Does anyone here have an ideological objection to Solar?

John_Pierpoint

grahamc2003 wrote: »

It may seem extravagant, but the fridge will then supply 2 or 3 hundred watts of primary reserve - a commodity which is very costly - it's usually supplied by holding steam at a higher pressure in boilers than is necessary for the generation, meaning as well as extra wear and tear on the station, the genset itself is operating away from its maximum efficiency point - hence the mega costs. (Primary reserve is the automatic response for small discrepancies between generation and demand which, if left uncorrected for more than a couple of seconds, would cause frequency limits to be breached and the resultant load shedding (i.e. blackouts for big parts of the country).

My electricity supply [as monitored by my "Aurora" inverter, if that is to be believed] seems to be erratic, especially in terms of voltage supplied by the grid.

However I appear to be the last house on the circuit coming from the West; could that explain the over voltage?

grahamc2003

John_Pierpoint wrote: »

My electricity supply [as monitored by my "Aurora" inverter, if that is to be believed] seems to be erratic, especially in terms of voltage supplied by the grid.

However I appear to be the last house on the circuit coming from the West; could that explain the over voltage?

That's a question for your dno/local low voltage grid bods, I only know about the national high voltage grid, so hopefully someone better informed will answer. Afaiia, at the end of the wire, you should get the lowest voltage of all, not the highest! I wonder if your inverter is increasing the voltage - maybe pumping in 3 or 4kW onto a single phase on the last connection could have that effect? Your dno should ensure the voltage is still within voltage limits under all circumstances of course (which is 230V +10%, -6%, so a max of 252V). Of course, if a few houses sharing your phase of the supply also have solar panels, then the cumulative effect may cause a higher rms voltage I expect - interesting if someone experienced in that area could shed some light.

zeupater

doughnutmachine wrote: »

Like it or not, a power generation system dominated by renewables is likely to be “feast or famine”. Plenty electricity in stormy/ sunny weather, but little electricity on a cold still winters night. Perhaps when people are paying a penny in summer for electricity and a pound in winter they will shift their power demand.

But the technology does exist to heat water to over 100 degrees… energy could also be stored in the likes of wax so that there is specific heat stored and enthalpy of fusion. But I agree to store weeks of heat in winter will be difficult.

Hi

The way I see it is that whilst there is a large generating capacity imbalance in favour of non-renewables then there's no real issue with the variability of supply. However, as the proportion of renewables increases, so does the 'feast or famine' issue .... this is where storage comes in and why the following was recently posted ....

zeupater wrote: »

...
I agree that energy storage is key, however, although there are a number of technologies for energy efficient storage being developed, the only really practible & cost effective technology in current use is pumped hydro ...

.... There was a discussion on this forum a couple of years ago regarding pumped storage capacity for something like a 10day energy buffer in a high wind-reliance scenario ... the costs and required capacities were huge ....

HTH
Z

John_Pierpoint

grahamc2003 wrote: »

That's a question for your dno/local low voltage grid bods, I only know about the national high voltage grid, so hopefully someone better informed will answer. Afaiia, at the end of the wire, you should get the lowest voltage of all, not the highest! I wonder if your inverter is increasing the voltage - maybe pumping in 3 or 4kW onto a single phase on the last connection could have that effect? Your dno should ensure the voltage is still within voltage limits under all circumstances of course (which is 230V +10%, -6%, so a max of 252V). Of course, if a few houses sharing your phase of the supply also have solar panels, then the cumulative effect may cause a higher rms voltage I expect - interesting if someone experienced in that area could shed some light.

I don't think it is anything to do with my PV panels as it happens at random on all sorts of days sunny and overcast. I cannot check after dark as the inverted goes to sleep for the night.

zeupater

doughnutmachine wrote: »

The british hydro org say there is potential hydro of 2,593,317kW in Scotland, this would generate an estimated 10,644,403MWh a year. The BHA say that 657,259kW of this hydro is economically viable, this viable hydro would produce 2,766,682MWh a year. I’d also imagine there would be some financially viable hydro in England and wales.

Solar produced 259,198MWh of power last year…. So financially viable hydro in scotland could produce ten times as much power as solar is producing now.

Hi

I think that those figures could be open to question ....

Of the 2.6GW capacity, how much would be classified as being 'pumped storage' ?

If it's all pumped storage then, assuming a generous system efficiency of 80%, then it should read "... is potential hydro of 2,593,317kW in Scotland, this would generate an estimated 10,644,403MWh a year and consume 13,305,504MWh from other sources, including wind & solar" .... therefore it cannot be justified on a stand-alone basis and must form part of an integrated energy policy ....

Looking at the viable capacity, it seems that there is something optimistic .... generating at full power for 4209 hours/year (2766682/657.259) is ~49% of the hours available, which, considering that it takes at least as long to pump the water back in a closed system, doesn't leave much of a margin for the system to stand idle or soak-up excess power - there would almost need to be dedicated schedulable capacity to achieve these run-rates.

