Octopus … Is there method in this madness ?

[Martin of WickParticipant @martinofwick]

And tidal streams run for 18 to 20 hours of the day.  Solar for half that if you are lucky in the summer and SFA in winter,  with its peak generation at a time of day when not required (unless we all fit heat pumps and use then for AC in summer). Storage would help, but it all costs money and would push up electricity costs even more.

 

 

 

[SillyOldDufferModerator @sillyoldduffer]

Well, don’t expect renewable energy to behave in the same way as nuclear, gas, oil and coal!   Actually all sources of energy have pros and cons.  Nuclear is good, apart from cleaning up after decommissioning.  Coal power stations cannot respond quickly to rising and falling demand, and are polluting.  Oil provides better response but is more expensive.   Gas is excellent because turbines can be fired up and down very quickly. And since 1990, gas has been very cheap.   Unfortunately low cost of gas is not guaranteed in perpetuity, and some suppliers are politically unreliable.

Energy has always been provided by a basket of different methods, and the methods are changing.  In the UK Town Gas is long gone, and Coal is now miniscule.   Oil and natural gas are both problematic, unless the source is local.  We have to change.

Renewable energy is free in the sense that no-one has to be paid to extract and transport millions of tons of coal, oil or gas.  Fossil fuels require a lot expensive middlemen, services and infrastructure between consumer and source.  In contrast renewables are simpler, going straight to electricity, which can be fed into the grid.   Though connecting to the grid is expensive, renewable electricity is still cheaper than other sources.    And much less polluting than burning carbon.   Whilst many don’t believe in global warming, they are wrong.  Failing to understand a problem does not fix it.

The disadvantage of renewable energy is it comes and goes depending on the weather and the planet’s position – sunshine, wind, tides, rainfall etc.  Dirt cheap, but not necessarily available when needed.  Therefore, some form of storage is needed.  Nothing new in that:  Dinorwig exists because off-peak nuclear and coal power was used to pump water into a huge mountaintop reservoir, and  discharged to top up the grid later.   Though horribly inefficient it was cheaper to burn coal continually during the night and pump water than it was to crank large boilers up and down.

Many storage options.  Using excess electricity to electrolyse water into Hydrogen and Oxygen; making Ammonia or Sodium;  pumping water uphill; pressuring gas; heating cast-iron blocks; charging batteries etc.  Giant batteries need not be expensive.  Expensive Lithium is needed for cars because it has a high energy density, but lower density storage is OK in a fixed installation, where Sodium is good enough.  Sodium is dirt cheap, especially when made with surplus renewable electricity…

The high cost of fossil fuels makes negative prices unlikely, though it can and does happen.  Oil went negative in the US a few years ago because deliveries exceeded the available storage capacity,  making it necessary for those contracted to store it to pay someone to take it away!  How markets are organised is important, and it’s not right yet, nor is the technology fully developed, and nor is the infrastructure in place.

But, there is nothing in switching to renewables that’s beyond the wit of man, either technically or in the mechanisms used to buy and sell it.  It will be different though.

What Octopus are doing makes sense in the context of how they buy and sell energy.  They wish to attract new customers, and will almost certainly be offering variable rate tariffs (via Smart Meters) that encourage customers to consume electricity when it is available, by dropping the price.   Very similar to Economy 7, though more agile.  All suppliers are going that way, step by step, so as not to frighten the horses, or make a major expense.

One thing for sure – burning fossil fuels isn’t sustainable.   In only 30 years, oil and gas will run short.  Sadly prices skyrocket when demand permanently exceeds supply.  I’ll probably be dead before petrol become unaffordable but my children will have to find alternatives.   Coal, gas and oil did us proud in the past, but they are finite natural resources.  God isn’t making any more…

Dave

 

 

 

[noel shelley]

On noel shelley Said:

The whole wind/solar idea seemed great on paper to the uninitiated but is in reality an uncontrollable monster. I have observed several big wind turbine farms all idle during the hot sunny spell we have been having, at least you can feather the blades ! Tidal is at least largely predictable !  Noel.

The whole lot is fully controllable.  No doubt about that, so absolutely nothing to do with the technology!

