Bandersnatch

My solar system has LFP batteries, which are the same chemistry as my BYD Seal. I imported them from China, but in recent years you can now buy similar batteries in Thailand. Regarding using old EV batteries for home use, in Thailand there are just not enough of them available yet. Thailand only started ramping up EV sales in 2019 If you are able to find one you have 2 choices currently, either dismantle the battery to gain access to the individual cells to make a new battery or find a way to communicate with the battery as a pack, bearing in mind many of the components you will need are probably still in the donor car Many of these problems have already been solved for older cars like the Nissan Leaf (which didn’t sell well in Thailand)

This is my setup:

The Nissan Leaf, one of the first EVs that you could buy in Thailand is being phased out resulting in some in some excellent deals as Nissan trys to clear stock. Case in point, you can lease an Nissan Leaf in the US for $20/month So I popped over to the Nissan Thailand website to see what was on offer here. First for some context, Nissan launched the 40kWh Leaf in Thailand for ฿2m back in 2018, when it didn’t sell the price was cut in half I was thinking maybe Nissan Thailand would drop the price to ฿500,000 but with CHAdeMO and no active thermal battery management, you could argue that the 40kWh Neta V would still be a better choice. Turns out Nissan Thailand have actually put the price up

Seal tire repair. Living in Thailand this is the sort of the job I will never do myself ever again.

Still waiting for a breakdown of your calculations for 15 year payback for solar You claim to have an EV, but no details offered as to which one. Let me help you with your calculations I make a saving on my previous PEA bill and powering my EVs of ฿8k a month let’s assume you save half that ฿4k x 180 months = ฿720,000 So your solar system would have to cost you ฿720,000! Let’s assume you get a quote for a 10:10:10 system Main Components would cost 10,000 Watts of PV @ ฿5/W = ฿50,000 10kWh Batteries @ ฿5k/kWh = ฿50,000 10kW of Inversion @ ฿5k/kW = ฿50,000 Total = ฿150,000 to which you have to add ancillary items like cables, rails, clamps, breakers, combiner boxes plus fitting A supply and fit quote would include mark up on your components as well but even so we are nowhere near ฿720,000 I’m calling bs on your 15 years payback

My car’s battery is designed to push a 2 tonne car at over 100km/hr for 160,000km and after that it is warrantied to still have over 70% capacity left. By comparison when I use it for my home backup I am drawing only a few hundred watts. How is that going to significantly shorten the battery lifespan compared to driving it? I can power my house all night and only use the equivalent of 50km or range. You have to crunch the numbers before making sweeping statements like "reducing the life time of your car battery"

Nice setup. I have found that my BYD Seal is much more efficient at providing backup power than my home solar setup.

The anti EV/PV brigade like to criticize long payback times for solar, but always fail to acknowledge that Payback ignores savings made after payback has been achieved and with solar panels having a working life of 20-25 years they are ignoring a lot of savings. The next line of attack is to criticize payback for not taking into account inflation claiming that future savings are worth less but again failing to acknowledge that electricity costs tend to rise faster than inflation. Case in point we are looking at a potential 44% increase in electricity costs this year. Those of us shifting from ICE to EVs and Solar are looking at increased savings as fuel prices also rise faster than inflation. Currently the Oil Fuel Fund has accumulated losses of over 100 billion baht after subsidizing diesel, gasohol and gasoline prices a situation that is not sustainable. Being an accountant I tend to be 'conservative" (with a small c) and use historic figures so as not to overstate the savings for solar and EVs

Payback and Net Present Value are separate investment appraisal techniques.

Did you read any of the earlier posts before posting? Thailand makes too much power at night that's why they sell it at half price. Most EV owners either have solar or a TOU meter. You clearly don't understand levelized cost of electricity by source. If you did, then you would know that Solar and Wind are the cheapest. Crying for "Coal /Gas / Oil/ Nuclear" will put everyone's bill up. "Solar isn't going to cut it" in the tropics? https://en.wikipedia.org/wiki/Cost_of_electricity_by_source

In addition: self consumption will always provide better value than selling back to the grid unless Thailand changes it’s feed-in rates to allow arbitrage like in the UK Unfortunately this is unlikely as the current flat rate ฿2.2 feed-in scheme has been closed to new customers apparently due to lack of money!

Can you provide a breakdown of your calculation or did you just guesstimate it? My setup: Main Components (at todays prices) 20,000 Watts of PV @ ฿5/W = ฿100,000 36kWh Batteries @ ฿5k/kWh = ฿180,000 20kW of Inversion @ ฿5k/kW = ฿100,000 Total = ฿380,000 Savings: PEA saving (no meter) ฿4,000/month based on my bills from a few years ago (prices might have gone up) Fuel saving for 2 drivers and 2 vehicles and 1 motorbike ฿4,000/month (based on Previous usage using ICE from a few years ago) = ฿96,000/Year saving Payback = 4 Years Based on what I actually paid a few years ago my payback is closer to 6 years

Due to low demand for electricity at night in Thailand many EV owners have TOU meters to charge their EVs with half price electricity. I use my home solar to charge my 2 EVs and an electric motorbike. I don’t have a meter.

