Solar panels
 

Does anyone have solar panels? Are they mainly used for heating pools or does anyone use them for providing electricity?

Judging by the previous posts about electricity companies and price hikes think I could be tempted to fit them when we buy a place!

Re: Solar panels
 

Well if you buy a new place then its law now that it has to be solar panel ready here. We got a quote for panels to "heat" our pool and it was about €2500 and we were told it would only raise the pool temp a couple of degrees, which frankly wasnt worth it.

If I had the choice I would probably have solar fitted for water heating, as I find the water heater can be quite a drain on the bill

Re: Solar panels
 

Hi

If a solar panel installation costs 25,000 and you take an interest rate of 5% then the interest alone is 1,250. If most people pay around 150 euros every two months, that is 900 a year. Then remember that you will need to change the batteries evry 10 years.

Do correct me if my figures don't calculate

Davexf

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25000!!! Is that what a full system costs :confused::eek:

Re: Solar panels
 

Hi Mitzy,

That's what I am left to believe for a full system powering electricity for a "normal" three bedroomed house with automatic backup generator.

At least - that's what the last pamphlet I threw away said !!!

Davexf

Re: Solar panels
 

I (seriously) looked into it. The basic installation was about 20k euros to produce 3.5Kw. Given that we would need to be connected to Ibedrola, for various reasons, this would have taken about 20 - 25 years to pay back and that's before you start to make a saving!!

Simply not worth it until the basic cost comes down or there is an incentive to do it (other than a moral one).

I can understand that if the property is to be passed on within the family, then you can accept a pay back in this kind of timescale, but I'm not sure that I can guarantee that.

Mmmmmmm.... nice to be green but ...

Re: Solar panels
 

There's an american publication I sometimes see called Home Power. One issue priced up a complete "off grid" solution as:

PV system, 720 W $12,000 (edit: this is for a 5kW/Hr capacity - very low, UK average is about 11)
4 wood heaters 10,000
PV water pumping system, 320 W 6,200
Cistern, 1,250 gal. 2,500
Rainwater catchment system 1,500
Greywater system 500
Propane-fired tank water heater 200
Total, Energy/House Systems $32,900

This guy spent about $36k getting his system (though being an american his energy consumption was, frankly, profligate) but he seems to have gone all-electric, rather than the more sensible approach of using a separate solar hot water system - or even just buying a couple of pullovers.

Re: Solar panels
 

Can you get grants still?

Re: Solar panels
 

I had a quote in for both water heating and photovoltaic (electricity generating) systems, and by gum it's a bit complicated.

From what I am led to believe the water heating panels, if you have enough, can be used for domestic hot water, underfloor heating or pool heating, but not all at once. For summer you'd just use it for hot water, which I reckon would be pretty hot too, spring and autumn you'd get a bit more life out of the pool and winter for underfloor heating. I think the cost for this system was about €15K, and considering my electric bills for Dec/Jan were €850 I am getting sorely tempted.

The photovoltaic system generates as much electricity as you have panels, and there are grants available retrospectively for particular systems, up to 30% I believe. The crafty bit is that you don't use it for yourself. You have a box next to your meter that measures how much you send back to Iberdrola and, wait for it, they pay you 4 times the going rate for the electricity.

Get your head around that one!

Ste.

Re: Solar panels
 

We have solar heating for our pool. The system is pretty simple and is basically a set of black pipes layed out on a shelf in full sunlight through which the pool water is pumped. It has minimal intelligence with a thermal switch that turns the pump on when the pipe temp is a certain number of degrees above the pool temp. Works very well in extending the useable pool period. Normally have to turn it off in the height of summer so as not to turn the pool into a bath.

it was already fitted when we bought our home but given it's simplicity I can't imagine that it is very expensive

Re: Solar panels
 

hi there are house runs on solar panels and wind generater plus batteries .we brought every thing from america 4 panels wind generater batteries power inverters all for 2000 pounds we installed them our selves there are several companys in spain i can email you with details its so easy every thing is run off these for are property. helen

Re: Solar panels
 

Well, I tend to think that photovoltaics aren't worth it, because of the high costs of batteries. Ditto wind power.

However, hot water is a no brainer. You can even, if a big water tank is a no-no on the roof, set up a big tank on the ground that can act as a trap for the hot water, (or set up a heat exchange coil) but that does need a water pump to circle the water round so it can get caught in the trap.

