Solar Power is cheap and it’s going to get even cheaper very soon.

[Bandersnatch]

Don’t listen to the barstool experts when they talk about solar being too expensive, they’re wrong - they usually are.

https://www.pv-magazine.com/2023/11/23/solar-module-prices-may-reach-0-10-w-by-end-2024/
 

Tier one solar panels are already at ฿6.5/Watt

 

 

 

Inverters are already as low as ฿4K per kW

 

 

Batteries are already at ฿5k per kWh with expectations to see further substantial falls this year

 

 

So just using the prices quoted above 

5kW of Solar = ฿32,000

5kW Inverter = ฿20,000

10kWh Battery = ฿50,000

Total cost = ฿102,000

or ฿52,000 without the battery 

 

[sungod]

thanks, Dumb question time, what can I run with a battery that size?

 

What would the installation cost be?

[Bandersnatch]

21 minutes ago, sungod said:

thanks, Dumb question time, what can I run with a battery that size?

 

What would the installation cost be?

 

The solar panels will provide power during daylight hours. If your household load a night is about 500 watts, the battery should see you through the night.

 

Installation is very difficult to estimate, because it varies so much based on the site and what ancillary equipment you use. Such as rails, brackets, cables and breakers. I think ฿20,000 would be a reasonable quote.

[sirineou]

7 minutes ago, Bandersnatch said:

 

The solar panels will provide power during daylight hours. If your household load a night is about 500 watts, the battery should see you through the night.

 

Installation is very difficult to estimate, because it varies so much based on the site and what ancillary equipment you use. Such as rails, brackets, cables and breakers. I think ฿20,000 would be a reasonable quote.

would I be safe to assume  that you could not run A?C overnight with that battery then? 

[KhunLA]

1 hour ago, sungod said:

thanks, Dumb question time, what can I run with a battery that size?

 

What would the installation cost be?

We could run our whole house on that, 10kWh ESS ... IF being more conservatives and not as wasteful as we are now, with the ACs.   We only added a 2nd ESS to prolong the longevity of our system's ESS/back up battery. 

@sirineou

We use about 6 or 7 kWh overnight (14 hrs), which now is only <35%, instead of 65% of battery, which will extend the life of the batteries considerably.  Wake up now to 65-70% batteries, instead of 35%.  That's with AC use overnight in the bedroom.

 

One less thing for the wife to concern herself about after I crap out.   Price depends on DIY or having installed, and what components;  better/longer (honored) warranties-maybe.

Edited February 13 by KhunLA

[atpeace]

Interesting!  I have been messing around with solar for a few years and could do this for much less but it wouldn't be pretty and probably electrocute myself in the process.  Interesting times...

[Bandersnatch]

13 minutes ago, sirineou said:

would I be safe to assume  that you could not run A?C overnight with that battery then? 

 

The first problem with Batteries is Depth of Discharge (DOD) and Li-ion batteries have a 80% DOD so you are only getting 8kWh out of a 10kWh battery. There are also some efficiency losses converting DC to AC to run the aircon.

 

Aircon sizes and power draws vary. I designed my house to be very well insulated and well sealed. I use 8,500 BTU aircons that have a max power consumption of 680W, but most of the time it’s only the fan that is running.

 

If you have big leaky windows your aircon will be constant cooling warm air that finds it’s way into the room so it will spend more time operating close to it’s max power consumption.

 

 

[Muhendis]

In my opinion, prices for inverters are not so much going down but rather more returning to what they once were some eight to ten years ago.

Solar panels are getting remarkably cheap now but not so noticeable in the local stores. They probably still have old stock which they need to sell at old prices.

The cost of batteries is looking good. I guess they may one day be on a par with lead carbon chemistry.

Overall good news for the solar brigade which includes me.

[sirineou]

20 minutes ago, KhunLA said:

We could run our whole house on that, 10kWh ESS ... IF being more conservatives and not as wasteful as we are now, with the ACs.   We only added a 2nd ESS to prolong the longevity of our system's ESS/back up battery. 

