Current Cost Support Forum

This note appears on the website here: http://www.currentcost.com/product-optismart.html

** PLEASE NOTE ** OptiSmart is not compatible with PV/micro generation.
It is vital that before purchasing any OptiSmart product you confirm it is compatible with
your meter.

Why is OptiSmart not compatible with PV if it's just reading flashes from a meter?

My OptiSmart has been fine monitoring my Solar PV system, much more accurate than using a CT Clamp. You can see the live data from my System here;

http://pvoutput.org/intraday.jsp?id=2476&sid=1872

The PV Generation data is from an OptiSmart on the Generation meter since September, but the Consumption data is still a CT Clamp. The data from the import meter's LED only gives NET Import or Export but you don't know which, so I still use a CT clamp which gives a reasonably accurate Consumption figure.

My generation meter is an Elster A100c I think, if thats any help.

I wonder if they mean you cannot legally use the data to claim your FIT from your electricity supplier.

....and after getting an optismart to monitor my household, I put the old clamp on the PV cable. It's not that accurate (I also have a load resistor-based wireless display from my invertor) BUT it's useful. I think the main issue is that it displays the invertors grid consumption AND the generation (i.e both directions of low) as output from the panel . However it's still useful as it gives me a broad idea of how much solar activity there was. I may advance to getting a second optismart for the PV. provided you have one of the supported meters on your PV I don't see what the issue would be. I think the point about it not being a recognised reporting mechanism for FITs is probably right, but that's not why you wnt to do it right ?

[quote="johnleeBest thing to do is to get an electrician, (5 minute job, so shouldn't cost more than £50 - I'm joking) to turn off solar & mains power at their switches, check solar isn't live, cut the the solar cable near to where is goes into the mains box, get him to add in a loop eg 20cm or so of insulated 13A copper wire to it, and then feed the wire, in a reverse direction (it'll be obvious from the reading if it is wrong) thro' the CT clamp that's on the utility meter cable. This'll then effectively 'subtract' the solar from the ct clamp reading, which is the household consumption + or - the solar & give you just the household consumption, because the CT sensor effectively senses the total current thro the 2 wires. Mr Maxwell cannot be wrong...[/quote]

Hi

This is exactly what I do, I got the installer to add the loop when I had the system installed. I would say its as accurate as a CT clamp is normally with its inherent Voltage and Power Factor errors.

They never used to say that...

I have found the real-time reading from the meter works well but have found the meter reading data keeps going up when the load on the meter is zero or reversed.

This problem only shows up if you examine the XML from the EnviR to get the meter impulse count (meter reading) as it is not yet implemented at my.currentcost.com

Automan.

Hi, Please tell me that why OptiSmart is not compatible with PV/micro generation. I am looking for its answer.

Please help!

My question - Will a 'loop' (as described above by johnlee) or and optismart meter reader be the best solution for the following problem?

I'm using current cost monitors (CT clamps) to measure (i) my PV generation and (ii) household usage. A qualified electrician has placed both CT clamps in the locations specified in the Current Cost install guide for households with a PV system.

However, the measurements produced for household consumption appear to be incorrect. Household consumption stays reasonably constant until the PV system starts generating about 600W (same as our background household consumption), and then the consumption meter starts to 'conform' to the PV meter, such that as more enregy is produced, consumption also increases and vice versa. The confusing part is the amount of increase is inconsistent (for example, a 600W jump in power generated may only lead to a corresponding jump of 300W in consumption). This is obviously holding all other factors equal (ie no appliances on in the background).

Even stranger is that increasing consumption (by turning on the kettle) leads to a corresponding reduction in the monitored consumption levels. This is only the case while the PV system is generating power - during the evening the consumption meter works as expected.

Any help or advice would be greatly appreciated. My aim is to have two separate measures of (i) Power Generation and (ii) Household consumption.

Kind regards,
Ben.