A wind generator can also generate heat, dumping the power into a hot water heater, so that is good for the winter, and if you can store a couple of day's hot water in the trap, then a sunny winter's day gives dividends.

Such a solar water heating system can be easily built (the turbine is a bit more techie) and I am sure that it wouldn't cost too much if you can do a bit of welding and fibreglass work yourself. The solar panels can be made as catenaries, out of fibreglass, and the purchase of an arc welder and a bit of study is a very worthwhile skill to gain. Soldering pipework is simple, and the panels can sit on the tank supports and feed the tank thru a thermosiphon.

Pressure can be solved with a feeder tank and ball cock, and the tank can feed the house thru gravity. I have just fitted the pipe work for our second bathroom, and in each bathroom there is a spur off the hot water pipe with a stopcock on it. Basically, to switch from the electric heater to the solar, you just turn off the tap on the hot feed from the electric heater and open the stopcock to the solar.

Re: Solar panels
 

have you tried this ???????? solar panels and wind generator work really well .would be intrested to see if your idear works . helen

Re: Solar panels
 

General Info,
A 5KW Solar system will power a 3 bedroom house with auto generator minimum 5KVA providing power for Heavier loads, or to supplement high usage cost would be 15k€, with a good open frame diesel generator at about 3000€.
Should you wish to reduce further generator run time and cost ,buy more panels. (however beware of the paybacks)
The fitting of Solar electric is rarely cost effective vs a Grid supply due to extended paybacks as demonstrated above, however, a few points to note,
Permanent power cut free electricity, no unfair price hikes, no Oil relate penalty's. reduced carbon footprint, future price and energy increases will be irrelevant, battery life, is normally in excess of 15years, if managed properly and carefully, indeed one supplier offers a 10Year guarantee, with life expectancy in excess of 20 years.
Solar Panels (Thermal/Hotwater) are unlikely to provide hotwater all the year round, with perhaps only a slight rise in temp in the months of Nov/Dec/Jan/Feb. I would say that a saving of up to 70% of water heating costs could be made on an annualised basis.
Solar pool heating, is rarely effective in the cooler months and the most to expect from a well engineered system would be an extension of the swimming period for 8/10 weeks front back of season.
Using solar heating for central heating is just not an option, as when you need the heating is when there is least Solar heat, IE in Winter, at night and when its raining or snowing!!!
You cannot just plug your panels into the grid, and I understand it Spain (Uniquely) does not allow this, (reversing meters are used in France, Germany, Low countries and UK), but in Spain you would have to put in a seperate dedicated system, which is then formed as a Seperate company, with its own meter to sell back to the grid, not as complex as it sounds, and you could put in a small system for about 50k€, with a payback of about 12/14 years @ current sell back rate, it was a lot better,
The rate of sell back was 42C per KWH, until the change in the Royal decree last year when it was dropped to 26C per KWH, there are slight differnces with different suppliers and regions. hence the sudden spate of Solar parks that were suddenly constructred rather quickly last summer.
Wind generators, are not as effective as Solar panels in my view, given both their power curves vs windspeed, and more importantly, in Spain we get about 320 days of sun, whereas the wind is a much more indeterminate thing, although most people will say it is always windy here, test we have done doesnt always prove that.
Self build systems are sometimes effective, but invariable require a inordinate amount of time to develop and perfect, ideal for the retired engineer, but not advised if you intend to work, have a family and want a steady reliable source of power.

Re: Solar panels
 

Well, like so many I lack the money. I am part way thru the 2nd bathroom, but it's a case of being able to buy the stuff I need. The solar water heating is so simple, that I can put it together easily once I have the parts, all I need is to get enough steel for the supports, the rods for welding it, the paint, and then the glass fibre, the insulation and waterproofing, the pipework and enough ply and glass to make the solar housing.

None of those on its own is excessively expensive (tho the fibreglass will hurt a bit), but the sum is more than I hav at present.

The wind generator requires a decent workshop, and that is something that I need to save up for.

Re: Solar panels
 

We looked at solar water heating when we built our house but decided against it on the basis of the capital cost vs savings.

We run a 200 litre electric water heater for 3 hours a night on the night tariff on a time switch and end up paying just 70 euros/year for our hot water. Left to its own devices 24/7 on the standard tariff it would cost 4 times that amount, which I agree is pretty expensive.

Re: Solar panels
 

No, as I understand it these were stopped in favour of 'buy-back'.

