SteamyTea

You also have different air film values for ceilings and walls that affect the overall R-Value. But as @Russell griffiths says, let the proper insulation do the real work. It is what it is made for.

Cellulose, the first commercially useful plastic was plant based. Many polyurethanes are as well. Last week's comic was all about chemistry. Endlessly recyclable plastics could fix our waste crisis Katharine Sanderson Untold amounts of plastic waste is polluting our land and seas. Now, we’re using chemical tricks to design infinitely and easily recyclable materials ../../../../wp-content/newsci_images/aHR0cHM6Ly9pbWFnZXMubmV3c2NpZW50aXN0LmNvbS93cC1jb250ZW50L3VwbG9hZHMvMjAyMi8wMy8wMjEwMjQwMS9TRUlfOTA5NTg2NjguanBn.jpeg Graham Carter One thing chemists do superbly is make bonds between atoms. We are now wading through the consequences of that success: plastic waste that ends up burned, landfilled or floating in the oceans. Plastics are polymers, long chains of molecules linked by strong chemical bonds. This is why they can be hard to degrade or recycle. Snipping apart those chemical bonds, to return to the small molecular building blocks, is often a tricky chemical problem. There has been varying success in dealing with the main plastics we use. The low-hanging fruit is polyethylene terephthalate (PET), which is used to make plastic bottles. It can simply be shredded and remoulded into fresh bottles. No chemists need apply. It is a different story with most other important plastics. Take polyvinyl chloride (PVC), which is ubiquitous in double-glazed windows and plenty besides. “PVC’s an absolute nightmare,” says chemist Anthony Ryan at the University of Sheffield, UK. There is no known way to recycle it, and even if you did, you would end up with vinyl chloride, a toxic compound that can increase the risk of cancer. One job for chemists, then, is to devise new reactions that can break plastics into molecules that can be reused. Susannah Scott at the University of California, Santa Barbara, has recently had success doing this with polyolefins, a class of plastic that includes polyethylene. She developed a technique that uses a catalyst to break down these plastics into smaller molecules without having to use bucketloads of heat. These smaller molecules could be used in detergents, paints or pharmaceuticals. We also need to design new plastics and plan from the start what will happen to them after they come to the end of their life. Chemists are starting to invent plastics that can be recycled infinitely or that break down into materials that nourish the soil. One example is the plastic devised by Ting Xu at the University of California, Berkeley. Xu added tiny enzyme-containing capsules to the plastic. The material can be processed, heated and stretched into useful objects. But when its life is over, all you need do is soak the stuff in lukewarm water for a week or so. This releases the enzymes, which digest the plastic into small molecules. We will need plenty of new materials like this if we truly want to eliminate the scourge of plastic waste.

Both very good points. I sit and have a coffee overlooking the inner harbour and chat to 'an old fellow'. Was a brickie until he retired. He was adamant that renewable energy was so expensive that none of us could ever afford it. Pointed out that it is the cheapest to deploy, and if we changed our planning policy, it would be even cheaper. Only now has he realised what I have been saying for a few years is true.

Yes, but it does go back to what the IEE said 30 years ago about decarbonising and replacing existing generation capacity. The electrification of all energy sources are not a new 'thing' that needs to shock people. The UK has consistently had a bad record of investing in the energy sector and has changed policy every few years. There has been no long term plan, and infrastructure planning has been, generally, left to town councils to approve. The same town council departments that hamper people building a home, or demand that a window has to be moved six inches. Yes, and for every lifesaving heart valve, we make several tonnes, if not hundred of tonnes or unnecessary products from plastic. No one is saying that transitioning off fossil fuels will be easy, just worth it. If I had said in 1974, 'I have seen the future of motoring, it weights 2 tonnes and does 20 MPG", I would have been laughed at. Almost 50 years on we are driving SUVs and supplementing them with secondary vehicles that are slightly more economic on fuel. Think that policy changed about a decade ago. They were starting, from a very low base, if you look at kWh/year.person, rather than TWh/nation. It is worth noting that energy is not all about solar and wind (actually the same thing), but also hydro, geothermal, tidal, and nuclear. It is the mental shift from combustion to non combustion that is hard part, not the actual technology used.