@sirineou

We use about 6 or 7 kWh overnight (14 hrs), which now is only <35%, instead of 65% of battery, which will extend the life of the batteries considerably.  Wake up now to 65-70% batteries, instead of 35%.  That's with AC use overnight in the bedroom.

 

One less thing for the wife to concern herself about after I crap out.   Price depends on DIY or having installed, and what components;  better/longer (honored) warranties-maybe.

I am not going solar yet, not because I don't think it's a good investment, but  there is only the two of us and even with 24/7 of A/C (12,000 btu) in our bedroom, our electric bills at this time are low enough not to want to be bothered, but I can see us making the move not in the far distance and I am trying to learn as much as I can .

I appreciate both your and Bandersnatch "s reply. 

[Guderian]

Forget the battery which is half the total cost and, for ~50K Baht + installation you could run a couple of air cons during the day and keep the house nice and cool. The problem I find when I try and do the economics is that the 5kW solar panel only delivers that at the peak, and its average power production during, say, 8 hours of daylight is less than 5kW. But how much less? On a clear and sunny day, does it deliver 4kW, 3kW, 2kW or what on average over the period?

[Bandersnatch]

11 minutes ago, Guderian said:

Forget the battery which is half the total cost and, for ~50K Baht + installation you could run a couple of air cons during the day and keep the house nice and cool. The problem I find when I try and do the economics is that the 5kW solar panel only delivers that at the peak, and its average power production during, say, 8 hours of daylight is less than 5kW. But how much less? On a clear and sunny day, does it deliver 4kW, 3kW, 2kW or what on average over the period?

 

A 5kW inverter is never going to produce more than 5kW, but if you oversize the panels with say 6kW of PV you will get more in the morning and in the afternoon.

 

This is one of my 5kW inverters with 4,845 Watts of PV. The Graph doesn’t show solar production but rather solar that was produced and consumed, as excess solar is curtailed. On this day I was charging my 2 electric cars so load consumption was quite high.

 

  

 

 

 

This is another graph where I was charging my BYD for longer

 

 

[Guderian]

2 minutes ago, Bandersnatch said:

 

A 5kW inverter is never going to produce more than 5kW, but if you oversize the panels with say 6kW of PV you will get more in the morning and in the afternoon.

 

This is one of my 5kW inverters with 4,845 Watts of PV. The Graph doesn’t show solar production but rather solar that was produced and consumed, as excess solar is curtailed. On this day I was charging my 2 electric cars so load consumption was quite high.

 

  

 

 

 

This is another graph where I was charging my BYD for longer

 

 

 

Thanks. Am I reading this right? You've got a 5kW inverter with somewhat more than 5kW of panels attached, and in the early morning it was producing around 2.5kW, which soon went up to occasional peaks of 4kW, maybe averaging around 3.5kW during that time between 10:30 and 14:00? I'd eyeball the average for the day at around 3kW. Is that fair?

[Bandersnatch]

4 minutes ago, Guderian said:

 

Thanks. Am I reading this right? You've got a 5kW inverter with somewhat more than 5kW of panels attached, and in the early morning it was producing around 2.5kW, which soon went up to occasional peaks of 4kW, maybe averaging around 3.5kW during that time between 10:30 and 14:00? I'd eyeball the average for the day at around 3kW. Is that fair?

 

4.8kW of panels

 

It’s not solar production, but solar production for which there is a corresponding load.

 

If you don’t want to buy a battery and your house load is 1kW you should be able to cover that load from 8am to 5:30pm 

[Tubulat]

7 hours ago, Bandersnatch said:

Don’t listen to the barstool experts when they talk about solar being too expensive, they’re wrong - they usually are.

https://www.pv-magazine.com/2023/11/23/solar-module-prices-may-reach-0-10-w-by-end-2024/
 

Tier one solar panels are already at ฿6.5/Watt

 

 

 

Inverters are already as low as ฿4K per kW

 

 

Batteries are already at ฿5k per kWh with expectations to see further substantial falls this year

 

 

So just using the prices quoted above 

5kW of Solar = ฿32,000

5kW Inverter = ฿20,000

10kWh Battery = ฿50,000

Total cost = ฿102,000

or ฿52,000 without the battery 

 

Batteries are not cheap, nearly 3 years ago I bought my lithium batteries for40,880.00 THB 48V 260Ah, that time already 20% cheaper.

