grid meter

[nodyland]

Hi all,

This is the scenario. A house and a lodge using one grid meter. The house and lodge have their own cu's. The house has solar panels, batteries and feeds back to the grid meter so both both the house and the lodge can benefit from solar. Obviously when sunny grid meter doesn't move. The lodge wants to pay for its own consumption. It has its own emlite meter. The problem is say the lodge uses 5kw on a Monday and it's sunny. The lodges meter is going to show that 5kw but because its sunny the Grid meter hasn't moved. How can this be overcome? I hope that makes sense?

Many thanks

 

[Murdochcat]

The best way would be to get a completely separate supply for the lodge

 

[morqthana]

Depending on what you mean by "lodge", and how it comes to be there, and how it's (supposed to be) used, might you also need to put money to one side to pay the lawyers if the council get uppity about a separate household being there?

 

[ericmark]

I have same, flat and house on same supply, but council still charges £1000 per year council tax on the flat.

The solar panels do show the power generated, and show in/out to the battery, but as to free power, down also to time of day.

The battery always discharges over night to 10 % so want to stop using heavy draw items this time of year by 1 PM or the battery will run out premature.

So it is set dishwasher, tumble dryer etc, on delay start time so likely finished before 1 PM. But I paid for solar panel to be fitted, so I should get the power it produces. A simple current transformer on the flat supply could tell me how much the flat uses with electric, but oil for heating and water is also shared, as is cost of gardener, and other building maintenance.

I would not dream of trying to work out cost and charge my daughter, I feel swings and roundabouts, she often does shopping for me.

The computer display does show 5 figures, import, export, solar production, in/out of battery, and state of charge for battery. As yet no smart meter so a single tariff, but likely once smart meter fitted then will look at duel or more tariffs, so only real way is agree flat pays x% of the joint bill's, it would be impossible to work out what real cost is.

If I did want to charge, simple, they pay what I say, or get out.

 

[aesmith]

Hi all,

The problem is say the lodge uses 5kw on a Monday and it's sunny. The lodges meter is going to show that 5kw but because its sunny the Grid meter hasn't moved. How can this be overcome?

Depends on the relationship, agreement or contract. If everything's metered it's not free electricity as it's reduced your export payments by 5kWh.

 

[ericmark]

Depends on the relationship, agreement or contract. If everything's metered it's not free electricity as it's reduced your export payments by 5kWh.

Yes electric can cost between 9 and 28 p per KWh depending on if exporting or importing and what tariff is charged at that time of day. But it is never free.

Each day I have a summary

I could work out the average cost per day, but with this as an example

Had my daughter waited until mid day to have a shower rather than around 9 am it would have cost me less. This shows a good day this month, and the window where use would only reduce export is 10 am to 3:30 pm, before or after that time it will cost me the import tariff. Yesterday it would have cost the import tariff all day, so I would forget the solar and charge at import tariff rate.

 

[aesmith]

Just out of interest what's your export unit rate? Question to both the OP and to ericmark i guess.

 

[ericmark]

I at moment get nothing, seems the rules changed between talking to salesman and the solar panels being fitted, and now one needs a smart meter to get paid for export. I due to be fitted on the 28th, and the application for the feed in will be on 29th, bit of a soar point really as they did not tell me rules had changed until I asked when I would get paid for export.

It seems there are three firms which will pay, Octopus Energy it seems pays 15p, Scottish Power 12p, and British Gas 6.4p if you don't buy from them, but 12p if you do, there are rules as to how often the smart meter reports, and you have to of course give the company permission to read your meter, and the money is paid every quarter not same as imported electric.

But there are so many "deals" when you have EV or batteries it is a night mare to work out which is best, and my solar panel installers do it all for me, so it seems likely will be Scottish Power.

My problem is they have not been in long enough to really be able to work out how much export or import there will be, and daughter temporary living in the flat, so hard to work out once she leaves what my consumption will be. Added to that out heat pump drier failed, seems lost gas, so was running far too long before it failed completely, so there will be an inflated usage.

