its a megawatt!

Martyn1981

EricMears wrote: »

By comparison, Solar Panels convert sunlight to electrical energy at something like 15% efficiency.

Eric, tongue in cheek picky point, but even if we ignore all the energy losses from digging up the coal, transporting it etc etc, to compare it fairly to solar panels we should really see where it came from.

Since all of the hydrocarbons will have originated as plants / plankton or the things that eat it, or the things that eat the things, then shouldn't we compare SP's efficiency to the photosynthesis efficiency of plants, which is approx 5%?

(He runs and ducks for cover!)

Mart.

jamesingram

Eric , I believe drax is one of the best coal fired station in efficiency, as Ben mentioned. Primary to usable energy loss in traditional gen. is a big problem, using the waste heat via CHP or other means could improve this though the infracturer cost would be enormous
(how about large greenhouse built next to power stations for a UK tomatoes crop ?)

How about this one ,so Drax spent £100 million to save 1 million tonnes of CO2 , what will £1 million of FITs payment save with PV?

The eff. of PV I believe isn't the issue it's EROEI ( energy return on energy invested ) that important , though financial cost must be considered.

HalloweenJack

talking of DRAX - you know the wind farm they built next to it? they had objections - on the grounds of NOISE and POLLUTION..... seriously oO


http://www.guardian.co.uk/environment/2012/feb/27/has-wind-revolution-stalled-in-uk

Ben84

jamesingram wrote: »

So converts primary fuel to electricial energy at 40% efficiency. Doesn't sound that good to me

It doesn't sound that good when we're used to hearing high figures for things like boilers, but really it's good for a typical thermal power plant as there are a lot more energy conversions, each causing losses taking place when you turn heat in to electricity.

Electricity itself is also a very desirable outcome as it does so many distinct things, from running computers to boiling a kettle in a minute or two, so the benefits gained in versatility, speed, cleanliness and convenience far outweigh the lost energy when it's made.

jamesingram

I agree Ben , electricity is very useful, though
it's 'cleanliness' in the UK is miss conception , in polution terms I think its far to say its dirty.
I think finding way ( I'm sure they've been thinking about this for years) of get more out of the primary energy is a design goal.

Ben84

jamesingram wrote: »

I agree Ben , electricity is very useful, though
it's 'cleanliness' in the UK is miss conception , in polution terms I think its far to say its dirty.
I think finding way ( I'm sure they've been thinking about this for years) of get more out of the primary energy is a design goal.

By cleanliness I mean there's no smoke, grime or ashes in my house when I use electrical devices. Of course, these have just been displaced to the power plant. Well, most my electricity comes from a nearby nuclear plant so there is very little pollution, but the outcomes is the same. I don't have to personally handle the fuel, which is nice when it's coal and pretty essential when it's uranium.

As for the total efficiency from fuel to energy used as electricity, improving that is important. I believe the UK is lagging behind other countries as many in colder parts of Europe capture the waste heat for district heating networks. Using the hot water for adjacent factories could work well too. Many factories, for example paper manufacturing and food processing use lots of hot water.

grahamc2003

Ben84 wrote: »

By cleanliness I mean there's no smoke, grime or ashes in my house when I use electrical devices. Of course, these have just been displaced to the power plant. Well, most my electricity comes from a nearby nuclear plant so there is very little pollution, but the outcomes is the same. I don't have to personally handle the fuel, which is nice when it's coal and pretty essential when it's uranium.

As for the total efficiency from fuel to energy used as electricity, improving that is important. I believe the UK is lagging behind other countries as many in colder parts of Europe capture the waste heat for district heating networks. Using the hot water for adjacent factories could work well too. Many factories, for example paper manufacturing and food processing use lots of hot water.

There used to be a few district heating systems using the waste heat from powerstations many years ago - in fact, we probably led the world in that technology. Battersea is perhaps the most well known of these.

When the government decided it would be a good idea (which it was) to link all powerstations and consumers into a single grid, the CEGB was formed to administer the whole shebang, and independent stations became a thing of the past. In their wisdom, the government of the day decided that the cegb's job was producing and selling electricity - so they got a license for that, and were prohibited from selling heat (not sure what happened to existing district heating schemes, maybe they were exempt from the restrictions).
The result of course is that about the same amount of energy which ends up as electricity gets dumped into rivers or the atmosphere via cooling towers - an obscene waste, all ultimately dictated by the government and their advisers.

I've never understood why the environmental campaigners have seemed blind to this waste over 40/50 years, and always seem to put their energies into issues of far less environmental impact.

demystified

EricMears wrote: »

By comparison, Solar Panels convert sunlight to electrical energy at something like 15% efficiency.

And 0% carbon dioxide emissions (not counting manufacturing)

jamesingram

grahamc2003 wrote: »

I've never understood why the environmental campaigners have seemed blind to this waste over 40/50 years, and always seem to put their energies into issues of far less environmental impact.

I agree, though I think serious environmental campaigner are well aware of the inefficiency of trad. generation and the likes of CAT , AECB have been promoting CHP in their own little way for years.
What surprises me is that there hasn't been an economic potential for the generator to find a way to sell this wasted energy, though I presume infracture costs make it a very long term return in investment so they only likely to do it if forced ?

Probably mentioned this before but here's Slough estates CHP ( now SSE )http://www.cospp.com/articles/print/volume-9/issue-1/project-profile/biomass-chp-plant-serves-uk-trading-estate-mixed-wood-waste-fuel-sourced-locally.html

been run on part locally sourced biomass since 2002
" a combined heat and power (CHP) plant, with potential generating capacity of 101MW and a current generating capacity of around 80MW, which produces electricity plus heat which is distributed via a steam and water distribution network; around 100km of underground electricity network plus substations; and around 3,000 industrial, commercial and domestic energy customers"

Ben84

grahamc2003 wrote: »

There used to be a few district heating systems using the waste heat from powerstations many years ago - in fact, we probably led the world in that technology. Battersea is perhaps the most well known of these.

When the government decided it would be a good idea (which it was) to link all powerstations and consumers into a single grid, the CEGB was formed to administer the whole shebang, and independent stations became a thing of the past. In their wisdom, the government of the day decided that the cegb's job was producing and selling electricity - so they got a license for that, and were prohibited from selling heat (not sure what happened to existing district heating schemes, maybe they were exempt from the restrictions).
The result of course is that about the same amount of energy which ends up as electricity gets dumped into rivers or the atmosphere via cooling towers - an obscene waste, all ultimately dictated by the government and their advisers.

I've never understood why the environmental campaigners have seemed blind to this waste over 40/50 years, and always seem to put their energies into issues of far less environmental impact.

I think Southampton also has a district heating network. I'm very enthusiastic about the technology as it provides a way to use otherwise wasted heat, which helps with pollution and could help people with the rising cost of central heating. Aside from using wasted sources, it can also provide a way to connect people to unconventional fuel sources that currently are little used for central heating, for example nuclear, energy from waste/sewage and generally fuel sources that aren't suitable for direct use at home.

It can also use a range of energy sources in a way home users can't, providing less impact from any single source increasing in price. Domestic boilers also are expensive to replace, so many people are using old inefficient ones to avoid the high initial cost of replacing them. A large system can be upgraded over time with smaller yearly investment from the users that is easier to manage. There's a lot of talk about fuel poverty, but there's also a significant, if not greater cost barrier to upgrading inefficient and sometimes poorly performing heating systems as well which is a significant part of why many people under heat their houses.