there won’t be a credible used market until there is a decent supply of new vehicles.

    Yes there is a hefty embedded carbon cost of a new vehicle, by some estimates in the region of several tonnes more than an equivalent petrol powered vehicle, but nevertheless the break even point is generally reached within 30k miles.

    The point of transition is however wider. Gasoline, oil, and natural gas have a relatively fixed carbon intensity (can be tweaked by blending eg e10 petrol) and the combustion also relatively fixed efficiency (probably less than 30% for a typical petrol engine). Once powered by electric however the carbon intensity of everything can be controlled through the energy grid supply mix. In other words, expansion of offshore wind, solar and hydro will halve the grid carbon intensity in the next decade and this further halves the carbon intensity of operating electric appliances including cars and heat pumps.

    I don’t personally understand these “self charging hybrids” as these seem focused only on reducing tail pipe nasties rather than CO2 overall.

    hope that helps.
    rbrian, Mosaix and Boca2 like this.
  4. Jimbo

    Jimbo Screwfix Select

    FWIW I have an ASHP, which replaced oil, and it has transformed the comfort of my home. Yes there are many examples of poorly specified and installed systems and they aren’t suitable for many properties due to relatively modest output and outdoor space, but the can work and work well and cost less to run than oil as well.
    rbrian and Starslikedust like this.
  5. rogerk101

    rogerk101 Screwfix Select

    The best thing anyone of us can do to reduce our carbon footprint is to NOT have kids, or at least limit the number of kids to 2.
    Bringing one kid into the world has a greater carbon footprint than every other thing that you could do for the rest of your life. Never drive a car, never heat your home, never take a flight, change to vegan local food, etc. ... all those cannot add up to the carbon footprint of an extra person.
    rbrian and OnlyGus like this.
  6. robertpstubbs

    robertpstubbs Screwfix Select

    Even keeping a meat eating pet eg cat or dog creates a large carbon footprint. Think how many cattle, chickens and fish you feed a pet over its lifetime.
    rbrian and Mosaix like this.
  7. jonathanc

    jonathanc Screwfix Select

    not to mention slippers, socks, other bits of random clothing get eaten :)
    Jimbo likes this.
  8. quasar9

    quasar9 Screwfix Select

    It all boils down to price ! In theory wind and solar power have no base fuel costs although heavy on initial investment. From an end user point, are you committed enough for the cause as new so called “green” technology is not necessarily better.
    1. You Pay higher price ( both initial installation and running costs for heating)
    2. Be a guinea pig for new technologies that have not bedded down. You could end up making an investment in a dead end branch of technology.

    But things like LED lamps are worth it when compared to halogen or plain GLS but those on CFL will only see a small improvement.

    Insulation, good quality door and windows are things you can also do now
  9. Boca2

    Boca2 Member

    Fully agree.... all of their energy comes from fossil fuels so are no greener than a traditional petrol or diesel.
    rbrian likes this.
  10. quasar9

    quasar9 Screwfix Select

    Much of auto engineers efforts on diesel and petrol engines are focused on “reducing emissions”. Often framed by politicians who cannot even pronounce science and technology, hence constant reference to STEM, making up rules as they go along. Engineers already try do that by improving performance and reducing fuel consumption but this is insufficient for the preachers. This has resulted in likes of diesel gate, where emissions are artificially suppressed during tests.
  11. WillyEckerslike

    WillyEckerslike Screwfix Select

    Does embedded carbon take account of the notion of not having a new car every three years but using the one you've got until it can't be repaired any more?

    I genuinely don't know if I'm doing the planet a favour by driving my 17yr old diesel car at 40 mpg+ rather than making 5 new ones over that time that might have better economy.
    Kingscurate likes this.
  12. quasar9

    quasar9 Screwfix Select

    A 17 year old diesel driven for another 30k miles is greener than a brand new electric car. Even a brand new petrol car needs to be driven 47k miles to offset the carbon used for producing the batteries for the electric. Data from Volvo as obtained from Jeremy Clarkson in Sunday Times.
  13. Adamfya

