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Exiled_Tyke wrote: »

. In this case PV could be making a very positive impact and therefore a decent government should be exploring ways to protect the stability of supply and the grid infrastructure whilst promoting it.

Whilst it is a statement of the obvious, solar doesn't generate at night and even in Spain often not during the day.


So the Spanish national grid still has to have sufficient generating capacity to cover periods when solar generates zilch; and conversely be able to instantly cope with excess solar generation.

kevin6666 wrote: »

You don't seem to be offering any sort of solution to the problem though. It seems in your world taking Spain as an example they should have done nothing. i.e. Left existing FITs Installs as they are and carry on allowing domestic generators to install PV with no charges for using the grid.

Couple of corrections there. Firstly you seem to be trying to say it's OK to retrospectively cut the subsidies in Spain. Whilst this might fit with your views, remember this is a very dangerous move when it comes to faith in investment. It goes beyond PV, as renewables investors (or even wider) will now be concerned about Spain.

Not sure why you slipped in that "no charges for using the grid". The cost of the grid can be covered by a daily standing charge, and since no payments are made for export, the suppliers could use the money they make selling that on. What I disagree with is the false use of an export tax, simply to artificially push up the cost of demand side generation. I don't think anyone believes it is anything other than artificial support for the existing suppliers.

kevin6666 wrote: »

Can you answer what happens when the major suppliers close or withdraw from Spain? Fine with the idea of the countrys national grid collapsing? Could well be the worst disaster is human history.

Bit dramatic aren't we!

Spain, like all countries, will have to adapt to the change in generation type, and the change in generation source. Think about your argument, you are simply saying that the public shouldn't rock the boat. Fine, but back to an earlier post of mine, do you own a car, do you own a TV? Should these have been blocked to protect the older industries?

I appreciate that change frightens people, but that's not an excuse to block progress. PV generation in Spain only has a 2:1 ratio (July v's Dec) at 35d pitch. At 50d pitch it's only 1.5:1 (suffering only a 3% drop in annual gen, v's 35d). So it's an excellent resource, and ideally suited to small domestic batteries.

Regarding Spanish solutions, and thanks to ET for pointing out that this isn't 'my' problem, and for mentioning investment in storage.

Spain has a very good mix of generation already, only about 30% is FF. A lot of it is intermittent (wind (and a bit of PV)), plus a large amount of hydro, which is intermittent but a little more flexible. It also has a lot of nuclear, which is relatively inflexible. All of these would benefit from investment in storage, to help with demand following.

Also Spain is southerly enough to deploy CSP (which it has done), the latest molten salt CSP plants can generate 24hrs in the Summer, and I think for 4+ hours after sunset in the winter months (depending on weather).

If demand side PV reduces that FF element, and provides excess for storage later in the day/night, then that sounds like a good solution for the environment ....... if not for the established 'old boys' ....... but hey, that's progress.

Mart.

Alan_Brown wrote: »

Personally I'd love to go off grid, but it's just not possible in the UK with solar and I don't have access to other renewable technologies.

Yep, second that. In the UK you really need some wind generation for off-grid, but small scale wind doesn't work very well. I chat on a renewables forum, and some folk have wind and some are off-grid. Wind seems to involve a lot of work (and love) lowering turbines before storms, or switching on dump loads to protect batteries, whereas these same folk are loving PV as the inverter can 'leave' the leccy in the panels when the batts are full. The guys with wind (so to speak) generally seem to refer to needing 200m of unobstructed space between the turbine and the main direction the wind comes from, in order for turbulence to settle down. House rooves cause so much turbulence that small domestic turbines may spend more time 'hunting' than generating.

If you're interested I managed to get some numbers from an off-gridder, and listed some kit here, but this was more with 'warm places' such as Spain or Aus in mind, where PV generation is higher in the bottom months:

Martyn1981 wrote: »

Well ....... that was fast, I think asking for advice from someone who has been called a liar regarding battery costs was a good idea!

