solar panel

[bankruatsteve]

29 minutes ago, Naam said:

and if 50kW does not suffice just look at a unit capable to deliver 100kW.

Yeah, I think she put a zero in by mistake.  UNLESS she was talking about your house. 

[bkk_mike]

On 9/16/2017 at 9:07 AM, Crossy said:

The issue with solar (or for that matter an inverter/charger) is that you need batteries. Maybe lots of batteries.

 

Let's say you want 12hrs power.

 

TV (100W), 2 fans (75W each), fridge (150W) and a 5 lights (low energy 20W each).

 

About 500W so you need 6000 Watt hours of energy, allowing 50% discharge that's 12000 Watt hours of battery. At 12V that's 1000Ahr!!

 

12V 100Ahr deep-discharge batteries come in at around 4,300 Baht, you need 10 plus an inverter and charger (mains or solar) that can re-charge them in a reasonable time (say 24 hours).

 

For 43 k Baht (and if you don't mind a bit of DIY) you can get a half decent, silent, diesel generator and a simple controller and auto transfer switch.

 

Maintenance? Our petrol generator gets the battery charged and a 1 hour run (on load) once a month and an oil change as a Christmas present.

 

Of course there's fuel to buy, I must admit I don't monitor how much we use, I just top up the tank when I charge the battery (after the test run) or if we've had a really long power cut.

 

Our power is much better than it was even 5 years ago when we moved in, but the genset still runs maybe once a month. Keeps Wifey happy with internet and TV, and her fish happy with water circulation and air.

 

 

 

 

 

 

Wouldn't people install lithium-ion batteries rather than deep-discharge 12v batteries nowadays? 

i.e. Tesla powerwall, LG Chem RESU, Sonnen eco, etc. Or are none of those available in Thailand? 

 

(I came across this old thread as I'm thinking about installing rooftop solar at my house in Bangkok next year, partly to reduce my electricity bills, and partly, with some form of battery, to give me power during the power cuts we often get in rainy season, and thinking longer-term, ready for charging an electric car at some point)

[Crossy]

13 hours ago, bkk_mike said:

Wouldn't people install lithium-ion batteries rather than deep-discharge 12v batteries nowadays? 

 

Initial costs, at least at the domestic level, are still significantly higher for the advanced battery technologies. Total cost of ownership is at least on a par but it's that big up-front wedge that puts people off.

 

There's a market in some parts of the world (not Thailand) in used, out of spec. EV batteries which, whilst not suitable for mobile applications, do just fine as a power wall type system.

 

http://www.thedrive.com/tech/19518/used-nissan-leaf-batteries-will-power-japanese-streetlights

 

 

[kamalabob2]

Bkk Mike: I attended the June 2018 ASEAN Sustainable Energy Expo at BITEC in Bangkok. I was very impressed with the advances made in Solar inverters | street lights | batteries | mounting hardware all on offer. Quite a few German solar experts were at booths. I took the time to discuss in English solar power options available for Buriram. Some booth staff were eager to discuss prices and delivery options to Isaan. If any expat was considering solar power it would serve them well to attend this Expo in Bangkok. BMW offered test drives in an electric vehicle. Honda concept electric vehicles with power walls, swapable batteries and well engineered solar options were showcased in a large booth. Tesla was not present, yet several booths offered similar looking power walls for solar installations. 

[Naam]

23 hours ago, bkk_mike said:

Wouldn't people install lithium-ion batteries rather than deep-discharge 12v batteries nowadays? 

i.e. Tesla powerwall

no they wouldn't once they see the initial capital outlay

Quote

How much does the Tesla Powerwall cost? The list price for a new Tesla Powerwall 2.0 battery, which offers twice the storage capacity of the original Powerwall, is $5,900. Supporting hardware adds another $700 to the equipment costs, bringing the total to $6,600.Jun 21, 2018

usable capacity 13.5 kWh

add to these 217,000 Baht the required solar panels, inverter and installation then a genset (as Crossy recommended) is the way to go but perhaps with a capacity a few notches higher.

 

[stud858]

I helped organise my parents grid tied solar installations a while ago.  But now am interested in adding a small backup non grid tied battery solar setup for when the power goes out.  

I've purchased a 3/6 kW mod sinewave inverter for 60 bucks. 

Charge controller for 10 bucks.  And look to be spending about 350 bucks on 3x 190 panels.

The only other major expense is the batteries.

Since its only for backup mostly I'll probably get away with even just using ordinary car batteries, but I'll try to get some old reco golf cart batteries 

Lithium too expensive and not really needed for my needs. 

I'm really curious to try standard car batteries to see how well they perform in solar.  I hope to score 4 or so larger batteries sitting in friends garages for free. 

Overall a solar system can be peanuts to set up.

I hope others share their experiences here in Thailand.

Have a hot and sunny day every one 

[Crossy]

If you can score some golf cart batteries, even used ones, they should be perfect.

 

The problem with using car batteries is that they're designed to give short, high-power bursts (starting the engine). Long, relatively low power, discharges wreck them. Never (ever) take a car battery below 50% charge in a solar application if you want it to last any appreciable time.

 

LiPo4 is getting cost effective due to it's long life and ability to approach 90% discharge without damage, obviously cost is always going to be an issue ?

 

[stud858]

2 hours ago, Crossy said:

If you can score some golf cart batteries, even used ones, they should be perfect.

