{"id":13674,"date":"2025-07-24T09:56:00","date_gmt":"2025-07-24T07:56:00","guid":{"rendered":"https:\/\/fotovol.com\/renewable-energy\/solar-thermal-with-solar-panels-real-opinions-and-keys-for-your-home\/"},"modified":"2026-06-17T22:43:05","modified_gmt":"2026-06-17T20:43:05","slug":"solar-thermal-with-solar-panels-real-opinions-and-keys-for-your-home","status":"publish","type":"post","link":"https:\/\/fotovol.com\/en\/renewable-energy\/solar-thermal-with-solar-panels-real-opinions-and-keys-for-your-home\/","title":{"rendered":"Solar Thermal with Solar Panels? Real Opinions and Keys For Your Home"},"content":{"rendered":"\n

Combining aerothermal energy with photovoltaic solar panels is one of the most cost-effective decisions you can make if you want to reduce your energy bill and stop relying on gas. However, not all systems are well integrated, and not all installers know how to configure them to work together efficiently.<\/p>\n\n\n\n

In this article we explain how the combination works, how much you can save, what those who already have it installed think, and what mistakes to avoid.<\/p>\n\n\n\n

How does aerothermal heating with solar panels work?<\/h2>\n\n\n\n

Aerothermal energy is a heat pump that extracts thermal energy from the outside air to generate domestic hot water, heating, and cooling. Its efficiency is measured by the COP: a COP of 4 means that for every kW of electricity consumed, 4 kW of thermal energy are generated.<\/p>\n\n\n\n

Photovoltaic solar panels generate electricity from the sun. The combination involves using that electricity, which in many cases would be surplus electricity fed into the grid, to directly power the heat pump.<\/p>\n\n\n\n

The result is a system where free solar energy is converted into heat very efficiently. Instead of using 1 kW of solar energy to directly heat water (which would yield 1 kW of thermal energy), that same kW is used to power the heat pump, which converts it into 4 kW of thermal energy thanks to its high COP (Coefficient of Performance).<\/p>\n\n\n\n

Does the air source heat pump connect directly to the solar panels?<\/h2>\n\n\n\n

Not directly. Aerothermal systems operate on alternating current (AC), and solar panels produce direct current (DC), which the inverter converts to AC. The system is configured so that the heat pump activates first when there is solar production, using energy management systems, surplus relays, or intelligent control systems integrated into the inverter.<\/p>\n\n\n\n

If you are considering installing solar panels to power your air source heat pump, our\u00a0residential photovoltaic installation<\/a>\u00a0service will help you size the complete system from day one.<\/p>\n\n\n\n

How many solar panels do I need to power a heat pump?<\/h2>\n\n\n\n

A domestic hot water heat pump consumes between 0.5 and 1.5 kW when operating. For\u00a0underfloor heating,\u00a0consumption can reach 3-6 kW depending on the unit’s power and the outside temperature.<\/p>\n\n\n\n

Use<\/th>Heat pump consumption<\/th>Recommended panels<\/th><\/tr><\/thead>
ACS only (family of 3-4 people)<\/td>0.5 \u2013 1 kW<\/td>3 \u2013 5 panels (400W)<\/td><\/tr>
Domestic hot water + heating for an average home<\/td>2 \u2013 4 kW<\/td>8 \u2013 14 panels (400W)<\/td><\/tr>
Domestic hot water + heating + cooling<\/td>3 \u2013 6 kW<\/td>12 \u2013 20 panels (400W)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

These are indicative values. The actual sizing depends on the geographical location, the orientation of the panels, the insulation of the house, and the heat pump model.<\/p>\n\n\n\n

What happens when there isn’t enough sun?<\/h2>\n\n\n\n

The system continues to function because the aerothermal system can consume electricity from the grid when there is insufficient solar production.<\/p>\n\n\n\n

The difference compared to a system without solar panels is that during the months with the highest solar radiation, the heat pump’s electricity consumption is mostly covered by solar energy. In winter, the system draws more from the grid, but aerothermal energy is still much more efficient than any conventional gas or electric system.<\/p>\n\n\n\n

