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Energy import benefits of UK Solar PV
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tberry6686 wrote: »The amount of gas saved by solar generation is likely to be a very trivial amount. This is due to the fact that no matter how many solar panels there are there must be an operational powerstation ready to take over from them at a moments notice.
It's a well known fact that for all the wind turbines, solar panels etc in existence not one conventional power station has been closed down due to re-newables (the truth is the only renewable that currently works outside of certain deserts is Hydrothemal power and is likely to remain that way for a long time).
Whilst you may need another power station (nuclear, coal, gas or whatever) on standby when solar power is being generated, such a power station will not be using anything like it's full working need of fuel for the hours that it is on standby. There must therefore be some saving of conventional fuels resulting from SP generation.
One 'renewable' that wasn't mentioned above but has certainly been very successful is hydro-electric power. There may not be a lot of it in the UK but there are many areas of the world where it's an outstanding success.NE Derbyshire.4kWp S Facing 17.5deg slope (dormer roof).24kWh of Pylontech batteries with Lux controller BEV : Hyundai Ioniq50 -
Now that we have to import increasing amounts of gas due to North Sea gas decline and the closure of coal fired plant, what are the benefits of PV due to reduced gas imports?
I think its highly likely that in the coming years we will see huge price increases in gas. If solar PV is reducing the amount of gas burnt at the power station then its reducing our imports and helping with the trade balance.
Anyone got any thoughts or numbers to play with?
Once you've worked it out, try doing the same again with Nuclear as the example. Then you save the gas 24 hrs per day, and you don't have to build the hundreds of inefficient small gas stations in the first place, and you don't have to burn gas for reserve duty to correct for the intermittent sun (and wind). You also don't have to have the inefficient operation of startup and shutdown of many stations every day, which of course leads to additional maintenance costs.
But it is an extremely cocked eyed way of looking at the situation anyhow.
Solar (and wind) aren't engineering solutions (i.e. the best system to satisfy a set of requirements), they are political imperatives, which are extremely costly to all consumers, due to
- duplication of capacity (each MW of solar/wind capacity has to have an equal amount of reliable capacity built, and maintained at operational status all the time)
- increased primary reserve requirements (i.e. other reliable stations have to burn fuel to correct for instantaneous changes in both demand and intermittent generation)
- the increasing costs of subsidies to inefficient generation as time goes on.
Don't expect the rate of increase of electricity bills to ameliorate anytime soon.(and that now applies to whatever we do tomorrow - we are in a situation we shouldn't be in at all, but hey ho, this is where we are. It would be pertinent for the powers that be to examine why we are currently in this desperate situation in order that we at least set a course for improvement in the future.0 -
One 'renewable' that wasn't mentioned above but has certainly been very successful is hydro-electric power. There may not be a lot of it in the UK but there are many areas of the world where it's an outstanding success.
There's quite a lot of hydro in Scotland. Engineers exploited that 'renewable' generation long before the word 'green' entered the dictionary. They also built pumped storage (probably not for the reason most think in Wales at least) - again, sensible and cost-effective exploitation of a resource many years ago, before every green blogger knew how best to run an electricty grid after a few minutes of googling. That's why we had for many years a cheap and reliable (the most reliable in the world, the design being exported to many other countries) electricity grid. I'm afraid there has been now been around 30 or 40 years where the grid development hasn't been following best practice, firstly with a lack of investment in new reliable capacity, and recently an obsession with investment only in unreliable ideological non-solutions to our needs.0 -
I live in Scotland. Hydro power up here is very common and as such is not usually counted as a renewable (probably because it has been in use here for so long before the modern renewables were being considered suitable alternative energy sources).Whilst you may need another power station (nuclear, coal, gas or whatever) on standby when solar power is being generated, such a power station will not be using anything like it's full working need of fuel for the hours that it is on standby. There must therefore be some saving of conventional fuels resulting from SP generation.
The amount of fuel used at peak generation for a power station is not that far off what it uses in standby mode. The reason for this is simple - they are designed to generate the electricity as efficiently as possible, not to be as efficient as possible in standby. Think of it as a car. A car is most fuel efficient at a predetermined speed and gear not when it is sitting still idling. It will use slightly less fuel sitting still but you still get most of the emissions and costs with none of the benefits.
Therefore any fuel saving is minimal and at a massively disproportionate cost.0 -
I'm not sure how much electricity is imported to the UK from the continent, but if it is inefficient to run a conventional power station at anything but full capacity, would it not be best to run our power generation plant at maximum capacity even when wind and PV are generating and just stop importing. This would help our balance of trade.Solar PV System 1: 2.96kWp South+8 degrees. Roof 38 degrees. 'Normal' system
Solar PV System 2: 3.00kWp South-4 degrees. Roof 28 degrees. SolarEdge system
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Location: Bedfordshire0 -
There is much discussion on this subject in the 'Green' section of MSE.
