epsilonGreedy

Not as constant as you think. The tidal current stops four times each day at a location because there are two high tides and two low tides each day (actually each 24 hours and 40 minutes). Also the UK does not have a remarkable tidal range everywhere, the Seven Estuary has a local geography that amplifies the tidal range. The central portion of the English Channel has a low tidal range.

This is a persuasive point. There are DC output MPPT controllers sold to boat owners but anything with a marine label is overpriced so I may as well generate AC and feed it into the overall house demand as you suggest. My thinking was that two daily showers would consume about 100 litres and it takes about 3.5kW hours to raise 100 litres of water from 7 degrees to 37 degrees. Hot water heating demand would roughly match daily output from a 1.1kW array on average over 200 days of the year. There would however be considerable wastage of PV generation capacity mid summer when people have cooler showers and the array's daily capacity would be above 4kW hours. The prompt for my question was the thought that if I stretch myself now to get PV on the roof could I obtain some benefit from the output as an interim solution before the house is fully complete and signed off. We are planning to move into the upper floor of the house as soon as it is habitable. I need to find a better solar calculator that provides a detailed breakdown of predicted daily generation across the whole year i.e. a calculator that reports "in May the daily PV generation from a 1.1kW array will be 5kW on average though on the best 10% of days 6.5kW can be expected and on the worst 20% of days it will be 2.8kW".

I am. Every time I type kw or KW there is a reciprocal pulse of energy in Cornwall greater than the experimental energy input.

Before midnight @SteamyTeawill have convinced me I am likely to create the first nuclear fusion plant in the world.

The dreaded DC arcing issue and the ghost of Jeremy returns to haunt another good idea! Ho-hmm. From the age of 5 to 20 my family home was cursed with an immersion tank heater that would literally raise the hot water temperature to boiling and the tank could be heard bubbling. We coped without requiring hospital treatment. In the world of unvented cylinders what is a safe maximum temp and how many kW does it take to raise 300l from 60 degrees to 70. Not looking for the answer, just thinking aloud to establish how often this thermal cutout activate across this direct PV DC feed.

The problem is that your "understanding of these things" tends to decline when your brain is starved of oxygen.

When writing my question I did wonder if an AC heating element might work. Panel efficiency, I overlooked that. Boating folk endlessly debate PV panel configs for optimum efficiency. I suppose such a direct DC setup starts with an advantage of no inverter efficiency loss which will be 5% to 10% based on my boating experiences. Hmm I wonder if the marine industry can offer a suitable DC water heating element that can soak up 1.1kW? Quite a technical counting challenge I guess if the voltage is yo-yoing up and from a directly coupled PV output.

I have not given PV much thought during the prior stages of my build and now I am exploring the fringes of the subject with questions like this. Given a 1.1kW 3 panel PV installation oriented 8 degrees east of due south on a 30 degree pitch roof at a latitude of 52 degrees I assume the most I could hope for is that it would provide the majority of DHW for two people 6 months of the year. With such modest expectations I am wondering if the PV installation could be simplified by connecting it direct to a 2kW DC heating element in the hot water tank thereby avoiding the cost of an inverter and the hassle of registration? I don't know if such a DC heating element is actually available and I am mindful of a recent post from @Nickfromwaleswho warned that the DC cable output from a solar array is one of the most dangerous cables in a home. As I said at the start I am just exploring the problem space to comprehend what is possible.

At £25 I am convinced. Before posting I had found meters priced over £200 which is a lot for an amp hour counting device.

After some digging I have this budget: Inverter - typically £500 to £800 for a standard 4 to 5 kW model but for a tiny 1.1 kW PV array the price drops to under £300. Here is a 1.5kW example for £228 https://midsummerwholesale.co.uk/buy/Growatt-inverters/growatt-1500tl-x dc isolator ac isolator - these are just big high amp mechanical switches it seems? Say £25 each? Generation meter - this something the DNO pings directly to obtain FIT export kW hours? If not can it be omitted in a low budget PV installation?

I have a stalker, does that make me a celebrity? What actually happened is that a forum luminary claimed PV is now so cheap it costs no more to fit than a regular roof if fitted during the initial build. At the time I trusted every post from the luminary and so I went off to investigate the claim hoping it would definitely be true in my case since a natural slate roof is more expensive than most other roof coverings. An hour later and very disappointed I reported back and disputed the claim. It was not true 2 years ago and is still not true today even given dropping PV prices. There might be parity of costs excluding the actual PV panel but that is still a big margin. Build time is clearly the optimum time to fit tidy in-roof solar particularly as scaffolding hire must be a big factor with a retrofit. Anyhow the original thread descended into pointless bickering once another now departed forum luminary joined in and started asserting that black is white.

Do you have a link to an example? Due to an anticipated problem with planning in a conservation area I would submit an application with a self imposed condition to only fit all back panels. Edit: To say I walk quoting inc VAT prices.

