Solar power setup for your home in Thailand

[buksida]

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Just a quick update to this thread, I purchased one of these home kits with a single panel, 40ah battery, and 1600w inverter. Have been experimenting with it for a week and it serves the purpose of a backup, running computers, internet router, and fans for a couple of hours in conjunction with my existing UPS during outages.

Naturally its not enough to run any high wattage appliances on, but it does work for fans, fridge, the pond pump, etc. Costs were about 6,000 including shipping from Lazada.

Would love to have gone the 'whole hog' with solar for the entire house but the quotes we had were cost-prohibitive (300-400k) and the ROI was 12-14 years (our bills are not that high, just very inconsistent). One day maybe Thailand will subsidize green energy for domestic use as they do in the West - but probably not in my lifetime.

[buksida]

Have been running this kit for nearly 4 months now and it has more than paid for itself. Over the past month, I have logged the days when there was a power disruption and the number comes in at a shocking (excuse the pun) 43% - 13 days out of 30.

Have now come to realize that this rudimentary system is not enough so will be expanding it with a larger panel (450w), a gel battery designed for solar, and a larger inverter (5kw hopefully).

[Nereus]

I have been fishing around the internet a bit after being asked to do a rough load survey for a solar system.
Generators I can do off the top of my head, but solar has a few different parameters and considerations.

The following bloke obviously knows what he is talking about, although it would be much better if he spoke English and stopped waving his frigging hands about! I understand that he is in Hua Hin, or at least has an office there.



I dont watch the following as a general course, and again he has an English speaking problem!



Some of his comments regarding connecting to the grid say it all!

[Nereus]

Have been running this kit for nearly 4 months now and it has more than paid for itself. Over the past month, I have logged the days when there was a power disruption and the number comes in at a shocking (excuse the pun) 43% - 13 days out of 30.

Have now come to realize that this rudimentary system is not enough so will be expanding it with a larger panel (450w), a gel battery designed for solar, and a larger inverter (5kw hopefully).

There is a bit more to it than just a bigger panel and inverter. The simple formula for watts, or kilowatts is:
volts x amps = watts
To run a 5kW inverter from a 12 volt battery: 5,000 ÷ 12 = 416 amps!
2 x 12 volt batteries connected in series: 5,000 ÷ 24 = 208 amps
3 x 12 volt batteries connected in series: 5,000 ÷ 36 = 138amps
4 x 12 volt batteries connected in series: 5,000 ÷ 48 = 104 amps

As the batteries are in series only the voltage increases, the amp capacity stays the same. To obtain an increase in amp capacity it becomes necessary to connect some batteries in parallel to form what is generaly called an "array"'.
That is a combination of series and parallel connected batteries.

It is generally considered that 48 volts and around 100 amps should be the limit. You can see the size of the cables that your existing unit has, which will draw around 83 amps at full load. Depending on the length of the cables needed, they will have to be at least half as big again to carry just100 amps.

Gel batteries are still lead acid batteries, albeit a bit stronger construction and a different form of electrolyte.
To obtain any sort of reasonable life out of them they should not be discharged more than 50% of their capacity. That is to say, a 100 amp hour battery should only provide 50 amp hours before risking permanent damage.

A suitably rated charge controller is required, which should include battery protection monitoring that disconnects the batteries when their voltage drops below a set point. SOME inverters can include battery charging and monitoring.

The size of the PV panel(s) need to be calculated to match both the voltage and the charging rate needed to maintain the batteries.

There is no free lunch with this stuff!!!

[buksida]

Good info, thanks. Will be gradually expanding the capacity of my rudimentary system this year.

[Nereus]

The following is about the best info site that I have come across. The owners are a bunch of "old mates" that do not publish BS. Most of the equipment that they recommend is available here, but as always in this country, Caveat Emptor!

The site is up to date and regularly posts about new devoplments in solar. The Blog section has some practical posts.

https://www.cleanenergyreviews.info/about-us

[Nereus]

There is no way a 3kw solar system is worth 200,000 Baht! Private rip off companies should not be involved in any type of "incentive offer" either, it needs to be a government controlled system. But not having a proper government shoots that down!

Solar startup estimates capacity to treble this year

https://www.bangkokpost.com/business/22 ... -this-year

Growing demand for solar energy from households and businesses as a result of new lifestyles transformed by the pandemic is expected to help energy startup Ion Energy Co expand its rooftop solar panel installation capacity from 5 to 15 megawatts this year.

Covid-19 has caused more people to work remotely from home, despite the government relaxing lockdown measures and reopening the country since late last year, said Peerakarn Manakit, chief operating officer of Ion Energy.

"Our estimate of triple growth is based on the skills of our staff and the trend of choosing homes with lower electricity bills," he said. (I have no idea just what this means!)

Ion Energy expects its installation capacity to reach 150MW within five years under its planned capital spending of 625 million baht.