Wind turbines can be turned off – not by feathering the blades but by turning the rotor away from the wind direction.  Feathering the blades is simply a means to maximise the power delivered, by the turbine, as they are designed to rotate at a set, controlled speed.  This can occur when the wind speed is too high for the safety of the structure.  All turbines turn away from the wind to avoid over-speeding.

It is different than constraint.  Constraint occurs simply where the grid cannot absorb the power, or the grid would not be able to absorb/deliver all the available instantaneous power (the grid cannot store electricity, it can only transmit it from source to user).

The grid sometimes cannot transmit the power because it was built as a radial system from fossil power stations and the less ‘robust’ parts are at the extremities.  Off-shore wind turbine power comes ashore where the transmission grid may not yet be reinforced – hence the off-shore generation must be constrained.

The contract to get that large investment (for the installation of large numbers of turbines required, the government, at the time, guaranteed that they would be paid compensation if the grid was not reinforced in time.  Clearly it has not been reinforced adequately by the National Grid and paying curtailment payments is far cheaper than the turbines never having been installed in the first place (they would still be burning dirty, expensive coal and gas instead of renewable energy from the wind).

The other end of the scale is when there is too much generation – either it is used or lost by turning off turbines or switching off solar generation.  Switching off solar panels is simple – one can easily flip your switch at home, to stop your installed solar panel generation.

It is at these times when any surplus is sold cheaply to anyone who can ‘turn up their wick’.  The generation system is such that at times the price becomes negative.

The problem is that the grid still relies on gas generators for a ‘black start’ if there were to be a power outage.  It’s called ‘spinning reserve’ – steam driven generators are still needed for this stand-by duty at the present time, so they have to be kept turning, even if making little generated power – hence there is always (yet awhile) a couple of Gigawatts of gas-fired generation.

The National Grid are working towards being able to restart the grid (after a black-out) by other means.  Black-outs are necessary when there is, for some reason, insufficient generation due to an unexpected failure within the whole grid.  It could be a local power outage (relatively easy to sort out) or might cascade into a major system shut-down.  The National Grid has statuary responsibility to maintain both voltage and frequency of the supply within tight limits.

The grid can easily turn off a generator if there is too much power, but not enough is another story!  Turning off any generator (they all have at least half hour contracts to honour) costs money.  We only hear about wind constraints as they have been in the news for years.

Hope that lot helps to explain some of the misapprehensions circulating.  I’m no expert on the subject and ‘‘contracts for difference’’are yet another set of ‘juggling balls’ for the system to cope with.

Let’s be clear, there is no madness, whatsoever, involved with Octopus Energy, so I still stand by my original post.  Just someone trying to make a mountain out of a molehill, IMO.

As for time-of-use pricing, that has been going on for decades.  E7 for domestic users and power agreements for industry (night time power was far cheaper because coal-fired generators could not easily reduce output while maintaining efficiency).

Power costs could include not only time of day/night rates but also reducing usage for up to two hours at a time with (I think) only one or two hours notice when requested by the grid.  I can’t remember exactly how much power I had to shut down at these maximum demand periods (2-5GW was likely) and we regularly used 10GW (or more) during the cheap night rate period compared to the day rate.

[MacolmParticipant @macolm]

Thanks for the useful explanation of how the grid is managed and continuously balanced. I do not wish to get into the philosophy of net zero policies, but government needs to come clean about the costs of the overall electricity generation system that they intend. Already, the high cost of energy in the UK has killed off many previously internationally competitive industries, and this process continues with the current closures in the chemical sector.

In the latter half of last century, average demand of circa 50 GW was produced by perhaps 65 GW of total generation capacity, which proved adequate to cover breakdowns and maintenance. The problem now is that the current rough average of 30 GW demand needs provision of that much thermal generation, the same amount again of wind power, and a further similar amount of solar, crudely three or four times demand. Then to feed the resultant large power flows from end to end of the country, the grid has also needed to be greatly reinforced, much beyond what once supported 50 GW nationally. All this CapEx seems suspiciously like the cause of our astronomic electricity prices, despite official denials. Trying to improve grid balancing slightly by targeted price reductions will do nothing to reduce general prices, already apparently too high to sustain a sound economy, and set to increase yet further.

