What's in your baseload?

zeupater

Oscargrouch wrote: »

Suggested to you once before: Wattson Monitor

My base load is 35 watts (only after sunset in winter) cos I have done the test via Wattson.
Examples:-

- Wattson Monitor & Transmitter
- Solar PV Inverter
- Clock Radio
- Boiler, Pump and Heating Controls (Off)
- Fridge/Freezer - (Off) for Test
- Garage Freezers X 2 (Off) for test
- Telephone chargers (Off)
- Broadband Router (Off)
- Oven Clock
- Microwave Clock (eco version so, Off; how many clocks do yer need, apart from yer watch)
- FreeSat Box (Off)
- LCD TV (Off)
- Desktop PC (Off)
- Plug In doorbell chime (power when in use only)
- Optiplug (Off after sunset)

:rotfl:

Hi Oscar

Our base-load is 0 when everything is turned off .... but that's not what base-load is supposed to represent.

Your base-load should be the average consumption for all devices which are normally on. Think about going away for a couple of days ... you would still need power for certain items although you aren't physically using them at the time, so that would normally include the fridge, freezer, house alarm, CH controls, telephone answer machine, clock radio etc .... without an accurate plug-in monitor to record energy for every separate piece of equipment over time, the best way to measure base-load is simply to take a couple of meter readings when nothing other than base-load equipment is being used ... that usually means averaging over a number of overnight readings if you've got pv ....

HTH
Z

Oscargrouch

EricMears wrote: »

Afraid it will be at least another month before I can offer a month's worth of new data.

However, I can already compare the Wattson data with that from the inverter and have to say I wasn't impressed. Here is the 'raw' data from Wattson compared with that from SMA :-

It does rather look as though that had got scrambled somehow so I've moved all the Wattson figures forward a day to get :-

It all looks beautifully neat in the editing box; shame about displayed result !

If I use the second batch and 'credit' the (now missing) 31st Oct Wattson result with SMA's true result of 4.9kW and add up both columns, I get 169kWh from Wattson but 181 from SMA (and the SMA results have always agreed very well with TGM).

Again, not a very impressive correlation.

Back to my flashcounter project !"

I hope that you remember that Wattson only stores data for 28 days..between each download to Holmes ? I do know that on the 27th of October, Wattson cannot handle 25 hrs in a Day..:D

In fairness, you are assuming that SMA is correct; you are also assuming that your Inverter is correct. I have no knowledge or experience of SMA, but my Inverter (Aurora Power One) is far, far, from correct; it sometimes reports xxy kWh one day and then adds that amount to the next.. May be worth checking what your Inverter gives as a generation figure todate compared to what your generation meter gives... :rotfl: You have persuaded me to run a test of Wattsons capabilities; I will, over the next 5 days or so, take a CU reading at no gen times, and then compare these with the recorded usage reading from Wattson for those exact times.... so much time to prove a point....:rotfl:

Oscargrouch

zeupater wrote: »

Hi Oscar

Our base-load is 0 when everything is turned off .... but that's not what base-load is supposed to represent.

Thanks Zeupater, you are quite right, I will repost when I check my night numbers from Wattson; rekon it will work out at 185 kWh ish in winter, perhaps more in summer when fridges/freezers are working harder at night, will vary on temperatures each day....Probably a variable amount so it is what it is....at the time of year..... etc.etc.etc.....:rotfl: My next experiment should do the trick Ref: Eric's posts....

legoman62

I have an SMA invertor and it's readings are incorrect!
When I had SP installed in Nov 2011 I was given a Sunny Beam monitor. During the winter months of low output I did not notice much of a variation. Once summer arrived and I compared Gen readings with the SMA invertor/Sunny Beam I found the invertor to be 1% higher than true.