Once a PV array is fitted on a roof what extra costs are incurred below the roof to get an array operational? The background is, I am tempted to install a small 3 panel 1.1kw roof PV array. Since I am DIY fitting the natural slate for my self-build, the marginal cost of switching 5 m2 of slate roof from slate to PV appears to be about £890. A PV panel plus a GSE in-roof tray is £300. I need to add about £120 for code-4 lead flashing because I hear that the non lead GSE kit flashing is not as good as lead and I am now more comfortable handling lead flashing. On the credit side I will save fitting £128/85 slates which means buying fewer slates for the garage later on. p.s. I am happy to skip any DNO registration costs because the FIT credit would be tiny on such a small array.

Roof PV is a controversial subject in my conservation area but I am wondering if I could sneak through planing permission for PV under a material variation as I did for a change of approved bricks earlier in the build. I have a planing condition that stipulates a natural roof slate and I would be looking for approval to substitute about 5 m2 of slate roof for a modest 1.1Kw 3-panel PV array inset into the roof with GSE trays. Total roof area is about 115 m2 and the PV array would be on a rear roof elevation. These all black panels mounted on in-roof GSP panels would blend in well I hope: https://www.lg.com/uk/business/neon-h-black p.s. For the technically curious... The 30 degree hipped roof has a complex L-shape and the principal elevations face east & west, hence a 3 panel array on the small southerly facing L-roof area is the largest that makes sense from a planning perspective. The largest roof area faces 8 degrees north of west. I hope a 1.1kw array will give us the two of us free daily hot water for 6 months of the year.

I was going to complete the build with a couple of in-line wallis heaters but assume the grant scheme will target retirement of gas or oil boilers. There is a gas safe plumber in the family and he usually has enough spare parts in his garage to make a boiler. I wonder if the boiler would need to be operational to qualify?

I can see you opted for a comprehensive job with a repointed chimney as well. Do you have a difficult neighbour on the left of the photo? I ask because on the right the dividing capping stones have been fully pointed or relaid but repointed to exactly the boundary on the left.

It sounds as though one of the post-sale plots will "own" the mains water feed before it branches off to the other property. The conveyancing solicitors should advised of this so that easements can be declared in the Deeds to grant access rights for usage and maintenance.

Ok. I will stick to my specialist subjects namely software and climate change science.

I thought the MAC address was fused into a network chip at fabrication time so could a procedural error in the fab plant cause this problem?

Defo the blocks, on a full size roof the straps should reach down across 4 blocks with a screw/nail in each. I suppose in the case of your single garage the forces will be lower. Having fixed many wall plate straps since starting this thread I suggest fixing with wall plugs particularly in the case of softer blocks under 10kg in weight (not to be confused with the compression rating typically expressed as something like 7N. @joe90offered an excellent tip in this thread which was to use a slightly undersized drill bit when drilling into soft lightweight blocks. In the case of my hipped roof I adjusted the regulation 2m strap spacing to ensure I had a strap on each wall closer to the hip rafter corners.

So am I. I need details to work out if it will be possible to complete my new build with a secondhand gas boiler plumbed in and then get the Government dosh to install an ASHP. As @IanRindicates the current info about the scheme in the public domain is superficial.

It is highly likely you are also a climate change denier. The recent forum thread on Insulate Britain was most revealing, I recall that all posters apart from myself piled in to express contempt of insulate britain whereas I was the only poster in that thread who commented that they might have a point and if so their actions are rational. Here is the main point I wish to make, most people are deniers relative to another more strident and urgent assessment of the climate situation. I image within the Insulate Britain group some dispute the actions of characters in the militant wing of Extinction Rebellion. These childlike binary categorizations of believers and evil climate change deniers fail to recognise there is a broad spectrum of interpretation of what rising co2 ppm will do to the climate and how soon and how humankind should respond.

Very well put like your other recent posts. I can cope with being described as an alien but they do not stop there, I am also a low intelligence alien with an undisclosed agenda to commit mass murder. I suspect these new 21st century fashionable causes attract people who need an outlet to express hate and to formulate mechanisms of subjugation against those humans they do not like. The cause is really immaterial because it just provides a convenient pathway into a corridor of anger which at the end of the day is the opiate of the hateful.

Lincolnshire has its own peculiar weather pattern, the national forecast is often described as "the depression will pass swiftly over Scotland with associated fronts bringing rain briefly to all areas except for the coast of England facing the North Sea because we expect the low to stall over Norway and introduce a northerly airflow. This airflow will pick up moisture from the North Sea and deliver 3 days of showers and grey skies over the coast fringe of Lincolnshire while the rest of the UK experiences bright fresh weather once the cold front has past over".

Who decides which emerging nascent ideas should be attacked or censored and which deserve further exploration? Real scientists understand that attempting such control of human inquiry is a hopeless and dangerous pursuit hence real scientists understand that scientific progress occurs when a minority dispute a consensus and propose a new idea. For that core scientific process to flourish, real scientists appreciate that an environment governed by the principal of "freedom of inquiry" is needed. Your daily posts here repeatedly demonstrate you are vehemently opposed to these two founding principals of science.