[not done it yetParticipant @notdoneityet]

The average power consumption is fairly irrelevant – it is the maximum (peak) demand that is far more important.

Hence the situations where ‘power shedding’ is necessary (usually in the winter months) and periods of potential glut (where it is far better to utilise that power than simply not generate it).  The government, IMO, has got it wrong – it has been biassed, and lobbied, by the fossil fuel industry for far too many years, along with huge subsidies paid to that sector (these payments far exceed the constraint payments to renewables).

Hinkley C generation will be costing far more than either fossil or renewables, when it eventually comes on line.  Strike price was (originally in 2012 ) £92.50/MWh – but that already equates to well in excess of £150/MWh.  That is while renewables’ strike prices have diminished to about £50 for solar.  Most off-shore wind is currently guaranteed to sell for around £75.  I’m not sure how renewables, stored in batteries and fed into the grid later, is accommodated in all this quagmire of pricing structure!  Nor am I sure how the sea beds, which are bought/leased/rented from the government comes into all this.

[NealebParticipant @nealeb]

I am surprised that only this specific Octopus offer has been mentioned. I am an OVO customer, and although they have suspended their scheme for the summer, during the higher-consumption months I have been used to receiving this kind of offer fairly frequently. Maybe several times a month. Usually, it is a request to reduce consumption for one, occasionally two, hours at a particular time. You receive a bounty in the form of a discount off the next bill for energy saved. The saving is calculated by comparing energy use for that timeslot against the average for that timeslot over the last month. Rarely, the offer invites you to increase consumption instead. Seems like a perfectly reasonable way of encouraging domestic users to tailor energy use to suit conditions. In practice, as we are fairly economical in our use of energy anyway, we do not see much benefit but considered as an improved version of the old Economy 7 scheme that can make use of current technology (in the form of smart meters), why not?

[noel shelleyParticipant @noelshelley55608]

The problem as I see it is that so few understand that the renewable s produce a type of electricity that we DON’T use, it is NOT 50Hz, or come to that 220V ! To make it usable needs for it to be converted into something that can be fed to the grid, certainly at 50Hz and within the spec to maintain synchronicity with all other generators – and this is where the trouble begins. What ever system is used MUST be reliable and at the moment that reliability is hanging by a thread – it will only want for a prolonged period of very cold weather to see the lights go out.

The relative prices are pointless if reliability is the real price we pay ! Has the current system been well thought out ? I think not !

I’m no expert but in the context of synchronicity a system based on a 50Hz RF transmission from a standard to all generators might work rather than trying to use a grid sampling, where by if the grid drops out it all stops.

Just a thought. Noel.

[John HaineParticipant @johnhaine32865]

I wonder why wind and solar are called “renewable”? All the energy comes from the sun and is just redistributed. Once used it’s eventually reradiated from the night side of the earth. On the other hand the energy is always there as long as the sun shines. Any ideas for a better term?

[noel shelley]

On noel shelley Said:

The problem as I see it is that so few understand that the renewable s produce a type of electricity that we DON’T use, it is NOT 50Hz, or come to that 220V ! To make it usable needs for it to be converted into something that can be fed to the grid, certainly at 50Hz and within the spec to maintain synchronicity with all other generators – and this is where the trouble begins. What ever system is used MUST be reliable and at the moment that reliability is hanging by a thread – it will only want for a prolonged period of very cold weather to see the lights go out.

The relative prices are pointless if reliability is the real price we pay ! Has the current system been well thought out ? I think not !

I’m no expert but in the context of synchronicity a system based on a 50Hz RF transmission from a standard to all generators might work rather than trying to use a grid sampling, where by if the grid drops out it all stops.

Just a thought. Noel.

Are you conveniently ignoring the approx 20% of the UK electricity power that is now derived from Europe and Scandinavia?  That all arrives as HVDC, so has to be converted to AC @50Hz.

Nothing at all to do with power cuts.  Black-out cuts are invariably due to a large unexpected loss of power to the grid.  The only single reason for the spinning AC generation is for the restart after such a major black-out.  Nothing more, except for the reducing periods – when gas is required as the “generation of last resort”.