There are methods which could be used to use more power in the day, and less at night, having the freezers set to a lower temp in day to night for example, which would inhibit them running in the night, so extend how long the batteries lasted, it seems there are some tumble driers with smart controls, however the iboost+ for the immersion heater uses a different CT coil to the inverter, there is no electrical connection between the two.

I have found the same with many smart devices, I can look on my PC or tablet and see when the TRV heads are still warming up the house, and when satisfied, but there is no link to the wall thermostat which also reports to my PC or tablet as to when it is still warming up the house, and when satisfied, and also both can be altered from the PC or tablet, but it requires a human to transfer the info between the two devices.

It seems the same with solar panels, it needs me to look out of the window, think looks like being a clear day, and setting the timers in the washing machine, dish washer, and drier to use the solar power. Where it all goes wrong is when the weather changes, or when my daughter also tries to use the same solar power, so two house holds using same solar array does not work, as each does not know what other has done.

So looking at yesterday, quite a good day, if me daughter had used power between around 11:30 and 15:00 it would have been free,

You can see the green and red line following each other, solar production and export to grid, but after 15:00 hours, it would have been using the battery, which means less available over night. So only around 3½ hours of free power, which was not used as neither of us were home.

And one really has no idea when the sun will shine, so even using at 14:00 may cost as the sun may go in and battery never recharge fully, as I go back day by day, there are very few days where power was exported. red is export to grid this month, the 5th we got 2.3 kWh but most were lower or zero, only yesterday did we get 5.9 kWh which had we been paid would be 88.5 p at 15p per kWh so really not worth worrying about. And I have paid for the panels so why should my daughter gain as a result? As said she lives for free as she is my daughter, but if some one else lived there then I would not be reducing the electric cost due to sun shining.

 

[aesmith]

It seems there are three firms which will pay, Octopus Energy it seems pays 15p, Scottish Power 12p, and British Gas 6.4p if you don't buy from them, but 12p if you do, there are rules as to how often the smart meter reports, and you have to of course give the company permission to read your meter, and the money is paid every quarter not same as imported electric.

Octopus offers 15p flat rate, but only if you are with them for import. I believe it's credited month by month.

 

[Why Not Indeed]

How can this be overcome?

Perhaps suggest what you want to happen, and we can suggest if it's possible.

 

[Diver Fred]

Hi all,

This is the scenario. A house and a lodge using one grid meter. The house and lodge have their own cu's. The house has solar panels, batteries and feeds back to the grid meter so both both the house and the lodge can benefit from solar. Obviously when sunny grid meter doesn't move. The lodge wants to pay for its own consumption. It has its own emlite meter. The problem is say the lodge uses 5kw on a Monday and it's sunny. The lodges meter is going to show that 5kw but because its sunny the Grid meter hasn't moved. How can this be overcome? I hope that makes sense?

Many thanks

Think this is a case where a picture of the power arrangement will help us understand what you have. Draw one out, photo it and post it to the thread, please.

 

[aesmith]

In terms of the OPs metering arrangements, I don't see how anything else could be done automatically. That would require his meter to charge a reduced rate if the electricity consumed would otherwise have been exported.

One possible compromise might be to apply a discount for days where he exported more than he imported.

 

[Why Not Indeed]

Meter what gets drawn by the house as well. At "billing time" [ie, once a month or whatever] use the two meter readings to split the grid bill proportionally.
If installing a meter is too much expense, you can fit two CT clamps on a Shelly EM.
EDIT of course the PV is downstream of the proposed metering point, so this isn't going to work.
I think you basically cannot do this in a simple way, without some rearranging of the wiring.

 

[aesmith]

You'd need to meter everything in both directions. You don't get billed on the net amount, even within on 1/2 slot if you export say 1kWh in the first half, and import 1kWh in the second half then these would each be billed and credited. Not cancelled out.