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Solar Panels and Energy Monitor
in Green & ethical MoneySaving
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But you can very easily move the sensors to alternative sites that you know will definitely be importing or exporting. The limitation comes when a basic meter such as EON sipply can only have one sensor.
.... and that's exactly why I've provided the OP with a link to posts which try to help explain what's happening ......
The majority of people who would be reading this forum would not want to consider dismantling their CU (fusebox) or rotary isolation switch in order to fit a split clamp sensor and in many/most cases it would be totally inadvisable and possibly extremely dangerous for them to do so, so let's just assume for now that the OP is likely to be one of this very large group .....
In which case they should consult an electrician. Indeed, the one who fitted their solar panels would no doubt be happy to help.
But it's just not true to say that the Wattson is no better than EON's offering - it does have multiple sensors which can be sited appropriately. Describing in great detail how to do so is obviously outside the scope of this column.
Please re-check my posts .... I have not stated that the Wattson is no better, what was posted was .... "if it's not possible to use a clamp sensor for the EON monitor to read load or generation then the 'Wattson' clamps would have exactly the same issue." ... obviously you can agree or disagree, so what in that statement is there to disagree with, and what's more, why try to argue ??
I am well aware that the Wattson has multiple sensors, it's also likely that if the OP has an SMA inverter with bluetooth capability that a SunnyBeam monitor could be purchased for a similar price to a Wattson which, if the OP can get the existing EON monitor working on the house load, could provide an alternative, and possibly better, solution ..... but we don't know, so let's not attempt to encourage the OP to spend money in a possibly wastefull manner and wait for feedback ....
Simply looking at the monitor won't tell you whether you are exporting or importing, but it's very easy to simply turn on an appropriate appliance and from the reading easily see the situation.
I use a 400W halogen heater (one element from a 1.2kW heater). If I'm reading 300W (that is, the modulus of the total consumption minus the total generation at that time is 300W), then if the reading goes to 700W, then I know I was importing, and if it goes to 100W, then I know I was exporting.
One or two points on this method. I use an Owl, and the readings below 200W are meaningless, so you have to make allowances for that effect (easy to do). The use of a 400W load gurantees that at least on reasonably accurate reading above 200W is made, so it's always possible to know the import/export state. (Devices below 400W won't guarantee that of course).
You can of course simply look at your import meter and, if it's like mine, will glow the red led counter constantly for export.
I haven't at any point tried to 'argue' - just pointed out the limitations of a single sensor meter but been told (wrongly) that multiple sensors wouldn't solve the problem.
A 'SunnyBeam' monitor (or similar) would indeed give a good indication of what is being generated - but would have no means of measuring what is being used.
The EON meter could very likely be relocated to a point in the circuit where total usage 'undistorted' by generation could be measured.
Neither piece of kit is capable of being interfaced to the other. To get a nett indication, it would be necessary to look at both and do some mental arithmetic.
Only a meter accepting multiple inputs can do the job properly and there aren't a great number of candidates. AFAIK, just the Wattson (which is relatively easy to set up) and the openenergymonitor system (which demands a huge amount of skill !)
Again, I must refute what you have inferred .... I have definately not posted anything to say to you "(wrongly) that multiple sensors wouldn't solve the problem" .... please take a little time to review what was actually posted, not what you have likely misread/misinterpreted, which was ....
"if it's not possible to use a clamp sensor for the EON monitor to read load or generation then the 'Wattson' clamps would have exactly the same issue."
... the meaning of which is that if the OP cannot clamp the existing single EON sensor to a cable which will show generation and another cable which will show consumption then attempting the same utilising the Wattson, having the same type of split clamp sensors and requiring them to be fitted in both these positions (if the dual input version of the Wattson is purchased), will result in the OP experiencing exactly the same issue.
Regarding the 'mental arithmatic', that's exactly what I do, between a SunnyBeam & OWL and it's not hard - however, new users will find that they will tend to be obsessed with the meters for the first few months until the performance of the system is understood, then will start to rely on the brightness of the clouds or how crisp the shadows are instead of referring to the meters all of the time ... it's surprising how tuned your eyes become to noticing changes in light levels when you have pv installed.
How many more times ??????
The EON has only got one sensor input.
To show nett consumption you need two (or more) readings.
With a Wattson (or the openenergymonitor system) you have the option of deciding where to put each sensor.
Nothing wrong with doing a bit of mental arithmetic - but before you could do it, you'd need to get a complete second EON (or similar) meter
I really do understand that you have the option to decide where to put the sensor and/or get a second monitor, which would likely be cheaper than a Wattson considering that the OP already has one, but it still comes down to the availability of suitable places to affix the sensors .... therefore understanding the cable layout is paramount and if suitable alternative sensor locations are available it's simply better to test whether separate generation and consumption readings can be monitored by the existing equipment before committing to further expenditure, whether that be another single sensor monitor, or a Wattson ....
The 'OP' was smartn in November 2010 and (s)he received explanations from several forum users the same month and thanked them immediately.
mspiteri asked a new question yesterday most of which was immediately answered by previous postings and I replied to that effect. Mark also queried whether his EON meter was now "rendered useless" which does rather imply that he would like to continue his monitoring exercise - hence my suggestion that he consider a meter with multiple sensors.
I fail to see how this endless whittling about minor details is of any help whatsoever to Mark. He hasn't posted any details of how his inverter output is shown (or indeed if it is but it would be most unusual if no provision had been made) so it's not possible to comment usefully on his best course of action.
Nothing in my postings can possibly be interpreted as suggesting that Mark ought to ferret around in his CU without taking adequate safety precautions and the idea that he might do so is rather contemptuous of him. I'm sure he's perfectly capable of deciding what his own limitations are and whether he wants to proceed further on his own or seek professional help. He's more than welcome to PM me with any specific queries if he wishes.