The problem with solar PV is firstly its unpredictable generation. An array on a house can be generating 4kW one minute and a cloud can drop the output dramatically.
Unfortunately you cannot 'shut down' power stations 'instantly' to cater for this unpredictable solar output.(1)
Secondly the period of peak consumption in UK is on a late winter afternoon, when solar is generating zilch!(2) So(3) no matter how much solar generation capacity in UK, we still need to have 'conventional' generating capacity in the shape of coal/gas/nuclear etc power stations to cope with that load. So(3) solar does not lead to any reduction in our generating capacity.
Above is a simplistic explanation, there are posters on MSE who worked on the National Grid who can elaborate.
(1) I didn't realise you had to 'shut down' power stations 'instantly' to cater for the unpredictability of a cloud going over a house.
(2) Was Solar ever meant to provide power for winter early evenings?
(3) Got to love your leaps of logic, and straw man arguments. Care to actually give proof or facts?0 -
tberry6686 wrote: »
The amount of fuel used at peak generation for a power station is not that far off what it uses in standby mode. The reason for this is simple - they are designed to generate the electricity as efficiently as possible, not to be as efficient as possible in standby. Think of it as a car. A car is most fuel efficient at a predetermined speed and gear not when it is sitting still idling. It will use slightly less fuel sitting still but you still get most of the emissions and costs with none of the benefits.
Therefore any fuel saving is minimal and at a massively disproportionate cost.
There are several types of standby, each catering for a different timescale, but all expensive because they are not contributing to the generation when in standby.
For instantaneous standby, steam plant hold pressures well in excess of that neede for generation - and that is extremely costly in terms of £ and fuel (and co2 if not Nuclear) - so costly that it made sense to build Dinorwig, the most expensive civil engineering project in the world at the time, just to supply primary reserve.
For corrections within several seconds, then theres spinning reserve, where the plant is hot and ready to generate and synchronised to the grid. In terms of the fuel used to do this, it isn't a high percentage of when it generates. But surprisingly, fuel costs aren't the major factor - it's the financing and maintenance costs which are high costs in a capital intensive industry. In the case of Nuclear, fuel costs are minimal, but I expect gas and biofuel costs to escalate rapidly in the coming years). The cost of spinning reserve is the cost of getting the plant available, the startup costs and the shutdown costs. It may not be called upon to generate anything during its period of reserve duty. With intermittent generation on the grid, you need lots more of this reserve.
For corrections within the few minute timescale, then stations of this level of reserve are ready to go following an instruction from the grid control centre. Again, it costs a lot to be ready to go.0 -
Dave_Fowler wrote: »I'm not sure how much electricity is imported to the UK from the continent, but if it is inefficient to run a conventional power station at anything but full capacity, would it not be best to run our power generation plant at maximum capacity even when wind and PV are generating and just stop importing. This would help our balance of trade.
There is no UK PLC energy policy.
Broadly speaking - it's a market.
You (as a residential supplier) can say 'I want 2.8GW from 9AM next wednesday for 6 hours' - and various suppliers will bid to supply (part of) that load, you pick the lowest ones.
The price if you say 'Eeek - unexpected cold snap, and I need 3GW in 2 hours' will be considerably more eyewatering, as it will involve likely the most expensive generators being brought online, and/or the costs of dropping supply to some large industrial customers.
Looking at the statistics for January, we were not always importing from france, but a substantial fraction of the time we were.
If the price of electricity in france is lower (perhaps they are having a warm day), then we will buy from them, rather than doing local generation. (to a degree).0 -
I believe that with the (possible) coming of shale gas it is more likely that the wholesale gas price will be static or may even drop compared to today's prices. Whether that will be passed on to the consumer is much less assured though.0
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(1) I didn't realise you had to 'shut down' power stations 'instantly' to cater for the unpredictability of a cloud going over a house.
They generally disconnect the wind farms as it is easier, less costly etc.(2) Was Solar ever meant to provide power for winter early evenings?
Solar was claimed to replace some conventional capacity and so logic dictates that it would be needed at peak times all year round not just in the middle of summer.(3) Got to love your leaps of logic, and straw man arguments. Care to actually give proof or facts?
As someone a lot smarter than me pointed out before, you can't prove a negative, but if you care to research how many conventional power stations have been replaced by renewables you will rapidly find your answer.
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