Beelbeebub

I'll try and dig out my wiring diagram but here's the box Incoming tails from grid come in, the SPD and it's breaker are connected there. The love and neutral the head via the SolaX RCD and the live via the MCB out to the solax. They also go into the "grid" input of each changeover switch. The output of each changeover switch then goes to each CU. The eps love and neutral come back from the unit and connect to tge other input of the changeover switch (the live via the eps breaker) Currently CU2 is connected to the grid, the inverter can power it but it will go down in the event of a power cut. CU1 is fed via the EPS and stays up in the event of a power cut. (not shown are some Henley blocks below to split the connections)

It's the edge case really - kettle, toaster, microwave (not uncommon at certain times) get us over 6kw with house baseload. Chuck in a couple of hob rings and a HP (it'd a bug house so would be a fairly hefty one) and we could exceed 8kw. That said, the point of the changeover box is we can easily run everything off the eps if we find exceeding 8kw isn't an issue. As it happens we currently have a fault which was tripping out the Rcbo to the inverter. It effectively gives us a mini power cut. Not a problem as we run on battery backup, but in the current weather we'll eventually run out of battery and then have an actual power cut. So I just flicked the changeover to grid mode and now it"s fine, although we don't have automatic changeover if there was a real power cut. I did look at givnergy and a couple of other makes that use a seperate changeover box. For various reasons like lead time, cost, local installers etc I ended up going with a Solax DC coupled system and they use the EPS model, which is basically an integrated changeover system. All the mucking about with two consumer units etc (thr house already had 2 consumer units so it wasnt any extra work) was just me hedging my bets abouy future loads. It didn't cost much, IIRC the pair of changeover switches were about £75 and the bigger box to house them was £50 more or so. It did make installation a little easier as it provided a convenient junction box for thr various meter tails.

My solution was a bit complicated. My solax has a "eps" output that stays live in the event of grid failure whilst the grid feed is disconnected (all internal) As it's an 8kw inverter it will be fine for most loads except if we have a HP or induction hob. So I have 2 consumer units. One for lighting, sockets etc and the other for heavy loads like the induction hob and (potential) HP. The "heavy" consumer unit is fed from the grid so will go down in the event of a power cut. The light consumer unit is fed from thr "eps" that stays up. So in the event of a power cut the induction hob and HP will go down but everything else stays up. The final bit is both consumer units are fed via manual changeover switches. This means I can choose to feed both, one or none from the eps (or grid). If the power cut loops like a long one I can choose to connect the heavy consumer to the eps feed and just be careful.with simultaneous loading. Alternatively, if there is some issue with the inverter unit I can isolate it from the grid and run my house as normal whilst it's fixed.

Inevitable, but a bit annoying as thr current (15p outgoing) rate almost exactly matches the E7 rate (13.8p) effectively making charging and exporting the same which makes organising charging times easy. I just charged at night and exported in the day. I'll probaly stay on outgoing but go back to fixed rate.

I'm pretty sure uk regs say double pole breaker. I think the issue is if the cable is severed then the neutral can become line and someone outside working could get a shock between the neutral and local earth. Your electrican should know all this and sort it out The single pole seems to the Australian regs.

With that level of heat retention your best bet is to maintain the slab at a fairly constant temp, prob 20C or thereabouts. Basically as it is. You probably could try take advantage if cheaper overnight electricity to charge the slab up. Your cop will suffer a little bit but your flow temps will still be pretty low so it won't matter.

Fracking has been mentioned a few times in this and other threads. Aside from the arguments around there simply not being enough gas left in UK rocks to economically frack, I thought it would be useful to see what fracking actual looks like. Here is a Google maps image of the area around the town of Wickett, Texas. The two itself is the slightly grey patch under the word "Wickett". Those regular white dots in a grid pattern.... They're the fracking wells, both active and abandoned. As you can see, they extend for miles. In fact if you zoom out you can just see it continues. The area.covered in just this one field is hundreds of square miles, it's the size of several English counties. You don't have to be a rabid environmentalist to see this would not be possible in the UK even if there was the gas down there in the first place.

Some interesting diagrams. First from UK gov https://assets.publishing.service.gov.uk/media/6887aa04be2291b14d11b01d/Energy_Flow_Chart_TWh_2024.pdf And Lawrence Livermore labs. Some notes - the UK gov is 2024, LLL is 2017. The LLL diagram use Peta Joules whilst UK uses TWh Conversion is 1,000 Pj is 278Twh The reason I included the LLL diagram is that it shows wasted energy (heat) And the crucial bit is the useful energy for the UK is around 2,800Pj or 775Twh. A lot of people concentrate on the left side of the diagram, primary energy which is somewhere around the 2,000Twh of fossil fuels at the moment (the diagrams don't match up exactly so that is a round number) That is around 20x our current renewables - so people rightly say "hang on a minute, we have to build another 20x wind turbines, solar parks etc.? That seems alot....." But renewables don't have as much inefficency so we should be looking at the 7-800Twh useful work. For example transport uses ~650Twh of delivered energy (primarily petrol/diesel) but only around 140Twh is actually used - the rest is heat. So if we could double our current renewables (+100Twh) we could replace about 2/3 of the petrol and diesel we use. Domestic heating uses around 275Twh useful. If we used heatpumps with an achievable 2.75 SCoP we could replace the vast majority of domestic heating with another 100Twh of renewables. So we could replace 2/3 of our petro/diesel and almost all of our gas heating by 3x our current capacity - not impossible.