With storage batteries, autonomy improves significantly, although the installation cost increases.<\/p>\n\n\n\n

Aerothermal energy or solar panels: which to install first?<\/h2>\n\n\n\n

If your biggest expense is heating and hot water,<\/strong> start with an air source heat pump. It’s the system that has the greatest impact on your heating bill and can work perfectly well without solar panels.<\/p>\n\n\n\n

If your biggest expense is general electricity:<\/strong> start with solar panels. You’ll reduce your entire home’s energy consumption from day one, and you can add heat pumps later.<\/p>\n\n\n\n

Ideal for a new home or complete renovation:<\/strong> install both at the same time. Integration from the start allows for a more efficient design and avoids duplicate installation costs.<\/p>\n\n\n\n

Aerothermal energy vs solar panels: it’s not a comparison, it’s a combination<\/h2>\n\n\n\n

Many searches present “aerothermal energy vs solar panels” as if they were mutually exclusive alternatives. They are not. They are complementary technologies that enhance each other.<\/p>\n\n\n\n

<\/th>Aerothermal only<\/th>Solar panels only<\/th>Aerothermal + solar panels<\/th><\/tr><\/thead>
Savings on hot water<\/td>Up to 70%<\/td>Up to 60% (sunny months)<\/td>Up to 85-90%<\/td><\/tr>
Heating savings<\/td>Up to 70%<\/td>Limited<\/td>Up to 75%<\/td><\/tr>
Savings in general electricity<\/td>Not applicable<\/td>Up to 60-70%<\/td>Up to 70%<\/td><\/tr>
Initial investment<\/td>\u20ac5,000 \u2013 \u20ac10,000<\/td>\u20ac5,000 \u2013 \u20ac10,000<\/td>\u20ac10,000 \u2013 \u20ac18,000<\/td><\/tr>
Return on investment<\/td>5-8 years<\/td>5-8 years<\/td>6-9 years<\/td><\/tr>
Energy independence<\/td>Average<\/td>Average<\/td>High<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Advantages of combining aerothermal energy and solar panels<\/h2>\n\n\n\n

Maximum energy savings:<\/strong> Aerothermal systems can save up to 70% on domestic hot water and heating. Combined with solar thermal energy, these savings can exceed 80% on an annual basis.<\/p>\n\n\n\n

Real self-consumption:<\/strong> solar energy that was previously fed into the grid at a low price is now used directly for heating and hot water, where it has the most value.<\/p>\n\n\n\n

All-in-one system:<\/strong> heating, cooling and hot water with a single system powered by its own energy.<\/p>\n\n\n\n

Gas independence:<\/strong> completely eliminates dependence on fossil fuels and their price fluctuations.<\/p>\n\n\n\n

Access to subsidies:<\/strong> many autonomous communities offer aid for the joint installation of aerothermal and photovoltaic systems.<\/p>\n\n\n\n

Things to consider before installing<\/h2>\n\n\n\n

Proper technical integration:<\/strong> the most critical point is configuring the system so that the heat pump is activated primarily with surplus solar energy, using energy management systems, surplus relays, or control systems integrated into the inverter. Without this configuration, the savings are significantly lower.<\/p>\n\n\n\n

Avoid using an electric heating element:<\/strong> Heat pumps have an auxiliary electric heating element that, if activated frequently, increases energy consumption. A properly sized and configured unit should not require it.<\/p>\n\n\n\n

Initial investment:<\/strong> the combination can cost between \u20ac10,000 and \u20ac18,000. It is recouped in 5 to 8 years depending on previous consumption and subsidies obtained.<\/p>\n\n\n\n

Space:<\/strong> Space is needed for the outdoor unit of the heat pump, the DHW storage tank and the electrical control panel.<\/p>\n\n\n\n

Performance in very cold climates:<\/strong> In areas with extreme winters, the efficiency of air source heat pumps decreases. Current models operate down to -25\u00b0C, but the COP drops at very low temperatures.<\/p>\n\n\n\n

Real user reviews of heat pumps and solar panels<\/h2>\n\n\n\n

What they value most:<\/strong><\/p>\n\n\n\n