SteamyTea

You trying to get rid of Granny.

Pretty close at CoP 3. The difference is probably lost in statistical noise. I would not be basing a long term space heating decision on today's skewed prices. 18 months ago the market was totally different. What we do know is that in the medium term we are heading for electrification, no getting away from that.

These phase change materials have been around for decades. They are usually a coated wax sphere embedded in a sheet material. If they were any good, we would all have them. None at all, thermal mass is a nonsense term. It assumes that the mass is the important part, not the heat capacity and the thermal conductivity. Paraffin Wax has a latent heat of fusion of 190 kJ/kg and a density of 900kg/m³. Plasterboard has a SHC of about 0.84 kJ/kg.K and a density of 1000kg/m³. So on the face of it, for the same mass, phase changing wax seems useful. But that is comparing phase change with non phase change. Paraffin wax usually has a SHC of around 2 kJ/kg.K. so a little over twice as 'good' as plasterboard. So adding thicker plasterboard would have, except in the small thermal window of phase change, the same effect. And that is if the whole area was covered in phase change material. If the miracle board had less than 45‰ wax in it, it would have very similar storage capacity and response times. So my verdict, not worth the bother. Thermal conductivity is of little relevance as any sheet material should be backed up with good insulation on the cold side.

Nor anyone else's. The energy budget for a PV module has to be better than the 150% that this design has achieved. PV probably pays back its energy deficit several dozens of times in its lifetime. And it is quiet, small and fits on the roof. Coal is radioactive, and has the advantage that it can be set fire to.

Well said. Just seen my coffee drinking mate who is convinced that an oil filled electric radiator is going to be cheaper than the electric panel heaters he currently has. He will see them as a success as, by the time he has fitted them, the outside are temperature will be 8⁰C higher. He thinks that the oil acts the same as the bricks in a storage heater. He likes Facebook and is a complete twat most of the time.

I would think it is a bit hard, probably achievable with a, and we have to say it again, properly sized and operated air to air heat pump. Thing is, not worth basing the whole running the cost on a few very cold days. If we did that, we would never have a spare room (mine has been used twice in the last 9 years), or a large car.

So many reasons. In all honesty, you will struggle to generate at 31p/kWh as that is just a small part of the OPEX. We could work out a price including the CAPEX and a truer OPEX. But it will be more than 33p/kWh. Adding in thermal energy recovery may change the numbers though.

After EDF sending out silly numbers, my bog standard, quartly billing, by cash/cheque, standard variable rate, in the most expensive place (SW), night rate (or in other words, the most expensive contract you can get) is 15.37p/kWh (before VAT). Personally I think that is pretty good considering my storage heaters are 35 years old and have never had any maintenance, not even a fuse changed. Did have to change the water cylinder a few years back, less than £300 with new elements and thermostats. So maintenance less than a tenner a year.

There are about 9.5 kWh of thermal energy in a litre of diesel. So 9.5p/kWh. If the boiler can deliver at an average of 85% efficiency, then that is 11p/kWh. So a heat pump needs to deliver at just over CoP of 3.

