Encid

Thai rats seem to leave PVC and PPR piping alone... but they love to chew on electrical cables. That's why electrical cables are enclosed in aluminium or PVC conduit in houses. I have heard tales of cars and pickups being disabled because of rats eating the wiring. I don't know if it's true but I have been told that rats eat wires and cause property destruction because their teeth are constantly growing. This is similar to claws on cats and dogs... since they are constantly growing, they have to be dealt with on a regular basis. By chewing on wires, rats get rid of the growing pains and they also keep their teeth in great shape.

They also appear to be imported from Australia. From what I have researched this afternoon the same model can be fully installed in Australia for around $5,000 AUD (or 125,000 THB).

Are you in Thailand? I just googled "Solarhart Thailand" and discovered that Boonthavorn sell them... this one appears to be a 300 litre model. And it appears to come with an Over-Temperature Protection System to prevent over performance during periods of higher solar radiation and lower hot water draw off.

Is the system pressurized by your home water pump? I note the use of PPR pipe and fittings for the hot water side. No additional insulation required? No temperature loss from tank to outlets in the bathroom(s)? How far away are the outlets? So apart from the immersion heater you don't have any demand electric water heaters?

FIL does that in the dry season after rice harvesting has finished. But with our new water well and solar pump he is considering year-round cultivation due to a plentiful water supply.

On the positive side the local couch grass and the vetiver grass is growing well and has stabilized the sloping ground. The grass has grown so well that there have been many offers from locals who want to cut the grass and use it as feed for their cows and buffalo, but we are not prepared to take the risk that careless cutting will result in our vetiver grass being damaged or killed. We have plenty of time and the ongoing rains are helping the grass get established (and assisting in soil settlement). Erosion is now minimal, and only in the areas where vehicles enter and exit the property via ramps.

An added benefit of having motorized external roller shutters and screens is security.

I really like the idea of converting energy from the sun into electrical energy and then into thermal energy. In Australia where I originated from I have seen many homes with solar panels and hot water tanks on the roofs of suburban homes (particularly in the northern tropical states)... but none at all in Thailand. Maybe they are out there, but certainly not in the areas where I live and travel around. My future home build will have it's own hybrid solar energy system, but to use that system to power high wattage demand electric water heaters seems such a waste of energy rather than using a dedicated solar water heating system. Have any forum members installed such a system and are you happy with it? Do you have a backup hot water service such as a demand electric water heater that can provide hot water when the weather is miserable like this?

KSS and Somfy both supply all sorts of motorized external roller shutters and screens. I am also looking into this option for our new build.

Let's hope that the junta does not hear about this and try to impose something similar here in Thailand...

You are probably correct although I have not been back to measure them. As the poles are 8m long we will request that the builder re-plants the fallen poles to 2 metres depth and back-fill with concrete, as well as add the guy wires I mentioned earlier.

@Bandersnatch Great topic and good to see your system's evolution! Does your system have a BMS that monitors the batteries, provides battery protection, estimates the batteries' operational state, continuously optimizes battery performance, and reports operational status? Or do the Growatt inverters do that for you?

Awww... that takes all the fun out of it...

Now we're getting serious...

If he's anything like me he probably prefers to use hot water for shaving. Shaving in cold water tends to give me razor burn and hot water seems to soften my facial hair. In my case, having hot water available at the sink is a must-have.

Yes I see now where I made an error... our current average monthly consumption is about 1800kWh, or 1,800,000 Wh, divided by 30 days = 60,000 Wh/day. The results look vastly different with the correct daily consumption figures plugged in.

I must be doing something wrong... I just plugged in the location of our farm in Isaan, added 10 x 450W panels (4.5kWp) to a flat roof, and also 2 x 9kWh batteries (18 kWh), and then punched in 3 kWh as our daily consumption (based on our current usage). The results above show a lot of excess energy not captured. Am I missing something?

That really is a great price! Just comparing it with @Bandersnatch who paid 37.3K baht per inverter (same model) delivered 9 months ago.

Don't forget a guy wire on the final pole. I cannot stress how important this is, especially as the cables (two wire single phase like ours?) are being run immediately after the poles have been planted and the excavated holes and surrounding soil will still be soft. Here is a photo of our final pole 1 week after planting. See the guy wire? Note the lean towards the cable strain/weight already? Fortunately for us and despite the heavy rain over the recent months the angle of the lean has not increased.

To properly size a demand water heater, you need to determine the flow rate and the temperature rise you'll need for its application in your home. If you don’t know the flow rate, you can estimate it by holding bucket under the shower head and measure the flow for a minute. The flow rate through the water heater should ideally be around 10-12 litres per minute. This of course can be managed to suit personal preference at the shower hot water tap or mixer valve. To determine temperature rise, subtract the incoming water temperature from the desired output temperature. Unless you know otherwise, assume that the incoming water temperature is 20ºC or you can also estimate the temperature by holding a thermometer under a cold-water tap. For most uses, you'll want your water heated to a maximum temperature of around 40ºC, again this of course can be managed to suit personal preference at the shower hot water tap or mixer valve. Side note: be cautious of possible water temperatures above 40ºC because it increases the possibility of scalding. In this example, you'd need a water heater that produces a temperature rise of 20ºC for most uses. However in cool season the desired temperature rise or differential may increase to around 30ºC, particularly in the northern provinces where it gets down to single figures at night. Having said that, an 8kW demand water heater is really only needed if you have a bath or spa to fill, when a large quantity of very hot water is needed in a short period of time. Most residences in Thailand would need water heaters sized from 3.5kW to 6kW to meet average family needs.

In our case we had to cross rice farming land first, and the cables had to be elevated so that farm machinery could get through. Also the bund walls between the rice paddies are regularly broken down and reinstated in order to control water level and flow during the rainy season, so routing cables underground in conduit was not an option. Having said that now that we have a power pole on the edge of our building site (approx 1.5 rai), we will be running the power underground to the building locations. As the OP has stated that he needs to run "some 130 metres down the fence line to the proposed site for a new bungalow" then an underground solution may be a good option.

C'mon Will... show us the photos! Have you got a house build topic of your own going yet?

When it comes to building our house I plan to be there every day observing. If something isn't being done correctly I will call the builder immediately and get him to sort his people out. If anything is done in an unsafe manner I will stop the work from continuing... there will be no injuries on my build if I can help it.

Our builder was most unhappy when he saw the first pole laying down... his people had only put minimal concrete in the hole as can be seen from the photo below. The pole was sunk deep enough (1.5m), but it should have been completely covered in concrete to the full width of the hole. As it was at a change in direction guy wires should also have been fitted to prevent the pole from being pulled back towards the cable run. It's all down to cutting corners and saving time and money. I bet he tore strips off the work crew!