Inverter confusion

[Pocster]

4 hours ago, Dillsue said:

AFAIK PW2 can be set to 0kw, 3.68kw(for G98 compliance) or 5kw export. Your SE3680 is limited to 3.68kw as it is without any other export limitation. If youre only see max 3.68kw from your PW then that seems set wrong. Maybe needs upping to 5kw if youve got DNO approval for that.

 

Not sure that photo of your schematic from your other thread is correct as the Gateway doesnt seem in the right place??

Yep . Back home soon - will log into Tesla gateway and check . I assume this is wrong 

[Pocster]

21 hours ago, Dillsue said:

AFAIK PW2 can be set to 0kw, 3.68kw(for G98 compliance) or 5kw export. Your SE3680 is limited to 3.68kw as it is without any other export limitation. If youre only see max 3.68kw from your PW then that seems set wrong. Maybe needs upping to 5kw if youve got DNO approval for that.

 

Not sure that photo of your schematic from your other thread is correct as the Gateway doesnt seem in the right place??

My export on PW is indeed wrong - set at 3.68.

I assume it's a simple case of contacting Tesla and they'll change it?

Presume they can validate themselves it's within the limitations of what the DNO has set.

Edited May 6, 2023 by pocster

[Pocster]

On 04/05/2023 at 15:34, S2D2 said:

If the SE is pulling 5kW you will only have 0.7kW left to go to AC due to the DC limit.

 

It was probably a fast track G99 or something, which was limited to 2x3.68kW devices.

Reached 5.4 today for a few seconds. 5KW into SE ; 0.4 to PW

 

The SE can only be charging or discharging. This creates a dilemma sometimes. PW nearly empty so you want to export SE. But then SE won't charge; so PW will get solar but only upto 3.6 - and of course that "solar" could be a mix of real PV and SE discharge "

 

I guess this is a limitation - trying to avoid any PV wastage.

[SteamyTea]

17 hours ago, pocster said:

Reached 5.4 today for a few seconds. 5KW into SE ; 0.4 to PW

If those few seconds had a duration of 20 seconds, then that is 30 Wh. 

At 50p kWh, that is 1.5p of energy.

 

[Pocster]

3 minutes ago, SteamyTea said:

If those few seconds had a duration of 20 seconds, then that is 30 Wh. 

At 50p kWh, that is 1.5p of energy.

 

Yeah , so ?

[SteamyTea]

14 minutes ago, pocster said:

Yeah , so ?

Was just wondering how much effort it is worth.

Good job I don't put a price on reading drivel on here. Might make going to work worthwhile.

[Pocster]

1 minute ago, SteamyTea said:

Was just wondering how much effort it is worth.

Good job I don't put a price on reading drivel on here. Might make going to work worthwhile.

An electric bill ( heating inc and low mileage EV ) of zero a year makes it worth it 😎

[Onoff]

9 minutes ago, pocster said:

An electric bill ( heating inc and low mileage EV ) of zero a year makes it worth it 😎

 

Impressive. What's the total outlay, payback time etc?

[SteamyTea]

10 minutes ago, pocster said:

An electric bill ( heating inc and low mileage EV ) of zero a year makes it worth it 😎

Only in the same way as saving up for a house and not having a mortgage.

 

You have paid for your power up front.

 

A decade ago, when PV system were between £2000 and £2500 a kW_p installed, even with the decent FiT rate, I was better off putting the money in the bank, got 6‰ on it in 2008.

[Pocster]

5 minutes ago, SteamyTea said:

Only in the same way as saving up for a house and not having a mortgage.

 

You have paid for your power up front.

 

A decade ago, when PV system were between £2000 and £2500 a kW_p installed, even with the decent FiT rate, I was better off putting the money in the bank, got 6‰ on it in 2008.

How many times must I have this conversation.

Is it worth it ?

 

No one notice we need to aim for zero carbon for sake of society and the planet ?

 

ROI for me ( I bought pw and 4K pv array ) a good few years ago when they were less expensive.

I estimate ( inc newer pv and se battery ) around 7 yrs .

Batteries warranty is 10 yrs . Pv life span around 20 yrs .

