Visibility of usage

robh71

Hello

We are in a new 'A3' rated home with 6 PV panels (Conergy PowerPlus 250P – 275P) installed using the Sunny Boy DC-AC inverter. I have recently connected the inverter to the Sunny Portal website, which is giving us pretty cool insight into power being generated. This insight, however is somewhat limited in information and I'd like to know how to go about confirming the following:

1) How to get visibility of the actual power we use generated from PV's
2) How much is given back to the grid (free of charge currently)
3) Are there schemes in place to get reimbursed for power given back to the grid. If so what is the process to follow to avail of this?
3) Is an import/export meter the only means by which we can avail of potential reimbursement?
4) ESB states cost of import/export meter is €350. Are there any ways around this, e.g. trials?
5) Do all electric providers provide an export tariff to allow us reimbursement?

Regards

Gumbo

robh71 wrote: »

Hello

We are in a new 'A3' rated home with 6 PV panels (Conergy PowerPlus 250P – 275P) installed using the Sunny Boy DC-AC inverter. I have recently connected the inverter to the Sunny Portal website, which is giving us pretty cool insight into power being generated. This insight, however is somewhat limited in information and I'd like to know how to go about confirming the following:

1) How to get visibility of the actual power we use generated from PV's
2) How much is given back to the grid (free of charge currently)
3) Are there schemes in place to get reimbursed for power given back to the grid. If so what is the process to follow to avail of this?
3) Is an import/export meter the only means by which we can avail of potential reimbursement?
4) ESB states cost of import/export meter is €350. Are there any ways around this, e.g. trials?
5) Do all electric providers provide an export tariff to allow us reimbursement?

Regards

1. This would be interesting. I can’t see it on my system either. I can see what the immersion takes and what the total generation is but not what is sent back to the grid. I have the MyEnergi Eddi unit and it tells me at any given time what I’m using, what I’m diverting to the immersion and what I am exporting. Not sure if there’s a log in the menu that tells me what I have sent to the grid. For example, today’s sun has already heated my 200L cylinder and at this moment I’m sending 1.6kw to the grid. That’s as I’m sitting here with the tv on, and cctv system running and all other house base loads.

2. As per 1.

3. No.

4. I didn’t need to pay anything to the ESB after my installation. It may depend on what your current meter is.

5. No.

Calahonda52

This is a data storage issue.
Instantaneous values are fine and easy to do: so you get a kW reading.

What follows if for 15 minute data, most PV arrays read it every minute, however some of the cheaper systems use a Unix based clock which can be inaccurate.


kW is a unit of energy, or back to the science class, a unit of work done.

If we exert a kW for one hour, we get kW by hour = kWh, which is what we get billed for.

So how do we measure it?

I am going to keep this simple.

The loggers measure the amps (A, or I ) in the power cable every 15 minutes and when multiplied by voltage (V) gives Power, in Watts, when divided by 1000 gives kW.
P= VI or VA

For billing purposes, the assumption is that the current, and thus the kW remains the same till the next reading.
[For big companies such as Intel, the readings are every second.]

So let’s look at six 15 minute Load/ Demand 15 minute values from the Load Profile report.

Electrical Load Profile: 15 Min Data: Tabular Data

[22/01/2018 00:00 - 22/01/2018 01:30]

Date/time
Demand (kW)
22/01/18 00:15
17
22/01/18 00:30
16
22/01/18 00:45
16
22/01/18 01:00
16
22/01/18 01:15
16
22/01/18 01:30
16

Now, how do we get kWh from this.?

The demand from 00:15 to 00:30 was 17, so 17 for 15 minutes or one quarter of an hour so the kWh for that 15 minute period is 17/4 = 4.25 kWh for 15 minutes
The demand from 00:30 to 00:45 was 16, so 16 for 15 minutes or one quarter of an hour so the kWh for that 15 minute period is 16/4 = 4.00 kWh for 15 minutes
The demand from 00:45 to 01:00 was 16, so 16 for 15 minutes or one quarter of an hour so the kWh for that 15 minute period is 16/4 = 4.00 kWh for 15 minutes
The demand from 01:00 to 01:15 was 16, so 16 for 15 minutes or one quarter of an hour so the kWh for that 15 minute period is 16/4 = 4.00 kWh for 15 minutes

So the kWh for any sum of 15 minute periods is just the sum of these 4.25, 4,4,4 numbers… in this case= 16.25

Which of course is the same as [17+3(16)]/4 = 16.25


Or for the 6 values shown: [17 + 5(16)]/4 = 24.25


So for the PV panels, the data needs storage and then some math, as well as an accurate clock.

If using 1 minute readings, then you / by 60, per second is / by 3600

robh71

Thank you both for responses. I have contacted ESB & Electric Ireland to see if they can assist in this visibility & insight. I'll update accordingly.

@Calahonda52 - Your calculations are base don what the PV panels produce. What I am looking for is, from the power these create how much do we actually use and how much gets handed back to the grid

P.S - I do get 15 min resolution data, as attached

Gumbo

Not sure what help EI will be to be honest.
I doubt they will comment on small microgeneration systems.

But I’m prepared to be proved wrong. Please update if they get back to you n

robh71

Thank you - Will do