# Solar panels



## andyviola (Aug 11, 2018)

A guy turned up univited and tried to talk about solar power but we don't share the same language ro a high enough level so he is sending an English speaking guy next week. Honest opinions please...is it a waste of time? I have no green aspirations and would only do it if it saved money and from what i google this seems unlikely as we would still be on the grid and pay them....


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## davexf (Jan 26, 2009)

Hola 

I looked into this some years ago and i know that modern materials have changed the figures but if you take the life of the solar panel, the life of the inverter, and the life of the batteries, divide the cost of renewal by the number of years, you get an annual cost. I found this cost be be much greater than my electricity bill. 

Davexf


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## MataMata (Nov 30, 2008)

Agree, it's not the panacea or money saver it's made out to be.

If you live in the campo and have no other option then fine but as a worthwhile and cost effective alternative to a traditional supply I think you'll struggle to make the sums work.


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## andyviola (Aug 11, 2018)

Thanks..also i live in a massive estate of big houses which would be perfect for panels and have failed to see even one using them. Telling!


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## Juan C (Sep 4, 2017)

Sorry this is slightly off thread

I fitted a solar water heating panel 18 years ago. We are a family of 2. During that time I have very rarely had to turn on the electric immersion heater which is in the unit’s storage tank.

I have never tried to calculate how much I have saved but it is many times the €1,000 I paid for the unit


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## xgarb (May 6, 2011)

It depends so much on your usage. The time of day you use electricity and what you are doing with it.

The cost of the batteries is the main consideration. If you need a high battery capacity then it's probably not worth it.

One option is to grid tie where you are still on the grid and sell back unused power but I don't know how practical this is with the Spanish electricity companies. If you go this route be aware that some inverters will cut your power when the electricity company cut theirs.

Here's a calculator: https://www.bimblesolar.com/solarcalc


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## davexf (Jan 26, 2009)

Juan C said:


> Sorry this is slightly off thread
> 
> I fitted a solar water heating panel 18 years ago. We are a family of 2. During that time I have very rarely had to turn on the electric immersion heater which is in the unit’s storage tank.
> 
> I have never tried to calculate how much I have saved but it is many times the €1,000 I paid for the unit


Hola 

I use hot water sparingly and have many "days & nights away" - i reckon to change my gas bottle twice a year - this year the cost was 25€ for two bottles; at 1% interest on 1,000€ that means you would save 15€ a year. 

But most people change their gas bottles for hot water more frequently 

Davexf


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## Megsmum (Sep 9, 2012)

I think the issue lies with some of the totally OTT costs of installing solar.

We have been here 6 years, solar only.. campo no chance of power.

Before we cameo researched on forums and the such like, totally ridiculous claims of €25K upwards.

We installed here, €7k. That’s for panels 8, inverter, batteries, wiring etc etc.
We have a contingency sum put aside for replacing batteries and the inverter.

We run
Fridge freezer
freezer
TV, Radios etc
Hairdryers etc
Pump for water to house
Pump from borehole to depósitos

Normal domestic stuff.


Having said that, if we lived somewhere where we had mains, I’d be tempted to put in a solar water heater but that’s about it. Savings will be swings and roundabouts, how much power do you use on mains. Friends in the village, 3- bed village house spend €120 pm month plus on electricity. So approx €1400 a year so based loosely on those figures we are now breaking even. As of next year. Apart from upgrades it’s free.


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## Isobella (Oct 16, 2014)

andyviola said:


> A guy turned up univited and tried to talk about solar power but we don't share the same language ro a high enough level so he is sending an English speaking guy next week. Honest opinions please...is it a waste of time? I have no green aspirations and would only do it if it saved money and from what i google this seems unlikely as we would still be on the grid and pay them....


Not sure about the pros and cons but I would never use a cold caller for anything.


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## DavidKS (Jan 28, 2020)

Juan C

What size panels and storage tank do you have?

