No PEA application required, if no feedback to the grid

[Opossum]

Hi

 

I was told by a solar-installation-company, that no pea application or any paperwork is required, if I have a solar-system, that is not feeding back to the grid. Anyone else made the same experience?

 

thx

[Crossy]

Like everything in Thailand it varies by office of course.

 

Our PEA office said absolutely no spinning the meter backwards (net metering) when we said we really weren't interested in the "My Solar Roof" feed-in tariff. On our way out the supervisor said "don't let the meter reader see it going backwards".

 

If you are not grid-tie you have no problem whatever even with hybrid inverters which top-up from the grid when the batteries / solar are not doing the job (there is absolutely no possibility of feeding back as the inverter doesn't have the hardware).

 

If you are grid-tie but have a "zero-export" inverter then you are potentially in the "unknown, here be dragons" area because you "could" export when nobody is looking.

 

In reality the worst I've heard of happening to anyone caught spinning things backwards is that PEA fitted a no-reverse meter. 

 

As with all these things YMMV.

[KhaoYai]

On 2/20/2021 at 11:27 AM, Crossy said:

Our PEA office said absolutely no spinning the meter backwards (net metering) when we said we really weren't interested in the "My Solar Roof" feed-in tariff. On our way out the supervisor said "don't let the meter reader see it going backwards".

Sorry to butt in but I'm going to be going solar before too long - I don't suppose any of the information on these different systems is available in English is it?

 

I think I've seen you mention the PEA scheme before, what's wrong with it? Waste of time, costs more than its worth???

[Crossy]

38 minutes ago, KhaoYai said:

Sorry to butt in but I'm going to be going solar before too long - I don't suppose any of the information on these different systems is available in English is it?

 

I think I've seen you mention the PEA scheme before, what's wrong with it? Waste of time, costs more than its worth???

 

Information on the various types of solar installation, on-grid, off-grid, off-grid hybrid, on-grid hybrid is readily available from Mr Google.

 

As to the PEA scheme, much depends upon what you actually want to do.

 

The issue is that the feed-in rate is (was, it's recently been increased slightly) pretty miserable, they pay you around 2 Baht for every unit you export during the day, then charge you 4.5 Baht to re-import that unit at night to run your lights and A/C. Also, due to the amount of paperwork needed, DIYing the system is pretty much precluded and the local contactors know this and charge a significant amount to install and authorise the system.

 

If you intend using a contractor the go for the scheme have a look at this thread 

https://forum.thaivisa.com/topic/1207148-my-issan-10kw-on-grid-solar-project-fully-installed-by-contractors-337500bht/

 

If you fancy going DIY and don't mind running the gauntlet of getting found out and potentially having a no-reverse meter installed then have a look at this thread 

https://forum.thaivisa.com/topic/1120934-how-about-a-solar-car-port-on-a-budget/

 

If you already have a "smart" meter rather than the simple disc-type electromechanical meter then you have no choice really, contractor ???? 

 

[KhaoYai]

2 hours ago, Crossy said:

Information on the various types of solar installation, on-grid, off-grid, off-grid hybrid, on-grid hybrid is readily available from Mr Google.

Cheers, I'll take a look.  The conversion is not imminent but I'm leaning towards a non-battery system at the moment.  I can see those being costly to buy and they will no doubt need replacing periodically which, as well as cost raises issues around disposal.

 

I saw a programme on UK TV recently where they were talking about using batteries that were at the end of their life in electric cars in domestic solar applications.  I don't see how that would work if the batteries are all but knackered and, given the amount of electric cars that there will be around in 15 years or so - disposal is going to be a real problem.

 

No doubt someone will invent a battery that can be re-energised before long.

 

One question regarding feed in or not - the non feedback inverters you mention, I take it they switch between solar and grid automatically?

[Crossy]

9 hours ago, KhaoYai said:

No doubt someone will invent a battery that can be re-energised before long.

 

One question regarding feed in or not - the non feedback inverters you mention, I take it they switch between solar and grid automatically?

 

Flow batteries are an upcoming technology, maybe. They use enviroment friendly electrolytes and the cells themselves are fully recyclable. When the electrolytes are finished simply empty them out and replace with new.

 

Using end-of-life vehicle batteries actually works well (solar enthusiasts have been using fork truck and golf cart batteries for years). A battery that's down to, say 70%, of it's original capacity may not be enough for continued use in a mobile application but would be just fine for use in a static location. Disposal of totally finished batteries, whilst a potential issue, should be addressable. A lithium cell is very recyclable, the current problem is that recovering the materials currently costs more than digging them out of the ground.

 

For your second question, the simple answer is "yes". What actually happens is that should the solar production be greater than the local energy usage, rather than export excess the inverter throttles its output to match the local load, nothing goes to the grid but the grid remains connected to take any large loads that may come along. If the inverter is a grid-tie hybrid excess energy is stored in the batteries to be used when the sun is sleeping.

 

[bluejets]

49 minutes ago, Crossy said:

If the inverter is a grid-tie hybrid excess energy is stored in the batteries to be used when the sun is sleeping.

 Not, however, if the grid goes down.

[Crossy]

10 minutes ago, bluejets said:

 Not, however, if the grid goes down.