 

The problem with using car batteries is that they're designed to give short, high-power bursts (starting the engine). Long, relatively low power, discharges wreck them. Never (ever) take a car battery below 50% charge in a solar application if you want it to last any appreciable time.

 

LiPo4 is getting cost effective due to it's long life and ability to approach 90% discharge without damage, obviously cost is always going to be an issue ?

 

Cheers. I've heard that the deep batts simply have chunkier plates.  Havent read anything definitive that explains the design differences.

I've read a lot about sulphate deposits on plates. I was thinking of collecting my own lead plates and making my own serviceable lead batteries so they can be opened,  plates cleaned and electrolyte replaced.  I have time to waste.  

[Naam]

40 minutes ago, stud858 said:

Cheers. I've heard that the deep batts simply have chunkier plates.  Havent read anything definitive that explains the design differences.

I've read a lot about sulphate deposits on plates. I was thinking of collecting my own lead plates and making my own serviceable lead batteries so they can be opened,  plates cleaned and electrolyte replaced.  I have time to waste.  

there are a number of gadgets in the market that claim they can rejuvenate old batteries without opening and manually cleaning them.

 

google "reconditioning batteries".

[stud858]

25 minutes ago, Naam said:

there are a number of gadgets in the market that claim they can rejuvenate old batteries without opening and manually cleaning them.

 

google "reconditioning batteries".

Cheers, I guess that type of way tries to chemically or electrically disulphate. Differing results from reports. 

Nothing would be as good as a good scrubbing over with sandpaper or a grinding wheel on the actual plates if they could be slipped out of the casing easily.  

Before my time,  but i think that's how they used to be made like. 

 

[stud858]

25 minutes ago, Naam said:

there are a number of gadgets in the market that claim they can rejuvenate old batteries without opening and manually cleaning them.

 

google "reconditioning batteries".

Cheers, I guess that type of way tries to chemically or electrically disulphate. Differing results from reports. 

Nothing would be as good as a good scrubbing over with sandpaper or a grinding wheel on the actual plates if they could be slipped out of the casing easily.  

Before my time,  but i think that's how they used to be made like. 

 

[Naam]

20 hours ago, stud858 said:

Nothing would be as good as a good scrubbing over with sandpaper or a grinding wheel on the actual plates if they could be slipped out of the casing easily.  

Before my time,  but i think that's how they used to be made like. 

that was the done thing 40 years ago in India and Pakistan. i was especially impressed when i saw them cutting open aircon compressors (with a handsaw!), rewiring the burnt coils and closing the casing by welding.

 

all the power to you... if you find the time.

[stud858]

2 hours ago, Arjen said:

Probably a stupid question, but what is 50% discharge? A "full" battery is 13.8V, an empty one is 12V. When you apply a load you are easy at 12.5, after removing the load, the battery moves back to 13V. Is 50% discharged then 12.9V measured without load?

 

Should you calculate the wattage a battery can supply, and stay under 50% from that load? Measuring voltages does not really work in my experience. 

 

Arjen. 

 

I found this video to be a great practical guide to discharge capability. 

[Fruit Trader]

3 hours ago, Arjen said:

Probably a stupid question, but what is 50% discharge? A "full" battery is 13.8V, an empty one is 12V. When you apply a load you are easy at 12.5, after removing the load, the battery moves back to 13V. Is 50% discharged then 12.9V measured without load?

 

Should you calculate the wattage a battery can supply, and stay under 50% from that load? Measuring voltages does not really work in my experience. 

 

Arjen.

 

 

Full cycle lead acid battery monitoring electronics would remove load at min set voltage (example 11v) and begin the charge cycle to saturation value. Any voltage rise after removing the load would be ignored as the circuit would be in charge mode looking for max voltage. Values will vary depending on the batteries deep cycle tolerance and min voltage allowed at the load. 

[Crossy]

9 hours ago, stud858 said:

I found this video to be a great practical guide to discharge capability. 

That, and it's companion videos are very interesting. Most useful viewing.

 

[SteveMack]

On 7/1/2018 at 2:19 AM, bkk_mike said:

Wouldn't people install lithium-ion batteries rather than deep-discharge 12v batteries nowadays? 

i.e. Tesla powerwall, LG Chem RESU, Sonnen eco, etc. Or are none of those available in Thailand? 

 

(I came across this old thread as I'm thinking about installing rooftop solar at my house in Bangkok next year, partly to reduce my electricity bills, and partly, with some form of battery, to give me power during the power cuts we often get in rainy season, and thinking longer-term, ready for charging an electric car at some point)

Hi Mike, What name and model of silent diesel gen( about 43,000) would you recommend ? and what and how  would I do to connect it to mains or Could I just get a junction box and connect tv, 2 fans and fridge to junction box, and juntion box to generator, Thanks for advice,

[stud858]

22 minutes ago, SteveMack said:

Hi Mike, What name and model of silent diesel gen( about 43,000) would you recommend ? and what and how  would I do to connect it to mains or Could I just get a junction box and connect tv, 2 fans and fridge to junction box, and juntion box to generator, Thanks for advice,

I've often thought why not have a second mutually exclusive solar system to give power in the case of your primary solar breaks or runs low on power.  Not in all circumstances this would be suitable,  I understand.  I guess you consider circumstance and costs of a generator.