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26 minutes ago, JBChiangRai said:

My room is 4m x 3m, no windows, I have a 9,000 BTU air con unit running 24/7. I have 3 grid-tied inverters and 3 hybrid inverters with LFP ESS, 2 Computer servers with 44 disks in them, also all the controller electronics for the elevator and it’s racked for wine with a few hundred bottles.  Just make sure there are no electronic items under your A/C unit and have it professionally cleaned every 4-6 months (or when it leaks).

Any idea of the average watt usage of the 9000 BTU air con?

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13 minutes ago, OneMoreFarang said:

What is your purpose of cooling it?

a) That the machinery and circuits are cool enough.

b) Or that you are comfortable in that room.

 

For a, air flow with 30 or 35 degree air temperature should do the job/

For b, air flow is probably not enough. 

 

 

Currently I measure 32 degree air temperature.. Goal is hat the machinery and circuits are cool enough. I guess temp will raise more with more routers pc equipment etc in the room.

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My 5m2 technical room have always been a cold room because no windows and how its built. After get 2 x  Growatt inverters in there its getting quite hot in there so I consider to find a way to cool the room down in a way that make sense. Maybe some cooler direct from a dedicated solar panel?

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28 minutes ago, TimeMachine said:

right ! Oops my mistake. I'm thinking as an Aussie. 80$au just for connection fee every quarter. I forgot Thailand is a zero elec  usage Zero fee country.

80 $au is quite allot of money to just be connected!

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7 minutes ago, TimeMachine said:

There are the benefits of being grid tied. No wasted power. It all gets used albeit poor FIT. And if your off grid system goes down, could be days before you get power back. No feeling of living like a King but with the cost of batteries not a terrible option.

Just keep grid as a backup option on a ATS.

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5 minutes ago, BritManToo said:

5Kw install without batteries would cost around 60kbht DIY.

At their prices you could have 15kWhr of batteries, be off grid 24/7 and not worry about selling anything back.

Good Point!

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On 10/7/2023 at 12:15 PM, Muhendis said:

Reasoning is that my house is completely solar powered but if batteries are too low at night then inverter will switch off 'till batteries are good again and ATS will switch over to GEC. Once the batteries are back up to something like full then the ATS will switch back to inverter output. I should point out that this condition has never happened in the 13 years

I was surprised today to see that i got quite good level of solar power even in a light raining, cloudy day. At 14.15 my batteries was recharged, so Im exited how long i can keep running without my ATS kicking inn.

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2 hours ago, gejohesch said:

Indeed, I forgot to say, that includes a contract (for 10 years if I remember right) to buy back excess electricity at 2.2 THB / Kwh. I guess that's what is meant by "grid feed" contract.

 

Whenever we need extra power (when solar generated not sufficient), we would buy at the standard rate. I checked, the average we paid over the last 17 months was around 4 THB/Kwh, but that would possibly increase a bit depending on how much we have to "import" (re. PEA price scale).

 

The packages I mentioned do not include batteries. We are not big users at night. 

 

I cannot remember the length of the guarantee , I'm not sure that was for that long as 10 years. Reason I'm a bit vague is that I considered that visit to the PEA office as a "first contact". We are not going to decide for any installation until some time next year. We plan to get a few extra AC's installed first and then watch for what our consumption becomes, then review the calculations.

Get AC's with inverter, used less less power.

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2 minutes ago, impulse said:

May work.  May not. 

 

Typical inrush (starting) current on electric motors can be 5-7 times the actual running current.  On an old timey diesel generator, you'd hear the generator lugging and slowing down just a bit, then back to normal after the motor is started.  Modern inverters just won't put out over their design amps.  And if you feed your rice machine less amps than required to start, it may not.  

 

Inrush only lasts a fraction of a second, and if the motor does start, it'll run fine.  But some motors just won't start.  Also depends on whether it's got a capacitor starting it, or just across the line and single vs 3 phase. 

 

If you posted the nameplate from the rice machine motor, it may have more info.  And the nameplate from your inverter.

 

Ok thanks for that info. My garage have grid supply so i just connect it there then to avoid any issues.

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Is there any reason to not run power greedy applications like a rice machine and power tools on solar power from hybrid inverter? Im getting 7k watt or so middle of day and our rice machine uses 3kw or so (4hp)?

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1 hour ago, KhunLA said:

Our 'installed/expensive' system, total off grid, but still conx to, should have a ROI in about 9 yrs, just energizing the house, if using 800 units a month on average, at today's rate.

 

Add the EVs to the ROI, and cuts that ROI time almost in half, if we continue to drive 20k kms a year.  Reality, probably 5-7 yrs ROI, as we'll probably drive less in coming years.  About 40% of the price of our system, are the ESSs (฿185k of ฿445k).

 

That 40% premium, only supplies 6-8kWh (~25%), overnight, of the 26kWh we use daily, on average.  Not exactly paying for itself, but, if prone to power outages (we're not) then damn convenient to have.

 

New build house, so we've had a digital meter almost from day 1.  As have every new house, about 13, built in the last 2 years here/PKK.

The EV will do the magic for your ROI and must be counted !!! Im "semi offgrid" I dont have any grid supply to my inverters but i do have a ATS with grid power so im very exited to see hoe much i can live without it kicking in with any grid power. I guess 2-3 rainy days...

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3 minutes ago, lom said:

So around 0.1c

 

ok so you only use around half of battery capacity before charging again.

