On Sun, 15 Nov 2020 12:35:06 +0000, Roger Mills
wrote:

Prompted by the Smart Meter 2 thread, it occurred to me to wonder
whether there was any way in which I could monitor my electricity
consumption in half-hour intervals in order to evaluate whether one of
these fancy tariffs would be good or bad.

You could do so more frequently than that, if you wanted.

[Before I had a water meter fitted by my water company, I fitted my own
meter and ran it for a year or so to see whether I would be better or
worse off with a meter.]

Good idea.

You can buy energy monitors which either use a clamp sensor round one of
the meter tails or count flashes on new-type meters. But they only
appear to give instantaneous readings and daily totals.

Some allow access to them via USB and allow you to access the (live?)
data ... that you could link to an Arduino / RPi and do what you like
with. ;-)

Does anyone know of anything more granular - preferable with the ability
to capture the data and insert it into a spreadsheet? Sounds maybe like
a Raspberry Pi application?

There are loads out there that, if you are into programming, could be
made to do anything you want?

If I were to have a smart meter fitted (which I've hitherto resisted!)
but to stay on a fixed tariff, could this be made to provide me with the
required data?

I would think there must be one that could? I had an early 'Owl' (I
think it was) that had a serial output, but I can't remember what it
gave you.

If I understand it right, if you have a meter with a flashing LED,
every flash indicates a certain quantity of electricity used, say
guess 1/10th of a kW.

If you count the pulses (clip on light detector) and integrate that
over time (seconds?), you should be able to get a reasonable live
energy usage?

If you want costings and have a multi rate tariff (E7 etc) then you
would have to know the current time (RTC modules are easily available,
or use network time if on the Net) and the cost/rate and then you can
also display / log / accumulate the costs (inc adding a standing
charge etc).

Something like an ESP32 might make a good platform for such a project
as I think they come with WiFi and BT so good for connectivity if you
need to remote the sensing from the display / logging.

Maybe we could come up with a uk-d-i-y solution between us (assuming a
suitable project isn't already out there etc)? ;-)

Cheers, T i m