Muhendis

Usually inverters are limited with output protection. I say usually because I tested a cheap one some years ago and it was not spec'd correctly. After a few days it sent out some very indigenous looking smoke signals and ceased to be an inverter. All the output transistors were totally destroyed. My current 8kW inverter has been in service for over 7 years and is frequently loaded with 4 or more kW by my woodworking machines. I also use an inverter type arc welder with no problems.

Putting such a heat exchanger on the primary or supply side would have minimal effect. Water would receive a little heat coming in but would be replaced by new cold water. The amount of heat gained in this way would not be worth the effort. To take advantage of solar water heating you would need to recirculate the water between the exchanger and a storage vessel. I this way, water warmed by the panel would be stored in the tank and then recirculated through the heat exchanger adding more heat as it goes round the system. So it would need to be on the secondary side.

My solar hot water is a direct system pressurised at around 3 bar. I don't know if such as mine is available commercially 'cause I built my own with copper pipe and ali. sheet for heat collection all enclosed in a polycarbonate/wood box. Fun project. Temperature of water gets up to over 50 C. I think there is no reason not to incorporate a solar water heat exchanger into your existing heat pump.

And neither does he.....

What cowboys indeed. All the surgical procedures I have had the misfortune to need have been performed by experts trained in either the UK or in the US. In my opinion, this country is second to none in the field of medicine.

In Thailand many installed solar systems are there for the savings. And why not too. Return on investment (ROI) is frequently referred to as the desired end result and, to that end, many anticipate a positive outcome. Here in Thailand, that (ROI) is not a difficult target to hit. We get loads of wonderful sunshine which gives us all the energy we need and more. Depending on the complexities of our system, whether we incorporate the local grid or become totally isolated from it ROI can be quicker or it can be slower. In Europe however, things are not quite the same. Researchers report that 53% of European freestanding homes could have supplied all their own energy needs in 2020 using only local rooftop solar radiation, and this technical feasibility could increase to 75% in 2050. The study shows that there is no economic advantage for individual households to be fully self-sufficient under current or future conditions, though in some cases the costs are on par with remaining on-grid. The researchers estimate that self-sufficiency will be economically feasible for 5% (two million) of Europe's 41 million freestanding single-family homes in 2050, if households are willing to pay up to 50% more than the cost of remaining fully grid dependent. https://www.sciencedaily.com/releases/2023/11/231102135037.htm I personally feel that this investigation is a bit lacking in terms of technical comparisons and component costs. One point raised regarding extra burden on less well off if only the rich go "solar" is, in my opinion only marginally valid. I see no reference to the industrial consumption nor do I see reference to the consumption of grid power by commercial business. Question is: Is this a fair report or not?

OK I think I know what you're saying. A fuller description of my system might help. I have two showers one which uses only solar hot water and the other which uses an instant 4kW electric heater (4kW is plenty hot enough at 80% of max.). We get plenty of hot water for a couple of showers from the solar heated water in the evening and there's still some left for a warm shower in the morning. That can be hotter if the previous day was particularly hot and sunny. The instant hot water shower I prefer in the mornings runs off the solar charged batteries which are then down to 70% of full which is what was intended by design. The inverter which powers the shower et.al. is a simple 8kW job

I thought all the old folk went to bed by 9 o'clock there.

I don't know about Air Source Heat Pumps, but what I use is a flat panel heat exchanger which cost about 400 Baht to put together. Like you, I have a 200L storage tank which is insulated, and a water circulation pump powered from a small 65W solar panel. The whole lot came to about 1,500 baht. So, with zero running costs and no maintainance costs (yet) I get 200L of hot water daily. Been like that for ten years or more now. Your post suddenly switches to topping up batteries from the grid. Why are you considering that?

Could be worse.

South Wales UK Boy-o

It's PTFE Ten turns of tape will do. I have some old joints which can still be moved but don't leak. You do not need to tighten them to maximum newton metres. Tapered threads are for gas and shouldn't need tape. It depends on how much water pressure is present but a few Bar is not normally a problem for a parallel thread with 10 turns of tape and no sealing washer.

Recommended treatment for iron infested water is O3 treatment. That's ozone to you and me. Ozone is generated by low power, high voltage electric arc. In the case of removing iron from water O3 is a very active gas. When it comes into contact with the mineral iron in the water, it will turn it into metallic and very rusty iron which is easy to filter out. These O3 gadgets are readily obtainable from your local water filter specialist. https://www.tank-o3.nl/en I first came across O3 many many years ago when I was developing a static electricity discharge generator for the plastics industry. The O3 generated was a by product of the static discharge. It is dangerous and, if you inhale enough, will give you a very bad headache as it kills you. Not a problem in a well ventilated water treatment room.

I have come across these things and other high frequency electronic coils purported to reduce calcium deposits. They all have some sort of effect but only locally. By the time water gets to the tap, it's back to "normal". You might like to look at this which really works but be warned. It will be cheaper to keep replacing your failed shower heads etc. than buy one of these.

That will, without a doubt, screw the growers well and truly.

Things are, like you say, changing ever so slowly. This sub-lightning speed of change is one of the reasons we went solar. We waited 7 years to get our permanent PEA supply. PEA weren't the people to talk to for us. We had to get approval from the local government office who would then pay for PEA to install the supply. They wouldn't do it until 6 or more houses needed it. That took us about 3 days to arrange. For that 7 year wait, solar was the only way to go for me. Just imagine the cost of 7 years at temporary/construction price of 8 Baht/unit. Any advance on 256k anyone?

