The_weeze

I have a similar setup, though single phase, but was told that 1.5Kw was the maximum. I'm keen to add a couple more panels since I have 2 free connections on the inverters and a hungry pool pump to feed so is the 3kw because it is 3 phase or is it that I am misunderstanding the rule. I am inclined to just add the other panels, they are in the garden so this will be easy.

zoff

That sounds great Score76, good info. I just moved full time to what used to be my parents house (previously my great grandparents property) and I'll be asking questions when I get ready to research solar. I'm living between Porches and Senhora da Rocha so it looks like we live close.

alf1956

I have been looking at the solar power issue for many years & I have put posts on various forums & the majority of answers I got were very negative & suggesting that the power companies are dead against it which surprised me no end in view of the amount of sun/light that Portugal gets.
So it appears that the self installation system is the way forward, I am wondering if there is any mileage in installing a solar battery pack to store the unused electricity that will be generated & use it after the sun has gone down?
We have solar panels at home & up until recently they were not cost effective but now they have dropped considerably in price its worth looking at especially if you have the old Economy 7 system which is an extremely low price per unit at night & it could be that you could charge up the batteries at night after you have used up al the power in them from the daytime charging & use it into the next day etc etc.
We have not done any calculations on the above yet & we do not want to ask the battery suppliers as they will feed you a load of crap & just tell you want you want to hear a bit like the solar panel suppliers do when you go to purchase a system from them.

Score76

I'd suggest the power companies prefer to buy their overpriced electricity rather than make your own ;-)

BillBullock

The EDP scheme suggests that I only need a 5 panel scheme of theirs to produce a mere 1.3 kW max at a cost of €2683.20. I actually need a lot more in the winter months to feed my night storage heating system instead of using the bihoraria cheaper rate electricity. They won't even quote me for a battery storage system for some reason. Needless to say, I have not signed up for their scheme, especially as they do not pay you for any feedback you make.

Ingles

Could not agree more , back in early 80's I was working in Greece, there was a law in place that was heavily enforced ,that every house/building etc etc HAD to have solar panel system to heat water to get a licence for habitation/use.
This was because they imported nearly all there electricity from Yugoslavia, & electricity at this time was the most common way off heating water.
Here in PT in 2019 ?????

wellinever

Hi Barlavento
You kindly pointed me to the directive about solar water heating. I have looked at the bits you highlighted and it does appear to say that
"4 - As an alternative to the use of solar thermal collectors, any other renewable forms of energy that capture, on an annual basis, energy equivalent to that which may be used for purposes other than heating water if efficient or convenient."

This is what my builder keeps saying to me, and surely it makes sense?
In my particular case the house is a single floor, with a flat roof of 120mtrs/2, but 10 mtres away slightly to the East is a large 8 mtre high tree and at the West at a similar distance is a 2 floor with high roof house. I noticed before I bought the plot that these could both be an issue for sunlight in the winter, and yes during construction it became evident that despite facing due south the rear garden would be in the shade for all but an hour of the day because of the tree and house. There is not and never designed to be access to the roof on a day to day basis and so I never anticipated using solar, which needs periodic maintenance. Therefore I did not look at the sun exposure of the roof during the winter, but being a single floor house I know it will not be much, and doubt if there is is actually sufficient sun to power solar water efficiently during winter months (when you need more hot water).
There also seems to be another `get out` clause mentioned in the law, and the 2 hour ruling may well apply to my roof during winter with low sun.
"3 - For the purposes of the previous paragraph, adequate sun exposure is understood as existence of a terrace or inclined roof with water whose normal orientation is in a range of azimuths of 90 degrees between southeast and southwest, which are not shaded by obstacles in the period that begins daily two hours after sunrise and ends two hours before sunset."

I have mentioned all of this to my original engineer, who says...I need to conform to the OPINION of the engineer doing the energy survey !!!
My response to her is....surely a law cannot be open to opinions of individual engineers?
My preference would be for photovoltaic but have no idea how big a system I would need give equivalent to a 200 litr solar water collector. Any ideas anyone??

Score76

Do the same solar PV panels I fitted not solve your problem too?

You need a standard 200L unvented tank fitted with an electric immersion heater. Typically these are in the order of 2.5kw, but in you case I'd suggest something smaller, or get one with 2 fitted. Gledhill are a good make, they do some for exactly this purpose, 2.5kw for when you want your hot water quickly, plus a "solar" one which would normally be something like 500w but you'd leave this on during solar generating hours, it turns off when your tank is fully hot.

In winter solar output is typically 25% to 30% of summer output so if you went with 1.5kw of panels you'd be sorted. Added bonus is that any electricity you generate that's not used by your hot water tank, you get to use for free and save off your EDP bill.

wellinever

hi Score76
Thanks for your input to my dilema.
My understanding of this is very limited.
I have looked at the EDP offer at the moment, but that only gives 250w. (photo attached of simulator), which does not sound like that much to me. But I dont really understand the whole thing. What would that mean for example for my fridge that uses 1.1kw/24 hours??
But the most important thing appears to be that any other forms of renewables must be equivalent in power to what is saved by using solar water heating. And it is suggested I would need a 200ltr system.

Score76

Hey wellinever,

The picture you attached of the EDP scheme shows a frame system with 3 panels. The detail around it only relates to one panel. So each panel is rated to generate 250w. With 3 of them, you'd get 750w. The 250w is what the panel should produce under ideal conditions. This can be affected by time of day (position of sun in the sky), cloud cover, temperature (oddly if the sun is too strong then the panels get too hot and they lose efficiency). It's not a problem though, it just means you slightly over spec the system to compensate. In terms of generated power you end up with a curve like in the attached.


Generation graph from yesterday

I'm near Porches in the Algarve, it got up to 36C in the shade here yesterday, so peak generation was a little down on normal, but overall still produced 17kwh.

In terms of your fridge, it will use in the region of 200-250w whilst the motor is running, 30w each time you open the door and the light comes on, and 5w at all other times. The power usage is peaky not constant. The quoted 1.1kw will be the sum of all the peaky usage over a 24 hour period. The key to getting the right system is to put some monitoring on first, once you know exactly what you're using you can size a system to match. In your case you'd add on 500w over this base usage to heat your water too. PM me if you want help with this.

wellinever

hi
Thanks for reply.
The house is just up the road from you in Armacao.
I am in the UK at the moment but return 1st week June.
I need to get this resolved when I get back as I need to get a habitation license for the house.
I think the edp simulation always shows 3 panels. 60 cells is I believe one panel??
Maybe we could meet up if you are still there.

Ana waters

Hi there,
I am trying to install a mobile solar power source on a window that runs from a basement to outside.
It is only to power up a 16mm projector.
I found something in the US , but i want to buy locally.

Has anyone any advice where to buy ?

barlaventoexpert

Can you please be somewhat more specific.

1) Are we talking about a 16mm Black & Howell movie projector? A 16mm spotlight? More specs please!
2) What are the power specs needed. Amps/Watts/Voltage?
3) Can you post-up the link to the one you found in the US?
4) What area are you in?

EMR

Try your local Leroy Merlin. Diy store.

barlaventoexpert

If it's a specialist unit, it may only be available in a couple of specialist outlets in Lisbon or Porto.

I happen know one near me.