Nuclear power : how visions change

Martyn1981

Mistermeaner wrote: »

Also re wind and solar you ignore both the ininital production cost ~ money as well as labour and raw mats and energy. Also solar panels degrade over time and need replacing after 20 or so years.

This isn't actually true. The costs of equipment, installation and maintenance are reflected in the price for the energy.

Solar panels should last for 30 to 40 years. The most common type of panel installed in the UK (mono-crystaline silicon) has an annual degradation of about 0.4% pa. So after 20 years, should still be producing 90%+ of original rating, and won't need replacing.

First UK grid connected PV system 95% efficient 20 years later

Mistermeaner wrote: »

The reason renewables need subsidising is that they are not economically efficient in watts / £ terms.

This also isn't true. On-shore wind and PV farm contracts are already being issued at £80/MWh, so cheaper than Hinkley now, and still falling fast, and with 15yr (not 35yr) subsidy periods, allowing for cheaper renewal/replacement of contracts.

The reason renewables need/needed subsidy support was that they had to compete against established technologies, and time was needed for production to ramp up, and costs to fall.

Also, we do not currently have a level playing field. Whilst the average price of leccy sold on the UK market is around £45/MWh, that doesn't include all the costs. It doesn't reflect current nuclear subsidies paid via general taxation. It doesn't include CO2 costs. It doesn't include the costs of pollution.

Coal burning costs UK between £2.5bn and £7bn from premature deaths

If the cost (which we still end up paying) of our leccy was reflected in the price of our leccy, then the price would probably be £80 to £100/MWh and on-shore wind, PV and even nuclear wouldn't actually need subsidies. Off-shore wind, currently bidding at £115 would probably also get there within the next decade.

Mart.

stator

kinger101 wrote: »

Wind is actually quite reliable, given that the wind is usually blowing somewhere in the UK.

It doesn't really matter if wind is 'usually' blowing somewhere in the UK because the fact is that sometimes it doesn't blow anywhere in the UK.
It may only be one day per year that wind output dops to 5% of it's maxmim, if the grid is reliant on wind power that would be one day of blackouts, which is unacceptable.
So every megawatt of wind or solar power has to be backed up by one megawatt of spare capacity in Coal or Gas. So if you want a mix that has significant wind or solar you have the pay for double the capacity you need!
This causes a problem because the Coal and Gas power plants don't want to stay open if they are only generating power a few days a year when the wind and solar aren't generating enough. They don't earn enough money to cover their running costs. So you get a situation like in Germany where Coal and Gas start shutting down because Wind and Solar are 'forcing' their way onto the grid. We are seeing this in the UK too with Coal plants closing down.
The UK government have already started subsidising spare capacity in the UK because of this exact problem. They spend a billion pounds paying Coal or Gas power stations to stay open that would otherwise close. So we are in the ridiculous situation where we are subsidising two 'competing' sides of the market. We subsidise the Solar and Wind because they are uneconnomical and we subsidise the Coal and Gas because they are now uneconomical. It's crazy economics.

The solution is relatively simple. Build new nuclear power stations with public money. Then increase pollution taxes on Coal and Gas to make sure the Nuclear power stations make money and then sell them off and get your investment back.

kinger101

stator wrote: »

It doesn't really matter if wind is 'usually' blowing somewhere in the UK because the fact is that sometimes it doesn't blow anywhere in the UK.
It may only be one day per year that wind output dops to 5% of it's maxmim, if the grid is reliant on wind power that would be one day of blackouts, which is unacceptable.
So every megawatt of wind or solar power has to be backed up by one megawatt of spare capacity in Coal or Gas. So if you want a mix that has significant wind or solar you have the pay for double the capacity you need!
This causes a problem because the Coal and Gas power plants don't want to stay open if they are only generating power a few days a year when the wind and solar aren't generating enough. They don't earn enough money to cover their running costs. So you get a situation like in Germany where Coal and Gas start shutting down because Wind and Solar are 'forcing' their way onto the grid. We are seeing this in the UK too with Coal plants closing down.
The UK government have already started subsidising spare capacity in the UK because of this exact problem. They spend a billion pounds paying Coal or Gas power stations to stay open that would otherwise close. So we are in the ridiculous situation where we are subsidising two 'competing' sides of the market. We subsidise the Solar and Wind because they are uneconnomical and we subsidise the Coal and Gas because they are now uneconomical. It's crazy economics.

The solution is relatively simple. Build new nuclear power stations with public money. Then increase pollution taxes on Coal and Gas to make sure the Nuclear power stations make money and then sell them off and get your investment back.

You didn't read the report I posted. Days where wind power could generate nil would be extremely rare. And somewhat predictable.

You always need overcapacity, even if you had only carbon-based fuels. There are always planned (e.g. maintenance) and unplanned (breakdowns) outgages in the power grid. And there are always fluctuations in demand throughout the day (kettles being switched on in morning etc).

The problem is partly solved by typically running stations at below 100% output and then ramping up if necessary. Or by having additional generators (gas turbines/hydro) if there is a sudden unexpected outage.

A bit more on it here (from Australia).

http://www.gizmodo.com.au/2015/07/how-much-does-wind-energy-cost-debunking-the-myths/

But in summary, wind power in the UK doesn't need any excess redundancy compared to any other form of energy. The idea that a back up generator has to be specifically built to account for still days is incorrect.

cells

kinger101 wrote: »

You didn't read the report I posted. Days where wind power could generate nil would be extremely rare. And somewhat predictable.