Thanks


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## Monkey104 (Aug 24, 2014)

I am thinking of fitting solar power to power my pool pump.
My electricity cost are between 40 and 50 euros a month I drained it a few months ago in order to have some steps built in and that is how much less my electric bill is.
So over 10 years the cost of electricity will be between £4800 and £6000. Solar panels last up to 20 years and a battery between 5 and 15 years so a battery would have to be replaced over the 20 years.
So if I can fit a system cheaper than that then I will be quids in.
Just waiting for a quote at the moment.


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## andyviola (Aug 11, 2018)

Im just totally confused. Live in a large house and electricity costs 1500 a year. We need quite high power cos of pool. All the estate is on mains so i have no clue whether they would take us off the mains and whether it would supply enough electricity. We are in Catalonia and only 50 cloudy days a year. But i just envisage stress and terrible after sales service judging hy what we seen so far in Spain ( boiler contract guys annual service was 5 mins and he failed to spot no pressure so didnt even test)
Probably just forget it as it wasnt even something i was looking for.
Better to find a job and bills wont look so bad hahahahaha


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## Alcalaina (Aug 6, 2010)

We looked at getting solar water-heating panels when we cam here but given how cheap the propane gas bottles are (see Dave's post above) it would have taken 50 years to recoup the cost.

I presume you are taling about photovoltaic panels though, which actually generate electricity. They are getting cheaper and the stupid "sun tax" the last govt wanted to impose has been dumped. 

You will still get mains electricity, the panels just top it up.

Worth getting quotes from a few different companies if you are planning to stay put for a while.


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## andyviola (Aug 11, 2018)

Thanks havent found anyone who uses it to replace their mains so i assume it cant be done.. though salesman seemed to suggest it can...so im not confident enough to proceed. Dont think it will reduce bills which is my only reason to take it


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## davexf (Jan 26, 2009)

andyviola said:


> Thanks havent found anyone who uses it to replace their mains so i assume it cant be done.. though salesman seemed to suggest it can...so im not confident enough to proceed. Dont think it will reduce bills which is my only reason to take it


Hola 

Yes it can be done - but it costs money to have enough panels to have enough batteries to have a big enough inverter to completely live on solar - and most people have a backup generator for the odd period when the solar / wind isn't enough. 

No it won't reduce the bills over the life of the equipment - but it is the only way of getting electricity for some people 

Davexf


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## andyviola (Aug 11, 2018)

Ah! Ok we are on grid so thanks no need


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## ninahlt (Feb 3, 2020)

I think solar panel efficiency is a measurement of how much of the sun's energy a certain panel can convert into usable electricity. That's all you need to know.


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## Juan C (Sep 4, 2017)

DavidKS said:


> Juan C
> 
> What size panels and storage tank do you have?
> 
> Thanks



Hi David, 
 I think it has a storage of 140 litres and 2.5 square meters. It heats the water ti a maximum of 78C so there is not ´blow off, waste,


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## snikpoh (Nov 19, 2007)

Monkey104 said:


> I am thinking of fitting solar power to power my pool pump.
> My electricity cost are between 40 and 50 euros a month I drained it a few months ago in order to have some steps built in and that is how much less my electric bill is.
> So over 10 years the cost of electricity will be between £4800 and £6000. Solar panels last up to 20 years and a battery between 5 and 15 years so a battery would have to be replaced over the 20 years.
> So if I can fit a system cheaper than that then I will be quids in.
> Just waiting for a quote at the moment.


Just remember that a pool pump can be around 2kW. 

Each panel generates less than 200W so you will need at least 10 of them to drive the pump.


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## ninahlt (Feb 3, 2020)

ninahlt said:


> I think solar panel efficiency is a measurement of how much of the sun's energy a certain panel can convert into usable electricity. That's all you need to know. I researched this great article about How Much Do Solar Panels Cost? - Solar Panel Prices | Websolarguide


Looks interesting.


