What would you do differently if you could do your PV install fresh?

[Marvin]

24 minutes ago, ProDave said:

Yes I don't want all that "control"  and heaven forbid if someone decides all ev's plugged in must be able to discharge to the grid on demand.

 

So should I buy a dumb EV charger now, to put away for when I want one, and dumb chargers are no longer available?

Yes you need a clever charger, a data cable between the charger and the smart meter and a smart meter to make it work, otherwise your safe.

 

Or use a plug in.

 

Edited May 8, 2023 by Marvin
further thought

[SteamyTea]

It is interesting that we tend to think that we should be allowed to charge our vehicles at home whenever and however we like.

Good job that gasoline car owners are not allowed to do the same.

[Marvin]

14 hours ago, RichardL said:

Go a little left field - levi parking and ulez's, i.e. don't try to tax cars when they're moving - tax them when they stop - much easier to collect.

The whole taxing fuel, taxing milage with technology, pictures of cars in locations to deduce distance etc etc -  far too complex.
 

Yes mileometer reading at MOT time??

[SteamyTea]

3 minutes ago, Marvin said:

Yes mileometer reading at MOT time??

If the UK government tried to organise that, it would be a disaster.

How would you know how many miles a car that is taken off the road had done. And can you imagine trying to collect the payment when someone moves, or just does not have the cash.

Much easier to just have a fixed fee, payable monthly, 6 monthly or annually, we are used to that, and we have the systems already in place.

What it really comes down to is what the charge should be, trying to make 'fair' for everyone just means we all loose out.

We really should treat personal transport as a privilege, not a right.

I hate public transport, really hate it. Why I pay the price to have private transport. 

Running my car cost me more than running my house. 

[TonyT]

2 hours ago, SteamyTea said:

Have you ever had a look at the parasitic losses on an EV?

I think I read (may have been about Our Jeremy's Model 3) that they can easily chew through 3 kWh/day.  So around 125W while doing nothing.

So you may be better off, if your tariff allows, charging it later.

 

currently consuming 1.5 watts according to the energy meter on the EV charger feed.

 

its 9 pence during the cheap slot compared to 38pence(ish)

so definitely worth charging at that cheap time

[SteamyTea]

21 minutes ago, TonyT said:

currently consuming 1.5 watts according to the energy meter on the EV charger feed.

That is just the charger right?  Not how much the car uses when not being driven.

[MikeSharp01]

2 hours ago, ProDave said:

So should I buy a dumb EV charger now

Too late I think as all @Gone West pointed out several months ago.

 

 

[jack]

4 hours ago, SteamyTea said:

 can easily chew through 3 kWh/day.  

 

I've never measured it, but 3 kWh would be over 12 miles at our usual consumption rate and it definitely doesn't lose anything like that when it's sat in the driveway.

[SteamyTea]

1 hour ago, jack said:

definitely doesn't lose anything like that when it's sat in the driveway.

 

From the horse's mouth.

 

https://www.tesla.com/en_gb/support/range#:~:text=It is expected for a,aftermarket equipment when not needed.

 

 

Why does estimated range decrease overnight while my car is off?

It is expected for a Tesla car to consume around 1% of charge per day while parked. In some cases, you may notice that consumption is higher. We recommend deactivating features such as preconditioning, Sentry Mode, Keep Climate On and any aftermarket equipment when not needed. It’s best to keep the vehicle plugged in when using those features when possible.

Note: Aftermarket equipment connected to the 12V system and/or third party mobile applications which collect data about your vehicle can decrease range while parked and reduce the battery lifespan. Tesla does not recommend using aftermarket equipment, and any damage to your vehicle’s hardware or software resulting from unauthorized access to vehicle data through non-Tesla parts or accessories is not covered by warranty.

 

 

[Gill]

6 hours ago, Nick Thomas said:

I did my install piecemeal, which I would definitely not do again. Plan it upfront, get the G99 upfront if your plan requires it, then get it all done in one go, including battery if you want one.

 

The plan is go get as much as we can all at once with whatever applications are required. 

 

I'll hopefully have the 1st assessment back in a few days and I have a 2nd company out on Friday. Some basic numbers have me leaning towards battery assuming we could size it for at least 10 KWh. If done at the same time as the solar there's some benifits with Home Energy Scotland.

 

I've read that some have slower charging and draw rates than others - any to avoid /give more consideration than others? 

 

 

 

 

[jack]

17 hours ago, SteamyTea said:

From the horse's mouth.

 

https://www.tesla.com/en_gb/support/range#:~:text=It is expected for a,aftermarket equipment when not needed.

