SteamyTea

When it is really cold, it is winter. The instantaneous power from the sun is quite low, maybe maxing out at 600 W/m². As the panels will only get about 20% efficient, that is 120 W/m². So while the voltage will be at maximum (PV modules are fixed voltage devices), the current is low, the MPPT will do it's thing and adjust the internal resistance to get the most out of the system. So should never become a problem. Panels are rated, and tested, at a standard temperature, irradiance and air mass. It is extremely rare in the UK to breach those limits. If you do get lucky, the inverter will 'clip' the power initially (the fan speeds up and dumps the excess power as thermal energy, and then will eventually disconnect if it cannot reduce the output voltage and current to the agreed limits (usually 253Vac and 16A per phase.)

Have we heard from @Garald recently, he probably knows about ladders.

The English make a simple job complicated.

Regarding the PV, Building Control may also want structural calculations i.e. wind and snow loadings. If a new build then the Structural Engineer should be able to supply the right paperwork.

Never looked into this, but have heard of it being done. You could split the system into two strings, with each string consisting of 6 panels paralleled up to another 6. That would halve the voltage while doubling the instantaneous current. That inverter can take up to 44Adc, but is designed to operate at 26Adc input. So it really comes down to what your panels can do, what is the maximum amps they are rated at?

It is, generally, not the ones that know we need to worry about. I work with some completely uneducated numptie, if they get away with something just once, that becomes policy, regardless of how often it has failed before or after.

You could look at single room dMVHR. When it comes to the heat recovery of the ventilation, you really need to know how airtight your property is. The only way to do that is to get it tested. If it not that air tight, a positive pressure ventilation system may be enough. There are lots of nuances when it comes to ventilation policy i.e. where are the air leaks, what do they leak into, fraction of overall losses...

I seem to remember that they do get taught it if they do a proper Level 3 apprenticeship. We were taught it on our Part P (limited scope) and that was specially designed for plumbers, PV installers, HVAC etc. Steico do this useful guide. Site_Guide_A6_online.pdf It is wrong that technicians, from other trades, should be making decisions about structural elements. We would not expect a painter (which has Level 3 qualifications) to be making changes to structures.

SMA are a bit iffy about people tinkering with their inverts. Is it still covered by warranty. Seem to remember they offered replacement once the old one is sent back. Call the local agent and see. That would fry it for sure, especially when written correctly, kW. But you mean kWh.

Should have painted it before foaming.

Do you hear that tapping sound, it is the hammering of the coffin nails.

Integral skin polyurethane foams do that. Used for making chair arm rests, and costing the steel hoop in car steering wheels. If you cut it open, you will find a 2 or 3mm thick skin. It is created by temperature difference between the injected liquids that react and foam, and the tooling temperature. With a bit of experimenting you can find the best temperature to heat the can up to get it to either skin on the contact surface or the air interface. Alternatively, and maybe easier, foam up with something strong enough, then coat the outside with non foaming PU. In effect, creating your own skin on outside. (Thinking while typing the above, paint the joint with non foaming PU, foam, then paint outside with non foaming)

Was a problem with honeycomb aluminium and composite plastic structures. Was fine for making the 'tub' of a racecar, but heat shielding was needed in the engine bay. Some of those impressive supercar fires on in YouTube are caused by heat induced delamination. Use with caution. There is a reason SpaceX use stainless steel for rocket bodies.

Will have to say the word sperm, so will get in trouble. Softwoods are gymnosperm, hard woods are angiosperms. Now it is early in the morning to be thinking about wood.

Often wondered about that. I did ask for my system to be completed flushed out at the 100k mile service (and it was). Think it is pink.

There are many answers. Can you temporarily bolt wheels to an axle and fit that at one end, or even bolt wheels to the side.

We have been discussing this here. Hoping to find answers as well.

@Marvin While I can see people's concerns about lack of space heating when the DHW is heating, I can't recall a time that people have actually had a problem. There is no reason that DHW cannot be heated in smaller time steps i.e. half hour here and there, this is what PV to DHW diverters do. One if the things I have tried to do at home is limit the maximum current that my house draws. So when the DHW is heating, I don't have the storage heaters recharging. This is purely a game I play as my supply, at 100A is not at risk. The other game is increasing the length of time that my house draws zero power (well less that 1 Wh). I think 3 hours is my record. Must have had something defrosting in the fridge. Putting those two games together means I can get a picture of how much energy needs to be stored, and how little needs to be delivered to keep the same living standards. Do you have monitoring equipment that logs at the Wh level, or are you using the smart meters half hour averages?

A boy from St.Austell. There is a reason we call it St. Awful. He supported Liz Truss, and was chairman of the ERG. Seems an odd person to appoint.