The company provides rooftop solar panel installation for homeowners and business operators in both megawatt and kilowatt scales.

For the megawatt scale, the service is based on private power purchase agreements (private PPAs), under which Ion Energy installs a solar system for free and charges no maintenance costs, but property owners are required to pay electricity bills, with discounts of 20-50% on the electricity tariff, to the company for a period of 15 years.

When the private PPA ends, the solar panels, which are designed to be used for 25 years, are transferred to the property owners, who can continue to produce and use electricity at no charge.

Target groups for the private PPAs are small and medium-sized enterprises.

Ion Energy expects the rooftop solar panel market using private PPAs to grow by 30% a year, up from 670MW in 2020 to 9,000MW in 2030.

With the kilowatt scale, homeowners pay for the solar panel installation but fully own the system, so there is no need for them to pay electricity bills.

The company is also using a pricing strategy to attract more prospective buyers with a limited budget.

Many buyers are looking for second-hand 3KW solar panels priced at less than 100,000 baht, said Mr Peerakarn.

He said this was the motivation behind charging this group a slightly higher price for new hardware.

The firm is selling 3KW rooftop solar panels for around 200,000 baht, said Mr Peerakarn, cheaper than the price offered by some large energy firms.

[buksida]

There is no way a 3kw solar system is worth 200,000 Baht! Private rip off companies should not be involved in any type of "incentive offer" either, it needs to be a government controlled system. But not having a proper government shoots that down!

Exactly, the thing putting us off the full monty setup is the ridiculous prices these companies are asking. We were quoted closer to 400K for a 5kw system from a firm in Hua Hin.

The "government" has no incentive to offer discount solar installations as it already has a monopoly on electricity and can charge what it likes.

[VincentD]

AFAIK the present administration went back on the proposal to buy excess solar production. Hence, all present (legal) solar setups are only designed to offset daytime electricity consumption and have no facility for storage at all.
This is why I still only have self-powered solar lights outside the house.
It is not worth the investment, and the ROI calculation is skewed in favour of ideal conditions. Unless of course you are an industrial user with lots of flat roof space and heavy daytime needs..
YMMV.

[Nereus]

It is not clear, but I think that what is being quoted in that article is for a "grid tied" inverter system. That is; a system without batteries that goes dead when there is a grid power outage. The feed in rate is not quoted, but the highest that I have found is 2 Baht per unit. Current regulations also limit a home system to 5kw's, can't have the plebs saving their own money!

Batteries are the stumbling block for any "off grid", or hybrid system. The following article is based on Australian prices, at the moment around 24 to the $AUD. I post it more as a reference to pros and cons of different batteries, rather than prices.

https://gosolarquotes.com.au/cost/how-m ... ries-cost/

[buksida]

That is; a system without batteries that goes dead when there is a grid power outage.

That would be utterly useless for me and anyone else that has several weekly grid power outages (they've told us it will be off all day tomorrow). Most regular users would want solar to save money and be more self-sufficient - the gooberment it seems has other ideas.

[Nereus]

That is; a system without batteries that goes dead when there is a grid power outage.

That would be utterly useless for me and anyone else that has several weekly grid power outages (they've told us it will be off all day tomorrow). Most regular users would want solar to save money and be more self-sufficient - the gooberment it seems has other ideas.

Yes, absolutely! What you have now, on a bit bigger scale, is a better option. Even if you were to instal a couple of dedicated circuits for electronic items.
If I was in that position I would be looking to install a standby generator, which with the correct charge controller, could also keep your batteries topped up.

[Scout]

I’ve been chatting with a few different folks that have installed grid tied solar systems on their house. When I’ve asked about their plan for installing batteries, with a wink and a nod they say they avoid the cost of batteries by turning the meter backwards with excess solar electricity production during the day, then pull that excess back off the grid at night. I’m pretty sure that’s not legal. When I mentioned it, one guy said the worst that will happen if he’s caught is PEA will install a one-way meter that will not turn backwards, at which time he will consider batteries or signing up to sell excess electricity back to PEA at a much reduced rate. I wonder, might he also be facing a hefty fine or even jail time ?

[buksida]

We were told it was illegal to feed power back into the grid in Thailand and the PEA is not interested in buying the excess from private homes. But like most things here, law enforcement is very flexible so that may work if you did it on the quiet (and made sure it wasnt running backwards when they check the meter every month).

[Nereus]

Yes, I guess the chance of getting caught out is low, but you can be assured that in the event of being discovered, the penalty will probably involve a huge "back payment" calculated how the PEA see fit!
That being before any legal action.

The meter readers are unlikely to even know which way a meter turns, and from what I have seen, the reading is done electronically with a hand held reader. With some older installations, especially old shophouses, I have seen Somchai using a small pair of binoculars to read the meter manually!