[bluejets]

As with many would be magical figures, many quoted are simply not feasible.

 

What is often forgotten ( or never really known) is the charge figures are never linear, nor are they reliable day to day, and Thailand does get a lot of cloudy /rainy days, together with the "forgotten RAC's and bath heaters."

 

Factor in about 50% derating might get one nearer the requirements.

 

Don't get me wrong, greatest thing I ever did was install solar but definitely not batteries.

 

[newbee2022]

Supplying your house will cost around 500.000 Baht.

Incl Battery for 20 KW. With that you can run more than 2 or 3 aircon, fridge, TV aso. 

So not a bargain at all.

[Bandersnatch]

4 minutes ago, bluejets said:

Don't get me wrong, greatest thing I ever did was install solar but definitely not batteries.

 

I have been basically off-grid for 5 years using batteries, now that I’ve given my meter back I’m definitely off-grid.

 

 

 

[Bandersnatch]

1 minute ago, newbee2022 said:

Supplying your house will cost around 500.000 Baht.

Incl Battery for 20 KW. With that you can run more than 2 or 3 aircon, fridge, TV aso. 

So not a bargain at all.

 

Can you support that ฿500,000 figure with some actual examples as in my opening post?

[newbee2022]

6 hours ago, Bandersnatch said:

 

The first problem with Batteries is Depth of Discharge (DOD) and Li-ion batteries have a 80% DOD so you are only getting 8kWh out of a 10kWh battery. There are also some efficiency losses converting DC to AC to run the aircon.

 

Aircon sizes and power draws vary. I designed my house to be very well insulated and well sealed. I use 8,500 BTU aircons that have a max power consumption of 680W, but most of the time it’s only the fan that is running.

 

If you have big leaky windows your aircon will be constant cooling warm air that finds it’s way into the room so it will spend more time operating close to it’s max power consumption.

 

 

I had already 2 different companies inspecting my house. We run 3 aircon by totally 52 Btu and cooking electric. 3 TVs and 3 fridges and a chest deep freezer. And in addition all necessary appliances as hot shower. The system I was offered included a 20-25 KW battery and 40 solar panels. 

[Photoguy21]

Sounds good but have the cost of replacing the solar panels been taken into consideration? At some point they will require replacing so it could e worthwhile to add a percentage in for that.

[UWEB]

Just now, Photoguy21 said:

Sounds good but have the cost of replacing the solar panels been taken into consideration? At some point they will require replacing so it could e worthwhile to add a percentage in for that.

Lifetime is at least 20 years, so why take this into consideration?

[Bandersnatch]

2 minutes ago, newbee2022 said:

I had already 2 different companies inspecting my house. We run 3 aircon by totally 52 Btu and cooking electric. 3 TVs and 3 fridges and a chest deep freezer. And in addition all necessary appliances as hot shower. The system I was offered included a 20-25 KW battery and 40 solar panels. 

 

Supply and fit can get expensive as the company makes a profit on the components and the installation. The good ones will warranty their work and offer after sales support.

 

However, there are some companies who think consumers have no idea of the price of solar components and they feel free to charge whatever they want.

 

hopefully with falling prices the savings will eventually start to get passed on to consumers. 

 

 

[KhunLA]

26 minutes ago, newbee2022 said:

Supplying your house will cost around 500.000 Baht.

Incl Battery for 20 KW. With that you can run more than 2 or 3 aircon, fridge, TV aso. 

So not a bargain at all.

