Where the electricity comes from.

[otherclive]

i am probably like a lot of other people who "just know" their house is not well insulated, and have never bothered to get it sorted, Its daft really because we all know the best way to keep our energy cost down, and avoid price increases, is to avoid using it.

My father was very aware of the benefits of insulation, but when a sales rep came to offer to insulate the house with cavity foam, my father said the house didn’t have a cavity. The sales rep was insistent that it did so in the end my father agreed for the work to be done. A surveyor arrived and after a while asked to look in the loft. He came back down and and told my father the house didn’t have a cavity. “That’s what I told your colleague“ said my father. But the surveyor was still puzzled when my father told him that the sales rep had asked when the house had been built. It had been built post war when cavity walls were being required. But since the house was bombed the rebuild funded by HMG had to reinstate it to the original building standard. Hence no cavity walls.

 

[bertieboy1]

That’s fine as long as all of your generating capacity is available. Tomorrow we will sit in a high pressure zone and wind renewables will be a bit slack so some alternative generating capacity will have to fill the gap. One way or another it has to be paid for.

The authorities make sure generating capacity is available by demanding generators not running are available at all times to generate.

 

[otherclive]

The authorities make sure generating capacity is available by demanding generators not running are available at all times to generate.

That’s basically what I said.

In a period of high pressure and/or reduced solar that capacity may have reduced output, or some elements have no output. Similarly in storm conditions wind turbines can be taken off line and not available. I did say “ some alternative generating capacity will have to fill the gap”. Those power sources that then have to be used have to be paid for even when they are not being used.

 

[RogerL]

We certainly would not recommend air source heating to anyone. Many people do not realise that the colder it gets the harder the machine has to work to produce heat and the more electric you use.
On many occasions during the past 9 years during the winter our Mitsubishi machine has become a big solid mass of ice as all the fins ice up even thouhg it has a defrost mode. If I cna find pictures I will post them up. Also if by chance the temperature dropped below -11C, then machine will not function.

As I understand it, ground-source heat pumps are far superior to air-source heat pumps - but way more expensive, not that air-source is cheap!

 

[Ern]

As I understand it, ground-source heat pumps are far superior to air-source heat pumps - but way more expensive, not that air-source is cheap!

Ground Sourced heat pumps can be prohibitively expensive and may not be permitted by LA's. Obviously the temperature is higher and stable, so ideal when compared to Air Sourced.

 

[Jcloughie]

So, what today is regarded as the "best" established building, wall insulation, for a late 1950s build?

We are very exposed* and the outer bricks are quite porous, having needed treatment for this, and we were strongly advised 30 odd years ago, by the surveyor never to have the cavities filled as ventilation here was essential.
Over clad the southern and west facing walls with say hanging tiles, and then cavity fill?

* a fetch to Venezuela!!!

Exposed Cavity walls with poorer quality brickwork are best NOT filled. The original purpose of a cavity was not to insulate, but as a physical barrier to moisture. NO thought was given to insulation at that time. To increase the effectiveness, the cavities were vented top and bottom in order to have a free flow of air to keep the cavity dry.
One of the issues with this method, which went on for 60 plus years, that was not understood. Is that when a house was heated some heat is lost to the inner leaf. This in turn warms the air in the cavity. Warm air rises driving the air through the cavity and drawing cold air in at the bottom. This draws yet more heat from the house. The warmer the house is made the faster this happens. It may be the also cause condensation.

One fix is to build the vents in and try to make the air in the cavity static. It then works as an insulator. But the surveyor is correct. Injecting insulation in those circumstances is very risky.

John

 

[Sam Vimes]

Consider also minimising draughts but still having adequate ventilation.

 

[Buckman]

Our air source heating has been frozen over since early morning and at 1pm it is still frozen over. Not sure if it affects its performance? It should be 20C in the lounge but is only 19.1C.

 

[RogerL]

If the air flow is restricted by frost, then it's performance will be reduced as a minimum.

 

[Sam Vimes]

It's my understanding that there should be a periodic defrost cycle to get rid of this. Your heat pump will still work under these conditions but the efficiency will be reduced.

 

[Buckman]

It's my understanding that there should be a periodic defrost cycle to get rid of this. Your heat pump will still work under these conditions but the efficiency will be reduced.

We have been complaining about it icing over for the past 10 years and periodically they send someone when it is not iced up. It has now defrosted as the sun is shining on it, but at times it can be like that for days.
I am not sure if the fins that are iced up help with the heating or actually how the air source works except that it is the opposite of a fridge.

 

[otherclive]

We have been complaining about it icing over for the past 10 years and periodically they send someone when it is not iced up. It has now defrosted as the sun is shining on it, but at times it can be like that for days.
I am not sure if the fins that are iced up help with the heating or actually how the air source works except that it is the opposite of a fridge.

A fridge takes heat ( low temperature) out of its compartment and transfers it into the room. The principles are the same. This article by Which might be useful.

https://www.which.co.uk/reviews/gro...,stored hot water for showers, baths and taps.

 

[Jcloughie]

In a fridge, the condenser can become restricted by dust etc. Particularly, if like ours, the condenser is in a block and has a fan to blow through it. (A bit like a car radiator). I have found a significant improvement in the fridge cooling by periodically cleaning the condencer.

I know the air source heating is the reverse. But perhaps they suffer in the same way. Or, for yours most likely the evaporated which would benefit from cleaning.

