ProDave

You should be able to get the self usage up to more than £150. I am estimating £250 self usage, I will report back in a year. The 2 key things are use big appliances in the daytime if you can, with a timer if you have to be out (for work) and dump excess power to water heating There is mention of a replacement payment scheme for export but nobody knows the details. If it is only payment for export, I don't expect to be exporting much so it may well not even be worth the paperwork. But you are right, at £6000 it is not worth it. You have to get it cheaper. That is still paying "MCS prices". @Stones just fitted his own small system and paid an electrician 2 hours work to connect it all up. Add say a days work or even lets be generous, 2 days to mount the panels you should not be paying more than about £500 labour. you can buy 2KW kits now for about £2000, so £3000 is more like what an installed price should be., At £250 self usage that gives 12 years payback, still twice what I am expecting. We need to get away from the rip off MCS pricing structure before non FIT solar PV will be viable for more than a handful of people like me willing to search for a bargain and DIY.

He muttered something about we are already paying council tax for the caravan so it is not urgent, and he has enough paperwork at the moment. I am tempted to fit my upstairs doors, but leave the downstairs ones off, at least until after June......

We have had another reprieve. I was just doing some stuff at home this morning when a strange car drew up and a man in a suit got out. It was the council tax valuer. He came into the house and got as far as the hall, at which point he declared "it's not finished is it See you again in about June. Thank you."

I would not like those inside a wall and inaccessible. I would want to make some form of access to them. Put them at socket height, and a 1G plasterboard electrical back box, with the back cut out, and a blank front plate would do it. Well what other suggestion do you expect from an electrician?

The trouble with scaffold / towers, is someone has to put them up and take them down, It's a lot of time, effort and hard work to get a tower up to the very top of our gable end. Don't under estimate the sheer hard work of getting all the metalwork and planks up there, done by lifting it up in stages. Sometimes it just might be safer to work off a ladder if a short job rather than put the scaffold up?

Just wire the ASHP in series with the Willis heater. Then you can use either. As already noted, just a bit more antifreeze. It needs to be about 25% to withstand temperatures down to -10

That is the budget that I am aiming for. I have been doing a LOT of the work myself to achieve that. When it comes to buying stuff, it always involves a LOT of searching to find materials at the best price, often on line, sometimes from abroad as UK prices can sometimes be silly. It also forces a choice sometimes to do things differently, or defer some less important things until later on. The cost of getting thin gs cheap, is it can sometimes take a lot longer to find where to source them from. Plenty of knowledgeable folk on here so when you get stuck looking for something, just ask.

Off topic but I found Aico make a combined heat and CO detector, perfect to avoid "ceiling clutter" in our kitchen / diner that also has the WBS

I started off with the concept of a "plant room" but rapidly decided different things needed to be in different places. The only thing in my "plant room" now is the MVHR unit and a pump and some controls for the central heating. It made a LOT more sense to put the hot water tank somewhere else, now is what will be an airing cupboard off the small bedroom where it has the shortest runs of hot water piping to all the taps. Don't get over fixated by trying to put all the "stuff" in one place, Some of it may be better somewhere else. I am reminded of my plumber friend who has a house twice the size of mine, with the hot water tank in the plant room in the diametrically opposite corner of the house tot he kitchen sink tap.

I have not yet found any of the arduino executables in any of those suggestions. Which Arduino returns nothing at all. Never mind, a project to waste time on when I am bored.

Now this project is drawing to a close, I am wondering what to do with the 2 spare panels. Initially I had thought to put them upright on the east facing end of the shed to catch some early morning sun and get generation starting earlier. That still seems an option. But I am noticing the generation from my E/W split tails off earlier in the evening than I had expected, there are some shading issues from next door beyond my control and where the panels are was the only option due to all the trees so I am stuck with that. But I do notice, the West end of the shed seems to get good sunshine at this time of year until sunset. but I don't think both would work there as again due to trees, one of them would get shading early on. So my current thinking is one each of the spare panels on the E and W ends of the shed. As only one will really be generating at any time, I could connect them in parallel to a small 350W inverter This would give a 200W or so boost first thing in the morning, and again in the evening up until about 6PM. Later in the year when the sun is higher the W facing one would get some shading later in the day, but by then I hope the sun being higher would make the neighbour shading of the main array less severe.

It's academic now as I have PuTTY working, but because I "like to know" stuff, just where are all the program executables stored on a Linux system? I can't seem to find them even with "hidden files" turned on in File manager. In other words what is the equivalent place to Windows's "Program Files" directory?

You seem to be like me that "house stuff" uses more than heating and HW combined

I like that, looks very neat and as you say the row of panels complements the window line so they do not look in any way ugly. @BMcN you only need to be MCS registered to claim the FIT. I registered my own system about 2 weeks ago now. You just have to fill in a form and provide a drawing. They accepted "Electrician" in the "Qualifications" box of the installer. Details in my thread here

Have you got a total measure of KWh used for heating and HW over the year?

