If rain can clean it how come our exterior wall will still be dirty after years of usage?

Even then solar panel guys been telling us, please clean the panels periodically.

No one is doubting the capability of solar generation but it shall never be glorified and advertised in such a way that it does not come with its challenges.

Read both sides of the stories.

Coz my system can monitor per panel production, when I feel the production is no longer there, I can consider to clean.

solar panel in Malaysia cannot ROI.
by the time you ROI your money , your battery and panel will require replacement.
Your total investment is RM47,000
if each monthy you save Rm1,000, that is 47 months .. close to 4 years but your battery will degrade over time and solar panel efficiency is also reduced, you won't be saivng Rm1000 each month.
According to friends in Japan who frequently have earthquakes , they do suffer frequent power shutdown. Their solar panel is for emergency . not to save money.

When you put returns like that it will be compared with other investment class. eg:- 5.5% epf , 3% FD, 6% ASNB but you cannot really compare them that way,
If you put 47k in FD, 3%  for 5 years you get 47k + (3%^5*47k).
The 47K that you put in is unchanged after 5 years

If you put in 47K in Solar and you claim 20% return.
By right at the end of 5 years you get 47K +(20%^5*47k) but you don't get it.
You can't sell the solar panels and your solar panels are not worth 47k anymore. . That is asset depreciation.

So technically, if you include asset depreciation. The first 5-6 years is 0% and then only after that is 20%.
You don't understand that you cannot get back the capital that you put in.

Nope, what ever credit you get, need to spend it in the current year.
Tnb will not pay you cash one. The vendor told me, if end of the year got extra credit ask your friends and relatives come charge their cars in November.

I got a quote in Johor.

10.53kWp for rm35,580. Jinko panel, Solis inverter, 30yr linear power warranty, 12 solar panel warranty, 10 year inverter warranty, 10 year system structure warranty, 2 year workmanship warranty for leaks just in case it starts to leak.

Washing panels is rm800/visit.
Skylift renting price if needed is rm700.
Other troubleshooting for onsite service is rm200/visit.

Recommended by close association. So far good. But my Bod...says Roi is 5-6 years so do not want.

They will calculate usage first then only deduct 

After speaking to about 6 companies and asking questions.

Here are my recommendation. Disclaimer, I am not affiliated anyway to the industry. I am just a soon to be consumer.

1. Some companies will bs story you, because their approach is to maximize profit. E.g. your house uses three phase power. They tell you single phase inverter will work. It is true, it will work, but it’s not optimize and it’s not best for you. Out of the 6 I spoke to, 4 of them tell me can install can use, which is true, but it’s not the best. It’s like selling you snow tires for use in Malaysia. It will work and can use. It’s just not the best choice available.

2. Choose a large company with long track record. Best if they have large corporate clients. Why? When you buy from them, they will be the one supporting you for the 10 year inverter warranty, 12 year panel warranty etc. Sure, Huawei inverters will be backed by Huawei Malaysia even if your installer close shop tomorrow. But it will be very hard to find another installer to touch your system and do the replacement for you. Nobody wants to clean up other people’s shit.

3. Out of 6 of the companies I spoke to, 2 of them is clueless. Just focus on selling. When I ask questions like send me the data sheet of inverter, she answer me the quote is based on my tnb bill. Don’t even know what I am asking for. Don’t even have basic product knowledge. Just sell sell sell — this company advertise heavily on Facebook, name start with a. Worse thing about them that scares me, they used to sell Canadian Solar panels. Now discontinued. Which makes me wonder if your panel got issue claim warranty, they don’t carry it anymore, what happens? Is the installer going to replace for you? Are they going to tell you sorry brand no longer in Malaysia you need to pay to replace with other brand? Make sure you ask.

4. Truth is, solar panel hardly needs cleaning in most cases. If the company start story say need cleaning, charge you how much. Can walk away. If your output got problem, maybe cleaning is one of the remedy — like Godzilla 💩 on your solar panel and the rain can’t wash it off. This is what the big company tell me. Usually don’t need.
Average save RM250 a month. You can go online find calculators. It’s a 5kW system.

Tis good deal? Using huawei , promotion partner with huawei

Using wat brand panel and inverter?

Ur solis inverter supp max 7kw system?
Sked in future wana add more panel also cant supp jo

Ur import will be high.

My DB is also in storeroom, same louvre door as you. I decided not to put inverter there because 1. Heat & 2. A bit small there in the future to fit batteries if needed.
I reckon about 12M. In any case it’ll mean that the DC cables will be shorter and more direct running adjacent to my rain water drain pipe. And the AC wiring to DB longer. Anyhow voltage drop for DC is higher but just size the cable properly should be fine.

Anyhow I’ll wait for their proposal and see what they say. My DB is dead center of the house below the staircase.

My house is strata landed, so the trunking pipe at the back yard wall have to be concealed, can't fix it on the wall surface

Ya, the installation company's technician said no issue. But of course if next time if the cable got issues, need to hack the wall to replace. I got no choice because management insist me to conceal the trunking pipe

Inside the house, my cable all hide in the plaster ceiling, all the way to store room, then only mount on wall surface in the storeroom cover with metal casing.

They more concern on the door of storeroom, must have ventilation hole. So the inverter and another device won't be overheating.

My own contractor hack the outside wall, and leave all hole on plaster ceiling follow installation plan, then solar installation team come to fix wire with trunking, then my contractor conceal and repaint it back. The installation team quote 3000 for conceal, my contractor only charge 1200, he charge cheaper as he was renovating my whole house that time.

How did your installation company advise? My installer said the inverter can not be placed too far from DB box because power will loss during transmission, the longer the distance, the lesser the power receive by DB from your inverter.

Can not open ventilation hole on your cabinet?

mine, also far away from under stair store room DB.

the inverter put outside house.

cause hot and noisy.