Supply and Fit Solar Electric

[pm]

I don't know what the rules are for pumping power back nor what the rate is. I'd be surprised if it was financially viable to install extra solar and pump the over produce back to the grid. It's bleeding expensive to purchase. We are doing it because it's that or stumble about in the dark and not watch Brazilian soaps.
If I lived in Portugal, I'd do water recycling for sure, and then solar water heating and only after that solar electric. With solar electric, you are paying a premium rate for the product (electricity) and paying for 20 years up front.

(Nobody has mentioned water recycling on the forum as far as I recall?)

[Homme Poco]

Morning Pete. If you have solar electric,I don´t think you´ll need solar water heating as well.As for recycling the water, we have mentioned this to the agent of a builder (ie using waste water on the garden)he didn´t think it was agood idea,are there other products/methods on the market.
HP
.

[pm]

You cannot possibly use solar electric to heat water. Seriously. A solar electric panel cost £400 and produces 100w.
With water you can treat the washing machine/shower waste with plants! and use that for lavatory flushing etc.
http://www.earthship.org/news.php?subac ... om=&ucat=1&


This is what I would really like to do. http://mywebpages.comcast.net/algooch/index.htm

or actually this http://www.wolfpen.org/NMpics%5CEarthship_4.jpg and http://www.wolfpen.org/NMpics%5CEarthship_3.jpg (real big pictures)

[jimc]

Wind turbines are audibly intrusive and probably best suited to the West coast where there is more consistent wind.

Just to give you an idea of the likely costs based on quality branded equipment (BP, Studer, Outback Power and BAE).
Note that there is a high 'fixed' cost element of an installation which makes a low power setup pretty expensive.

If we are only talking Telly, Lights and Fridge with 3 day backup:
1) Generate 2.5KWh plus a bit each day based on solar insolation average of 4.5 hours per day => 4 x 175W solar panels (3.15KWh)
2) Store USEABLE power of 3 x 2.5KWh = 7.5KWh with reasonable battery life implies around 30KWh of batteries => 12 x 12v x 200Ah
3) 2.5KW inverter
4) Charge and Maximum Power Point controller
5) Cables, DC disconnects, frame etc & installation

Costs based on retail prices (1) €4368, (2) €2362, (3) €1725, (4) €592, (5) €1000 all including 12% IVA - all in around €10.000

[pm]

That's more or less the spec that we will be having. I can't comment on your prices except that I thought inverters were much more than that, or at least sine wave ones were.

[jimc]

Yeap - thats the price for Pure Sine wave inverter (actually its a 2.3Kw Studer) so you can even run your PC and radio from it (but we've only thought of TV, Fridge & Lights!).

[tbbr]

Watched re run of Grand Designs last night.

House in question was not linked to grid.

Had two small wind turbines ( less than 1 metre diameter ) plus solar panel to heat water.

THis was in the UK tucked away in a wood.

One of the advanatges of the algarve is the " constant wind " that cools in the summer and high number of sunshine hours.

Maybe a combination of both methods would be the most efficient and cheapest.
If it works in the UK it should be better in the Algarve ??

[pm]

I saw some of it and wish I'd seen the whole thing. How were the straw bales secured?

A 1m prop will generate around 400w at 25mph but only 100 odd at 20mph so you do actually need quite a bit of wind to get it to produce much. A 3kw prop is going to be around 4 to 5 metres across and up a 20m pole, which is getting pretty big.

They can't have used much electricity, I wouldn't think they had a tv or washing machine.

[tbbr]

The family in question did not look the type who would need all mod cons so the power output was probably sufficient for them.
This house used locally supplied timber in many forms to build and hold the structure together.
Others using straw bales have used chicken wire to keep them together before appying the surface plaster

I am not a great fan of large scale solar installations as in addition to cost and appearance the manufacture of this product is hardly eco friendly being a very toxic process.
Wind is free and windmills have existed since the iron age and without them much of lowland europe would still be under water.
Understandably much of the antipathy towards them arises from the huge scale windfarms and 50mtr rotors they use.
But maybe there is a place for this method of generating power on a smaller scale.
How do the costs compare to solar installations ??

[pm]

I think roughly the same for 1-3 kw setup

I can't find any sensible wind speed stats. I have found averages, around 9-10 kt, more or less the same every month. But that's no use, like the bloke who drowned in a stream although on average it was only 1/4m deep

[Homme Poco]

Bom Dia PM
This solar electric seems as if it is rather complicated,would you still be doing it if you had a main supply on hand.
I ask,because it is obvious that you have looked into it at great depth.
Kind Regards
HP

[pm]

The costs don't stack up. Even without taking interest into account you are paying several times the amount for not very much power and doing it 20 years in advance.
Even so, I do very much like the idea of being self sufficient

And yes, I read up a huge amount.
It's actually not that complex, panels, batteries, some smallish boxes on the wall. Probably a standby generator just in case, and that's it. It could well be more reliable that Portuguese mains anyway. We stayed in one house in the west where all the lights dimmed if you put the kettle on. And then the whole lot went off for a day.