I did try Screen, but it would not seem to recognise the "serial" port dev/ttyUSB0 But anyway PuTTY is working fine. So I can report success on the first day of live testing the dump controller. After a grey wet start the morning turned out ideal testing conditions with a rapid change from bursts of brilliant sunshine then back to cloud, giving a good chance to see how the immersion power ramped up and down with changing loads and changing generation. Later the sun came out for longer but behind high thin clouds so generation has been lower this afternoon. It never quite got to enough surplus power to run the immersion at full power, the highest it got to was 80% duty cycle. So far today the PV has generated 6.3KWh and 2KWh of that has been sent to the immersion heater lifting the temperature in the HW tank 3 degrees. Total import for the day is registering as 1KWh most of that will have been this afternoon when the washing machine was on, and it's heater power exceeded the generation at the time. Next job is to connect my export meter and see how much power is "escaping" and tweak things a bit if too much is going "to waste"

Don't forget @Construction Channel on you tube

My observation from my own ASHP is that is spends typically 4 half hour busts each day doing hot water, so it is "out of service" as far as heating is concerned for that period. Yes you do need to consider what energy regime and if you want to do it all over night on E7 then the output for that period will need to be higher. And good point for allowing extra for particularly cold spells.

So December needs 973.2KWh that is 31.39KWh per day or an average power 24/7 of 1.3Kw You probably don't want to run the heating 24/7 so assume it is on half the time it will need to produce 2.6Kw of heat for that time. A 5KW ASHP should do you comfortably.

I have split mine E/W to try and make a longer (but lower) generation period throughout the day. The fly in the ointment about adding a third string later to charge batteries, is to be completely "legal" that would have to be entirely off grid, i,e the loads the batteries supply are different circuits to the house. As soon as you connect a battery storage system to the grid, that too has to be notified to the DNO. I have not read the rules about that yet.

I have just been trying PuTTY. All I get is giberish on the screen. I have set the Arduino baud rate to 250000, the fastest it will go when @Ed Davies found the buffer / timing issue. The Arduino Serial monitor works at that. I wonder if PuTTY only does "standard" baud rates and not 250,000? EDIT yes that is it. PuTTY is now working at 230400 baud.

While I wait for the sun to come out.... Are there any Linux / ubuntu experts on here? The arduino programming environment has a Serial Monitor built in. To access it you first open the Arduino IDE then you can open the Serial Monitor. I want to be able to open the Serial monitor directly. I did this previously on a PC by locating the executable file for the serial monitor and creating a shortcut to it. But I don't know my way around the Linux / Ubuntu file system and a cursory look has failed so far to find where all the Arduino IDE executable files are stored. Any help?

Downstairs cloaks is way too small. Don't under estimate how much coat and shoe space you need. EDIT for "cloaks" do your really mean "WC"? Upstairs I would shrink the master slightly so that Bed 3's wall to the right of the door in, does not have to step over. I assume the en-suite between bed 3 and 4 is a Jack & Jill? I would put all the coat and shoe storage under the stairs. I assume the front (bottom as shown on plans) of the house faces (roughly) south? I would make the door to the left hand living room double as well (this is what we have done) When entertaining, both sets of double doors really opens it up as a big space. Otherwise not much to dislike.

A bit of an update. I spent the day sorting out mostly hardware issues. My plan to put the current transformer loads in the plant room, thus sending 2 current signals down a 5 pair telephone cable proved a spectacular failure. I was getting massive crosstalk between the house current measurement and PV current measurement. Eventually I reverted to having the CT loads in the meter cupboard and just sending the resulting voltage signal up the phone cable to the plant room. That seems to work much better. Initial tests showed I needed more filtering of the house current signal. As soon as the first burst of immersion heater firing turned on, the house current monitor was reading that as way more than the average current it was. So some playing with filter time constants was needed. I also added some software averaging of the house current to smooth out transients. Then I found I had scaled the PV current transformer for a max of 4KW, but scaled the house current transformer for a much higher load. That meant at the sort of values it was working at, it was down in the noise. So I re scaled that so the house current monitor now saturates at about 10KW and gives better resolution at low power levels. It is only low (<4KW) power levels that are important for this. The fact that a >10KW load will saturate the monitor is irrelevant. By the time I had done all this the nice sunny morning had passed and it's grey and raining. I await the next sunny day to check it's operation under real conditions. Frustrating business.

I ended up buying the 12L expansion vessel kit as it was available at the time on the bay, slightly cheaper than others were selling an 8L one. I actually installed if for my first HP but when that didn't work the replacement HP I was given has an expansion vessel inside the HP, so I now have two as I never saw any point removing the one I had fitted.