 

1.   I was responding to you about EVs in general, not Teslas, since that's what you were referring to:

 

23 hours ago, SteamyTea said:

Have you ever had a look at the parasitic losses on an EV?

 

2.   Assuming the 1% number mentioned by Tesla is reasonable for other manufacturers, my battery should lose up to 0.38 kWh per 24 hours. That's less than 2 miles, which is exactly in line with my comment:

 

19 hours ago, jack said:

I've never measured it, but 3 kWh would be over 12 miles at our usual consumption rate and it definitely doesn't lose anything like that when it's sat in the driveway.

 

3.   The numbers given by Tesla in the link you provided suggest a 3 kWh/day standing consumption is far too high. Assuming a 54 kWh battery (which is what Jeremy's would have been, I think), 1% is 0.54 kWh, which is about a sixth of 3 kWh.

 

In summary, parasitic losses are a thing, but are nothing like the thing you implied.

 

 

[SteamyTea]

2 minutes ago, jack said:

In summary, parasitic losses are a thing, but are nothing like the thing you implied.

Why I mentioned it, I don't have an EV.

But it seems that, with the Teslas, if you leave some features on, then it is quite a high standing loss.

Would be nice if you could measure it though, say when you park it up for a few days without usage.

[Gill]

I've now had a few Installers out and one quote back. 

 

Given the advice to go big (and benifits from vat saving), I'm trying to wrap my head around the inverter piece /G99. 

 

One installer quoted for 5.2 kW system with giv 3.6kW inverter and 2x5.2kW giv batteries. 

Am I correct to think that 3.6 inverter means I could not use more than 3.6 KWh concurrently from either the battery or the panels? That would be very limiting in the winter months. 

 

They also mentioned a bigger sized system at 13.5kW was feasible and even 16kW if we used West facing roof as well. The advice was start with a small system and upgrade later as G99 could take 9 months.  Anyone have any time lines on Scottish power g99 application? If G99 was rejected does that then limit me to 3.6 inverter or is there alternative configurations. It would seem crazy to upgrade later at higher cost. 

 

Lastly - does three phase come into the equation at all? I think we have three phase (eco 7) but need to work out how to confirm. 

 

Thanks 

[S2D2]

28 minutes ago, Gill said:

Am I correct to think that 3.6 inverter means I could not use more than 3.6 KWh concurrently from either the battery or the panels? That would be very limiting in the winter months. 

Yes, 3.68kW if you go the G98 route. Back on topic, the one thing I'd change is to go G99, there are a few more fast track options now which let you get to 7.36kW which would save some complicated battery management I've set up to ensure capacity remains for excess PV when the inverter is running full whack. Ask the DNO early, no point putting 16kWp panels up if they say no to anything but G98.

[Gill]

Thanks @S2D2

 

I'll get onto Scottish Power. I'm hoping they can at least confirm if not feasible without having to make an application and wait for months. 

 

7.36kW would be perfect. That would allow heating to draw from battery (assuming that I find a suitable battery to support that draw). 

 

[Dillsue]

3 hours ago, Gill said:

Thanks @S2D2

 

I'll get onto Scottish Power. I'm hoping they can at least confirm if not feasible without having to make an application and wait for months. 

 

7.36kW would be perfect. That would allow heating to draw from battery (assuming that I find a suitable battery to support that draw). 

 

We've got the same DNO as you, SPEN, but likely a different engineering office as we're in N Wales. We had informal agreement to double our export from 3.68 to 7.4kw within a few days. Formal offer took a month or 2 but nothing like 9 months. Definitely speak to them as theyll likely be able to give you an idea of the export theyll allow over the phone.

 

If you are constrained by what you can currently export, theres 2 things to remember. First you can have a big system with export limitation so you could have an inverter/batteries that will feed 7kw to the house but is limited to 3.68kw to the grid. Second is that the rules on who pays for grid reinforcement have just changed so if theres export limitation because of grid capacity, the DNO pays for upgrades whereas previously the customer often did

[Gill]

5 minutes ago, Dillsue said:

We had informal agreement to double our export from 3.68 to 7.4kw within a few days. Formal offer took a month or 2 but nothing like 9 months.

That's really good to know - thanks! We'll get applying for home energy scotland loan (6k battery / 6k solar) but once we get agreement the loan offer clock starts ticking and you've got 9 months. 

 

7 minutes ago, Dillsue said:

First you can have a big system with export limitation so you could have an inverter/batteries that will feed 7kw to the house but is limited to 3.68kw to the grid.

Interesting. I thought the inverter would limit all throughput. Does this setup require multiple inverters? 

