10 mayo, 2019 Off By admin

The idea of ​​using the sun as a source of energy is very old, going back to the 7th century BC when magnifying glasses were used to generate fire.

But it was not until the 70s when solar energy began to gain prominence after the oil crisis (1973-1979).

A crisis that led to a global rethinking in the energy field.


The solar energy arises, then, as a serious alternative for responsible consumption environment where turning point was the 1997 Kyoto Protocol A convention in the United Nations Framework on Climate Change that took an international agreement with the firm objective of reducing global gas emissions. A change that returned solar energy to the focus of the energy field.

And it is that the development of solar technology began in the 1860s, but at the beginning of the 20th century, with the arrival of coal and oil as non-renewable sources of fuel, easily accessible and cheap, I lead to the loss of prominence of solar energy.

A trend that has changed in recent years leading to solar energy, and in particular to photovoltaics, to be the energy that has grown the most in the last year (32%), accumulating 47% of all the new generation capacity energy within renewable energies.

Solar energy by active and passive heating

Solar energy is a type of clean and renewable energy that is obtained from solar radiation. Taking advantage of this radiation to generate three types of solar energy: photovoltaic, thermal and passive.

In this sense, if we focus on the heating of homes, we can talk about active (photovoltaic and thermal) and passive heating. A way to supply heat in a sustainable and ecological way.

Passive heating

To be able to talk about passive heating we have to start by explaining that it is passive solar energy. This type of energy is a  t centrein use of solar energy through a set of construction techniques can transform heat and use it without other devices such as gas heaters or boilers.

Getting consumption to be less than 15W / m2, and allowing comfort in homes to be superior to that of a habitual residence.

But not only that, but a passive house  allows to optimize all possible heat . But how?, Obtaining the heat that is produced  through the light and the solar radiation that enters through the windows ; of the  heat generated by appliances  when they work; or even with the own  corporal heat  of the inhabitants that are in the house.

All this makes it possible that not only the assisted air conditioning (heating or air conditioning) is not necessary, but the energy consumption decreases. A technique capable of consuming only 10% of the energy of an average property .

Active heating

In the case of active heating, like the passive one, solar energy is obtained from a sustainable and completely renewable energy that can help improve our consumption and efficiency. To understand it a little better,  did you know that the planet earth receives around 1,336 watts of solar radiation per square meter?

Active solar heating differs from the passive one, in that  energy is transformed into heat in homes through solar panels or collectors . A solar panel allows a reduction of pollution in about 100 tons of CO 2  during the time it is used, helping to improve the quality of the environment and lower CO 2 emissions .


According to the report published by the UN Environment ” Global Trends in Investment in Renewable Energy 2018 “,  solar energy generated, worldwide, more electricity than energy transformed through fossil fuels  (gas, diesel). Adding about 98 GW more than any other power source.

The future is in renewable energy , where solar plays a leading role.


Passive vs active solar heating

As we mentioned before, unlike active solar systems, liabilities work without any dependence on external devices. How is it achieved?

In fact, there are different  techniques or devices that can be applied to opt for passive solar energy  in our house. For example, use  large windows  to collect light and solar heat; use absorbent material with thermal mass  on the floor and ceiling; or even, in a water tank to transfer the heat obtained to the interior of the house.

In addition to having  curtains or insulating blinds  to control and prevent the house from overheating; use  glazing or collector walls facing south  to capture more solar energy; or even  through natural lighting using reflective panels  that transfer light into the interior of the home.

As we can see, the  objective of passive heating  is to  take advantage of the direct contribution of solar radiation  without any type of mechanical element or device, as would be the case with active solar heating systems.

When we talk about  active heating , we refer to a system that also obtains energy in a natural way but is mainly based on  capturing, converting and distributing said energy generated with solar heat .

Carrying out this process  through collectors or solar panels and transforming heat into thermal and / or photovoltaic energy . With the  aim  of  producing electrical or mechanical energy  for the  home supply  of cooling devices, ventilation or simply store it for future use.

This type of heating has innumerable advantages, such as being an inexhaustible source of energy, having a low cost in consumption, and being easy to assemble and reuse.


Similarities of passive and active solar heating 

  1. Energy that respects the environment:  neither of them needs any combustion process. So it does not pollute and helps protect the ozone layer, the greenhouse effect and avoid phenomena produced by pollution.
  2. Responsible consumption:  passive and active heating allows to control consumption responsibly. Since we decide how much energy we want to produce. For this it is important to know the amount of energy we spend in our home monthly.
  3. 100% renewable energy:  by benefiting from solar radiation it can always produce heat. Now yes, depending on the time of year and the climate the energy production will vary.

The concern for global warming, together with the continuous rise in the prices of fossil fuels, the oil insecurity itself and the ambitious 2020 plan for Energy Efficiency of the European Union, convert solar energy in particular and other energy Renewables in very important assets for the global energy future.