SteamyTea

Yes. I hate seeing this. It may well be totally safe as disconnected at the other end, but one never knows at first sight.

And two weeks of very sunny weather and the associated loss of FiT payments.

That is odd as most systems are turned off on the AC side first. The DC side can be delivering quite a high current to the inverter and arcing can occur. Turning the AC side off first and the inverter will automatically shut down safely ass it mimics a power cut.

An inverter not only turns DC to AC, it also synchronises the AC waveform to the grid waveform. But much more importantly it is a safety device that disconnects your system from the grid if there is a power cut. This is to stop 230V flowing down the line to where people may be working.

Oh dear.

The left hand side switch (black) is the DC isolator, right hand side one (red) is the AC isolator, yellow box is the inverter and the little grey box with the LED display is the generation meter.

Sounds like he does not have much experience with PV. You can get PV diverters that will switch on a load when there is excess PV generation to reduce exports, but that does not sound like what he is saying. In general a PV system has two isolators, one on the DC side from the roof modules, and other on the AC side after the consumer unit (fuse box). Between those two are the Inverter and the generation meter. The Inverter is what does all the magic in converting, conditioning and controlling the PV generation, the meter just shows a record of what it has delivered.

MGH Where M = mass flow rate kg.m-1.s-1 G = gravity, call it 10 m.s-2 H = height in metres, m

An encased virgin, just waiting for @pocster to turn up.

I am not full of self pity. I wonder if he is still hiding at his mum's near Newquay.

TL;DR (except for @pocster's first ultimate solution). But why not an electromechanical isolator? Shoot the dog and stop washing cars, it is now illegal to entice a boy scout with your puppy for a bob-a-job.

I wonder if titanium is really a suitable material for an immersion heater. Great in a Warthog, but doing a very different job. Inconel is possible better. Water types may also make a difference. What works in my very soft water may not last long in the Chalking Chilterns.

I tried to buy something from eBay using PayPal the other day, said it does not use PayPal anymore.

Do resilience bars work like a spring/damper combination. Simple harmonic motion.

Yes, best ignored. The confusion comes about because of the testing method. During testing the modules are given a flash of light, at a known intensity and while the modules are at a known temperature. Those condition will be extremely rare events in the real world. So rare intact they probably never actually happen.

Work out the mass of the blocks, and the surface area. Concrete has a specific heat capacity of 0.8 kJ/kg and a thermal conductivity of around 2.4 W/m.K. Add to that, the very small amount of energy that can be absorbed in the room, not going to be worth it. I had a thermally leaky door to my porch, so always kept the connecting door shut. I fixed the thermal leaks, now I don't need to keep the connecting door shut. Worth remembering that when the air in the room is hotter than the storage medium, the store is cooling the room as it absorbs the excess energy (which as shown us half a coffee cups worth). Most of the time, the air in the porch will be colder than the concrete storage, but only by a K or 2. So not enough to drive a meaningful temperature change. High mass houses i.e. brick and block, overheat, or underheat, the same as low mass houses i.e timber ones. The important thing is the thermal conductivity and the associated U-Value. There may, on a very rare day, be a time when all the energy inputs and outputs align up and give the impression that 'a news system of heating has been invented'. It is an illusion based on a small sample, and generally not from research done in the UK. We have seasons because of our latitude, and a variable maritime climate because of our geographical location. You can't change those two.

Except for the exception, when at the start of a sentence.

Are we going back to the padded shouldered 1980s?

F = ma Where F = Force in newtons, not Newtons, that was the man, Sir Isaac Newtons. m= mass in kg a = acceleration in meters per second squared, m.s-2. To really confuse, read this about weight. https://en.wikipedia.org/wiki/Weight

Aluminium and steel cables are much more efficient, 3‰ losses instead of 60‰. Fuel cells, fool's cells.

Bitumin is around the 9 mark on the PH scale. Best to keep the soil similar. Not good for growing stuff. Sodic soil has water retention issues as well.

Hydrogen power.

Registration is the first step in controlling a population. Who remembers the fuss when they wanted to issue your NI number on a bit of plastic, instead of card that that the acted like blotting paper.

I find burning paint off, with a flame, very relaxing. The fumes are worrying though.

Staining bar, used to be very common in Morrocan toilets. Or was that just my experience.