You always need overcapacity, even if you had only carbon-based fuels. There are always planned (e.g. maintenance) and unplanned (breakdowns) outgages in the power grid. And there are always fluctuations in demand throughout the day (kettles being switched on in morning etc).

The problem is partly solved by typically running stations at below 100% output and then ramping up if necessary. Or by having additional generators (gas turbines/hydro) if there is a sudden unexpected outage.

A bit more on it here (from Australia).

http://www.gizmodo.com.au/2015/07/how-much-does-wind-energy-cost-debunking-the-myths/

But in summary, wind power in the UK doesn't need any excess redundancy compared to any other form of energy. The idea that a back up generator has to be specifically built to account for still days is incorrect.

fossil generators or any load following capability is a highly reliable source of power

If you have 1 generator which has only 1/20 chance of being offline and you have a backup thats 1/400 change of it being offline together and add another and its 1/8000

with wind its sometimes the case that nil production can be guaranteed. so adding another wind farm doesnt do much at all to guarantee supply

also the backup choice available for fossils are OCGTs which are cheap whereas whats the backup for wind? an expensive connection to norways dams which are insufficient to buffer europe or batteries that cost a lot and have a finite life?

the truth is a renewable system locks in coal and gas as they are needed for backup. a nuclear system can get rid of the coal and gas. anyway all of this will be clear within ten years.

stator

kinger101 wrote: »

You didn't read the report I posted. Days where wind power could generate nil would be extremely rare. And somewhat predictable.

You always need overcapacity, even if you had only carbon-based fuels. There are always planned (e.g. maintenance) and unplanned (breakdowns) outgages in the power grid. And there are always fluctuations in demand throughout the day (kettles being switched on in morning etc).

The problem is partly solved by typically running stations at below 100% output and then ramping up if necessary. Or by having additional generators (gas turbines/hydro) if there is a sudden unexpected outage.

A bit more on it here (from Australia).

http://www.gizmodo.com.au/2015/07/how-much-does-wind-energy-cost-debunking-the-myths/

But in summary, wind power in the UK doesn't need any excess redundancy compared to any other form of energy. The idea that a back up generator has to be specifically built to account for still days is incorrect.

I disagree. Wind needs 100% backup provision, as does solar. The UK currently has less than 5% spare capacity. With more wind and solar we would need a lot more spare capacity.

chris_m

stator wrote: »

I disagree. Wind needs 100% backup provision, as does solar.

Especially solar - considering that it can only operate for an absolute maximum of 50% of the time

kinger101

stator wrote: »

I disagree. Wind needs 100% backup provision, as does solar. The UK currently has less than 5% spare capacity. With more wind and solar we would need a lot more spare capacity.

But you're disagreeing because you can't be bothered to read reports by experts.

http://www.ukerc.ac.uk/news/ukerc-dispels-myths-surrounding-intermittent-renewable-energy.html

Is the Earth flat too?

kinger101

cells wrote: »

fossil generators or any load following capability is a highly reliable source of power

If you have 1 generator which has only 1/20 chance of being offline and you have a backup thats 1/400 change of it being offline together and add another and its 1/8000

with wind its sometimes the case that nil production can be guaranteed. so adding another wind farm doesnt do much at all to guarantee supply

also the backup choice available for fossils are OCGTs which are cheap whereas whats the backup for wind? an expensive connection to norways dams which are insufficient to buffer europe or batteries that cost a lot and have a finite life?

the truth is a renewable system locks in coal and gas as they are needed for backup. a nuclear system can get rid of the coal and gas. anyway all of this will be clear within ten years.

I'm struggling with your logic here. The grid doesn't care where it's electricity comes from. It's not going to demand any reduction in wind is met by hydro from another country. Or that you use gas is a coal station is out. I didn't even say we should use only wind and solar. I'm saying we should get as much low-carbon as possible. With includes nuclear and renewables. Provided you don't exceed a certain amount with wind, you don't really need that much more redundancy that you would with fossil fuels. I the UK, we could manage 20%. Denmark produces most of it's energy from wind.

You're using straw men and false trade-offs.

Generali

If only we had some sort of way to store electricity. I would call such a thing a battery.

Martyn1981

kinger101 wrote: »

You always need overcapacity, even if you had only carbon-based fuels. There are always planned (e.g. maintenance) and unplanned (breakdowns) outgages in the power grid. And there are always fluctuations in demand throughout the day (kettles being switched on in morning etc).

As you point out, the over-capacity in the FF generation we currently have is often ignored by those criticising renewables.

Gas generation fluctuates on a daily basis by about 15GW (from around 5GW to 20GW.)

Coal, in the GMT months fluctuates by about 5GW (from around 10GW to 15GW.) In the BST months a number of coal plants are shut down for maintenance. Generation still fluctuates by about 5GW (from around 5GW to 10GW.)

Replacing coal with gas, would give us 35GW* of demand following generation, based on the current mix. The question then, is what mix of renewables, storage and interconnectors (plus possible additional gas back-up) would ensure coverage of the ~20GW shortfall from 5pm to 7pm in the GMT months on days when intermittent generation is poor.

[Edit: *Actually, 25GW is a fairer figure as that represents the status quo, with what we accept today as gas and coal capacity that is not actually used all the time.]

Mart.