Looks to be a little simplistic to me ....
HTH
Z

pwllbwdr

Er no. The BHA website is mostly about hydro generation, not pumped storage - you seem to have made an assumption there.

Continuous flow falling over a decent head gives potential for continuous generation, except perhaps in summer if the water course becomes low flow.

doughnutmachine

zeupater wrote: »

Hi

I think that those figures could be open to question ....

Of the 2.6GW capacity, how much would be classified as being 'pumped storage' ?

Z

the BHO never said it was "pumped storage". So i assume the answer to your question is...... "drum roll"...... zero ... "bang on cymball".... "wild applause"....

zeupater

grahamc2003 wrote: »

if you are blessed with an independent mind and apply a couple of logical & typical scenarios, and additionally understand the requirements of the grid, then you'll possibly appreciate advantages of a smart grid which not unsurprisingly escapes others.

Two mega costs of the grid are meeting the peak and frequency stability. Everything else is simple and cheap. While you sort of addressed peak demand and how a smart grid can ameliorate that either by pricing or direct control, I'm not sure you mentioned the frequency stability aspect.

Due to the cost of meeting the peak, any generation which doesn't is of limited and extremely low value - irrespective of any other consideration (and your and my solar panels produce this inherently low value generation). Since smart meters will -eventually - help lower the peak by shifting demand to a lower demand period, it is an extremely valuable addon to the generation itself.

Frequency control is necessary at all times, and the ability of smart meters - eventually - to exercise a degree of control over many households discretionary load, almost instantaneously, means they'll be able to relieve other stations of the need to provide so much very expensive primary reserve. (for which they burn fuel and cause co2 of course, even when supplying no generation at all).

Intermittent generation necessarily increases the primary reserve requirements of the grid (so wind and solar are not zero co2 when connected to the grid as many seem to think), so smart meters will help offset the extra reserve requirements brought on by solar and wind.

I'm afraid, from the grid engineering perspective, solar has the pretty unique and unfortunate characteristics of not supplying power at the peak, while at the same time requiring more system primary reserve. Smart technology, which incidentally is nothing new and was being discussed in the cegb research labs 35 years ago, has the opposite characteristics.

Hi

The referenced post was simply addressing the point of smartmeters, specifically the issue of utilising smartmeters to reduce load at peak time ... smartmeters without the ability to control, or be controlled, are just meters which can provide HHM & be read remotely ....

Regarding solar not providing power at peak times .... well isn't that where storage solutions such as Dinorwig come into play - taking non-peak generation and releasing it at maximum peak times ?? .... surely there's nothing to say that daytime pv generation isn't aiding or couldn't aid this process.

Smartmeters provide the energy suppliers with a new carrot and a new stick, both can be used to reduce energy usage and power provision requirements, however, it's quite obvious that one can benefit the supplier's margin far more than the other ....

HTH
Z

zeupater

John_Pierpoint wrote: »

Would we not just buy a "digibox" for our existing freezer and that would do the turning on / turning off?

Hi John

That's what I meant by "some form of control device" ....

zeupater wrote: »

.... The issue with smartmetering is that smartmeters are simply an integrated component of a smartgrid, which then requires householders to invest quite heavily in smartappliances or some form of control device .... without the appliances being in place the smartgrid demand smoothing theory simply falls apart ....

I doubt that there would be any rush for the energy suppliers to provide such equipment free of charge and they would likely prefer to use the stick (HHM charging) to maintain a healthy margin on such devices ...

HTH
Z

spgsc531

grahamc2003 wrote: »

You ask 'Was solar ever going to fullfil the role of supplying power at the period of peak demand'.

Given that sensible generation always has the capability to supply at the peak, you might as well ask 'Was solar ever meant to be a sensible method of electricity generation'.

The answer to both is 'no'.

I see you cherry pick one question and avoid the others.

Peak demand could be described just as easily in the summer as in the winter, where solar could well contribute at peak demand time.

You could ask the same thing about other types of renewables. You may not like it but that is the world we are moving into. 29% of electricity generation by renewables by 2020, 35% by 2030 in the UK.

This is a commitment the whole of the EU has undertaken. The world is taking Carbon emissions seriously enough now to introduce these policies.

That's why those who understand the implications of connecting solar (or any other intermittent generation) to the grid see it as such a waste of resources (and therefore, being such a waste of resources, not environmental at all).

Good luck in voicing how your right and the world is wrong.

Incidentally, you said you didn't understand my post detailing some characteristics of the grid and how it works - no problem with that, not many do actually understand. My problem is seeing how you can form the opinion that solar is a good method of electricity generation when connected to the grid if you (understandably) don't know how the grid works and therefore the implications of connecting solar to it?

I said I didn't understand your post, then went on to explain why. Again, you didn't answer my questions.

spgsc