Nuclear fusion researchers have achieved historic energy milestone A controlled fusion reaction has generated more energy than was put into the system for the first time, bringing viable fusion power another step closer to reality PHYSICS 13 December 2022 By Matthew Sparkes The National Ignition Facility in California Damien Jemison For the first time on Earth, a controlled fusion reaction has generated more power than it requires to run, researchers have confirmed. The experiment is a major step towards commercial fusion power, but experts say there is still a vast engineering effort needed to increase efficiency and reduce cost. Rumours of the experiment at Lawrence Livermore National Laboratory (LLNL) in California emerged on 11 December, but the news has been formally announced in a press conference today. In an experiment on 5 December, the lab’s National Ignition Facility (NIF) fusion reactor generated a power output of 3.15 megajoules from a laser power output of 2.05 megajoules – a gain of around 150 per cent. However, this is far outweighed by the roughly 300 megajoules drawn from the electrical grid to power the lasers in the first place. There are two main research approaches aiming to achieve viable nuclear fusion. One uses magnetic fields to contain a plasma, while the other uses lasers. NIF uses the second approach, known as inertial confinement fusion (ICF), where a tiny capsule containing hydrogen fuel is blasted with lasers, causing it to heat up and rapidly expand. This creates an equal and opposite reaction inwards, compressing the fuel. The nuclei of hydrogen atoms then fuse together to form heavier elements and some of their mass is released as energy – just as it is in the sun. Until now, all fusion experiments have required more energy input than they generate. NIF’s previous record, confirmed in August this year, produced an output that was equivalent to 72 per cent of the energy input from its lasers. Today’s announcement confirms that researchers have not only reached the crucial break-even milestone, but surpassed it – albeit if you ignore the energy required to power the lasers. During the press conference, Jean-Michel Di-Nicola at LLNL said that at peak power – which NIF only achieves for a few billionths of a second – the lasers draw 500 trillion watts, which is more power than output by the entire US national grid. The White House Office of Science and Technology’s policy director Arati Prabhakar said reaching the milestone was a “tremendous example of what perseverance can achieve” and that the results brings viable fusion power one step closer. “It took not just one generation, but generations of people pursuing this goal. This duality of advancing the research, building the complex engineering systems, both sides learning from each other – this is how we do really big hard things, so this is just a beautiful example,” she said. Jeremy Chittenden at Imperial College London says the experiment is a historic moment for fusion research. “It’s the milestone that everyone in the fusion community has been striving to achieve for 70 years now,” says Chittenden. “It’s a major vindication of the approach that we’ve been trying, for ICF, for nigh on 50 years. It’s very significant.” Most fusion investment is currently poured into the alternative approach of magnetic confinement, in particular a reactor design called a tokamak. The Joint European Torus (JET) reactor near Oxford, UK, began operating in 1983. When running, it is the hottest point in the solar system, reaching 150 million°C (270 million°F). Earlier this year, JET sustained a reaction for 5 seconds, producing a record 59 megajoules of heat energy. A larger and more modern replacement, the International Thermonuclear Experimental Reactor (ITER) in France, is nearing completion and its first experiments are due to start in 2025. Another reactor using the same design, the Korea Superconducting Tokamak Advanced Research (KSTAR) device, recently managed to sustain a reaction for 30 seconds at temperatures in excess of 100 million°C. Read more: DeepMind uses AI to control plasma inside tokamak fusion reactor LLNL director Kim Budil said at the press conference that the delay between the experiment and the announcement was because a team of third-party experts was brought in to peer-review the data. She said that now it has been confirmed, it is likely that a laser-based power plant could be constructed within a “few decades”, but that the technology for tokamak reactors was more mature. “There are very significant hurdles, not just in the science, but in technology,” she said. “This is one igniting capsule, one time, and to realise commercial fusion energy, you have to do many things; you have to be able to produce many, many fusion ignitions per minute, and you have to have a robust system of [laser] drivers to enable that.” Currently, NIF can be run for an extremely short period, then it has to spend several hours cooling its components before it can be turned on once more. Approaches being tried by new commercial start-ups may prove a better way forward, says Chittenden. “If we stick at trying to do this through massive scale projects, which take billions of dollars to construct and tens of years to develop, it could well be that fusion arises too late to have an impact on climate change,” says Chittenden. “What I believe we really need to do is to concentrate upon increasing the diversity of approaches so that we can try to find something that has a lower impact cost and a faster turnaround, so that we might be able to get something in 10 or 15 years’ time.” In addition to providing invaluable data for engineers working on practical reactor designs, Chittenden says NIF’s results could lead to other advances in physics, as the reactions seem even more intense and rapid than those in our sun, and more like those happening in a supernova. “We’re at extremes of pressures, densities and temperatures that we’ve never been able to access in the laboratory before,” he says. “These are processes that allow us to study what’s happening in the most extreme states of matter in the universe.” Gianluca Sarri at Queen’s University Belfast says the findings will allow all those fusion researchers to press on, safe in the knowledge that extracting energy from fusion is possible. “Now it’s just, and I say ‘just’ in inverted commas, a matter of refining and technical adjustments. It’s not going to happen tomorrow, obviously, because there are technical issues. We’re still far from a reactor. But we are on the right road,” he says. “In terms of clean energy, this [fusion research] is definitely the most ambitious route, but eventually will be the most rewarding because the amount of energy that you can unlock is potentially limitless.” Sarri says that his intuition is that the first working reactors will be tokamak devices, but that ICF research still has a vital role to play. “Both routes should go ahead, because they inform each other. There’s a lot of exchange of information between the two schemes,” he says. “The way they work is, in concept, similar.”