 

Which is why most (if not all) grid-tie hybrids have a "critical power" output which stays on using the batteries/solar during a power failure. Most seem to be limited to 3kW or so meaning you can't just put the whole house on the critical output.

 

With the grid off the solar would continue charging the batteries / powering critical load if the sun was awake.

 

My good lady would definitely place the TV in the "critical" category.

[bluejets]

Might be well worth mentioning that any "critical load" can in no way be connected to the grid.

 

Reason behind all of this isolation is if the supply authority decide to drop the grid for repairs etc. the last thing they want is for uncontrolled solar systems backfeeding the gid in any way shape or form.

[bluejets]

Just now, bluejets said:

Might be well worth mentioning that any "critical load" can in no way be connected to the grid.

 

Reason behind all of this isolation is if the supply authority decide to drop the grid for repairs etc. the last thing they want is for uncontrolled solar systems backfeeding the gid in any way shape or form. You may find any "critical load' systems are disallowed in some countries.

 

[Crossy]

9 minutes ago, bluejets said:

You may find any "critical load' systems are disallowed in some countries.

 

Any examples?

 

The critical output should be fully isolated from the grid when in island mode, that would be essential for the safety of workers (and the inverter which wouldn't be happy trying to power the whole village).

 

It's not really much different from a computer UPS and I'm not aware of those being disallowed anywhere.

 

[KhaoYai]

4 hours ago, Crossy said:

 

Flow batteries are an upcoming technology, maybe. They use enviroment friendly electrolytes and the cells themselves are fully recyclable. When the electrolytes are finished simply empty them out and replace with new.

 

Using end-of-life vehicle batteries actually works well (solar enthusiasts have been using fork truck and golf cart batteries for years). A battery that's down to, say 70%, of it's original capacity may not be enough for continued use in a mobile application but would be just fine for use in a static location. Disposal of totally finished batteries, whilst a potential issue, should be addressable. A lithium cell is very recyclable, the current problem is that recovering the materials currently costs more than digging them out of the ground.

 

For your second question, the simple answer is "yes". What actually happens is that should the solar production be greater than the local energy usage, rather than export excess the inverter throttles its output to match the local load, nothing goes to the grid but the grid remains connected to take any large loads that may come along. If the inverter is a grid-tie hybrid excess energy is stored in the batteries to be used when the sun is sleeping.

 

Thanks for all the info, it seems there's a lot to consider.  I hadn't heard of 'flow batteries' but I appreciate that battery technology is changing all the time.  I may reconsider my 'no batteries' plan when I'm ready to go ahead. Its going to cost me considerably more than just the solar conversion - I have a tin roof that will need changing before too long and the structure will probably need to be upgraded to support a tile conversion.  It would be crazy to fit solar panels until the new roof's in place.

 

Your point on materials costing more to recycle than to dig them out of the ground illustrates one of the reasons we are where we are with climate change etc.  We've always looked at baseline costs rather than the environmental costs - something that needs to change.  We live in a 'throw away' world - most things just aren't fixable any more and they're made that way.  I saw that coming in the motor trade years ago when everything started becoming modular - I became a fitter rather than a mechanic. Even wheel bearings became a bolt on 'hub unit' - when you examine these things, the reasons they are used is clear - speed of production and de-skilling of the workforce = lower costs..................I'll try not to get myself going on the subject though ???? save to say, non recyclable materials in a solar power system kind of goes against the whole ethos of using solar. 

 

I would of course like to see some cost benefit from the conversion to solar power but that's not my main reason for doing it.  In a country where there's so much sun and aircon units running full pelt, it seems very strange that the uptake of solar is so poor. Still, how nice it would be to whack the aircon to max and not have to worry about the cost. I realise that its probably way too expensive for a large proportion of the population - I just wonder whether or not the Thai government will ever encourage some sort of long term finance facility to persuade more people to change to solar?

 

I haven't looked into the current government policy (if they even have one) but from driving around it seems that the way things are going, solar farms selling power to the grid are on the increase rather than individual homes having their own.  I don't know if that's a government sponsored or encouraged thing or whether its just individuals doing their own thing.  The way farmers moan about the price of rice - the whole of Isaan could become one huge solar farm ????.  Whatever, those farms (some huge) seem to be springing up all over the place.  Seriously though, I question the sense of turning agricultural land in to solar farms on a large scale - it may be more profitable than farming but we are back to the same old problem that's put us where we are.........profit over environment!  Every building has a roof, I can't see any justification for solar farms on a grand scale.

 

 

[Crossy]

If only the farmers read ThaiVisa ???? 

 

Many of the major stores / malls in our area (Makro, Global, Mega-Home, Future Park) have sprouted panels in the last year or so, so roofs are being used.

 

[Muhendis]

2 hours ago, Crossy said:

Many of the major stores / malls in our area (Makro, Global, Mega-Home, Future Park) have sprouted panels in the last year or so, so roofs are being used.

They certainly are. My local electronics component and (thump, thump) hi-fi store in Buriram has just fitted a small solar power system for their lights and I presume, their computers with a car battery on charge controller. I guess the battery's more of a UPS backup but well done them.