Why isn't it the solution? Wind power in the UK produces about 70,000 GWh a year. If Hinkley Point was running, it would produce less than half that.

Just been listening to You and Yours, it is about how energy prices are affecting you. The first caller claimed that her car fuel bill had gone up from £30 to £60 for the same amount of fuel, and she actually does less mileage. No idea where she is filling up, and where she got fuel at 80p/litre in the past. Some people need to be given arithmetic lessons. I also found it interesting that she lived in an old, leaky house, and both her, and her daughter had health problems, with her daughters caused by the cold house.

All depends on your DHW usage. Cut it down to 50 litres/person @50°C and probably not. 300 litres per person @80°C, then probably.

Quite. I am not sure if a higher than average local voltage is more if a problem than a lower voltage. Something to ponder.

That is quite interesting. I live in a row of 6 houses, all electric. Assuming my neighbours all use the heating/DHW in a similar fashion to me i.e. E7. Then we can all easily be pulling an 8 kW load at night for a few hours. During the day this will drop to a couple of hundred watts, with spikes of a couple to three kW each house. I would have thought there would be no need to upgrade where I am Trouble is, hard to get even 3 kWp on the small roofs, so technically not a problem. But it makes me wonder about some of the larger, newer developments on the North Cornish Coast that are off the gas grid.

Yes, it take parts of randomness and chaos, drizzles them with new means of old words, then claims to be the answer.

I had the great pleasure of showing David Elliot around my university back in 2006. He tells interesting stories about nuclear power decision making in government.

Send that in for the SE side, the electrical certificate, the inverter certificate of conformity and the agreement with the DNO. Can't think you would need anything else. But just incase, list the mounting system components and manufacturers.

Oil hit £94/b So that will be 6p/kWh Considering about half is turned into heating/transport fuel, that isn't too bad. About 16p/kWh at my local Tesco.

https://mcscertified.com/wp-content/uploads/2019/08/PV-Book-ELECTRONIC.pdf May help.

Did you get it signed off by a structural engineer, assuming it is roof mounted. That is the only thing, apart from all the kit being approved (manufacturers datasheet should cover that) that you may need.

Citation required Bollocks to citations at that cost, I would be burning coal in the back yard. Maybe drip some water on it to make H and CO. The H as fuel, the CO to speed up the end.

Yes, but it was more from a practical viewpoint. What is the fundamental differences in circuit design. Though these days it seems you buy a complete chip that can do the lot. My gut feeling is, if you run things at a higher voltage, you can get away with 'lighter' cabling and controls.

Our old mate, @Ed Davies has been looking into this. https://edavies.me.uk/blog/ as did I a while back. As usual, no real conclusion.

I asked a question, a year or so ago, about the best way to control the power of a resistance heater. Control the current or the voltage delivered? Not sure if it was a good question in reality, but no one answered it anyway. Really a matter of what is the best way to control power when there are several variables. (While I was the best in my class at university, better than the lecturer, my knowledge is very limited in reality)

Then in most cases it won't get done As they say, "Can't help stupid". It will highlight that bewildering mentality that when property prices rise significantly above inflation (as they have done in many places for 25 years), people think they are better off. Not as if you can pay the gas bill with a brick from your mansion wall.

Isn't part of the problem that PV cells are basically current source devices, and the current they produce is proportional to the light they receive.

That is easy, the property owner. I am a bit miffed that the daily rental on the electricity meter has gone up, in part to pay the debt on the failled suppliers. No one, who save on their bills through these bad businesses, offered to but me a coffee even, let one pay part of my bill.

Gives me something to work to tomorrow.

Chicken. Ultimately, I want to use the least amount of power for a reliable connection. It is a very good fix all the same.