Solar Power Murcia, Spain

Hi everyone, I’m about to embark upon a sola installation in South East Spain (Murcia) and wanted some expert opinions please.

I’ve attached the materials below (note one option is to do it in stages - hence the two separate quotes (from the same company).

My key questions were about does the price seem ballpark correct - and is the proposed set up sensible?

Given that I think i’ll need 45 300 watt panels, I would have thought it made sense to go for the 330 kw panels instead and perhaps to have monocrystaline over polycrystalline.

Phase 1

Phase 2:

adds another 30 panels, 2, victron regulator blue solar, 1 more Victron Quattro inverter, one more byd batter pack, and some fitting charges and cabling all totalling EUR 18,000

So the overall complete project is at about EUR 52,000 and I need to factor in the groundworks to house the steel frame for the solar panels.

Any thoughts most welcome.

Regards, Carl

Hi Carl,

Just from what you have posted about your consumption (70 kWh) I would estimate you would need minimum 80 x 300W panels (24kW). Is this an off-grid system?
The specifications listed in the quote seem to be way too small for an off-grid system with 70kWh daily consumption. Who is designing and installing the system?

I would use AC coupled solar inverters not solar controllers. This is not looking very good for your requirements. Where did the 70kWh number come from? Did you fill out a load table?


Hi Jason, we have mains power up to 9.5 kwh capacity to back up on although after paying that outlay I’m hoping we rarely need it.

We’ve been monitoring currently usage over the past month and on busy days we are using 60 kw in total per day.

Regards, Carl

G’day Carl,
I would recommend you use the latest panel technology !

I’m very glad to show you my analysis of different methods for your project.

1. 50x 325W, 60 cells MONO 12bb Half-cut panel with PERC: $8’600.
$0.53/watt, (60cell, 168×99×3.5cm, 20kg), RECOMMENDED Panel.
Good Low-light performance, Excellent performance under low-light environments.
High efficiency, Dense bus bars shorten the current conduction distances between bars and lower serial resistance; increases 7~8W power output.
Minimise Crack Effect, Collected more current, almost no power generation efficiency lose by internal cells cracked. The improve reliability, Improve product reliability; minimise the probability of pressure and battery fragmentation caused by thermal stress.
That provides a Longer lifetime, Minimise the heat resistance due to internal cracks, bringing longer life span and less attenuation.

2. 40x 380W, 72 cells MONO 6bb PERC: $6’888.
$0.44/watt (72 cell, 196cm x 99cm =1.94m2, 21kg)
Low price, but low efficiency. though we can provide it at this price, but the efficiency is low, we don’t suggest most our customers to use them. These panels are the next best panel for low income market such as Africa, India and so on.

3. 30x 96 cells MONO 6BB per 500W: $6’600.
$0.44/watt (96 cell, 196cm x 131cm =2.57m2, 25kg)
Comparing other panels, it is a big panel. This panel is not standard, and big panel means the increasing of the cost because more numbers of brackets and heavy and stronger brackets are needed. And most of 500w panels don’t have TUV certificate.
So, we don’t recommend customers to use 500W panel, unless they have small energy consumption, as they may only need 4+ panels.

I hope that helped.

thanks, but I see 50 x 325 watt panels would generate 16,250 per kwh - now taking into account 25% wastage, I think would still give 12,350 per kwh. If I perform my calcs in the winter period of 7 hours in southern Spain then I would have 86,450 kw in total generated in one day which is more than I need.

What am I doing wrong/?

By mono I assume you mean monocrystaline panels? Which brand are you suggesting? Again the European brands may be different.

Regards, Carl

Hi Carl,

I was working on 60kWh a day, so without knowing your Latitude & what you type of panel Racking you are looking to install !?

So, I was assuming it would be Fixed, Tilted North facing install, you would have approx. 4 hours of peak, plus obscure (ramping) harvesting either side of midday!
Calculating: 50x 325W =16.25kW x 4 hours = 65kW day, But I am not sure how you calculate 25% loss, as that appears high.
What is your calculations on 25% loss ?
Suppose you are taking into account, shading, inverter, dirty panelling & power losses etc.

Yes Monocrystalline panels, they are Chinese panels, there are apparently only a handful of companies currently manufacturing the 12BB, with Half panel solar panels.
NB: A good thing about the Half-panel technology, is Shading, as the panel is virtually two panels in one, this assists to increase the harvesting in partial shading …etc.

Most Chinese manufacturer make very good panels, If you pay a premium, But I assume you are looking to purchase European Panels, that are 2~3 times the price, meaning that if there is a catastrophic failure, you could replace them & still be in front, but that is the worst scenario.

Two brands, LUCK SOLAR is good on manufacturing of PV panels in a group of two factories located in Yancheng and Changzhou with annual production of 1 GW. Amensolar is doing differential operation on design and construction of distributed PV plant, BI-facial PV, products for solar energy system.

Don’t be fooled by the common Marketing term Tier-1 panels or manufacturer, as that term is a deceptive sales statement, Tier1 has nothing to do with panel quality, it is just who sells the most panels!
I understand, the Tier rating was started by Bloomberg Energy Finance Corporation to rate solar panel manufacturers in terms of financial stability.

Hi @carl99

It’s the x 7 that is the issue I believe. You should be working off more like x 4 for winter in Spain:

According to

Also, regarding panels. There aren’t many manufactured in Europe, maybe some Q Cells still are manufactured in Poland, bust mostly not. Just get any brand on the list here:

Regarding price, 50k Euro is an awful lot of money, but getting an off-grid system for 70kWh a day is going to be very expensive. Step one is most definitely doing absolutely everything to improve your energy efficiency. It’ll save you a huge amount. Filling out a load table will help you identify the big energy suckers.

Probably worth doing some reading about off-grid setups too. Jason mentioned AC coupled, you can read about that and also checkout different battery and inverter brands and info here:


@carl99, just pondering this one a bit more. I think the best thing you can do now is find a good installer, as they should be able to walk you through all of these considerations. Where about in Spain are you? @matlindley got an install near Granada I believe, recently. Would you recommend the installers @matlindley, and do you know if they are a national company, or just local? It would be good to have a few recommended installers in southern Spain, as seems there is plenty of interest in solar down there.

Ah, I see you said Murcia. Not too close to Granada, but not too far. Might be relevant.

Off-grid - BYD, Victron Quattro quote review - Granada, Spain

The guy who did mine is in Lanjaron, his name is Julio. His email is I would give him a big double thumbs up. He is very passionate about solar and can explain the complex in simple terms focused on what you want the electrity to do for you.

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thanks guys, really appreciate the help.

I am using an installer and what I’ve shared are his recommendations.

The brands are a bit different in Spain and Tesla for example still have no licence to offer their Powerwall 2 batteries in spain they tell me.

I think the pressing questions I have with my proposed set up is that they want to use 300 watt Sharp ND panels. I’m no solar god by any means but feel as though the 330 panels would simply give me more juice. Also not sure how good Sharp panels are (although they seem to rate highly for value for money). Also many of the parts are Victron which seems to be a great company, so I’m at a bit of a loss as to understand why my guy then suggests having BYD brand batteries and not Victron branded batteries. He tells me that Victron recommend BYD, but why wouldn’t they push their own brand of battery over that of a competitor?
I’m possibly asking some really stupid questions here but it’s a great opportunity to learn for you guys.

Many thanks, Carl

Hi Carl, how did your solar installation end up going?