Probably badly You had used 20 kWh in 9 hours. As kWh is power (the kW) multiplied by time (the h), dividing by the time cancels itself out and makes the power the subject (what they used to say in maths lessons). So kWh / h = kW 20 [kWh] / 9 [h] = 2.222...... [kW] Rounding, or truncating, gives 2.2 kW. When the compressor, and the associated fan, is on, by huge difference. Yes. The ASHP controls may be monitoring the temperature difference between the flow temp and the return temperature, this is used to know if more energy is needed. Hard to do that if there is no flow and helps keep the system in the optimal range.

kWh I suspect. 50 kW would blow the main fuse on a single phase installation.

At what temperature difference? Watts is power, kWh is energy. So while this small area may be uninsulated, it is probably going to be better than a window.

They just do the switching though a smart meter. My neighbours have smart metering and E7. I still have an old radio switch, but some people still have mechanical timers I am sure. Mechanical timers would be great as you can wind them on a few hours.

Something to do with very high rainfall in November maybe. I think we had a rapid loss of air pressure yesterday, which helps down here went from 109 to 103 hPa) Ice still evaporates. Temperature, is the mean free path speed, or the mean vibrational frequency, depending if it is a gas, liquid or a solid. Because it is a mean speed, or frequency, some molecules will be moving faster, some slower. The fastest ones detach from the main material body and escape as a gas. This lowers the overall temperature of the main material body (it is how adding laser light, to make helium boil, actually lowers the temperature to very close to 0K). It also accounts, in part, for phase change in materials and the associated change in heat capacity. By changing the energy levels, the material tries to expand or contract, this can change the arrangement of the molecules (partly why we don't use nobles gasses as refrigerants, they are don't like to be rearranged). It is this molecular arrangement that changes the properties. A loose jumble in a gas, to neatly arranged, because of molecular polarity, in a liquid, to a fixed position in a solid.

Was 20 kWh for 9 hours. So about 53 kWh/day. That is about 2.2 kW of power, or 12W/m2. I am currently using about 18 kWh/day, which works out at 15 W/m2, and my temperatures are not as low.

Do you cook on LPG?

Right, there are a few of things. Is it a new build, if so, may still be drying out. How high is the flow temperature and do you keep the heating in permanently? Power is kW, kWh is energy, it is energy you pay for, not power. Do you use a lot of hot water, how hot is it stored at. How well insulated is your house, floor included? How does it match your heat loss calculations? It is 7⁰C down here on Penzance Promenade.

You could look at dMVHR. Basically though the wall extractors with heat recovery. May need two, and a cooker hood in the kitchen, lounge, diner. Have you considered summer cooling? This could change the whole ventilation design somewhat. Not that it is really needed down in the SW. the sea keeps the temperatures suppressed.

Should be easy enough to calculate it from first principles. As long as you know all the material's properties, and their surface area ratios, and the angle of the roof, should be easy enough to calculate.

Isn't that called what Governments, and social scientists do? If I want to scare people, I tell them they have a 5% chance of dying, not a 95% of surviving, and never mention the activity risk of death.

People need to be told that during primary school science lessons. If 8 year olds cannot be taught how reducing a flow temperature, or a flow rate, will reduce energy transfer, then school teachers need a kicking, not a (expletive deleted)ing pay rise. This reply was partly prompted by two women in the cafe talking about increasing the boiler temperature in their homes because, and this is their words 'it saves money', 'that but on the news was bollocks'.

Not always as simple as that. LPG (and combustion bi products) is very corrosive. So care has to be taken with choice of which motor, induction and exhaust, is used.

I don't object to a smart meter and get begging letters asking me to have one fitted. Shame after 2 attempts they (EDF) cannot get it organised. They cannot even organise the smart meter at my 'vunerable' Mother's home to be replaced. So shall just have to wait till the E7 radio signal is switched off and EDF are forced into action.

Welcome So am I, I don't think damp is a Cornish problem, crap housing stock is though. As other have said, you really need MVHR, just a matter of designing it in from the start. As you are having UFH, what floor U-Value are you designing to? ICF seems popular down here at the moment, we did have a member that was working for a local company, but he seems to have vanished. Can't remember who it was now.