More on Solar
#1
I've looked at previous threads about solar but I'm just getting more confused (again) 
It's been suggested that I have a solar hot water system installed. I can understand that bit - the water gets heated while the sun is out and should I need to top it up I use my existing supplier.
The next phase that has been discussed with me is that I have a bank of solar panels on the roof connected to a battery system to run appliances, lighting etc. I've already said I'll wait and see what my EDP bills do for maybe 3 months after the hot water system is installed as there's only me here except when I have guests staying so the outlay may not make it worth it.
Can anyone please explain in very simple terms:
Why do I need 2 separate systems - one for water and one for everything else?
If panels are connected to a battery, does that mean that I can store what I generate during the day to use at the times I'm most likely to need it - lighting, cooking, aircon in the evenings/at night.
Do I need permission from EDP to run solar? I realise I can't be paid for anything that feeds back into the grid but it would have to be connected, presumably?
Thanks.

It's been suggested that I have a solar hot water system installed. I can understand that bit - the water gets heated while the sun is out and should I need to top it up I use my existing supplier.
The next phase that has been discussed with me is that I have a bank of solar panels on the roof connected to a battery system to run appliances, lighting etc. I've already said I'll wait and see what my EDP bills do for maybe 3 months after the hot water system is installed as there's only me here except when I have guests staying so the outlay may not make it worth it.
Can anyone please explain in very simple terms:
Why do I need 2 separate systems - one for water and one for everything else?
If panels are connected to a battery, does that mean that I can store what I generate during the day to use at the times I'm most likely to need it - lighting, cooking, aircon in the evenings/at night.
Do I need permission from EDP to run solar? I realise I can't be paid for anything that feeds back into the grid but it would have to be connected, presumably?
Thanks.
#2
I'll keep it simple;
Get the solar hot water, forget the electric [for now].
Definitely don't get anything that needs batteries, and don't believe any salesmen!
Get the solar hot water, forget the electric [for now].
Definitely don't get anything that needs batteries, and don't believe any salesmen!
#3
Banned










Joined: Oct 2012
Posts: 26,724











. It will be a few years before domestic solar systems based on battery storage are a viable and eonomic alternative. to main supply.
#4
I still dont believe it..







Joined: Oct 2013
Posts: 2,787
From: 12 degrees north











Solar electricity was able to compete with the cost of city supplies in true terms 20 years ago. Remember you are comparing the entire cost of a house based photovoltaec array+controllers+batteries verses power stations, a high voltage grid, transformer yards, big cabling etc etc etc. many years ago i worked for a small unit - part of lucas car components - that supplied systems where the alternatives were ridiculous eg singapore airports approach lighting in mountains re-batteried by helicopter every few weeks or medical fridges in the desert in saudi. We did many mobile phone masts in Tanzania.
Anyhow, 50k pounds per house was considered comparable given its zero maintenance for 25 years with a 50 year life. Its cheaper now, but of course you have to have the capital, plus a room for some big batteries if you are really doing it properly, feeding aircon etc. Of course you can do just lighting much cheaper.
Anyhow, 50k pounds per house was considered comparable given its zero maintenance for 25 years with a 50 year life. Its cheaper now, but of course you have to have the capital, plus a room for some big batteries if you are really doing it properly, feeding aircon etc. Of course you can do just lighting much cheaper.
#5
I still dont believe it..







Joined: Oct 2013
Posts: 2,787
From: 12 degrees north











Harva - government rules, regulation to protect power co’s, rules on feeding power back to the grid, exclusivity of supply agreements, can seriously distort costs and viability, as of course can grants or cheap loans or tax breaks.
Solar electricity will be the norm - but not yet - but if fusion power becomes reality thats a singularity.
Solar electricity will be the norm - but not yet - but if fusion power becomes reality thats a singularity.
#6
So in conclusion, scrap the idea of a full system and only get the hot water.
That was my gut feeling because I just don't understand the battery-system-thingy.
That was my gut feeling because I just don't understand the battery-system-thingy.
#7
BE Enthusiast





Joined: Nov 2017
Posts: 798











I'd go for the hot water and replace all the light bulbs through the house with LEDs.
#9
BE Enthusiast