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## andyviola (Aug 11, 2018)

Well they never turned up again. Maybe they saw a hopeless indecisive Englishman


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## baldilocks (Mar 7, 2010)

> Originally Posted by ninahlt View Post
> I think solar panel efficiency is a measurement of how much of the sun's energy a certain panel can convert into usable electricity. That's all you need to know. I researched this great article about How Much Do Solar Panels Cost? - Solar Panel Prices | Websolarguide


The figures could well be irrelevant given that they are for the USA and no mention is made of the latitude (a more northerly location will get less sun than a southerly one.) 

Best way to make use of the sun's energy is to heat water. approx 1200€ will get you a panel roughly 1200mm x 600mm and a 180 litre storage tank. We have been making use of the warm sunshine this year since the middle of January. We are at 37½° North.


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## 95995 (May 16, 2010)

Just remember that you don't need full sun for solar panels or solar hot water systems to function - they do just fine with light cloud cover. And I would be very surprised if these days a decent system did not pay for itself over its lifetime (often longer than the specs say because the specs are conservative).

Oh, and whilst bottled gas might be cheap now, that perhaps won't continue to be the case - IMO it vey likely won't continue to be the case.


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## Juan C (Sep 4, 2017)

I installed my solar water heater myself 19 years ago. It has an electric immersion heater in it. It is set to just warm the water, however I hardly ever switch it on

The unit cost about 1,000 euros. I have not made any attempt to calculation how many times over I have saved the initial cost. 

I am though fortunate that I live on the top floor and have a large terrace so the unit does cause any inconvenience.


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## NickZ (Jun 26, 2009)

It's 2020 unless you live off the grid nobody uses batteries. You grid connect the system. That means during the day you're selling power to the electrical company. At night you buy it back. Much better than batteries.

There are also heat pump hotwater heaters that can be hooked up to a solar hot water heater. Much better than just the electrical heater inside the solar hotwater tank.

You can also rig the whole system up to help with home heating. Even better if you've got in floor low temperature heating. 

Does any of this make sense? Only after you've done all the easy stuff. 

Replace your appliances with the latest modern highest efficiency models you can find.

Replace windows and doors.

Insulate

The less energy you use the smaller the system you need. The less it costs.


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## Barriej (Jul 23, 2012)

NickZ said:


> It's 2020 unless you live off the grid nobody uses batteries. You grid connect the system. That means during the day you're selling power to the electrical company. At night you buy it back. Much better than batteries.
> 
> There are also heat pump hotwater heaters that can be hooked up to a solar hot water heater. Much better than just the electrical heater inside the solar hotwater tank.
> 
> ...


Until recently it was not possible to sell back to the grid in Spain. In fact you got 'taxed' for generating too much power.

As of October 2019 Spanish power companies are supposed to buy any extra power from you but there doesn't seem to be much info out there. 
I know of one company who are trying to deal with this and they are not getting very far, so until the situation becomes clearer they are still fitting batteries.


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## NickZ (Jun 26, 2009)

How much did they tax you on the excess power?

Batteries cost money. They need to be maintained. They eventually need to be replaced. Usually you oversize the whole system to deal with winter.


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## Barriej (Jul 23, 2012)

NickZ said:


> How much did they tax you on the excess power?
> 
> Batteries cost money. They need to be maintained. They eventually need to be replaced. Usually you oversize the whole system to deal with winter.


I still live in the Uk until July. My Father in law lives in Spain and some of his neighbours are not connected to the grid (location etc)

I can't answer what the tax was as I don't know anyone who was grid connected. I helped with a couple of installations a couple of years ago.

But I do know that one of the power companies in Spain pay 6c per unit you sell them and charge you 12c when you buy. However they still bill the standing charge for every day.

With some clever engineering and switching circuits, its possible to 'bank' connect the cells so the load is managed to get the maximum possible rate and time from the cell. In fact there is a way to cross connect the cells so as you draw from one the others then recharge the lowest one.

Winter in Spain has a blessing as solar panels are more efficient when cooler as they drop off the hotter they get. So as long as the room the cells are in is kept at a constant temp they don't degrade very fast.

I know of one Uk company that is looking at the cells Tesla use for the cars to be used at home. In fact Tesla in the US have a home unit.


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