If the National grid was able to forecast an excess of demand, over generation, it can arrange for more gas plants to come on line.

First is to bring on line the already spinning reserve.  Given adequate time combined circuit gas plants would be started from cold (likely over an hour). The next option is to start up the open circuit gas plants – they can be started in about 10minutes if kept on stand-by.

If that lot cannot cover the demand, major industrial users would be requested to shed power.  The next (at the moment) would be controlled, short term power outages (these are quite common when local supplies fail).  The next would be controlled widespread power outages (for only as long as required).

The real problem is when a large proportion of the grid input fails in a very short time-scale – as was the last major outage – when automatic systems simply close down supplies in cascade, over a few seconds, to maintain the voltage and frequency demanded by law.  The subsequent restarts are usually within minutes, but the  power has to be returned to the grid in a controlled manner –  GW by GW.  By this time pandemonium has already occurred with public transport, for instance – trains stopped on the tracks and city transport seriously disrupted, dependent on the time it happens.

The last major grid failure was caused by two gas fired plants going off line along with one large wind farm which may have tripped unnecessarily (nothing to do with actual renewable failure.

This ‘repeated problems as some individuals see it’ is rather more complex – and little, if anything, to do with renewable generation.  The National Grid works 24/7/365 to balance the Grid and does a good job with what they have in their ‘armoury’.

The Grid tirelessly working towards operating without ‘spinning generators’ and eventually ‘reserve spinning generation’.  Nuclear power stations will, hopefully, soon be the only regular generator making electricity using steam driven equipment.  We all need to stop burning fossils as fuels.

[noel shelley]

On noel shelley Said:

The problem as I see it is that so few understand that the renewable s produce a type of electricity that we DON’T use, it is NOT 50Hz, or come to that 220V ! …

Or is it Noel who has misunderstood?  All power stations generate kilovolts, and then transform up and down as necessary across the distribution network.  Consumers get 240V single-phase, but most of the network and all the big generators are 3-phase with lots of volts.   The main exception is domestic solar-panels, which back feed 240V into the single-phase system, and the HVDC interconnectors.

The technology needed to convert DC or AC other than 50Hz to 50Hz has been available for about 40 years.  Possible to alter frequency and phase of a source to whatever is necessary to match to the grid, which is almost never exactly 50Hz!   When the first sustainable generators appeared it made sense for sustainable sources to synchronise to traditional sources.  If the grid went down, the system couldn’t restart from a green source.  But this was never a technical limitation : today sustainable sources can and do provide ‘black start’ capability, and it makes sense they should now that a third of Britain’s power is green.  It just needs the right infrastructure and control system.

On the subject of HVDC, forum friends might be interested in the Xlinks Morocco Project.  This is about to start building ‘11.5 GW of renewable generation, 22.5 GWh of battery storage and a 3.6 GW high-voltage direct current interconnector to carry solar and wind-generated electricity from Morocco to the United Kingdom.’   Solar and wind-power isn’t restricted to local rooftops, it can come from the Western Sahara.   I hope the idea of electricity from Morocco doesn’t cause conniptions: not when most of our oil comes from the Middle East…

Dave

[SillyOldDuffer]

On SillyOldDuffer Said:

On the subject of HVDC, forum friends might be interested in the Xlinks Morocco Project.  This is about to start building ‘11.5 GW of renewable generation, 22.5 GWh of battery storage and a 3.6 GW high-voltage direct current interconnector to carry solar and wind-generated electricity from Morocco to the United Kingdom.’   Solar and wind-power isn’t restricted to local rooftops, it can come from the Western Sahara.   I hope the idea of electricity from Morocco doesn’t cause conniptions: not when most of our oil comes from the Middle East…

Dave,

Latest breaking news? I’ve been watching this proposal for a long time.  But you need to read the proposed ridiculous development shown in the reference number 36.

The sort of decision expected from our current government energy representative? (trying not to get political about this).

Three times the hinkley C capacity for likely less investment than one nuclear site which is virtually owned and will be run by the Chinese.  Doubtless he will be looking for more chinese money to build the second proposed copy of hinkley C – that of Sizewell C.

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