Joined: Nov 2017
Posts: 798











Well done. It's amazing what a difference it makes!
#10
Batteries are expensive, and need replacing after some years. Running your AC at night, or a washing machine, would need a battery bank costing tens of thousands of Euros!
You only want batteries if you don't have mains power.
Since EDP hardly pays for power you sell them, but charges a lot when they sell it to you, electricity generating solar panels on your roof are worthwhile if you use that power as you make it. since most of your power use is at night, that doesn't work.
If you run your AC during the day, more than [say] 100 days a year, it might be worth attempting solar power; it would require a huge array, but it could be done.
For you, as a non-technical person, just forget it.
the black glass panels that heat water are completely different things, although they look similar and have a similar name.
Those are worthwhile for almost everyone.
You only want batteries if you don't have mains power.
Since EDP hardly pays for power you sell them, but charges a lot when they sell it to you, electricity generating solar panels on your roof are worthwhile if you use that power as you make it. since most of your power use is at night, that doesn't work.
If you run your AC during the day, more than [say] 100 days a year, it might be worth attempting solar power; it would require a huge array, but it could be done.
For you, as a non-technical person, just forget it.
the black glass panels that heat water are completely different things, although they look similar and have a similar name.
Those are worthwhile for almost everyone.
#11
Batteries are expensive, and need replacing after some years. Running your AC at night, or a washing machine, would need a battery bank costing tens of thousands of Euros!
You only want batteries if you don't have mains power.
Since EDP hardly pays for power you sell them, but charges a lot when they sell it to you, electricity generating solar panels on your roof are worthwhile if you use that power as you make it. since most of your power use is at night, that doesn't work.
If you run your AC during the day, more than [say] 100 days a year, it might be worth attempting solar power; it would require a huge array, but it could be done.
For you, as a non-technical person, just forget it.
the black glass panels that heat water are completely different things, although they look similar and have a similar name.
Those are worthwhile for almost everyone.
You only want batteries if you don't have mains power.
Since EDP hardly pays for power you sell them, but charges a lot when they sell it to you, electricity generating solar panels on your roof are worthwhile if you use that power as you make it. since most of your power use is at night, that doesn't work.
If you run your AC during the day, more than [say] 100 days a year, it might be worth attempting solar power; it would require a huge array, but it could be done.
For you, as a non-technical person, just forget it.
the black glass panels that heat water are completely different things, although they look similar and have a similar name.
Those are worthwhile for almost everyone.
#12
Forum Regular



Joined: Aug 2008
Posts: 150

Interested in a hot water system in Tavira. Can anyone recommend a supplier and installer?
#13
Forum Regular


Joined: Aug 2019
Posts: 92

Did you go for a solar water heater? Did you have some pre-solar water heating bills vs post-solar water heating bills, so you could determine the savings, and figure out how long it would take you to recoup your costs?
We looked into it for our place, but as it's only used 3-4 months out of the year, and we have a gas boiler, I had calculated that it would take 10-12 years to recover my outlay. After we move, we're expecting to use the house more like 9-10 months out of the year, in which case, the numbers are in our favour.
We looked into it for our place, but as it's only used 3-4 months out of the year, and we have a gas boiler, I had calculated that it would take 10-12 years to recover my outlay. After we move, we're expecting to use the house more like 9-10 months out of the year, in which case, the numbers are in our favour.
#14
I had a survey done for solar water. Because of the pitch and direction of my roof, I'd have needed panels on both aspects. The pipework would need to have run the length of the house so the guy said it really wasn't worth it given there's just me.
A short time after the survey, my hot water boiler went kaput. The same guy fitted me a new one for a ridiculously low price and since then my electricity bill has rediced by a third. It's now so cheap to heat my water that solar just wouldn't be worth it even if the installation were straightforward.
The other things I've learned are that replacing my log burner with a pellet burner has been a revelation. It's like having a gas fire, it's so controllable and clean. I scrapped the idea of heating upstairs - I was considering infrared panels - I just haven't needed it. I had an aircon unit fitted in my bedroom which also heats it or dehumidifies on the rare occasions I've needed it. It's currently the only unit in the house and hopefully I won't need to put more in. I've now had 2 summers and 2 winters in the property so I think I've got it all sussed.
A short time after the survey, my hot water boiler went kaput. The same guy fitted me a new one for a ridiculously low price and since then my electricity bill has rediced by a third. It's now so cheap to heat my water that solar just wouldn't be worth it even if the installation were straightforward.
The other things I've learned are that replacing my log burner with a pellet burner has been a revelation. It's like having a gas fire, it's so controllable and clean. I scrapped the idea of heating upstairs - I was considering infrared panels - I just haven't needed it. I had an aircon unit fitted in my bedroom which also heats it or dehumidifies on the rare occasions I've needed it. It's currently the only unit in the house and hopefully I won't need to put more in. I've now had 2 summers and 2 winters in the property so I think I've got it all sussed.
#15
BE Forum Addict






Joined: Mar 2008
Posts: 1,917











my advice...but i read that you have already sussed this one out...well done
if you have a gas supply install a gas esquentador (water heater only).
Heating water by solar is an outdated useless expensive, high maintenance rip off (lots of IVA for the gov tho). Storing 200 litrs of hot water is ridiculous, remember every time you draw off 40 litres for a shower then 40 litrs of cold goes into the tank, thus reducing the overall temperature. Then when there is more than one person and you have a shower at night, there is no hot water in the morning, unless you use the immersion heater at 3kwH (about €0.70 an hour to run.)
Use a cheapo esquentador, esp as there is only you...immediate hot water any time of day or night and any time of year.
if you have a gas supply install a gas esquentador (water heater only).
Heating water by solar is an outdated useless expensive, high maintenance rip off (lots of IVA for the gov tho). Storing 200 litrs of hot water is ridiculous, remember every time you draw off 40 litres for a shower then 40 litrs of cold goes into the tank, thus reducing the overall temperature. Then when there is more than one person and you have a shower at night, there is no hot water in the morning, unless you use the immersion heater at 3kwH (about €0.70 an hour to run.)
Use a cheapo esquentador, esp as there is only you...immediate hot water any time of day or night and any time of year.