If you read around that post you'll find more info, but don't stray too far, most of the thread is me (and others) arguing with a pro-coaler, whose numbers were (to be polite) a little pessimistic.

Also note those batt prices are lead acid, so we're talking serious off-gridding, battery room/shed, for tonne(s) of storage.


Lastly, something I mentioned on the flow boiler thread, if you had batts, then it might (just might?) be practical to use a CHP boiler instead of a back up generator. That way you could run the boiler for heat, even if leccy isn't needed (into batts), and run the boiler in shorter harder stints, to maximise the generation potential (again with batts in mind, not needing to time match heating and leccy demand). But these CHP's aren't cheap, so just a thought going forward. In the non-heating months, an appropriately sized PV and batt probably wouldn't need back up.

[Edit: So I don't expect a flood of UK households leaving the grid, but as battery storage improves, I would expect to see PV households able to reduce their demand on the grid, especially in the early evenings, when batts will (presumably on average) be at their fullest (weather dependent), since that's the point in time when you'd expect to move from charging to depleting. M.]

Mart.

I genuinely don't know if this is serious. My understanding of the solar roadways campaign was that it simply didn't make economic sense, but does this?

France to pave 1,000km of road with solar panels

I'd have thought road side canopies, car park canopies etc etc, would be cheaper than traffic proof PV. However, if it works, then that's space sorted ...... if it works.

Mart.

Martyn1981 wrote: »

Yep, second that. In the UK you really need some wind generation for off-grid, but small scale wind doesn't work very well. I chat on a renewables forum, and some folk have wind and some are off-grid. Wind seems to involve a lot of work (and love) lowering turbines before storms, or switching on dump loads to protect batteries, whereas these same folk are loving PV as the inverter can 'leave' the leccy in the panels when the batts are full. The guys with wind (so to speak) generally seem to refer to needing 200m of unobstructed space between the turbine and the main direction the wind comes from, in order for turbulence to settle down. House rooves cause so much turbulence that small domestic turbines may spend more time 'hunting' than generating.

If you're interested I managed to get some numbers from an off-gridder, and listed some kit here, but this was more with 'warm places' such as Spain or Aus in mind, where PV generation is higher in the bottom months:



If you read around that post you'll find more info, but don't stray too far, most of the thread is me (and others) arguing with a pro-coaler, whose numbers were (to be polite) a little pessimistic.

Also note those batt prices are lead acid, so we're talking serious off-gridding, battery room/shed, for tonne(s) of storage.


Lastly, something I mentioned on the flow boiler thread, if you had batts, then it might (just might?) be practical to use a CHP boiler instead of a back up generator. That way you could run the boiler for heat, even if leccy isn't needed (into batts), and run the boiler in shorter harder stints, to maximise the generation potential (again with batts in mind, not needing to time match heating and leccy demand). But these CHP's aren't cheap, so just a thought going forward. In the non-heating months, an appropriately sized PV and batt probably wouldn't need back up.

[Edit: So I don't expect a flood of UK households leaving the grid, but as battery storage improves, I would expect to see PV households able to reduce their demand on the grid, especially in the early evenings, when batts will (presumably on average) be at their fullest (weather dependent), since that's the point in time when you'd expect to move from charging to depleting. M.]

Mart.

I was thinking about this over the weekend and was wondering if you were on mains gas and whether you'd thought of trying to go off-grid with that?

For example, someone with a well insulated home with electric showers and air sourced heat pump technology, etc. who also had solar PV and an immersun device could move away from gas and go completely electric. Whether the savings on the gas standing charge vs the fact that gas is cheaper than electricity works out financially, is one point, but the other would be the potential that you coul dgo clean energy with your home, especially if you could add to your generation with additional solar or wind turbine.

Another potential for going off grid would be water. With a borehole providing drinking water with rainwater or greywater recycling and and a cesspit, you could go off grid.

It might cost you a little more to be off grid rather than on, but it'd be good to get away from the money grabbing utility companies.