Earth Notes: Diarycast - Smoke and Snow to Census Jab (2021-03-21)

Updated 2024-04-11.
From Yuletide air pollution to snow and vaccination! #podcast #lockdown
217s "20210321" (captions) Uploaded . Downloads:


Hi, I'm Damon Hart-Davis, and welcome to Earth Notes podcast on all things eco and green and efficient @Home!


Lockdown continues, though our kids have been back at school a couple of weeks, and the pubs may open (outside) on the 12th of April...

The 21st is census day. And I've had a first (AstraZeneca) coronavirus vaccination!

Here is a brief round-up since Christmas, so pretty much the first quarter of 2021.

  • 2020-12-25: I stayed at home for Christmas while the family went to visit granddad in our bubble. On Christmas day I was Getting festive wafts of burning food and sounds of smoke alarms through my MHRV: truly yuletide!
  • 2021-01-24: we had snow! Thus little to no generation from the grid-tied system, but some from the vertical panels off-grid.
  • 2021-01: it looks like ~20% of this month had a grid carbon-intensity low enough that heating water by electric resistance would be lower carbon than gas. [There's some extra technical detail on the podcast Web page.]
    % gzip -d < data/FUELINST/log/202101.log.gz | wc -l
    % gzip -d < data/FUELINST/log/202101.log.gz | awk '$2<190' | wc -l
    % gzip -d < data/FUELINST/log/202101.log.gz | awk '$2<190' | head
    2021-01-03T03:25Z 186
    2021-01-03T03:35Z 182
    2021-01-03T03:50Z 185
    2021-01-03T03:55Z 185
    2021-01-03T04:05Z 185
    2021-01-03T04:15Z 182
    2021-01-03T04:25Z 180
    2021-01-03T04:35Z 180
    2021-01-03T04:45Z 181
    2021-01-03T04:55Z 183
    Low-carbon 'leccy was available on ~18 days of the month, in all cases enough to capture at least ~6kWh, more than our average 4kWh/d consumption. So maybe we could have avoided running our combi for DHW on those days:
    % gzip -d < data/FUELINST/log/202101.log.gz | awk '$2<190{print substr($1,1,10)}' | uniq -c
      28 2021-01-03
      46 2021-01-04
      37 2021-01-05
      13 2021-01-10
      51 2021-01-11
      33 2021-01-12
     107 2021-01-16
      78 2021-01-17
      51 2021-01-18
      50 2021-01-19
      48 2021-01-20
     101 2021-01-21
      42 2021-01-22
      22 2021-01-25
      21 2021-01-28
      41 2021-01-29
      96 2021-01-30
      42 2021-01-31


  • 20210211 battV 2021-02-11: it was nominally -8°C overnight here last night, and a Record low temperature for the UK this millennium at the Braemar weather station of -23.0°C. But now my off-grid battery is FULL for the first time since late October!
  • 2021-02-14: the outside temperature at noon was back up to ~11°C today.
  • 2021-02-15: the "Beast from the East II" lasted from about the 6th to the 15th of the month, with gas demand peaking one day at just over 40kWh.
  • 2021-02-16: I have tentatively expressed interest in additional solar PV storage in a "Solar Together" group-buy scheme.
  • 2021-02-16: I'm interested to Try Before You Bike for an e-bike (eg borrow for a month for a free) in the local scheme, assuming that it's all still running when we're allowed out again.
  • 20210221 B1T 2021-02-21: at around 3pm it was warm (~14°C) and sunny enough to have washing drying on the line, and lots of windows open to air the house a bit (with the heating turned off, of course)! The off-grid battery warmed up to 12°C.


  • 2021-02-27: for science, I'm testing if the new Park Brewery 2l "growler" might avoid landfilling or recycling any packaging in the course of regular vitamin B(eer) intake. For example, by having two 2l growlers in the fridge, and exchanging them each week for full ones, like milk bottles...
  • 2020-02: annoyingly, we had record high electricity consumption this month, partly due to both kids doing lockdown schooling from home, each using a computer all day.
  • 2021-03-08: we're starting regular home self-testing for everyone from this week, for covid...
  • 2021-03-16: I'm (slickly and easily [via SMS and on-line]) booked in to get my first covid-19 vaccination shot in a few days' time...
  • 2021-03-19: it's sunny enough to recharge my entire stash of NiMH AA cells on my desk that I use in Radbots etc, off-grid!
  • 2021-03-21: it's census day and AstraZeneca jab today!

The first person to DM me on Twitter, or email me about this, in the next few days... I'll get you a tenner, GBP10 or equivalent!

There's more on my "Earth Notes" Web site at Earth.Org.UK.

Show Notes

An out-take from the diary!

Transcribe time

Running Transcobble on my M1 MacBook Air this 03:37 piece took approximately nine minutes to transcribe at the highest accuracy setting.