Absolutely, but in that scenario your maximum earning is saving your entire electricity consumption. Some people bank on making even more by exporting lots to the grid. Currently this works But if you are investing assuming you can export lots to earn even more you could be left flat footed. Ultimately about grid scale battery storage to reduce the need for more transmission capacity. Say Scotland. At certain times there is way more local power than they can use or export to the south because the transmission lines are at capacity If Scotland could store that excess and then release it when the wind isn't blowing, either to power themselves *or* to continue to export at the maximum the existing lines can take, there would be less pressure on upgrading the line. This could be achieved with battery farms, but it has been pointed out 50kw+ car battery could output 2kw for 24hrs. 5,000 cars could provide 10MW for 24hrs Kia UK sold 7,000 EVs in one quarter. Potentially 40MW of "generation" (or absorption) availible every quarter from Kia alone. Maybe they could use all the EV's the conspiracy nutters think are parked up somewhere in the UK after being pre-registered to inflate thr sales figures. 😁

The special tarrifs (cosy, go etc) might vanish. I suspect economy 7 is going to stick around for quite some time. The 15p fixed export will surely have to go sometime. I also suspect that the "agile" ie half hourly variable tariff types will become more common - I believe Spain has them as the norm. So when making the financial case for batteries don't rely on export remaking 15p. Don't rely on using your special 7p overnight car charge or cosy charging times. Do think about storing enough electricity to run through the night or at he very least the 4pm to 7pm peak Home batteries have the potential to really help the grid by massively reducing the peaks and dips and allowing less infrastructure upgrades or more efficient use of existing infrastructure. Potentially V2G could really help. Again, home batteries, rooftop solar and electrification of transport are often seen through the "Net zero" and "green" lenses, but they are also vital to energy security and cost reduction.

That was what I was toying with.

Carbon capture via trees only works if we don't burn the trees afterwards. Locking the timber up in building materials is good but ultimately the destiny of most wood is to burn or rot. Think of how many tons of trees used to cover the UK 300 years ago, and how much of that timber is still around in buildings, ships and furniture.... Not much.

Regarding your large dT What is your room temp and what is your floor surface temp. Depending on your levels of insulation /Air exchange the difference between your room temp and floor surface temp will vary. For example my old place was well insulated. For a 22C inside air temp I only needed my slab to be 24C or so when it was 5C outside. Of it was below zero I might need a floor temperature of 25C. The floor temp is usually fairly close to your return temp, as long as you have a decent floor surface. If you habe carpet, thick wood, rugs it may be lower. The goal is to get your floor slab to the correct temperature to keep your house comfortable in the current conditions. Once that is reached you heating system only needs to put in the heat you are losing. It looks like you were getting to the right return temp when you stopped. The second thing is your long loop will probably need a higher flow rate to achive the power output at a smaller dT. If it is most of the ground floor you might need to put out a kw or two of heat. That requires a fairly substantial flown rate at dt5. It may be you are hitting the flow rate limit of a 15mm pipe (which is roughly what an ufh pipe is) so thr dT needs to be larger to put the power out.

I argue that the cheapest way to increace our domestic energy production is via increacing renewables at or above the rate currently proposed.

Views on what is practical may vary to a degree, but not all opinions are equal. For example, if I said I thought it was practical to generate the entire primary enrgy demand of thr UK using fusion energy by 2030, that would be entirely impractical.

My understanding is the Adia kit replaces the TRV and you wind the lock shield fully open ie all thr flown adjustment is via moving the TRV plunger up and down. The TRV valve isn't really designed for this but it will work. The key is very pricise control of the plunger. Adia use a. "TRV" than can move the plunger in 1% increments (sonoff do one - might even be the same unit rebadged) I tried (before I moved) controlling thr flow temp of my ufh system by using a similar approach. It worked OK, but because I was using a thermal wax valve, precise control.was very difficult. I had to pwm the power to the valve to start to melt the wax, then when the desired opening level was reached, back off the pwm so the melting stopped. The level of pwm needed to hold at a specific opening % was very variable as factors like ambient temperature, flow temperature and heat soaking of the assembly all varied. If I had access to the Adia style valves back then it would ha e been a lot easier. So for UFH I would say the flow setting valves would be wound open and the regular thermal actuators replaced with Adia units the system would then treat them as radiators.