After speaking to SMA I was told "the piece of kit measuring generation in the invertor only costs a few pence so it will not be as accurate as the Gen meter"

After buying what I thought was a top brand model (still do apart from this small annoyance) I felt disappointed with SMA's reply.
So I sold the Sunny Beam but still use Sunny Explorer on my PC and whenever I give my readings I deduct 1% or the days total.

Periodically I "reset" the invertor output to match my Gen meter.;)

I am also using a Wattson and will compare numbers over the next few months:D

zeupater

legoman62 wrote: »

I have an SMA invertor and it's readings are incorrect!
When I had SP installed in Nov 2011 I was given a Sunny Beam monitor. During the winter months of low output I did not notice much of a variation. Once summer arrived and I compared Gen readings with the SMA invertor/Sunny Beam I found the invertor to be 1% higher than true.

After speaking to SMA I was told "the device in the invertor only costs a few pence so it will not be as accurate as the Gen meter"

After buying what I thought was a top brand model (still do apart from this small annoyance) I felt disappointed with SMA's reply.
So I sold the Sunny Beam but still use Sunny Explorer on my PC and whenever I give my readings I deduct 1% or the days total.

Periodically I "reset" the invertor output to match my Gen meter.;)

I am also using a Wattson and will compare numbers over the next few months:D

Hi

Have you calculated the cable & connector losses between the inverter and the TGM as well as the inverter self consumption to see if the difference was expected ? ....

HTH
Z

EricMears

zeupater wrote: »

Hi

What's your average mains supply voltage throughout the day & what's the monitor set to ??

... we're usually mid/high 240's for voltage, which would have almost the same difference on our OWL as you can see if it was set to 230V .... eg - ((181/169)x230)=246.3 ...

HTH
Z

Ours is also mid 240s. I've tried setting Wattson to 245V but it just reverts to 240V. I assume it can only be set to a whole multiple of ten and since 250V is definitely too high I leave it alone at 240V

EricMears

Oscargrouch wrote: »

you are assuming that SMA is correct; you are also assuming that your Inverter is correct.

The column marked 'SMA' is the inverter set of readings of course. Some inverters may be inaccurate of course but ours is pretty good. After 3y3m running, TGM reads 8018.4kWh and SunnyBoy 8006.67kWh. Unusually TGM reading is a bit higher than inverter but with an error of only 0.15% who cares !

I'm not (yet) assuming that my flashcounter is correct - it's a bit difficult to check a 3 decimal place result when you've only got an integral reference value. However, after several runs when I've compared its output with the official meter, I've yet to see a result that was inconsistent with it being correct.

legoman62

zeupater wrote: »

Hi

Have you calculated the cable & connector losses between the inverter and the TGM as well as the inverter self consumption to see if the difference was expected ? ....

HTH
Z

No, but my invertor almost sits on top of my TGM (OK a couple of metres away:D) so feel any losses should be minimal.

Yesterday at 15.30, I turned everything off, apart from my Wattson transmitter and my invertor, to check consumption.
At the time invertor output was very low, and Wattson gave a reading of 61w-66w

In the past I have played with the Sunny Design program from the SMA website but my Win 8 PC doesn't seem to like it:(

Oscargrouch

legoman62 wrote: »

No, but my invertor almost sits on top of my TGM (OK a couple of metres away:D) so feel any losses should be minimal.

Yesterday at 15.30, I turned everything off, apart from my Wattson transmitter and my invertor, to check consumption.
At the time invertor output was very low, and Wattson gave a reading of 61w-66w

In the past I have played with the Sunny Design program from the SMA website but my Win 8 PC doesn't seem to like it:(

I find the same with Wattson, as soon as the Inverter wakes, Wattson registers around 60W, but I have also noticed that the Inverter is showing a Gen. of 40W and yet the Gen.Meter has not woken up yet....ie. the red light has not gone out. This makes me think that all generation meters have a threshold before they are activated.... being ripped off yet again...??:mad:

EricMears

We're getting a bit OT so I've started a new thread on Wattson Accuracy