You can pay ฿500k, or more, but there certainly isn't any need to.   Our system cost ฿445k, installed, 8kWh inverter w/20kWh of ESSs/battery.   Basically off grid, though still conx to PEA, costing <฿30 a month, JIC.

 

Our system is probably one of, if not the most expensive (per kWh), of AN members that DIY'd it.  Could have easily knocked about 100k off if DIY, maybe, even more so with the price drops the last 1.5 yrs.   Our ESSs were a large chunk of the cost @ ฿185k (90 & 95k).   Looks as though (from OP), could have knocked 75k off just that part of the install.

 

System provides just enough on the crappiest days, and when sun is shining, can charge the EVs, and probably run a neighbors house, if we had neighbors 

 

Will easily produce 50kWh a day.   We've used as little as 350 kWh a month, and more than 1000 kWh a month.

Edited February 13 by KhunLA

[KhunLA]

30 minutes ago, newbee2022 said:

I had already 2 different companies inspecting my house. We run 3 aircon by totally 52 Btu and cooking electric. 3 TVs and 3 fridges and a chest deep freezer. And in addition all necessary appliances as hot shower. The system I was offered included a 20-25 KW battery and 40 solar panels. 

Think they could lower that number of panels if using higher spec'd panels.   We only have 18, and enough to run the house and recharge our 20kWh of batteries.  Batteries usually topped up between 1000-1200hrs, unless crappy out.  Using 6 or 7kWh overnight (14 hrs), w/ AC & air purifier, on in the bedroom the whole time, along w/2 frigs.   Laptops & 65" TV till midnight or beyond.

Edited February 13 by KhunLA

[Guderian]

1 hour ago, Bandersnatch said:

 

4.8kW of panels

 

It’s not solar production, but solar production for which there is a corresponding load.

 

If you don’t want to buy a battery and your house load is 1kW you should be able to cover that load from 8am to 5:30pm 

 

What I might be after is the ability on hot days, i.e when the sun is shining and the solar panels should be working fine, to run two air cons from the power produced, one 24 kBTU and the other 12 kBTU. I think that's around 4kW of power consumption, not 1 kW. On cloudy days and at night I'm happy to use the mains electricity. From what I saw from your graph, the peak power output availability is far from steady. Does that mean I'd need to generate far more power than I actually need to guarantee the necessary 4 kW to run the air cons, as they're probably not very happy with a fluctuating and unsteady power input? Or does it simply mean I would have to have a battery? Or can it all be configured so that I would use all the solar power available, and it could be topped up in the day to the required level by the mains if need be?

[newbee2022]

46 minutes ago, KhunLA said:

Think they could lower that number of panels if using higher spec'd panels.   We only have 18, and enough to run the house and recharge our 20kWh of batteries.  Batteries usually topped up between 1000-1200hrs, unless crappy out.  Using 6 or 7kWh overnight (14 hrs), w/ AC & air purifier, on in the bedroom the whole time, along w/2 frigs.   Laptops & 65" TV till midnight or beyond.

I agree what you said.

However, when I calculate the costs  vs price/kw then it was my conclusion that in old age it makes no sense to invest let's say 400.000 Baht for my last 10 years. If I would be in my 50s I would do it.

[KhunLA]

34 minutes ago, Guderian said:

 

What I might be after is the ability on hot days, i.e when the sun is shining and the solar panels should be working fine, to run two air cons from the power produced, one 24 kBTU and the other 12 kBTU. I think that's around 4kW of power consumption, not 1 kW. On cloudy days and at night I'm happy to use the mains electricity. From what I saw from your graph, the peak power output availability is far from steady. Does that mean I'd need to generate far more power than I actually need to guarantee the necessary 4 kW to run the air cons, as they're probably not very happy with a fluctuating and unsteady power input? Or does it simply mean I would have to have a battery? Or can it all be configured so that I would use all the solar power available, and it could be topped up in the day to the required level by the mains if need be?

Here's a typical sunny day, input/output, which was hard to find, us not charging one of the EVs, or out & about.   March 11th 2023, so assuming we were using both ACs, 24 & 13 BTU (inverters).

