How about a solar car port on a budget?

[Muhendis]

15 hours ago, ArranP said:

 

Didn't buy a combiner box...  worked out the components in side it instead and mounted them on the gypsum board next to the inverter.

• lightning arestor
• 2 pole fuse
• pv array string fuse 
• ground pole

 

 

Just to note, if using a transformerless inverter both the positive and negative leads from the each pv string need to be fused, otherwise if the inverter has a transformer only the positive needs to be fused.

 

example of a combiner box available on aliexpress or alibaba this is for an inverter with transformer as just the positive leads are fused.

 

 

 

 

 

Firstly: the output topology of the inverter has nothing to do with the combiner box. The solar panels connect to the inverter input which is the MPPT charge controller. The output from this charge controller then feeds the inverter input. 

Secondly: looking at your picture of the combiner, I see no blocking diodes. These are an essential part of joining multiple strings of panels into a single output. 

[Crossy]

If anyone is interested you can see the current performance of the system on my ThingSpeak channel

 

https://thingspeak.com/channels/991448

 

[bankruatsteve]

Neat!  It took forever to load, but maybe just me.

[Crossy]

8 minutes ago, bankruatsteve said:

Neat!  It took forever to load, but maybe just me.

 

Nah, not just you.

 

Thingspeak seems to go through slow phases. I expect it's getting lots of traffic with everyone "working from home".

 

I never really intended getting in to IoT (Internet of Things) it just sort of happened when trying to use WiFi to talk to my dummy load.

 

Current headache is getting the clock on the monitoring system to sync to an NTP server (the on-board clock drifts horribly).

[Metropolitian]

4 hours ago, Crossy said:

If anyone is interested you can see the current performance of the system on my ThingSpeak channel

 

https://thingspeak.com/channels/991448

 

Very nice chart software . I like it.

Mine is on a chinesium site, had tried to intercept the log the data that is being sent but till now no luck. It has no public page and need a login to see the data.

 

Two days ago.

 

 

The other, live, data like volts and MMPT status I only can see when using the phone app and bluetooth.

 

And login locally on the inverter gives me the settings option but no data.

 

 

Is the net-metering day on the 18th with you? Or another reason why the monthly reset is on that day?

[Crossy]

 

17 minutes ago, Metropolitian said:

Is the net-metering day on the 18th with you? Or another reason why the monthly reset is on that day?

 

Meter reader comes on the 17th, so I reset at midnight to keep track of what the actual bill should be. It's not perfect because he comes at various times of day but it's close enough.

 

By the way, the data doesn't come from the inverters, I've given up on that route. I have a couple of cheap electronic meters with RS-485 (Modbus) talking to an Arduino Mega with a few bits nailed on.

 

[Metropolitian]

1 hour ago, Crossy said:

 

 

Meter reader comes on the 17th, so I reset at midnight to keep track of what the actual bill should be. It's not perfect because he comes at various times of day but it's close enough.

 

By the way, the data doesn't come from the inverters, I've given up on that route. I have a couple of cheap electronic meters with RS-485 (Modbus) talking to an Arduino Mega with a few bits nailed on.

 

Mind sharing the sources? I have all the hardware for it, I think.

[Crossy]

3 minutes ago, Metropolitian said:

Mind sharing the sources? I have all the hardware for it, I think.

 

Sure, I was going to start a thread soon anyway.

[Metropolitian]

5 minutes ago, Crossy said:

Sure, I was going to start a thread soon anyway.

StayHome brings us more time to finish plans ???? And you know (or not) what are still in the jars / boxes that you kept on the shelves ????
Got bracket for the lifepo4 batteries arrived just today, finally have something to continue with the mini-powerwall project!

 

[Crossy]

A weekend of solar re-configuration is at hand.

