Posts

Showing posts from June, 2021

How much of the UK's arable land will be needed to make it's biofuel?

Image
According to this story on today's BBC news website the UK government is set to mandate the proportion of ethanol in standard petrol is increased from 5% to 10%.  The 5% grade is known as E5 and the new grade will be known as E10. So, how much of the UK's arable land would be needed to make this, if it were made here? The article says " Ethanol is a kind of alcohol manufactured from plants, including sugar beet and wheat ".  Since sugar beet can be grown successfully in the UK, and it has a higher ethanol yield than wheat per square metre, I'm going to assume that we make the ethanol entirely from sugar beet.  So let's see if we can work out what proportion of the UK's 60,000 sq km arable land would be needed to power 10% of it's vehicle miles: In [ 1 ]: beet_ton_per_sq_km_per_year = 1320 In [ 2 ]: litre_biofuel_per_ton_beet = 108 In [ 3 ]: litre_biofuel_per_sq_km_per_year = beet_ton_per_sq_km_per_year*litre_biofuel_per_ton_beet In [ 4 ]: gallon_b...

Mass Extinction and ... Flying Cars!

Image
What's Strange about this clip?   (fair use)   This programme about the future appeared on my TV last night, and it touched on an issue close to my heart: the future viability of life on Earth.     The first 3 minutes 45 seconds delivers some of the stark evidence for what we are doing and projections for where we are heading.  There's no emotion on display, but that's fine - we can't be emotional all the time and there's room for dispassionate analysis as well as appeals to the heart.  But then something strange happens at 3:48 - the presenter Hannah Fry introduces the next subject with an incredibly chirpy "Flying Cars! There - I've said it". Watching this one is left thinking:   Either I'm mad or everyone else is.  We've just been told that the average population decline across all species between 1970 and 2020 will be 67%.   And after dedicating three and bit minutes to that we're now talking about flying cars!  I'm worri...

Why are we talking about hydrogen boilers?

Image
  Hydrogen is an incredibly inefficient way to heat your home compared with heat pumps.  Heat pumps move about 4 times as much energy in the form of heat as the electrical energy they consume.  With hydrogen boilers the heat is created from chemical energy rather than moved and so there's no such upscaling.  In fact it's worse than that since the hydrogen has to be created in the first place and if you're creating it from renewable electricity about a third is wasted. Despite the horrendous waste, hydrogen boilers may have a role.  Heat pumps require an insulated hot water tank and many houses, especially in the UK, will not have space for an airing cupboard.  So perhaps the solution will be to install heat pumps where-ever possible and then use the much-less efficient hydrogen boilers to mop up the rest.  The risk, however, is that the government's enthusiasm for Hydrogen will slow down the decarbonisation of our heating sector. We are in a deadly ra...