Solar Pool Heating in Spain – What’s the Best Way?

Considering heating your pool in Spain using solar energy?

Heating your pool all year is a dream for any homeowner in Spain. But we’ve spoken to people who bought a pool heater, paid €800 extra in their electricity bill, and turned the heater off.

I can’t count how many I’ve seen gathering dust in a client’s garage.

So is solar pool heating the way?

In this post you’ll learn:

• Why thermal solar pool heating isn’t a good idea
• A comparison of 4 different ways to heat your pool with solar
• Our recommendation for the only solar pool heating setup that pays for itself

Let’s get into it!

Can I heat my swimming pool with solar energy in Spain?

Yes, you can.

There are two ways to heat a pool with solar energy:

• Photovoltaic solar panels (sunlight into electricity)
• Thermal solar panels (sunlight into heat)

Marblanc Solar specialises in PV solar panel installations. So I am biased…if you dream of a heated pool all year round, you should rule out thermal solar panels.

Here’s why.

PV solar panels vs thermal solar panels – which is best?

Thermal solar panels

Thermal solar panels do not generate electricity.

A thermal solar panel warms water directly using the heat of the sun. There’s usually a mass of black pipes behind the panel, which attract heat.

The warm water is then pumped in to your pool.

Thermal solar panels are great for extending the swim season a few weeks either side of summer.

But they come with some disadvantages:

• You can’t heat your pool in winter  
• You can’t heat your pool on cloudy days 
• You pay extra for electricity to pump more water

Photovoltaic solar panels 

Photovoltaic solar panels generate electricity.

Sunlight is converted into direct current (DC) electricity through solar cells contained within the panel. This electricity is converted into alternating current (AC) by a solar inverter, so it can power home appliances.

Using a pool heater with PV solar panels has clear advantages:

• You can heat your pool in winter 
• You can heat your pool on cloudy days 
• You can save on electricity to power your pool pump and heater

Now, that’s not the full story…

What’s an Air-to-Water Heat pump?

PV solar panels will not provide enough power to run a conventional electric pool heater – even on a sunny day. (Unless you have an extremely large array of panels.)

But if you combine a solar panel installation with an air-to-water heat pump pool heater, you can keep your bills surprisingly low.

So what is an air-to-water heat pump?

Heat pumps use electricity to move heat from the outside air to pool water. They don’t generate heat directly, like an electric heater.

If that doesn’t make any sense…

This will.

Conventional electric heaters need 1kW of electricity to produce 1kW of heat energy. But a heat pump can turn 1kW of electricity to generate 3kW, 4kW and even 5kW of heat energy.

This is why the combination of PV solar panels and air-to-water heat pumps is so popular:

• You can heat your pool up whenever your want
• You can run the heat pump using only solar panels
• You can use the heat pump after dark (or with a solar battery) and need far less power than a conventional heater

How much does it cost to heat a pool with PV Solar and an Air-to-Water Heat pump?

The answer depends on many factors.

As a rough guide we’ve estimated how much it would cost to heat three different sized swimming pools from 16°C up to 26°C – and then keep it warm for a whole month.

The estimation assumes the air temperature will remain between 12°C to 15°C for the whole month, which is roughly the temperature range for March on the Costa del Sol and the Costa Blanca in Spain.

For the three swimming pools we’ve estimated the monthly costs for three different kinds of pool heating:

• Conventional electric heater
• Air-to-water heat pump
• Air-to-water heat pump powered by solar panels (and no solar battery)

What’s the most cost-effective way to heat my swimming pool in Spain?

The most cost-effective solution for solar pool heating in Spain is to install PV solar panels for your whole house, and add an air-to-water heat pump for the pool.

Why is that?

Many people ask if they can just have a heat pump connected to an isolated set of solar panels. But the problem is that you won’t be able to use the heat pump on cloud days or after dark – and if the panels don’t produce enough, the whole system will shut a down.

A home solar panel installation with a heat pump is the only way to allow for flexible pool heating, while keeping the monthly costs as low as possible.

Even in winter.

Of course, you may have a cloudy day or you might need to ramp up your pool heater’s operations during very cold weather. But you can add a solar battery to a home solar energy system and still have surprisingly low monthly bills.

How do I know what pool heater and how many PV solar panels I need to heat my swimming pool in Spain?

Air-to-water pool heaters come with a range of power outputs from 1kW all the way to 30kW and beyond.

The right one for you depends on three main factors:

• The size, depth and volume of your swimming pool
• The climate, shading and sun your swimming pool gets
• The seasons you wish to use your swimming pool in

You’ll need a specialist’s opinion and a site visit in order to determine the right pool heater and solar panel installation for you. 

Contact Marblanc Solar today for a Free Solar Survey and we’ll answer all your questions.