Solar panels and their costs?

Dear Henk,

You do give the amount of the quote, but not what you get in return.
Furthermore: how much total nominal power (in Watt) do the 4 air conditioners, the 5 refrigerators, the 3 geysers (I assume you mean electric shower heating) and all 7W lamps?

In general, it is not profitable in Thailand to generate electricity using solar panels. Perhaps if you have permission from the grid operator (MEA*, PEA*) to feed your generated power back to the grid. Consent is rarely given.

MEA: Metropolitan Electricity Authority
PEA: Provincial Electricity Authority

Google: Chaweewan Group solar, they are on Facebook company of a German.
Has good videos explaining how it works and what it costs.
Jeroen.

Dear Henk,
I am also working on it myself, I also have a resort, but I have not bought anything yet, I am still studying about it and of course saving.
What I already know is that it is better to opt for a resort on-grid, the batteries are still expensive and do not last very long (about seven years).
Furthermore, there is a difference between a 1-phase or a 3-phase solar installation, a price difference of approximately 10%, the 3-phase would be better.
After contacting several suppliers, we always arrive at a price below 30.000 Baht per kW yield, so a 10KW installation costs a maximum of 300.000 Baht, of course there are more expensive ones, but the price I am talking about are quotes from decent suppliers in Hua Hin and therefore proper installations.
Which installation you need, you can calculate that by reading the consumption on your electricity bill, in my opinion you should not completely eliminate that consumption and you will be better off with your installation, the invoice will still be very small.
Best of luck!

3 geysers? Heaters I assume, 3000 or higher W/pc. Of course they are used interchangeably.
Profit when the sun really shines.
Refrigerators work all day and night, but what cooling capacity?

It is advisable to monitor the consumption/day first, so read your meter every day and also view it during the day and night. Separate. When is the most consumption?
Many lights 7 W. You can calculate. If you leave 1 light on for an hour, it costs 7 WX 1 hour = 7Wh or 0.007 kWh. So if you have 100 lights, it costs 100 X 0.007 = 0.7 kWh in an hour.
So you haven't lost a “unit”/hour yet. If the lights are on for 5 hours, then that is X 5.
However lights come on when it is dark usually.
This way you can determine the consumption and costs of each device.

What is the peak power for the panels? The higher, the more efficiency, eg 300 Wp.
Of course there is a price tag, the higher, the more expensive.
Temperature has a negative effect on the efficiency of the panels, the warmer it is, the worse the efficiency. This would be – 0,4%/degree, assuming optimum panel situation at 25 degrees.
So if the panel gets to 50 degrees on a sunny day, you lose 10%. The panel must therefore be “reasonably cooled”.
AND the panel itself has, without a certain efficiency, conversion from light to electricity.
This also determines the price of the panel, of course.

There are also different panels: monocrystalline and polycrystalline, there is not much difference in efficiency, but still. I thought poly were “better” at high temp, more efficiency.
In addition, you get an inverter that transforms the generated voltage to 230 Volt.
This must be chosen for the maximum power to be supplied by the panels.
Placement close to the panels.
There are also various price ranges here.
There are also micro controllers, in which case transformation takes place per panel and a poorly functioning panel has no influence on the total delivery. For example, when a shadow appears over the panel, when it breaks, it becomes dirtier than the other. Of course this costs more.

What are you going to do with the installation? Do you want to save for the evening? Then you need “deep load” batteries.
These also cost and come in different price ranges. The higher the battery storage, the more expensive. Indicated in Ah. You don't have to buy a large one, but you can place several small ones in parallel.
And where are you going to put it? The best is as close to the panels as possible. Not in full sunlight of course.
If a large piece breaks, which is also super heavy, you have to replace it. With smaller ones you can replace / piece and are lighter.
For a large one I'm talking about 200 Ah, for a smaller one I'm talking about 50Ah. So you can place 4 smaller ones in parallel and that saves weight and costs. A 200 Ah battery costs more and quickly weighs 120 kg.
There are very large special batteries, but they cost more than your panel installation.

An example: https://www.zonnepanelencentra.nl/12-zonnepanelen-325-wp-trina-solar-tsm-325d06m-05-omvormer-growatt-3000tl-xe?gclid=EAIaIQobChMI7e2BtrLF9gIVlud3Ch0eIAiNEAYYASABEgKR5fD_BwE
That is a complete set of 3900 Wp, but not yet built.
My neighbor (the Netherlands) has 16 panels and I thought I had lost 5000 euros all-in total.

So what do you have? How many Wp, how many panels? Is it all inclusive? Are there batteries, the inverter(s)?
I come back to what I said first, what is your daily consumption? Monitor your meter / day and also important, how full is your guesthouse? Is there 1 guest or are there several?

Another item is, where are you going to place the installation? On your roof? Is your roof strong enough, since a solar panel weighs about 20 kg per piece. Is your environment often filled with dirty air? Dirt settles on your panels and you will have to clean them for optimal yield.
Consider dissipating as much heat as possible, as heat negatively affects the installation.