Energy saving spotlights

Ben84

zeupater wrote: »

Hi

Decent post until the above was written, I was going to post on biogas, but no need now .... Anyway, regarding the above - how does a nuclear plant work ? .... what does it do with the heat ? .... would the heat provided by nuclear be more or less efficiently utilised if converted to electricity at source and delivered via wires or piped to the customer as steam ? ... what are the relative losses (resistance vs thermal) over distance ? ... how many reactors are close enough to a population density to make this economical ? .....

HTH
Z

Ok, I don't have all the numbers, but it's not total flying cars fantasy either District heating from nuclear plants is already being used in Switzerland and Russia, plus some others I forget where now. All examples I know of are CHP plants that use largely the excess heat produced when generating electricity (roughly 40-60% of total energy emitted by a thermal plant, which typically in the UK is wasted), although some also consume extra fuel to produce heat.

District heating can be an efficient way to distribute energy, it's used extensively in many cities to deliver heat from fuels like gas, oil and coal at reasonable prices, so it seems reasonable as a way to deliver energy from nuclear plants too.

As for how close, there were plans in Finland to link their existing district heating in Helsinki to a nuclear plant about 100 km away. The plans fell through I believe, but not because of technical issues. It would apparently have cut their national carbon emissions by around 6%.

Ben84

rogerblack wrote: »

District heating only really works when you can do whole districts.
This means that it works really well if, for example, you could build a whole new town, or suburb, putting in the very large required pipes at the same time as the sewers and other utilities, from a central power station.

I'm sure it helps to design in from the start, but you can install successfully in existing cities. Many systems are running in cities and areas where the buildings are very old and pre-date the district heating. There are also greater potential pollution savings from attaching older buildings.

AdmiralX

Ben84 wrote: »

Gas too can be made from non-fossil fuel sources. There's a new pilot plant at Didcot which turns sewage in to methane, cleans it up and pumps it in to the gas supply where it's burnt in cookers and boilers just the same as fossil fuel gas. Farm waste and food factory waste can also be used.

In the future we may start using more district heating systems to deliver heating, perhaps as a way to use the thermal output of nuclear power plants. It would be good to have houses that are completely nuclear powered, both for electricity and attached by pipe to supply hot water for washing and space heating.

All that is useful. I am glad somebody raises the nuclear possibility, as it has to be at put on the table sometime - excuse me I have no opinion on that. What I have read the problem lies here: what to do/ where to dump with the nuclear waste (in France, I know they bury it deep even near Paris and there is a map)

Loads of these energy possibilities should be the hot topic but have taken low priority in R&D but time to hurry. The problem with the nuclear is the standard and... honesty required for maintenance and how to keep it.

There are other possibilities of energy but all need generous support for engineering and science.

Ben84

AdmiralX wrote: »

All that is useful. I am glad somebody raises the nuclear possibility, as it has to be at put on the table sometime - excuse me I have no opinion on that. What I have read the problem lies here: what to do/ where to dump with the nuclear waste (in France, I know they bury it deep even near Paris and there is a map)

Loads of these energy possibilities should be the hot topic but have taken low priority in R&D but time to hurry. The problem with the nuclear is the standard and... honesty required for maintenance and how to keep it.

There are other possibilities of energy but all need generous support for engineering and science.

With such significant pollution reductions needed, I believe nuclear as the one major well developed low carbon technology that delivers large amounts of energy, will out of necessity be used more than ever before. In which case, I hope we get the most energy possible out of each unit of fuel as it too is limited in supply and I do not believe it can disposed of.

AdmiralX

Ben84 wrote: »

With such significant pollution reductions needed, I believe nuclear as the one major well developed low carbon technology that delivers large amounts of energy, will out of necessity be used more than ever before. In which case, I hope we get the most energy possible out of each unit of fuel as it too is limited in supply and I do not believe it can disposed of.