Please don’t mention “ inverter breaks down , optimiser fails etc etc “ . Yes of course it’s possible - just as much as boiler breaks down . As a LL I have modern boilers - not 1 year goes by without a repair on one .

if I buy an 60k Tesla motor no one’s says a thing . If I then charge it off my PV everyone thinks it’s wonderful . That’s a very expensive battery !! - but with the additional benefit of wheels . Roi on that ? Is it worth 50k to go from A to B and save a few pence on charging ? 
That depends on the owners view . On size does not fit all .

If it were possible I’d have another PW but DNO won’t allow it ( then I’d look at flux ) . Tempted by another SE battery though now that all the caveats are understood.

[Onoff]

9 minutes ago, SteamyTea said:

You have paid for your power up front.

 

A decade ago

 

The theory being he's protected against ever increasing prices. 

 

Without knowing what those increases could be it's I guess impossible to calculate the "savings".

 

Saying that it doesn't have to be about saving per se, if you've the money and want to play with this tech then why not. 

 

Spares could be an issue if it all goes to pot with China maybe?

[SteamyTea]

It does raise some interesting environmental questions.

And yes to almost net zero.

We actually have to be on a path to net minus.

~425 ppm C02 is, as we are finding out, too high for our current, and near future, global infrastructures.

Personally I don't think we have to worry, in the developed world, about electrical energy production. Economics has done that for us.

Transport and, the really hard one, agriculture, need to be the next two. If we could, in the next decade, cut the carbon dioxide equivalent emissions to the same extent as the UK has cut them in electrical generation  i.e. from around 600g/kWh to 200g/kWh, then we can let nature help us a lot i.e. let land and sea plant life absorb the excess.

I don't think that tinkering with a few home battery packs is going to actually help, and may hinder.

Large scale storage is a different matter, as is demand reduction.

[SteamyTea]

23 minutes ago, Onoff said:

theory being he's protected against ever increasing prices

Not though, fluctuations in interest rates, variable weather and system reliability all have an affect to.

[Pocster]

Agree with everything said 

Only 1 planet earth …

[Pocster]

Until government does massive projects to supply zero carbon energy ( which could take decades ) its down to people to take what responsibility they can for their consumption and pollution 

[SteamyTea]

42 minutes ago, pocster said:

Until government does massive projects to supply zero carbon energy

Why should the government do it, they are there to set the regulations to encourage private investors.

Apart from dithering on the overturning of the moratoriums about onshore wind, they seem to have created a good framework in the UK.  We have a lot more RE generation now than a decade ago, and still plenty of sites that can be developed.

42 minutes ago, pocster said:

its down to people to take what responsibility they can for their consumption and pollution 

Not many people do a true energy audit, and even less include pollution in it.

I think I am the only one that has posted up a time series of usage, faction of resources and generation type.

 

This is what has happened in my house this year.  I have used 0.000002% of the available electricity in the country, which is basically (expletive deleted) all.

 

Edited May 7, 2023 by SteamyTea

[Pocster]

21 minutes ago, SteamyTea said:

Why should the government do it, they are there to set the regulations to encourage private investors.

Apart from dithering on the overturning of the moratoriums about onshore wind, they seem to have created a good framework in the UK.  We have a lot more RE generation now than a decade ago, and still plenty of sites that can be developed.

Not many people do a true energy audit, and even less include pollution in it.

I think I am the only one that has posted up a time series of usage, faction of resources and generation type.

 

This is what has happened in my house this year.  I have used 0.000002% of the available electricity in the country, which is basically (expletive deleted) all.

 

So it shouldn’t be government and single installs like mine don’t contribute enough ?

Reminds me of my planning feedback “ what’s the point of a single build it doesn’t contribute to housing stock “ . What a prik I thought . It contributes 1 . It’s not THE answer to housing but it contributes- same argument with pv etc. 
Do it ; don’t do it . Someone has to do something. Doing nothing is the easiest and worse non solution - but we know the majority will do that .

Edited May 7, 2023 by pocster

[Onoff]

18 minutes ago, pocster said:

Reminds me of my planning feedback “ what’s the point of a single build it doesn’t contribute to housing stock “ .

