Our hot water comes courtesy of the sun: that’s the assumption, isn’t it, when you install solar water panels? That was our romantic assumption when we installed the system.
This is true, for eight months of the year. The fact of the matter is, there is simply not enough continuous light throughout the winter to reliably heat enough water to supply a household. Even in Spain. With the best intentions, we have found it practically impossible to be 100% solar-reliant for hot water. 
So, we have a two-fold system. From April onwards, we switch our system to solar. We have four panels, placas, mounted on the kitchen roof [above] which heat the water in the storage tank in the boiler room [below]. These placas are designed specifically for this task, and are not to be confused with photovoltaic panels used to generate solar electricity. 
From November, we switch the system to our gas-fired boiler [below]. 
Our standby gas supply consists of 10 35kg tall bottles of bútano, butane gas, which are stored in a locked cage at the side of the house [below]. 
We have a contract with a local supplier which delivers to our area twice a week, on average we need two deliveries a year of five bottles [our hob is also gas, the oven is electric]. The bottles are connected in two groups of five on a switchable connection, so one set is used at a time. We have never run out of gas, or hot water.
The placas on the kitchen roof are loved by the sparrows, who use the supports as nesting sites. So, solar = environmentally-friendly and sparrow-sustainable! And the geckos live in the gas store.
5 to remember
el calentador – boiler
el envase – gas bottle/canister
la sala de calderas – the boiler room
un contrato – a contract
una entrega – a delivery
Notes on a Spanish Valley 
I keep getting nuisance phone calls asking me if I want solar panels – in the UK!
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Mmm, be v careful! SD
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Woah! You keep a lot of gas bottles there, Sandra! We don’t have solar panels at all, so we rely on our gas water heater all year round. We also have a gas hob with an electric oven). We just have 3 of the 12.5kg-size bombonas. We find that one bottle lasts us 3-4 weeks at a cost of 17.50 euros.
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Yes, but we are v rural and access not always possible. SD
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Sure – I understand 🙂
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Do you mind us asking – roughly how much did the 4 panels cost? (materials and installation)?
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A rough guesstimate: €5500 for the 4 placas, water tank & installation (exc boiler). That was 6 years ago so probably cheaper now. SD
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My dad has solar panels – in Wales! He calls them his “rain generators,” though actually they generate enough power to give him a decent return through the feed-in tariff. I’ll have to keep a closer eye out for the sparrows!
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Re sparrows, it is nice when something is multi-purpose. SD
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How interesting… I’m glad you got it figured out. And I loved the part about the sparrows and geckos. 😉
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Thx, it took us a while. Very much a case of learning by experience! SD
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