Re: Solar panels
 

Grants are available for qualifying installations of up to 40% this varies depending on region, IE a house with no electric in the campo which takes the decision to go Solar electric would almost certainly qualify,if you put a Solar water heater on your house to replace existing fossil fueled system you may qualify. Solar Farm installations do not qualify for grants. ( Heatpump, Geothermal and airsource used for hotwater or CH may qualify but not for heating the pool) the snag is to know how and when. It is very much about allocated amounts, timing of application, and making sure you follow it through personally.
In Valencia, the grant system is run by an agency called AVEN, the window for this year to submit application opens in March (I think) for about 6 weeks, if your application is not submitted in this time then you will lose it. Results are not guaranteed and seem dependent on how you approach the system rather than strict allocation, % amount received depends total fund allocated for grants and successful applications . On new builds the promoter has usually claimed the grant and pocketed the money before you even know it has happened.
There is a specialist in Elche, who will do all the documentation, submit and follow through to conclusion.

Re: Solar panels
 

Google DIY solar heating systems and you will be overwhelmed with info on how to make them.

Jim

Re: Solar panels
 

The most effective and economical system to heat a swimming pool is installing a heatpump.
Heatpumps are up to 500% efficient wheras a boiler or electric element type heater at maximum efficiency could only attain 100% efficiency Watts consumed = watts output.
A heatpump can consume 2kW but provide up to 10kW of heat energy.

Main consideration is to install a good cover and make sure it is used whenever the pool is not in use to retain heat.
Once the pool is at the required temperature it will only loose 1 or 2°C overnight which is soon made up again.
Cost to run a heatpump is around 1~3 Euros/day once up to temperature, the ideal is to put the unit on when the temperature starts to drop in September and it will automatically maintain it.

RegardsDave

Re: Solar panels
 

We have 'solar' panels to heat our pool. That is, big (purpose built) black sheets in which the sun heats the water. These have proved to heat the pool by as much as 7 celcius. The system is fully automated - comes on when the difference between pool temp and panels is greater than x and goes off when the difference gets to y - it's most efficient.

When we looked into this we were told that, taking everything into consideration, this was more cost effective than a heat pump.



I also have a summer cover which again raises the temp when the pool is not in use (or even overnight if I can be bothered), stops loss of chlorine and also stops water evaporation. For longer spells, we have a much heavier winter cover.

Re: Solar panels
 

HI Most effective and economical are not compatible in this context,

a Heatpump for a 8x4 x1.5m pool will cost about 3500€ running cost would be about 300€ PA, maybe more, depends on how hard you try and what Tariff you use, and it can be more effective if the sun dont shine!!

Solar Black panel system about 4500€, running cost per annum minimal, but I would guess at 75€ being excessive,

500%,, optimistic, best I have ever seen declared is 4.9 which is probably under lab test conditions, I would say about 300% is more a realistic median taking into account operating conditions FWT etc,

Re: Solar panels
 

Blimey. Is that black panel a proper vacuum tube jobbie?I wasn't thinking of a black panel, but a home made parabolic trough collector, which I am hoping will cost me a lot less, and have an almost zero running cost. We must pay about 100 a month for power, and even if that were all hot water, the installation you describe would take 5 years at least to pay back

Re: Solar panels
 

were are you getting these prices from we have solar pannels wind generator etc and use nothing else these are not home made cost us a fraction of the cost for the whole system 2500 some one is ripping poeple off some where

Re: Solar panels
 

No, its a sheet of plastic with millions (well many anyway) of microtubes running from top to bottom. As water runs through them, they get heated by the sun. So, cold water in the top, hot water out the bottom and then pumped into pool. etc. etc. That's why a proper panel like this will be many times more effective than garden hose painted black.

But then you get what you pay for I guess...

Re: Solar panels
 

That explains the price, but it seems to me that a parabolic trough system will do as well, if not better, and would be one hell of a lot cheaper.

Unless I'm missing something?

Re: Solar panels
 

A heatpump will provide a heated pool for most of the year 10~11 months and at a good temperature 27~30°C+ if you want it - a cover is essential.

A heatpump will occupy a small space, in comparison Solar would need 50% of the pool size in sq.m. 25m2 for a 10 x 5 pool most people don't seem to want that size of system in their garden.
Although once installed they are low cost to run but not as reliable a source of heat as a heatpump.

