7 hours ago, NSS said:

27,000 mile per year

Yes

And my house uses very little.

Just done some estimates to compare our house CO₂ with my car CO₂.  The house is -0.9 CO₂ tonnes/year, and if I assumed that the car was always charged from the grid then my ~6,000 miles per year would generate about 0.7 tonnes CO₂/year.  In reality, roughly 50% of the car charging comes from the house PV system, so the car is probably responsible for about 0.35 tonnes CO₂/year.

 

So, for us, the house PV system effectively sequesters more CO₂ than the house total energy consumption and car total energy consumption combined.  It looks like the CO₂ total from our energy usage for transport, heating, lighting, cooling entertainment etc comes to around -0.55 tonnes CO₂/year, so we're helping a little bit to offset someone else's CO₂ generation.

46 minutes ago, JSHarris said:

so we're helping a little bit to offset someone else's CO₂ generation.

Get a bigger system and I shall carry on driving my old car.

1 hour ago, JSHarris said:

Just done some estimates to compare our house CO₂ with my car CO₂.  [...]

 

Thats really very interesting indeed. 

Would you be kind enough to get me started on how to do a calculation like that for myself? Just a hyperlink or reference will do fine.

45 minutes ago, AnonymousBosch said:

Would you be kind enough to get me started on how to do a calculation like that for myself?

I was having a cuppa after one of my medium length walks yesterday.  There was a couple of 'Yummy Mummies' and there just adorably dressed offspring.

One was complaining that that the disposable compostable cups did not actually compost in her bin.

Apparently it was something to do with 'needing a high temperature'.

Back at the car park, I noticed them safely strapping in the children.

One had a RangeRover, the other a Jeep.

Probably lived next to each other too.

 

Look up your CO₂/mile emissions and multiply by your mileage.

Then do a VW, except that was NOX.

2 hours ago, AnonymousBosch said:

 

Thats really very interesting indeed. 

Would you be kind enough to get me started on how to do a calculation like that for myself? Just a hyperlink or reference will do fine.

 

 

TBH, Ian, I sort of cheated.  I just grabbed the data for the CO₂ equivalent for charging an EV from here: http://www.carbon-calculator.org.uk/ which is a useful site, as it has typical CO₂ figures for just about everything.

 

The house CO₂ figure came from our SAP chit, which gives an annual CO₂ "production" of -0.9 tonnes.  That's probably slightly wrong, now, as the grid has become less CO₂  intensive in the years since that was done, and the current version of SAP has different emission factors than the version I used when our house was signed off.

18 hours ago, Tim731 said:

To Bitpipe

 

Idea of costs :

 

Water £7 per month toilets off the rainwater havester using a pump to top up a tank in the loft

Gas average £16 per month

Gas is low due to the solar tubes heating the tank to provide around 66% heating and 80% of the water

Electric £25 per month but 30% of this is the genvex a 315 vpc

 

Build airtightness 1.34 m3/h.m2 at 50 Pa brick and block , Followed Mike holmes ideas for airtightness (Holmes on Homes ) 

Tank was 1500 liters linked to a gavity tank in the loft with a spliter so it can draw on mains if no water in the tank

 

Thanks Tim

 

That's pretty respectable - we're averaging £1 for gas and £1.50 for electric per day over the year (we have about 3.8KW of solar PV facing SE) and the house is a bit under 400m2. We're 0.55 ACH or 0.817 m3/h/m2 but it was a timber frame with guaranteed passive airtightness performance vs brick and block.

 

We both work from home most days so that probably pushes up the electricity usage a bit. 

 

What's your view on the saving of the rainwater - do you have any idea how often the mains needs to take over from the stored water? Guessing the power for the pump is minimal.