    Adamfya Active Member

    What do you do for holidays Boca2 ?
  14. Bob Rathbone

    Bob Rathbone Screwfix Select

    If you have an electric car you must realise that 40% of our electricity is generated by burning gas in stations that are only 50% efficient at best (BBC news last week during the discussions on why gas prices affect electricity prices), so the gain is not that great, also add that coal fired stations are being re commissioned to make electricity as the gas price is high. That does not sound like a green option to me.
    Oil boiler for a heat pump. well maybe if the system is old and shot, but if the boiler is newish, you should replace it only when maintenance costs get too large to sustain.
    Now the ONLY cost effective and sure fire way to cut carbon emissions is to change all of your lights, fluorescent as well as incandescent, with LED lights. It won't cost as much as a heat pump or electric car, but £ for £ it has the best reduction effect on carbon emissions.
    Kingscurate likes this.
  15. Jimbo

    Jimbo Screwfix Select

    But it will be driven 47k miles across its useful life. And other studies show much shorter payback - this one only 13,500 miles.

    The UK electricity carbon intensity is available for all to see at Carbon Intensity and some historic carbon emissions stuff at Dashboard – MyGridGB. The last 12 months average is 236g; in terms of progress, in 2007 it was 507g, 2016 it was 308g, 2030 target is 100g. The current gas situation is impacting prices for sure but the carbon intensity right now is under 180g (and getting close to zero in Scotland).

    As an example: Hyundai's Kona EV has a range of 300 miles with 64kWhr of battery. Assuming 80% range achievable and 80% charging efficiency then it travels about 3 miles per kWh. With a carbon intensity at 236g per kWhr (rolling 12mo average) that's 78g CO2 per mile or 48g CO2 per km. The 1 litre petrol equivalent is quoted at 142g CO2 per km and unlikely to achieve that in the real world (and has about half the bhp). That equates to a saving of 1 tonne per annum of use and over 10 tonnes over it's expected useful life. The grid will be further decarbonised in that same period meaning the actual savings will be higher, not withstanding the increased embedded carbon of the product.

    A lot of numbers there, but the EV provides a step-change in lifetime CO2 when compared to an ICE vehicle.

    The RHI scheme will pay for almost the entire cost of installing a heat pump in many cases. In the UK, the average heating demand is 10,300kWhr. Heat pump is probably 236/4=59g per kWhr whereas gas boiler is 185/0.9=205g per kWhr. As the grid is decarbonised, the heat pump will improve by 2030 to 25g per kWhr. Already, there is a carbon saving of 1.5 tonners per year on average. Also running costs are about the same currently with gas being about 6p and electricity about 24p according to a quick check on uswitch this morning.

    Against oil (or even worse, coal) the gains are even higher.

    The key to electric is that the government can control the grid energy mix and therefore reduce carbon intensity of everything attached to it. By contrast, it is not possible to materially alter the CO2 performance of fossil fuel appliance or vehicle after it's manufacture. Heat pumps and EVs already provide far lower carbon intensity than their fossil equivalents.
    rbrian and Starslikedust like this.
  16. Adamfya

    Adamfya Active Member

    I like the ic engine. Im a big fan of the workings behind it. I dont want to see it dead.
  17. sparky steve

    sparky steve Screwfix Select

    Not convinced that all plans/suggestions to save the planet at the moment, are indeed a solution or not ? Will they become yet another problem in the future to try and resolve?

    For example. Will EV batteries be easily recycled?

    Seems there is never much thought given to what may be considered as the solutions of today, on what impact they may have on the planet in the future.

    CFCs ( chlorofluorocarbons )were thought to be a great invention?Then it was discovered they were responsible for depleting the ozone layer as they attack and destroy ozone molecules.

    CFCs were banned in many countries in the mid-1990s after it was found that they were breaking up the Earth's ozone.

    Allegedly plastic bags were invented to save the planet, The bags were developed as an alternative to paper bags, which were considered bad for the environment because they resulted in forests being chopped down.

    Undoubtedly thought to be considered great ideas/inventions at the time! In reality believe they created more problems than they actually resolved?
    Boca2 likes this.
  18. AnotherTopJob

    AnotherTopJob Screwfix Select

    EVs for low mileage drivers are a lot worse for the environment, not to mention cost per mile.
    The batteries could need replacement after 10+ years but the car may have only done 50k or less. An ICE vehicle with careful maintenence should last 20 years on the original engine.
  19. AnotherTopJob

    AnotherTopJob Screwfix Select

    What is the cost comparison of your ASHP? I've heard of stories of bills tripling due to the increased electricity needed to boost the heat required.
  20. Starslikedust

    Starslikedust Active Member

    rbrian likes this.

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