Excess solar power

zeupater

silverwhistle wrote: »

... but how do I cost the gas I save? Annually put 1120 kWh to water but, as pinnks points out, efficiencies and unit rates/standing charges obscure the issue.

Hi

We measured our gas usage for heating DHW by using gas to heat DHW and measuring it .... .... doing it now (between Summer/Winter extremes) should provide a fair reflection of average standing heat-loss and usage. I'd record usage daily for a decent period (at least 1week+1day ??) and ignore day1 readings for the series (because it may not be a typical heat provision) then use that data to calculate your (standardised) daily average gas usage for DHW ... don't forget to turn the proportional diversion off whilst running the test ..

A simplistic approach but it'll provide the information you need for your particular setup with a fair degree of confidence ... testing over a longer period will provide a better average, but it'll also burn more gas! ...

HTH
Z

silverwhistle

zeupater wrote: »

A simplistic approach but it'll provide the information you need for your particular setup with a fair degree of confidence ... testing over a longer period will provide a better average, but it'll also burn more gas! ...

HTH
Z

Thanks.
Even that could be an expensive test! Last bill was 6th September and I haven't tripped over a single unit yet, so used less than 10 kWh.

I could obviously afford to do the test, but as I'm sure you appreciate, it's the challenge of not using gas. Some people here (no name, no pack drill) don't seem to understand that people do, in fact, have positive motivations.

[Deleted User]

ajbell wrote: »

Done it! Wired a 13a fused single socket to the second output and plugged in a 700w oil filled radiator, as soon as the water tank was hot it switched to output 2 and started putting 0.83kw into the radiator.
Any idea why my 700w radiator draws 0.83kw?.

Should get my finger out and do this as well


Cheers