BYD Chargers ฿4/kWh

The Confusing Mess that is Hybrids. I agreed with most what was said in this video below. However, I successfully drove a PHEV as an EV the vast majority of the time and don't know what to make of the claims in the press that many PHEV owners never plug them in. There is a widely quoted study by International Council on Clean Transportation but it never claims that PHEV owners admitted they never plugged in. What it actually says is "The low real-world electric drive share we calculate indicates that many PHEVs are not plugged in daily" which is not the same thing I was also surprised that Toyota's "self-charging" Hybrids didn't get a mention.

Japanese automakers under threat as Thailand shifts to EVs https://youtu.be/56B6m9pkVuw?si=uVC7-g_41bzyg6M3

If you want a supply and fit you could try getting a quote from Chaweewan Group Solar https://www.facebook.com/groups/300126774329850 SolarThailand.biz

You can set the priorities for your inverter Solar, Batteries, Utility SBU uses solar first to meet the load of the house then tops with some power from the battery, then finally adds from the grid. SUB uses solar first then tops up from the grid and only uses batteries in a power cut. I use USB as I am off-grid and plug my EV into the Utility connection on the inverter. So when I draw from the EV at night there is no solar and I prefer to use my 86kWh EV battery which is much more efficient than my 36kWh home batteries

1 PEA unit is 1kWh unfortunately the only way for a solar system to match your household load 24 hours a day is to have batteries which are expensive. Here is a graph of one of my 5kW inverters and you will see that solar ramps up during the day, producing too much power in the middle of the day and requires batteries for 12 hours of night time use. Your PEA Bill tells you how many kWh you use in the month but not when they are used. Many people install solar for daytime use and rely on the grid for night time. Another option is an energy monitoring system that tells you when you are using most power. Here is a video I made about my system: After monitoring you will probably find that with 24 units per day you are probably not using more that 2kW during the day and closer to 500W at night. So a 5kW inverter and 5kW of panels will probably cover most of your daytime load. Sizing a battery system is more difficult if you want to cover 100% of your night time use. Here is a video I made about sizing batteries for solar systems As for costs, I published component costs above, but most people usually go for supply and fit which can be quite a bit more expensive.

I suggest posting the ad in https://aseannow.com/forum/319-alternativerenewable-energy-forum/ and asking for feedback- lots of guys have experience building their own systems and will be familiar with the best brands

I came back to my BYD Seal yesterday to see 3 young Thai guys studying the back of my car. Turns out they were looking for the exhaust pipe, the pickup truck that they had arrived in had a particularly large after market one. I explained that it was electric. “But it has an engine as well?” “er no, just electric” ”what happens when the electricity is empty” ”we fill it up at home from solar or on a trip many pump stations have electric chargers” They didn’t look convinced. I was surprised that they had never heard of a BEV.

As I said above, the bigger your bill the bigger the savings My Main Components (at todays prices) - doesn’t include installation 20,000 Watts of PV @ ฿5/W = ฿100,000 36kWh Batteries @ ฿5k/kWh = ฿180,000 20kW of Inversion @ ฿5k/kW = ฿100,000 Total = ฿380,000 Savings: PEA saving ฿4,000/month Fuel saving for 2 drivers and 2 vehicles and 1 motorbike ฿4,000/month (based on Previous usage for ICE) = ฿96,000/Year saving Payback = 4 Years Based on what I paid a few years back my actual payback is closer to 6 years.

Tier one solar panels are already at ฿6.5/Watt Inverters are already as low as ฿4K per kW 5kW of Solar = ฿32,000 5kW Inverter = ฿20,000 Total cost for main components= ฿52,000 You will need various comments like brackets and rails to fit the panels, Cables and breakers etc. Then you will need someone to fit the system. The prices for all of these will vary. Most people just get a quote for supply and fit which will be more expensive. Solar will ramp up during the day here is a graph for one of my 5kW inverters

Payback is a popular financial analysis tool because it’s simple to understand, but it’s not very sophisticated. For example a single 500W panel and matching inverter will never produce more power than you can use so no curtailment (wasted power) such a system could produce a payback of less than a year but the savings would be very small. The bigger the system, the bigger the savings and the longer the payback. You said you wanted to include opportunity cost and cost of capital, these are different tools so have to be applied separately. A 10 year payback is an investment that is producing a 10% return on investment. The opportunity cost is cost of the lost opportunity. So if Daft Coin made 20% last year, not investing in it this year potentially lost you 20%. I have an off-grid system (no meter) Due to the diminishing returns with solar, the closer you get to 100% covering your electric bill the bigger your system needs to be. Batteries are expensive, but adding a small (say 5kWh) battery means that you will get more value from your system as the battery acts as a buffer for times when solar production drops. The bigger your current electric bill is, the bigger the potential savings are. I have 2 EVs and an electric motorbike and my solar system powers them and my house without a meter. I do use my EV for extra backup power. My payback is 6 years.

OK we won't