 

They could always build social housing or a halfway house on top!

[SteamyTea]

6 minutes ago, pocster said:

So it shouldn’t be government and single installs like mine don’t contribute enough ?

I think you may be getting what I am saying confused.

One problem with uncontrolled nano generation, is that locally, it can affect grid stability.

Grid stability is expensive to control, and horribly expensive to rectify with current generation mix.

Once we get a lot more large scale Wind and Solar on line, we can get back some fine local control again.

Large scale wind and solar, and especially solar, is, in grid terms, pretty small ~1 to 5 MW. A small gas plant is 500 MW.

Distributed generation does not work in unison, as one generation block, it is very much local.  Until we have a robust, real time, centralised control system for most RE generation (except large hydro as that is already controllable), local switching of local loads i.e. diverters, may be doing more harm than good because to balance the grid, our current thermal plants have to be adjusted.

At the moment, the National Grid uses historical data and weather reports to predict demands.  It does a fantastic job, this weekend, which is an odd 'bank holiday weekend' has probably been a real challenge as they did not know how many people will stay in to watch the telly, and how many would not.

You can look here for recent charts: https://gridwatch.templar.co.uk/

Yesterday was less peaky than the Saturday before.  Wind power was also way down, which may have been management, more than lack of resource.  The week has be quite volatile though.

I can't look at the data closer at the moment, but it may make for some interesting analysis when it is a rainy day.

[Pocster]

47 minutes ago, SteamyTea said:

I think you may be getting what I am saying confused.

One problem with uncontrolled nano generation, is that locally, it can affect grid stability.

Grid stability is expensive to control, and horribly expensive to rectify with current generation mix.

Once we get a lot more large scale Wind and Solar on line, we can get back some fine local control again.

Large scale wind and solar, and especially solar, is, in grid terms, pretty small ~1 to 5 MW. A small gas plant is 500 MW.

Distributed generation does not work in unison, as one generation block, it is very much local.  Until we have a robust, real time, centralised control system for most RE generation (except large hydro as that is already controllable), local switching of local loads i.e. diverters, may be doing more harm than good because to balance the grid, our current thermal plants have to be adjusted.

At the moment, the National Grid uses historical data and weather reports to predict demands.  It does a fantastic job, this weekend, which is an odd 'bank holiday weekend' has probably been a real challenge as they did not know how many people will stay in to watch the telly, and how many would not.

You can look here for recent charts: https://gridwatch.templar.co.uk/

Yesterday was less peaky than the Saturday before.  Wind power was also way down, which may have been management, more than lack of resource.  The week has be quite volatile though.

I can't look at the data closer at the moment, but it may make for some interesting analysis when it is a rainy day.

Oh yes . Me adding another PowerWall ( for storage not generation ) causes problems for my DNO . The infrastructure can’t cope . Ultimately ( as the new rules have been introduced) the DNO is obligated to update infrastructure for new developments. Easier at National / local level than nano - of course it is . But we can’t really afford to all wait .

[Pocster]

On 04/05/2023 at 15:34, S2D2 said:

If the SE is pulling 5kW you will only have 0.7kW left to go to AC due to the DC limit.

 

It was probably a fast track G99 or something, which was limited to 2x3.68kW devices.

Actually witnessed 5.9kw today . Makes me wonder what the true ‘maximum ‘ is …

[SteamyTea]

53 minutes ago, pocster said:

Actually witnessed 5.9kw today

It gives, when new, the name plate rating when under standard test conditions. It is easy to exceed those conditions.

[Pocster]

4 minutes ago, SteamyTea said:

It gives, when new, the name plate rating when under standard test conditions. It is easy to exceed those conditions.

Yeah ; it’s just how much can they be exceeded ??

[SteamyTea]

Just now, pocster said:

Yeah ; it’s just how much can they be exceeded ??

Probably up to 25% when the stars align.

 

[S2D2]

1 hour ago, pocster said:

Actually witnessed 5.9kw today . Makes me wonder what the true ‘maximum ‘ is …

Yes I've seen 6.2kW today on a 5.5kW "max" - never for long, I assume it's a nominal max which it can go over for short bursts.

Edited May 7, 2023 by S2D2