BlackBeardie

Mr Bife wrote "In my view yes. Aircon is only really required during heat of summer when solar panels are working most efficiently."
EsuriJohn may want to use the aircon throughout the year. As a heating system in winter and autumn. This would scupper the idea of having a small battery bank completely. Solar PV is just not cost effect for heating in winter due to the insolation being severely reduced and having to store what energy you can collect for the night - which means a large surface area of solar panels and a huge battery bank.

BlackBeardie

Does anyone know if there are any co-operative type schemes in the Algarve for generating renewable energy using solar, wind or biomass technologies?
Thank you.

EsuriJohn

Yes you are correct ours is an inverter Aircon system and the bedrooms have no other heat source so an hour before bed the units go on at a reasonable 22*C and when it comes time to strip off it is comfortable. We do have a dual tariff meter so for 14 hrs a day we get our electricity for 1/3 cost but not unfortunately in that hour before bed.

liveaboard

Who is your energy supplier?
My dual tariff only gives me 1/2 off at night.

EMR

I think you will find that Esuri lives in Spain.

liveaboard

What!?
Not those pesky Spaniards again...

MrBife

My own house is heated by solar power spring, autumn and winter using a large bank of water filled solar panels (20m2) that heat a 1200 litre buffer tank - enough water to keep a large'ish house at 22 degrees day and night using underfloor heating. For me the only requirement is summer cooling using fan-coils and a heat pump which could certainly be run using PV generated power during sunshine hours. No battery power storage required.

Its easily (and cheaply) possible to use the building structure as a heat store or use solar generated electrical power to heat a large tank full of water (or a heat pit full of gravel) then extract the heat and use it outside solar hours. Lead acid batteries are expensive to buy, not very efficient and don't last many years + you need an inverter to bring the power to grid voltage for feed in or to run standard single phase appliances.

EsuriJohn

Fraid so, somewhere between a half and a third is what it seems to be

Lazza Parks

That's a very interesting setup you've got there Mr Bife. It's the first time i've come across anyone using solar thermal for underfloor heating. Any chance of any photos?

amideislas

I can envision how solar underfloor heating would work, and it's probably a good idea. I like it.

Pipes under the floor, solar panels on the roof (or elsewhere with direct solar access), a collection tank and a small pump in-between. Simples.

MrBife

Sent you a PM

liveaboard

I'd also like details; I've done a lot of research on the subject, but have yet to start any actual construction of it [other than the underfloor heat tubes, we put that in when renovating the house].
I did an experiment with a "mini collector", which achieved 118C on December 22. Energy is there for the taking.

I wrote out my findings and plans for solar home heating;
http://www.aljezurfarm.com/DIY%20sol...%20heating.htm

BlackBeardie

That's interesting to know Mr Bife. I tried testing a couple of my panels (320W total) connected to some small immersion heaters (24V), in the autumn. The temperature they could raise the water was almost insignificant compared to my black irrigation pipe which was heating the water to well over 45ºC. But I do like your (and liveabroads' ) idea of having a large insulated heat storage tank somewhere.

littlemanor

We're moving in June to a quinta in the Alentejo near Elvas, and very interested in setting up solar power as soon as we can. We are already familiar with underfloor radiant heating (in a much colder climate) though it would be much more practical in Portugal, so we're very interested in that as well as a grid-tied solar panel system.

We'd appreciate any advice about systems or people to contact—and if you could PM us, Lazza, that would be great.

BillBullock

I like MrBife's setup but would worry about the excess heat produced in the typical Algarve summer. Some of the hot water could be used to heat the swimming pool (7500 litres) until that that got too hot. Could the solar panels be screened effectively from the solar rays I wonder?