 

The current plan of action is:-

Phase 1

• Fully populate the car-port roof with panels, there's room for 18.
• Install a new 6kW GTI.
• Store the existing baby GTIs for later.
• Sort out how the do-not export function works and if it can be controlled via the app.
• Assuming not then link a relay across the CT controlled from an NTP time clock to enable the function (disable export) on and around meter day.

Phase 2

• Add an extension to the car-port roof for 6 more panels 4 of which can run with the existing micro-inverters and cover the base load, add the other two to the 6kW beastie which would put it at capacity.

 

Hope we don't get sussed by PEA for now.

 

But assuming we will eventually end up with an electronic / no-reverse meter look at adding batteries and a controllable charger to store excess power for use later.

 

Photos once it's done.
 

[gamb00ler]

50 minutes ago, Crossy said:

A weekend of solar re-configuration is at hand.

 

The current plan of action is:-

Phase 1

• Fully populate the car-port roof with panels, there's room for 18.
• Install a new 6kW GTI.
• Store the existing baby GTIs for later.
• Sort out how the do-not export function works and if it can be controlled via the app.
• Assuming not then link a relay across the CT controlled from an NTP time clock to enable the function (disable export) on and around meter day.

Phase 2

• Add an extension to the car-port roof for 6 more panels 4 of which can run with the existing micro-inverters and cover the base load, add the other two to the 6kW beastie which would put it at capacity.

 

Hope we don't get sussed by PEA for now.

 

But assuming we will eventually end up with an electronic / no-reverse meter look at adding batteries and a controllable charger to store excess power for use later.

 

Photos once it's done.
 

 

Phase 22

• buy an electric vehicle?

 

[Muhendis]

On 6/13/2020 at 9:32 AM, Crossy said:

A weekend of solar re-configuration is at hand.

 

The current plan of action is:-

Phase 1

• Fully populate the car-port roof with panels, there's room for 18.
• Install a new 6kW GTI.
• Store the existing baby GTIs for later.
• Sort out how the do-not export function works and if it can be controlled via the app.
• Assuming not then link a relay across the CT controlled from an NTP time clock to enable the function (disable export) on and around meter day.

Phase 2

• Add an extension to the car-port roof for 6 more panels 4 of which can run with the existing micro-inverters and cover the base load, add the other two to the 6kW beastie which would put it at capacity.

 

Hope we don't get sussed by PEA for now.

 

But assuming we will eventually end up with an electronic / no-reverse meter look at adding batteries and a controllable charger to store excess power for use later.

 

Photos once it's done.
 

I guess the "Solar Car Port on a Budget" is infinitely budget flexible. Do you still enjoy watching the watts?

[Crossy]

1 hour ago, Muhendis said:

I guess the "Solar Car Port on a Budget" is infinitely budget flexible. Do you still enjoy watching the watts?

 

My engineering jobs are never really "finished", there's always some minor improvement (or major rethink) in the pipeline. I'm one of those people who enjoys the journey more than the actual destination.

 

Anyway, whilst the "budget" is indeed climbing it's not infinite and none of the major components is being abandoned. Apart from some cable and connectors everything is being re used.

 

All good fun, just having a break and a cuppa, been at it since 4.30 this morning.

 

EDIT 11AM Not happy right now as the new inverter isn't working, I'm probably being an idiot somewhere.

[Muhendis]

2 hours ago, Crossy said:

All good fun, just having a break and a cuppa, been at it since 4.30 this morning.

Aah, the enthusiasm of youth. Well done.

I agree absolutely about the fun of the journey.

[Crossy]

Phase-1a is working after some frantic emailing to the manufacturer's support line, very responsive and helpful, a software update was performed and we are now working with the new inverter and the original 8 panels.

 

The rest of the panels will go up on Sunday when my step-son visits (he does the climbing thing).

 

Inverter and assorted bits box containing 30A mains breaker, mains surge suppression and DC surge suppression (will be installed when the beasties arrive from Lazada). Cables to be tidied when the panels are all up.