 

I have 5x5KWh (500Ah)  of stacked batteries which is barely enough to take me through from 17 to 07 at which time I charge with whatever the panels can deliver up to a max of 150A which is equal to 0.3c

The batteries are then under best condition fully charged around noon, sometimes not until 16 or  some dark days not fully charged at all.  They are charged with 57.6V and steps down in charge current when they reach 98% SOC where after they get trickle charged with 5A dropping down to a few hundred milliamps while climbing up to 100% SOC.

The deviation between the cells is typical around 20-25mV at 100% SOC and that is good enough for me.

Yes you are correct in morning i use to see 55-65% remaining capacity. Last day i see 5W at 05.55. 08.xx I use to have more solar power than usage so charge start, then finish around lunchtime. I have set charge limit to 50A.

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29 minutes ago, lom said:

How high is your charge current when charging at such low voltage? How long time to fully charge the battery?

I have very few days to refer too but charge current most of the time 20-30A. Charge time have been 4-6 hours. With latest settings there is very little or no balancing needed in the end today.

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28 minutes ago, MJCM said:

Sorry for my ignorance, but is the difference in V in the cells not solved by Balancing them? Or does charging solve that as well?

I can only speak from my experience this days. With voltage 56v and before that 57v some of the cells picked up much faster on the higher voltage and then BMS got quite busy to try balance out that most by discharging.

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Done some small adjustments on JKBMS settings and reduced Growatt charge voltage to 55v  and now it charge in a better way and very less volt difference between the cells.

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3 minutes ago, ChaiyaTH said:

If you want to make money, you have to do your own research. I already gave you the essential clues: ant miner up to 2K usd, bitcoin, no energy cost. The reason so few people make money, or make money with this, is because almost nobody is willing to invest some time into doing the research that is relevant to their specific situation, let alone to then also act on it.

You can do it clearly, so do it, you will be happy in just 6-12 months already (will break even the cost). A few cents is when you mess around with a graphic card driver and also have to pay the average western rate of energy. Not comparable.

 

If you assume it's break even in 8 months, and it lasts 12 months, you make 4 months money with 200-300 dollar per month, not sure your hourly rate, but sure that can deserve some time to invest into the matter to know. And it can easily run a few years.

Thanks for the info, yes  im on it researching.

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7 minutes ago, ChaiyaTH said:

If you have quite a bit of energy and can afford a Bitcoin antminer for up to 2K dollar, you would actually be able to cash daily 10-20 dollars. Would not start with anything else, just do that, and even sit on the coin you collect as the price isn't that high now.

 

It's kind of sad in a way, just to have this with solar, can be better than a fulltime job as a Thai.

Ok thats quite good. I see many talks about cents per day per unit on mining now. What you mine? Do you have some links and details to share? Feel free to share here or PM me with any info you have to share.

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57 minutes ago, Bandersnatch said:

 

I have an ice making machine which runs during the middle of day. My chest freezer is on a timer that switches off at night. Any other load shifting you can do.

Do you have a link to the ice make machine?

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1 minute ago, ChaiyaTH said:

Mine crypto with the difference in energy if you otherwise waste it anyway. 

Im researching same now... You have some details to share?

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44 minutes ago, Bandersnatch said:

 

I have an ice making machine which runs during the middle of day. My chest freezer is on a timer that switches off at night. Any other load shifting you can do.

Good idea. How much the temperature in your freezer down just before its power back up?

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Anyone thought of any usage of the excess solar energy some of us have after batteries are full and its still much energy who could be used for something usefully?

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12 minutes ago, lom said:

3.35V (53.6V)  is 100% SOC (at least on my batteries)  they are currently at 53.1V or 97% SOC but I have also seen them at 55.2V. 

I'm using Seplos BMS's which are set for a max charging voltage of 57.6V which the BMS has told my Deye inverter to provide. Maybe you need to raise the charging voltage?

Anyway, don't charge or discharge when balancing, it takes forever to get balance if the there is additional current flowing through the cells when balancing. 

Your JK BMS has a good balancer compared to the ones (passive, low current) in my Seplos BMS's.

Thanks for that info.. I got same 100% SOC on 3.35 so all is fine then. I also want to be moderate on charge and battery voltage so then all fine.

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16 minutes ago, Crossy said:

Google "DIY solar forum" or link from one of Will Prowse's videos, loads of JK BMS setup info.

 

I have watched quite a few and I think the setup is ok. The question is if its normal or not for the batteries to struggle to get over 3.35v? Capacity wise it seems ok..

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36 minutes ago, lom said:

Most important is to not balance while charging. A balancers algorithm is based on measuring cell voltages which must be quite stable or the algorithm fails. Cell voltages are not stable enough during charging, they vary a lot.

I see some of my batteries not easy to charge over 3.35 or so I guess the new settings on 3.30 as starting level was better but maybe 3.35 will be better from what i see from my batteries.

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One more day with charging. My growatt and JK BMS show batteries full just before lunchtime. This 2 days i wake up to around 50-60 A left battery capacity. It seems that some batteries not easy to get over 3.35v but im not sure if thats even needed? After some balancing it look like 3.3x v per cell. 277 amp. 99% capacity is the standard i can expect. When balancing  over3.3 look like its 80% done by de-charge who is higher  and very less added to lowest batteries. So 55.x will end up with 53.x when finish balancing.

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