Measured after how long after turn off? At that temperature, I still don't need to heat the house. Usually start heating when the daily means is 9°C or less. 23°C IAT is a bit higher than my mean temperature, but not by much. Are you going to try DWH at different times if the day to see if there is any difference?

Right, the important times are October, November, December, January, February and March, with the really problematic months being December and January. So October you will get a mean generation, the kWh (not Kwh), of 191 kWh, November 126 kWh, December (the worst month) 85 kWh, January 98 kWh, February 162 kWh and finally March 274 kWh. Starting with heating hot water, it takes 4.2 kJ (kilojoules) or 0.00117 kWh, to heat 1 litre of water by 1 K (kelvin, which uses the capital K). One kelvin (uses lowercase first letter when used in science, except at the start of a sentence) is, in this case, the same as 1 °C. So in October, you have enough energy from the PV, on average, to heat up 4310 litres of water from 12 °C to 50 °C, which is 139 litres a day. Quite a useful amount. November would be 95 litres/day, December 62 litres/day (not much), January 71 litres/day, February 131 litres/day and March 199/day litres. Now I have no idea how much hot water you use, you will have to work this out (a measuring jug, thermometer and a stop watch). This does assume that all your PV production goes solely to heating hot water. In reality, with a diverter, you may only get 2/3rd diverted (depends what else is going on in the house at the time). If you diverted to a heat pump, when it is running, you may, with careful timing i.e. run it from 10 AM to 2 PM utilise half your production, but you will get about 3 times that electrical energy converted to thermal energy. So October you will get 208 litres/day, November 142 litres/day, December 93 litres/day, January 107 litres/day, February 196 litres/day and March 299 litres/day. Now as you will be importing energy at the day rate from your supplier, you may find that during these months there is not much difference in running costs, but from about mid March to Mid October, you will be saving, but you will have to have bought a heat pump and possibly a domestic hot water cylinder depending on what you have installed already. Now let us consider battery storage. There are energy losses during the charge/discharge cycle. These vary depending on the rate of charging and the amount of charge that is already in the battery. The fuller they are, the harder it is to charge them the final bit. 10% losses would be a reasonable starting point. So rather than look at what can be done heating water, we will look at how much PV energy can be stored and extracted per day. October 5.5 kWh/day, November 3.8 kWh/day, December 2.5 kWh/day, January 2.8 kWh/day, February 5.2 kWh/day and March 8 kWh/day. Now it should be possible to store most of your PV production into the batteries with some clever diversion, though it may be more sensible to work on 80% utilisation. So October 4.4 kWh/day, November 3 kWh/day, December 2 kWh/day, January 2.3 kWh/day, February 4.2 kWh/day and March 6.4 kWh/day. If we convert that to amounts of hot water. October 100 litres/day, November 68 litres/day, December 45 litres/day, January 51 litres/day, February 94 litres/day and March 144 litres/day. So less energy is directly put into the hot water than heating directly from the PV. Any shortfalls will need to be made up by imported energy at whatever rate you pay. But remember that if you fully charge your batteries during a cheap period, there may not be any spare capacity to store excess PV generation. You may find that doing some simple and cheap improvements to the fabric of your house will give a better saving overall. There are also behavioural changes that can make a huge difference (why half the time my house uses no energy at all). The biggest change you could probably make is to change your car, and use it less. In the last decade I have gone from a car that does 53 MPG to one that does 65 MPG on average. That is a 22% reduction, considering I drive 35k miles a year, that is 1050 kWh/year. With my house using about 3,000 kWh/year (down from 11,000 kWh/year when I moved in) I am now hard pushed to make any great savings without spending a fair bit of cash.

Get yourself on a laptop or desktop and try this link. Mobile phones are useless on their site. https://re.jrc.ec.europa.eu/pvg_tools/en/ You should get a screen like this. Zoom in on the map and put a click/pin where you live, choose any of the solar radiation databases, they are all similar (at this stage). Change any angles if you need to, as well as the size of the system. Then click on Visualise Results. While this seems like a simple solution, the devil is in the detail. When your system cannot supply enough energy, you may be drawing from the grid at a much higher financial rate. Also these Time of Use tariffs are, generally, being trialled by suppliers, and may be withdrawn, which makes medium term decisions hard. Our electrical energy market is basically in turmoil and different political parties are using it to attract voters. So be wary.

Styrene Butadiene Rubber, which is SBR has quite a high melting point, so should be able to handle 100°C for quite a long times. If it is mixed in with a render, then thermal creep should not be a problem, if as a coating, then it may soften and move. Why has it been suggested that SBR is added, it is usually as a waterproofing agent. Always best to avoid combustion inside a building, so anyway you can ditch the burner.

What sort of heater is it? It is nearly always worth fitting PV as the energy is useful and easy to shift about.