-rick-

Why not just get these: https://www.amazon.co.uk/Shelly-Pro-Dimmer-2PM-Consumption/dp/B0CV843RRW?crid=2TWY1PEEZZV5N&sprefix=shelly%2Bpro%2Bdimmer%2B2pm%2Caps%2C118&sr=8-6&th=1 Amazon price much lower than elsewhere. £25 per channel is not much more than the aliexpress impulse relay, but this does dimming, has local control (can direct wire switches) and in build wifi/ethernet/logic so you can program it to do what you want.

True you need a voltage or current sensor on each circuit for feedback, vs having 2x the number of coil drivers/retractive switches. Suspect the european market might have 'smarter' versions that do some of this for you (not looked).

Oh. Looking at that datasheet makes me think I misunderstood something about how they do it there. Traditional latching relays have one coil for on and one coil for off. But this seems to be an 'impulse' driven latching relay which I think means it will flip between on and off each time a connection is made on the switch line. This is much simpler for the rest of the circuit and I'd guess cheaper once you have the relay module. Nice.

Sure. I started replying because it sounded like you were against using concrete because it wasn't renewable which is true but the decision is much more nuanced. 👍

Feels like this is one of those new technology startup issues. Turbine size is still growing but I'd guess we are near the stabilisation point where its not worth going bigger. Once that happens then replacing like with like at end of life is likely something that can planned for. Not sure it's necessarily been something on the radar up to this point.

Congratulations on your first shower in the new bathroom!

They are, though I don't think this is really an argument that can be used against wind turbines or similar. The amount of concrete used in them (even if massively expanded) pales into insignificance compared to other big projects. Concrete + steel are pertty good in the end. Steel can be endlessly recycled pretty much. Using ground concrete as filler for other things is relatively good compared to many of the other things we do in terms of materials recycling. I believe ground concrete can be used in place of virgin sand/aggregate when making new concrete at least in a decent percentage of use cases. Concrete over its life absorbs a lot of the CO2 put out during manufacture and if we can switch from gas firing to renewable heat we lower the carbon footprint a decent chunk. A lot of more renewable building methods have overinflated/misreported environmental credentials once the full lifecycle is considered and once those things are considered concrete really doesn't seem that bad, especially given it's about the cheapest construction method. At a societal level spending more for a more environmental construction method may mean less money for more beneficial environmental spending.

My point is that they haven't replaced the cores on the existing fleet that is going to last to 50 years. They have had to do some very expensive repairs, some of which were particularly expensive because the design didn't allow for them. New designs shouldn't make the same mistake and either design out the need for those types of maintenance or plan for them. Well quite. That gets to the bottom of my issue. I don't particularly have an issue with nuclear power if it is competitive price wise. Given the ginormous construction costs the only way it can make sense is if the plants last a long time.

Yeh if it's a case that the financals work out for 30 years but the plant has been designed to last longer then fine. Someones planning for future profits, that's a different issue. If we get to 30 years in and they then turn around and say we need further massive investment if you want to continue for another 20 years then given the previous massive investment it's very poor planning.

Sure. I would expect that for a plant opening today that very few of the components would be original in 30 years time. But that to me is maintenance. If our existing fleet is running for 50 years, it just seems like we should design new plant to have the same life (with the expected maintenance). It's the parts that can't easily be swapped out that need to be designed to live the longest. And if we have managed to get parts that we built 40-50 years ago to live until today then we should be able to design the new parts to do the same. Not maintenance free for 50 years, but to last 50 years with planned and scheduled maintenance. Most importantly with a design that allows for all the maintenance tasks we have found necessary on the old plant to be possible and planned for on the new plant.

Prices at Bimble Solar don't seem much higher than last time I checked. Guess they have older stock but worth looking at if looking to buy.

Well quite, it's why I'd expect a new plant to be designed to last at least as long without the expensive life extension. Obviously maintenance, even fairly expensive maintenance, will be required to last that long. But if planned for upfront it's a lot cheaper than just building for 30 years and dealing with extension at a later date.

Yeh you clearly have the design right for the 'rip it out and replace with dumb wiring' option. But personally I want a solution to be that plus 'if the central hub fails, the light switches still work'. This is easy with sonoff style smart solutions (the switch modules can be programed to work like normal switches if the central hub is down). Little more difficult to find solutions with centralised dimmers. If installing a relay based solution then the european way of doing it works well (assuming you can get three way retractive switches and use latched relays). Switches on the wall are directly wired into the on/off coils of the relevant relays and in parallel you wire your smart system. Thus a switch on the wall directly triggers the relay but so can your smart system.

Honestly surprised by this. Given the cost of it (financial and environmental) I was thinking it was more like 50years. AFAIK, the last gen of nuclear is generally delivering 50 years ish of life.

*tongue in cheek* That's not the answer I expect from someone who decided there weren't any good heating installers so became one himself. Time to become a 'pv and heatpump' specialist