 

 

EDIT And now it seems that the unit I've been sold is a "not for export" model, so Sofar Support won't help me change the language from the default Chinese. Hoping for help from the seller who is also very responsive to questions (one reason I keep going back to them).

 

I do have the Chinese manual, so scanning and online translations are in order too.

 

Luckily I quite enjoy these challenges, I'll get there in the end. If it saves me a few $$$ I'm happy (I count my time as no-charge). 

 

 

[carlyai]

6 hours ago, Crossy said:

Phase-1a is working after some frantic emailing to the manufacturer's support line, very responsive and helpful, a software update was performed and we are now working with the new inverter and the original 8 panels.

 

The rest of the panels will go up on Sunday when my step-son visits (he does the climbing thing).

 

Inverter and assorted bits box containing 30A mains breaker, mains surge suppression and DC surge suppression (will be installed when the beasties arrive from Lazada). Cables to be tidied when the panels are all up.

 

 

EDIT And now it seems that the unit I've been sold is a "not for export" model, so Sofar Support won't help me change the language from the default Chinese. Hoping for help from the seller who is also very responsive to questions (one reason I keep going back to them).

 

I do have the Chinese manual, so scanning and online translations are in order too.

 

Luckily I quite enjoy these challenges, I'll get there in the end. If it saves me a few $$$ I'm happy (I count my time as no-charge). 

 

 

Cunning, very cunning. So instead of going for more incoming phases, you're going to get what your single phase can't supply from the sun. 

[Metropolitian]

On 6/13/2020 at 10:26 AM, gamb00ler said:

Phase 1

• Fully populate the car-port roof with panels, there's room for 18.
• Install a new 6kW GTI.

 

6 hours ago, Crossy said:

Phase-1a is working

 

Then, it is a 3phase inverter and I am wondering how is the generated energy balanced over the phases?

All the energy divided by 3 for each phase? Or is is fast enough to pump charge the toroid 150 times (or three of them?) in a sec and delivering to all phases? Or just giving out to each phase sequentially?

 

I've monitored my inverter and it's dumping and charging each second. You can see that pattern with an analog meter or oscilloscope at the DC side.

 

Also, curious as what it does with the 'over-generated-power' on a phase is it going to waste or giving it to another phase.  (3 phase loads in the house with one of the phases using lesser then the generated power)

[Crossy]

Ah, it seems we have a spot of wrong end of the stick grasping and it's my fault ????

 

I'm using the term "Phase" as in phase (stage) of the job rather than phase of a 3-phase supply, should have been clearer.

 

To clarify, it's a single-phase inverter on our single-phase supply, I'm not doing anything clever there.

 

And I've completed Stage-1a to this point, the rest of Stage-1 (filling up the roof with panels) is next weekend.

 

Stage-2 is currently not scheduled, let's see how we get on for a few months with what we have.

 

[Muhendis]

I have been trying to find out more about your SoFar inverter but not getting much info. (Just found the spec. for it. Looks very impresive). Did you get it locally or imported from China?

Edited June 16, 2020 by Muhendis
new information

[Crossy]

18 minutes ago, Muhendis said:

I have been trying to find out more about your SoFar inverter but not getting much info. Did you get it locally or imported from China?

 

Manufacturer's website http://www.sofarsolar.com/

 

This is the unit I have http://www.sofarsolar.com/product-detail/462/SOFAR 6KTLM-G2

 

Chinese import (AliExpress). Be aware that the unit I have has been identified by Sofar support as a "Mainland China Only" variant!

 

The support chap at Sofar has been very good even after identifying the unit as a grey-import.

 

EDIT They are available in Thailand, the 5kW version is 24000 Baht on Shopee

 https://shopee.co.th/กิตไทร์อินเวอเตอร์-5Kw-Grid-tie-inverter-SOFAR-มีกันย้อน-รับประกัน-5-ปี-i.18653128.2460737043

 

EDIT2 My grey-import 6kW init was 17,300 Baht all in (including shipping and duties).