I did my fridge with a radiator brush and a hover. And also cleaned the fan blades with soap and water.


John

 

[Sam Vimes]

This is bit of a long read but it will tell you in reasonably simple terms how the heat pump works and about defrosting.

How to Defrost a Heat Pump in Winter - Evergreen Energy

When the temperature drops, the heat pump will run a defrost cycle to fix the problem, the whole process is fully automated. Read on why that happens.

www.evergreenenergy.co.uk

 

[otherclive]

This is bit of a long read but it will tell you in reasonably simple terms how the heat pump works and about defrosting.

How to Defrost a Heat Pump in Winter - Evergreen Energy

When the temperature drops, the heat pump will run a defrost cycle to fix the problem, the whole process is fully automated. Read on why that happens.

www.evergreenenergy.co.uk

That’s an excellent article. Even our domestic dehumidifier has a frost sensor to activate a defrost cycle, which basically just switches it off. But it rarely has to defrost as it sits in one of the bathrooms and the room temperature is normally high enough to prevent frost build ups

 

[otherclive]

Going back to the title of this thread the link below may be of interest given that not much has been said recently in the media about new wind farm projects. But the scale of the latest enterprise is vast and would make Scotland one of the worlds largest generators of renewables, and provide work and income for many local communities too. It is also all offshore and well out to sea.

https://www.bbc.co.uk/news/uk-scotland-59980279

 

[Sam Vimes]

Interesting.... I just hope that they get the interconnectors in place and they are reliable, because I reckon most of this extra capacity will be beyond Scotlands needs.

Below is another interesting site that has a map section showing where all the generators are. The panel on the RHS - on my screen - can be used to just select a specific type of generator.

Energy Dashboard - real time and historical GB electricity data, carbon emissions and mapping

Live and historical GB electricity generation facts and figures, showing technology and fuel type, cumulative data and supply & demand analysis including embedded energy.

www.energydashboard.co.uk

 

[otherclive]

Interesting.... I just hope that they get the interconnectors in place and they are reliable, because I reckon most of this extra capacity will be beyond Scotlands needs.

Below is another interesting site that has a map section showing where all the generators are. The panel on the RHS - on my screen - can be used to just select a specific type of generator.

Energy Dashboard - real time and historical GB electricity data, carbon emissions and mapping

Live and historical GB electricity generation facts and figures, showing technology and fuel type, cumulative data and supply & demand analysis including embedded energy.

www.energydashboard.co.uk

Shouldn’t be beyond the wit of man to install the interconnection terminals and cables, They could route under the sea until required to come ashore as it will generate about 25% of UK requirements. So routing some cables south will be required and sea bed installation could be cheaper than land installation unless the exiting grid network from Scotland south can be used as main power stations become decommissioned.

 

[Woodentop]

The international interconnectors from such as France and Norway use direct current. Does anyone know what the turbines feed to long cables? (Solar panels also generate d.c of course.)

 

[Hutch]

Today, with the weather being a bit warmer, 8c we had an upper window open and the lounge window open for about 4 hours. To clear the possible covid germs. Closed them at 4 pm. At 7pm checked the "Paranoid meter" and we have used £2.50 more to reheat the house.

Not going to be great if the prices of fuel go up.,

 

[Hutch]

As a follow up, we have used less water this last 6 months as we are not washing our hands as much as we were 6 months ago. Last December until june estimated, usage £268. July to December, actual usage £91.

 

[Sam Vimes]

There is already a Western High Voltage DC Link in place between Scotland and North Wales. Its bi-directional but I believe mainly used for exporting the surplus renewable energy we generate here. Unfortunately it's had a bumpy start - like most projects of this scale - late to get up and running and then prone to a few outages.

There is in the planning stage I believe an Eastern Link from Scotland to England. If its of the same type then hopefully lessons have been learnt from the Western project.

I have a feeling that large scale wind turbines generate AC as its easier to connect to the grid. Smaller 'home brew' turbines tend to be DC.

 

[ProfJohnL]

One of the inherent benefits of of using AC is how it is relatively easy to change its voltage simply by using transformers, and that is why its become the de-facto standard for virtually all mains power supplies that consumers come across. But for the businesses that generate and transport power, the picture is not quite so simple.

There are some very good reasons to use very high voltages to transmit power over long distances, but there are some more complex reasons whether to choose AC or DC transmission.

AC has the advantage of being relatively easy to convert to different voltages just by using transformers - and that is how most of the UK's and much of the worlds electrical power is managed.

However in recent years as high power ultra long distance transmission has advanced, there are some benefits to using DC rather than AC.

 

[Buckman]

Isn't the loss over distance using DC greater than using AC? All MPANs have a loss number calculated into the MPAN number and this varies even with domestic supplies and can affect the cost per kw.. The MPAN loss number is the third set of numbers from the left and is 3 digits.

 

[Sam Vimes]

Isn't the loss over distance using DC greater than using AC? All MPANs have a loss number calculated into the MPAN number and this varies even with domestic supplies and can affect the cost per kw.. The MPAN loss number is the third set of numbers from the left and is 3 digits.

The choice of DC vs AC for High Voltages transmissions is complex. There are losses in both systems, but due to different causes, and its hard to work out, unless your an expert, what the rationel for using one over the other is. According to some, DC is a better transmission system ( I guess taking into account all the pros and cons) than AC but AC is the main system as its easier to drop down to usable voltages.