This chart shows how my gas (heat and hot water) varies through the year.  My peak requirement for heat is approximately 14kWh per day.  That's approximately the capacity of a Tesla Powerwall 3 and that doesn't include the electricity used.  This also implies the need to completely charge the Powerwall every 24 hours.  However to provide electric heat the most likely solution would be a heat pump.  A heat pump installed correctly would use about 1/3rd the power, so about 5kWh.  If we add in the electric my total consumption would be about 6kWh per day.

Domestic solar panels don't generally track the suns path through the sky.  In the UK they are pointed south at about 30 degrees.  This is a compromise that gets the most sun while keeping the install simple.
I snagged these images from Viridian Solar's website.   You can link to the relevant pages here:

• Average daily light energy through Year
• Effect of orientation and inclination

What should be obvious is that the amount of energy available from solar is significantly less in winter and the orientation of the panels is important

If we assume a target of 6kWh electricity consumed and a Powerwall or similar as a buffer battery how many panels do we need?
​I assumed the panels could be placed ideally.
Using this calculator I reverse calculated required installed peak power kWp to be about 70.   

Now we need to figure out how many panels are needed to get to that 70kWh figure.  Obviously it depends on a bunch of factors but it seems like the answer is around 160.  I've seen some widely varying figures for the number of panels needed btw. 

Here are a couple of example websites suggesting the number of panels needed:​

• www.homebuilding.co.uk/advice/how-many-solar-panels-do-I-need
• https://heatable.co.uk/solar/advice/how-many-solar-panels-do-you-need

Obviously this isn't practical for most homes and would be very expensive. 

Maybe we need to think more about home design and try to go for something like the passivhaus standard which claims to barely need heating at all.  Hard to believe and a topic for anther day. 

Also it isn't all doom and gloom. A moderate solar system like that installed on many homes will reduce the amount of gas burned over the year to generate electricity and will also save some money for the owner. 

The conclusion I'm drawing (assuming no solar or incentives) is that a heatpump will emit significantly less co2 but it will cost the user more because electricity is a lot more expensive than gas. 

​Maybe a sensible solar installation could make up the cost difference between gas and electric while providing another reduction in co2.   If you could generate 1.5kWh per day from solar in the winter rather than 6 that would cover the cost while reducing co2 by another 25%.  You would still need a sizable solar array to achieve this.  Possibly as many as 30 panels. 

I use this blog mostly to collect things I think I might need later.  It's kind of like a notebook. 
I'm not a professional. 
I know less about houses than most people I know. 
Prices vary a lot over time.  Solar panel technology gets better over time. 

​There's a good chance my numbers are off somewhere or I've misunderstood something, in which case, let me know and I'll update. 

​You should probably do your own research, starting by being clear what your motivations and goals are. 

​I’m basically a vegetarian for climate change reasons but I still eat some chicken, fish, eggs and cheese. Also I never learned to cook meat. I don’t waste a lot of food which the chart assumes.
I’m going to estimate my food footprint at 1800 kg  of co2.
That's significantly more than my car and my heat combined, which is crazy.
​The article gives a nice chart of various food co2 impacts per kg.

​​Are you as surprised by this, as I was?

For context a return flight from London to San Francisco in economy is 2600Kg of co2. 
​That's more than my food and heat combined. 

Yet again this was a case of youtube to the rescue. This wasn't the approach I was going to take. It's better.

​Obviously I wasn't smart enough to figure this out without watching a bunch of youtube videos like this one...   :-0 

All the cgi was done in Blender, with texturing in Substance Painter. Edited in Vegas.  I used text 2 speech tools for most of the characters. They are still a bit limited even with the emotion controls, but if you pick the words carefully the results are ok I think. 
When I started this project, the idea was to bang something out really quickly. I thought I could do it in a couple of weeks, but actually it was probably more like 2 months solid work spread out over the summer.  Will he ever learn? :-0  
Different to most of my other films, I didn't make storyboards or even have a script until I'd made most of the shots, but because the scope is so limited it didn't burn myself as I've done in the past, so that's a kind of progress I guess.