[Muhendis]

Fanless and IP65 ????

[Muhendis]

Did you need to wait long for delivery of the inverter? 

A bit off topic but the reason I ask is that I am finding deliveries from AliExpress seem to have have stalled at the moment.

[Crossy]

1 minute ago, Muhendis said:

Did you need to wait long for delivery of the inverter? 

A bit off topic but the reason I ask is that I am finding deliveries from AliExpress seem to have have stalled at the moment.

 

2.5 weeks via "Thailand Special Line", duties paid by the seller (included in the shipping price).

 

https://forum.thaivisa.com/topic/1165517-anyone-used-evereast-special-line-shipping-china-to-thailand/

 

I've got half a dozen orders "stuck" somewhere in limbo. Things seem to appear at random.

[Metropolitian]

6 hours ago, Crossy said:

Ah, it seems we have a spot of wrong end of the stick grasping and it's my fault ????

 

I'm using the term "Phase" as in phase (stage) of the job rather than phase of a 3-phase supply, should have been clearer.

 

To clarify, it's a single-phase inverter on our single-phase supply, I'm not doing anything clever there.

 

And I've completed Stage-1a to this point, the rest of Stage-1 (filling up the roof with panels) is next weekend.

 

Stage-2 is currently not scheduled, let's see how we get on for a few months with what we have.

 

I was wondering this ????  First I read the 'Phase' as in the stage, as your intention was, but.. 1a is populating the carport roof, 1b was the inverter. 

That is where I had to change my understanding and changed it into a 3phase inverter

[Metropolitian]

21 hours ago, carlyai said:

I do have the Chinese manual, so scanning and online translations are in order too.

Double check your translation results , don't try to accomplish the same outcome as this

????‍♂️

[Crossy]

The new inverter seems to be more efficient than the little micro-inverters.

 

Using the original 8 panels and micro-inverters the most we got in a day was 10.1 units (last Saturday), with the same panels and the big beast the last 3 days have been 11.1, 12.8 and 13.5 units.

 

Same monitoring hardware and software so only the inverter and cable arrangements have changed.

 

[Muhendis]

15 hours ago, Crossy said:

The new inverter seems to be more efficient than the little micro-inverters.

No surprises there.

You had a lot of heat dissipation with the micro's so much so that you needed a fan to keep them in working temperature range. That, without a doubt is inefficiency.

Some things from China are well designed and a pleasure to own and some things not quite so. Your choice of inverter is good. How long did you look before you found it?

[Crossy]

It's about now that one realises that, whilst they are all about the same size, solar panels are not actually a standard size. So we have 3 different panels which are different widths, lengths and thicknesses. Oh well they all make electricity.

 

 

We have:-

String 1 - Eight new Trina Tallmax TSM-345PE15H 345W panels (these are half-cell panels, supposedly more efficient and more reliable).

String 2 - Eight Trina 300W panels (our original ones) + two 345W Lazada cheapies.

 

Inverter has two independant MPPT channels so mis-matched strings are no problem.

 

Total installed solar power = 5,850W. Recommended maximum for the inverter is 6,600W (max 3,500W per channel) so I think we are pretty much optimal. I may add a couple more panels later we shall see how it performs.

 

 

[Crossy]

9 hours ago, Muhendis said:

How long did you look before you found it?

 

I was actually looking for on-grid hybrids and suffering from serious sticker-shock when these popped up on my favourite AliExpress seller. Spec looked good (it can do zero-export), price was right (particularly as it came duty / VAT paid).

 

The hybrid and batteries can wait until we run foul of PEA installing a no-reverse or electronic meter.

 

Sofar do do a hybrid of similar spec so it should be an easy (but not cheap) change over if it becomes necessary.

 

[BritManToo]

13 minutes ago, Crossy said:

String 2 - Eight Trina 300W panels (our original ones) + two 345W Lazada cheapies.

I predict the 345w panels will damage the 300w panels.