I think, strictly speaking, we do have to include this choice too, under these circumstances - of course until more other forms are developed, dont know when.... Nuclear can be a solution but takes several years to built one plant; So decisions need to come soon. the constructors are japanese and they make 2 a year. The corporate body which runs the plants needs to be honest during safety inspections in other words They must have clean hands and must not lie about breaches in safety - it happened in Fulushima but the investigation did not go ahead there because of the earthquake. Unfortunately when there is an "accident" in a nuclear power plant all evidence has been destroyed. Such nuclear inductry has to be watched by the public because it has links with other sectors and the problem is to avoid cartelisation.


What we could do I believe is this: the electorate should watch about clean up and safety standards all the time, nothing should be left just to regulations. Should be like neighbourhood watch. I see my MP, have written to her about energy saving and my concerns etc. MPs have street surgeries and residents should storm them: where do we get energy next?.

Dave_Fowler

We have 6 x 50W 12V spotlights in the kitchen. Each has its own switch-mode transformer.

I have replaced 2 of the bulbs with 4W LED bulbs. Light output of the LED lamps, measured on a lux meter, is 1/3 of the output from the original halogen bulbs. This is just about adequate. However, interference from the power supply wiped out all FM reception in most of the house. Not wishing to cause problem in the local area I have reluctantly decided LED lamps can not be used with our (brand new) spotlights.

Dave F

rogerblack

Dave_Fowler wrote: »

Not wishing to cause problem in the local area I have reluctantly decided LED lamps can not be used with our (brand new) spotlights.

Unfortunately, at the moment, LED lamps are hugely variable in quality. Ones purchased direct from non-mainstream vendors are more likely to not have had emissions, or other testing.
The same makers other models may be just fine - there is no way to tell.
It's certainly not general that LED lights cause issues with FM.

Dave_Fowler

rogerblack wrote: »

Unfortunately, at the moment, LED lamps are hugely variable in quality. Ones purchased direct from non-mainstream vendors are more likely to not have had emissions, or other testing.
The same makers other models may be just fine - there is no way to tell.
It's certainly not general that LED lights cause issues with FM.

I was thinking it more likely that the power supply did not like the low load. Needs more investigating. I'll try a pure resistive load of a few watts and see what happens.

Dave F

Ben84

Dave_Fowler wrote: »

We have 6 x 50W 12V spotlights in the kitchen. Each has its own switch-mode transformer.

I have replaced 2 of the bulbs with 4W LED bulbs. Light output of the LED lamps, measured on a lux meter, is 1/3 of the output from the original halogen bulbs. This is just about adequate. However, interference from the power supply wiped out all FM reception in most of the house. Not wishing to cause problem in the local area I have reluctantly decided LED lamps can not be used with our (brand new) spotlights.

Dave F

There are 35W halogen bulbs from a few manufacturers that have an infra-red coating to boost heat retention, so that they emit as much light as 50W bulbs. Not as good savings as LED bulbs might provide, but totally compatible with dimmers and good quality light while saving some energy.

Dave_Fowler

Dave_Fowler wrote: »

We have 6 x 50W 12V spotlights in the kitchen. Each has its own switch-mode transformer.

I have replaced 2 of the bulbs with 4W LED bulbs. Light output of the LED lamps, measured on a lux meter, is 1/3 of the output from the original halogen bulbs. This is just about adequate. However, interference from the power supply wiped out all FM reception in most of the house. Not wishing to cause problem in the local area I have reluctantly decided LED lamps can not be used with our (brand new) spotlights.

Dave F

I have now done some experiments with the LED bulbs and my spotlights.

I replaced the LED bulbs with an equivalent 4W resistive load (used several resistor values between 47 Ohm and 24 Ohm). There was no interference on FM. I next replaced the spotlight power supply with a 12V DC supply and fitted the LED bulbs. Again no interference on FM.

So the problem appears to be an interaction between the LED bulbs and the power supply fitted to the spotlights.

Dave F