 

Production/Consumption (blue/red), and batteries topped up by 1000hrs, so only producing to supply house load beyond 1000hrs.  Spikes are cooking, possibly some clothes washing. shower (3.5kWh or less) but no constant draw of electric, besides ACs.   Once up to temp, they / ACs don't draw much.  Total for the day was P 17.7kWh / C 17.5kWh.

 

We don't have East facing panels, why no excess to the batteries, till after 0730 or 0800hrs.

 

 

 

Edited February 13 by KhunLA

[KhunLA]

4 minutes ago, newbee2022 said:

I agree what you said.

However, when I calculate the costs  vs price/kw then it was my conclusion that in old age it makes no sense to invest let's say 400.000 Baht for my last 10 years. If I would be in my 50s I would do it.

For us, without the EVs, it would be a 8-10 ROI, and we abuse the AC pretty good.   If just me, agree, lucky to break even, if I live another 6-8  years, but the wife is 22 yrs younger.  So more for her, than myself.   Though spiteful person that I am, probably would do anyway, just to free myself of PEA 

 

We don't have any power outages here or even roaming brown outs, unlike when we lived in Udon Thani area, in which we would have, just for that reason.   At least a small system.

[billd766]

A few years ago I looked at getting a solar network to power my house. I worked out the cost then to be around 300,000 baht and replacing the solar panels after 10 years max.

 

I have looked back at my past bills from 2017 forwards  and the most power I used was in April 2023 when I consumed 41.56 units a day for a monthly bill of 7,184 baht.

 

I was running the downstairs a/c for 13 hours a day, my bedroom a/c for 10 hours, my sons bedroom a/c for about 12 hours a day. We also have 2 freezers, 3 fridge/freezers, various lights, fans and water pump etc 24 hours a day and we were using 41.65 units per day on average for April.

 

What I would like to do is have a network that will supply at least 6 or even 7kW constantly per day, as it seems to be getting hotter year on year. A project that size should also be OK on dull. cloudy and rainy days

 

Space is no problem as we live on about 15 rai of land.

 

My problem. apart from paying for it, is that I am 79 and my wife is 58. I will probably be dead before the solar panels and also the batteries need replacing.

 

My PEA bill for 2023 was nearly 59,000 baht, but now my son is at university the bill should come down a bit this year.

 

It may be possible to resell the surplus electricity back to the PEA.

 

My wild guess is that a system like that will cost about 400.000 baht all in and the ROI will take about 7 years to pay for itself.

 

Is that a reasonable assumption?

 

What yearly maintenance would be required? 

 

 

[Bandersnatch]

54 minutes ago, Guderian said:

 

What I might be after is the ability on hot days, i.e when the sun is shining and the solar panels should be working fine, to run two air cons from the power produced, one 24 kBTU and the other 12 kBTU. I think that's around 4kW of power consumption, not 1 kW. On cloudy days and at night I'm happy to use the mains electricity. From what I saw from your graph, the peak power output availability is far from steady. Does that mean I'd need to generate far more power than I actually need to guarantee the necessary 4 kW to run the air cons, as they're probably not very happy with a fluctuating and unsteady power input? Or does it simply mean I would have to have a battery? Or can it all be configured so that I would use all the solar power available, and it could be topped up in the day to the required level by the mains if need be?

Most on grid folk will set their inverter priority to be Solar, then Battery, then Grid. You shouldn’t see any drop in power as they switch between sources. 
 

A cheap and easy solar entry system is 5or6kW of PV and a 5kW inverter. The next step would 10 and 10. You have to make a choice of not enough on 5kW or possibly too much on 10kW.

 

As you seem to not want batteries there is nowhere for excess solar power to go.

 

Sounds like the cheapest solution for you is 5 and 5, no battery and a bit more PEA. The thing about PEA as a backup you are only paying for the power you actually use.

 

Although I am completely off-grid I wouldn’t recommend it if you’re only considering financials