 

Been having a read up on 3 phase which if I've followed correctly means we could export 3.68 on each phase without g99. Need to do a bit more reading but anyone able to confirm from this picture that it's three phase or not ? Or is this one i need to get a my spark to confirm? 

 

 

 

[Dillsue]

1 hour ago, Gill said:

I thought the inverter would limit all throughput.

 

Been having a read up on 3 phase which if I've followed correctly means we could export 3.68 on each phase without g99.

 

The inverter does limit all throughput but it matches its throughput to the house load. It monitors the power leaving the house and as soon as it sees export go above the limit it's been set to, it throttles the throughput so that export stays within set limits.

 

Yes you can export 3.68kw on each of the 3 phases without getting permission via G99. With 3 DNO fuses Id guess youve got 3 phase to the house but the house is only using 1 phase. Youd need a new meter and a new consumer unit to hook up the 3 phase. Except for the meter, your spark should be able to sort out the rest.

 

If youre only looking for 7kw export it would likely be easier/cheaper to stick with single phase unless SPEN object

[Ajn]

Ok.. while this thread seems more about "how they are going to tax your EV" than the "what would you do differently" of the original question.

So we are looking at PV again. Had full FIT on the old house, just paid for it's self and a full year of it was paying for our electic and gas bills ... then we moved... dam..

So this new project is signed off and we are thinking about PV.

We have currently one south facing elevation 14m x 2m that is at 36 degrees.

Later we will have another 12.5m x 2.8m of elevation split 50/50 south and west that will be available.

So around 4.5kw for the first bit and 4 ish for the later bit.

We have 3 phase so G98 will do. We have a GSHP. Just need to work out the battery size to cover out use plus a bit of peak time export if we can.

Need to work out what we are using and when but the not so smart meter just gives a total per day.

 

I am thinking to size the battery, if we can use 100% of our needs from the battery and top it up with off peak and solar it will be a saving whatever. Then on my 160th birthday we will have 100% free electric.

[SteamyTea]

11 hours ago, Ajn said:

So this new project is signed off and we are thinking about PV.

Do you have an electrical energy usage profile?

Without one you are just hoping that lots of PV and oversized storage will cover your needs, this may not be the most effective way to design a system.

 

Below are some charts (as we all like charts), that are from the coldest week I had last year.

First chart is for the whole week, then charts for each day to show the variations in usage.  There is not a great variance in usage, which reflects the decrement delay and consistent lifestyle I had that week.

 

 

 

 

 

 

Below is the coldest day

 

 

 

 

 

Edited May 17, 2023 by SteamyTea

[Ajn]

4 hours ago, SteamyTea said:

Do you have an electrical energy usage profile?

Yes we do from the not so smart meter. I would have liked to see what each of the phases used but it is just one reading. They did the meter last September (on the second visit) so we have values for the winter period if nothing else. We know what the heat pump did from its log so we can extract that from the total. We do seem to be using a lot of electric £12 a day but it is five years since I paid a bill. our annual bills were around £500 for electic at the old house (4 bed detached late 70's) and £1200 for gas. I did have 3.5kw on the roof.

The current place is 320sqm for the main bit and 90sqm ish for the annex but all electric.

 

We do have a solar survey man comming on friday to identify our needs and give us a quote. I just hope he is a bit better than the man who phoned to book the appointment. He asked a few basic questions including heating type... "it is electric and uses a GSHP" his next question was why do you need solar if you are getting the electic from the ground......

So we will see what Friday brings... looking foward to it.

 

 

[SteamyTea]

8 minutes ago, Ajn said:

Yes we do from the not so smart meter. I would have liked to see what each of the phases used but it is just one reading. They did the meter last September (on the second visit) so we have values for the winter period if nothing else.

Chart the data by date and hour, then you should get a good idea of that is happening just from the load values.

[Ajn]

On 17/05/2023 at 13:40, Ajn said:

So we will see what Friday brings... looking foward to it.

So they are offering 28 panels of 1.7m x 1.1m @405kW each... on the flat roof of a building that is 14m x 4.5m

12 panels on a building that is not built yet

Then there was stuff about a 10kW single phase inverter. and a 5kW battery oh and a 5kW inverter for the 12 panels.

Would this be a G99 application then? oh no it would be limited to G98. Would you not use the 3 phase then? That would not change anything.

Then he said we can give 30% discount.  I did say I thought this was solar and not double glazing we were talking about....

 

Lets see what the next one brings.

Edited May 21, 2023 by Ajn

[DougMLancs]

Sounds like my favourite game: cowboy PV installer bingo! Was the discount for a limited time only too? 😂 From my own experience- a decent installer is normally far too busy to do on site surveys for an initial quote. No need with Google Earth. Fingers crossed for number 2!