The DIY Solar systems are potentially dangerous and could result in injury if not installed according to regulations - always consult an expert if you are unsure and ensure they know local regulations for any system being installed.

Regards, Dave

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I was looking at the price quoted above at some 4.5 K.

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Hmmm. I'm prepared to make a small bet as to the profession of this gentleman.

Building a small wall is potentially dangerous too. Obviously people undertaking such work should have their wits about them, and research the subject thoroughly. However, if we left everything to the experts, the rest of us would seldom expand our abilities and knowledge base.

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No, he is a salt pool man. ;-) ;-)

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Hi Bil

This is on youtube may give you some hints as there are a number of comments as to use of materials rtc.

http://www.youtube.com/watch?v=kXXOwfZA2Rk

Jim

Re: Solar panels
 

Thanks Jim.

The parabolics are fairly hard to draw out accurately, this guy is doing a simple semicircular one, but the problem is that it gives a less focussed beam, so that can reduce yield.

The interesting thing to look up is to do with catenaries. These are faux parabolas, created in the way that a chain hangs between two points. If the ratio of width to depth of the loop is 4:1, a catenary has a shape very close to a parabola, I think, (and also will focus light a bit less perfectly.)

On the other hand, it is capable of putting the beam onto the same spot, no matter where it comes from. That would be useful when building a static array that can't track the sun.

As has been pointed out, these create a powerful beam and need to be treated with respect. I would also suggest that the focus pipes be made out of a single tube. Soldered joints would be melted in a flash should the water drain out, and I'm not 100 % sure of the melting point of copper even.

All needs to be researched before starting. I used to melt lead airgun slugs with a 9" lens, so bear that in mind.

Re: Solar panels
 

Hi Jdr,
Thanks for your defence..... But
The company I work for supplies all approved systems for swimming pools that means approved firstly within Europe and also by the company so we can visit bars without fear of being lynched or chased out of town :ohmy:

Happy to advise you about what to look for and how to do it whether you do it that way or not is up to you and if I don't know, I know a man who does.

Regards, Dave

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Hi Bil
Simple method of drawing a parabola is to use the 2 pins and a pencil method. First developed by Johannes Kepler some 400 years ago. I remember we had to do this when we were doing dish theory.

http://mathforum.org/~sanders/geomet...9Parabola.html

Jim

Re: Solar panels
 

I just noticed a British lady had trouble with her immigrant workers in Murcia They had no tea making facilities on site, So being a true Brit she had built the item you see in the Pic below in order to provide hot tea brewing water.. I notice the kettle to the left of the group so evidence of a recent brew maybe. Like the builders always say....Nowt like a cuppa to wash down the lama sandwiches. :beer::beer::beer:

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Soory if I wrongly branded you as a solar installer . Tell me, these regulations re fitting solar items (not photo voltaics). What sort of things do they cover please?

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Thanks for that. That looks a simpler method than I have seen elsewhere. The parabolas do give a very tight focus, but the system I am thinking of (for reasons of being broke) need to be very cost effective. I want to get one of those little laser pointers and have a play with a catenary curve, because a parabolic trough will only give a good result when pointed at the sun, and a catenary is alleged to keep the focus constant (even tho it is a fuzzier focus, and obviously will diminish a little as the sun tracks), and that will save me the cost of a tracking system.

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Basically it's the safety aspects of the system venting 100°C hotb water into the pool, if you could imagine someone standing in front of the water return jet and the solar system decides to het the pool, the valve changes position and boiling water is pumped into the pool the return is in the shallow end and most likely place for children and elderly, children are attracted to the jets.
So it is simply a heat exchanger should be between the Solar system and the pool water - make sure it is a titanium heat exchanger or titanium and plastic as some of them are nowadays.

Regulations for heatpumps: cable suitable for the electrical load fed from it's own suply breaker, Unit connected to a Local copper earth stake, local electrical isolation switch within sight of the heatpump.

Regards, Dave

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Ah, that explains it. A baffle or something would make enormous sense.Me, I am looking at providing hot water for the house, so the problems there are no more than apply to water supplied by the boiler. I plan to feed the hot water tank with a header tank plus a heat relief pipe venting into said header, which was the system I used in our old house in the UK.

Re: Solar panels
 

Hot water systems require a tyemperature controlled combiner valve to regulate the hot water temperature delivered to the tap, shower etc.

Solar systems can get very hot and it's possible to get steam

Regards, Dave