Earth Notes: On Visualisation, Sonification and Modelling Tools for Energy

For example, I have being trying to understand how the carbon intensity of the UK's electricity grid changes with time (by hour/week/month). Even my feeble attempts at charting have really helped me understand.

Can We Live on Renewables in the UK?

Ignoring issues of supply intermittency, Chapter 18 of MacKay's book illustrates with simple red and green stacks of consumption and generation the difficulties of living on 'our' renewables in the UK. This including PV farms in remote deserts, and other generous assumptions.

I'm trying to make this even easier to understand by making it more of a 'what-if' tool, usable by almost anyone, but good enough for policy makers and decision takers!

You can try the early working mockups at your own risk, and you can also see some of its evolution and earlier revisions here: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 (IE fixes), 13 (spreadsheet I/O), 14 (IE fixes), 15 (copy to main site). You will need JavaScript enabled in your browser for this tool.

Bandwidth

How much space do alternative renderings of blocks of raw data take? Visualisations (etc) are mentally more-digestible renderings.

A simple well-compressed PNG chart/graph can be 10s of kBytes, such as this temperature chart of 1280x480 pixels at 13kB.

Making audio (audifying, sonifying, or just recording) in reasonable hi-fi, eg MP3 128kbps joint stereo, is about 1MB/min (1 megabyte per minute), eg see Adam's green living podcast episode. Uncompressed (FLAC) is maybe 3x the bandwidth, and VBR mono MP3 maybe 1/3rd. Typical 64kbps mono MP3 for podcasts is ~0.46MB/min.

As of 2018-08-31, Podbean said that it supported/encouraged .mp3 and H.264 based .mp4 amongst other things, with audio recommended to be stereo at 44.1 kHz, 128kbps.

Making reasonable fidelity video to embed in a Web page can be many Mbps (eg The H.264 standard defines maximum bit rates for 1280x720@30fps as between 14.000 and 42.000 kbit/s, depending on the profile) or maybe in the ballpark of as many as 10s of megabytes per minute. For example, the OpenTRV mashup video as medium quality 540p MP4 export from iMovie is ~60MB for under 2 minutes. Compressed and fit to 800px wide it is nearer 7MB, or ~3MB/min, the low-fi version half that again, so ~1MB/min, so not miles from good MP3! Compression effort and codec parameters can make a huge difference.

See H.264 (mp4/m4v) tips which reports several standard video sizes used eg in podcasting, from 640×480 "Standard Definition" 4×3 to and beyond 1280×720 "High Definition" 16×9 "Widescreen" (720p). It lists bandwidths of the above as 65MB/minute and 190MB/minute, for example.