Yeah. I agree about the armoured cable but those UK regs. don't actually apply to Thailand. What other diy'ers do is to dig a trench, lay an HDPE pipe then feed their cable into that. As Crossy said, if you do that don't forget the internet feed in another smaller diameter pipe.

555 Have you budgeted for NYY cables for the underground bits?

If you can arrange your south facing roof pitch to be between 15 to 17 degrees and incorporate a walkway that should do the trick.

Solar panels loose about 1% per year although there are claims that the newer models are a bit better Also be aware that the output from solar panels is highly temperature dependent and when hot, will give an output considerably less than under ideal conditions. The ideal conditions are with a perpendicular light source of 1kw/M² at a temperature of 25ºC with a gentle breeze blowing across them. The loss of output in Thailand can be as much as 20%. Carbon lead batteries are same as Lithium LiFePO4 batteries in terms of cycles.

Is your well a bore hole or is it a surface water well. It makes a difference how much filtering and what media to use Bore hole water from deep down is normally clear of germs and other organics because of lack of spare oxygen in the water but there could be loads of minerals like calcium carbonate (CaCo2) or iron (Fe) These minerals will give hard water and stain everything brown. Surface water on the other hand, can contain loads of organic material and possibly fertilizer and pesticides. Not difficult to deal with using the right filter eg activated carbon, resin, 5 micron and i micron PP filters and, for drinking, reverse osmosis.

It is indeed surprising until one looks at the demographics. The vast majority of people leave school and, for employment, go into shops, offices or factories and have no interest in technology beyond the on/off button or the keyboard. A very small part of a percentage go to uni. and become engineers. I applaud those non-technical folks who develop an interest in technology with or without the background which was or should have been learned at school. How many of us can remember physics and chemistry we had drummed into us all those years ago at school.

An abridged history of my installation and the reasons for it. Arrived from the UK in my new farm house here in Buriram in 2012. The only electrickery available was a temporary/construction supply at about 8 Baht/unit which was totally variable from 175v up to almost 220v. If anyone was doing welding in the village 1km away I would know about it. I wanted solar for reasons which included consistency of supply and because .... well..... I just wanted it. No thoughts about saving the world although the problems of preserving our world have always been at the back of my mind. My first installation, being as how I know about such things and don't have unlimited funds, I did myself. Batteries (VRLA valve regulated lead acid) rigged for 96v and solar panels were cheap and cheerful from China as was the 8kW inverter which ran very well. Shortcomings were noticed and so the system evolved. Batteries went first after 3 years quickly followed by the inverter. I went through several inverter manufacturers before the one I am now using which has proved very reliable after I changed the internal electronics (I am sometimes referred to as an electronics engineer in the UK, but more often I get referred to in more derogatory terms). Meanwhile the batteries. The originals were changed after 3 years, for some cheap FLA (flooded lead acid) deep cycle ones from a company in Bangkok. They were a pain in the arse what with automatic watering systems etc. so when they died I went over to Gel which was a whole world better. They died a few months ago and I am now running on lead carbon. All the dead batteries were turned into cash at the local scrap dealer which returned 10% of the original cost. I went through the a few iterations of inverters and deliberately steered clear of the all-in-one jobbies and went for separates ie. solar panels to charge controllers to batteries and no grid connection in the inverter. I can still use grid as I sometimes do, by switching over using an ATS (automatic transfer switch) but that is only for the heavy motor loads of my mini rice mill. (I get about 20 tonnes of rice to mill annually). My solar panes are the original ones and take care of all my needs including my cheap woodworking machines and occasional welding. I use air con. most nights and an electric shower daily. My wife produces the most fantastic pizza's you could imagine from the 2.5kw oven. Apart from that there are all the usual lights, TV computer, water pumps et al. To check my solar requirements, I did a spreadsheet on which I listed all my electrical devices and, more importantly, the time of day they would be running. That seemed to tell me I needed 12kw but in real life, 8kw is more than enough. My inverter is a low frequency transformer isolated output. The transformer might get a little warm above 8kw continuous but the electronics which drives it is good for at least 12kw. For me this is a fun project which seems to have provided a lot of fun, entertainment and given me bragging rites for the foreseeable future.

I looked at NiFe batteries some time ago and the only good thing about them seems to be that they will outlive me. Far too many negatives especially cost, for general household use. Also another negative not mentioned is the electrolyte. I seem to recall there is a requirement to mix up your own electrolyte. You might like to check out what to do if battery performance decreases for any reason. "Never happen if you take good care of them" I hear someone muttering but don't forget Murphy's law. Anything that can go wrong will go wrong.. For the domestic home user it really needs to be fit and forget.

Those sort of prices are scary. If you are a bit handy you could make your own battery. That's what I have done and it's worked out quite nicely over the past ten years or so. Mind you, I don't use these new fangled lithium things. I am now into my third set of lead acid. The type I am now using is lead carbon. They have a similar performance to lithium but are considerably heavier. I could wax lyrical about them but at this time of night I am in lazy mode but you can get a good idea of how they work from this: https://batteryuniversity.com/article/bu-202-new-lead-acid-systems In a nutshell they have better charge acceptance (they charge quicker). Can go to a greater depth of discharge. Don't have sulfation problems. Can live longer in a wider temperature range and have an extended life. This in comparison with "normal" lead acid. I have a bank of them which amounts to 36kWh at 48V. Their anticipated life span is about 11½ years at30% dod. Price was about 140k Baht and so far they do what they are specified to do.