I don't know how much wind/solar capacity could be constructed for the £22bn he mentions is being spent on Carbon Capture,but it's infinitely better value.

Indeed CC is, alongside Hydrogen boilers, a load of bollocks. And we should be pragmatic. The problem is nobody can agree on what is achievable or not. I was arguing (I know think of it) with a chap on YouTube who was convinced only new builds could use heatpumps, they cost upwards of £33k after subsidy and required you to give up you gas cooker. *if* that was true then yes, the idea of moving the country to electrified heating is impractical without vast cost. Of course, it isn't true. One thing to think about is Octopus are arguing strongly for a local electricity market, almost certainly with heavy skew to ToU tariffs. I doubt thr CEO of an energy supplier heavily invested in the digital infrastructure required for individual real-time pricing of electricity is pushing for a move to individual real-time pricing of electricity out of thr goodness of his heart. I'm not saying there isn't value in the proposal, only that he is far from an honest broker in the debate (as in he is undeniably partisan not as in he is dishonest)

Are you sure? He is big into heatpump and renewables.

The outgoing head of national grid said the transmission costs are about £25 a year an an average bill. With the investment to connect wind etc that will double (watch for daily mail headline) to £50,but the savings on constraint costs by having more capacity will save about £40, so a net £10 a year increace <https://open.spotify.com/episode/5PuyXuWML9xvzb2iHcIrUH>

The price of electricity is ultimately an entirely politically driven thing. The government could pass laws that subsidised or taxed one or other form of energy to make it cost whatever they wanted it to. They could make petrol 1p a liter via massive subsidy or £5 a liter via huge tax hikes. Electricity could be 100% nationalised, the cost borne through general taxation and the electricity provided for free So you can snort and say "Not until someone radically alters the way electricity pricing is calculated" and be correct - because it would be correct in any situation. You could equally argue that massive drilling for the oil and gas isn't worth it because it won't reduce the price "until someone radically alters the way electricity pricing is calculated" But that misses the point. It is alot easier to lower the price of something that is cheap than it the price of something expensive. The more cheap electricity that is produced the easier it is for politicians to put policies in place to make electricity cheap to consumers. Whether they do this is an entirely seperate question

Sorry which undeniable fact? That the UK oil and gas production will keep falling? That renewables are the cheapest source of electricity? Or that a cheaper source of electricity has the potential to reduce bills? Which one of those is flying in the face of reality?

The orginal point of this thread is that, despite what some political parties would have you believe, the UK's production of oil and gas are going to continue to fall, no matter what we do. We therefore have the choice between "Net zero" polices like demand reduction and electrification of heat and transport or becoming even more dependent on oil and gas from other countries the majority of which are not friendly. Renewable electricity is cheaper to generate than any other type. Therefore it has the potential to reduce the price of energy. This is undeniable. People are already starting to get cheaper electricty by using variable tarrifs to take advantage of times when you can get a khw of electricty for a penny. The fact that our current market setup doesn't pass this cheaper electricity price on to consumers isn't the fault of renewables. To blame the high price of electricity on renewables - that is the blatant lie, often told here (and in the media).

@botusbuild is correct. Because we are part of a larger market uk generators (like our hypothetical magic generator) will be able to export some of their electricity via the interconnects so we are "competing" with European energy prices. This is why the French experienced a spike in their electricity prices despite having lots of nuclear generators - French consumer were having to compete with British consumers for French nuclear electric. Of course this is governed by the interconnect capacity more than anything. At some point the UK will have so much capacity that it simply cannot export enough if it to boost the price - sort of like the problem Scotland has already... And a larger better connected grid is better. Ultimately we could be benefiting from Spanish solar, they will benefit from British wind, Norwegian hydro, solar and wind across Eastern Europe etc. Across Europe, the sun is usually shining somewhere and the wind is probably blowing somewhere. So yes, lowering the energy price isn't quite as simple as ditching the auction. On the other hand it is an artifact of our (wider) market so by making changes the price could probably be lowered - unless the current system and mix is (by some miracle) thr absolute optimum already.... 😁

But as has been pointed out continually - the prices remain pegged to gas because of the auction structure. If we had a magic electric generator that produced 25GW 24h a day for a penny year, that would provide nearly 70% of the UK annual electric demand for 1p yet the wholesale price of electricity would have remained the same under the auctions system and people would be claiming that magic electric generators increaced our bills. We do need to come up with a new market mechanism that allows the savings of cheaper generation to be passed on to consumers whilst also maintain investment and reliability. That is a separate issue from "Net zero". But fundamental to coming up with that solution *is having the cheaper generation capacity in the first place*