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Energy Efficiency and renewables

We can try to be the smartest people in the world, still we might not be able to be 100% efficient. Our house conspires against our goodwill. 

Current technologies make it possible to make "passive" houses. But what is a passive house?  

Passive dwellings are buildings capable of maintaining thermal well-being without the need for heating or cooling systems. Passive houses need about 85% less energy than a standard home. 

To make a house passive, it is necessary to properly insulate the house from the inside, simultaneously ensuring proper transpiration and insulation that make the internal temperature and healthiness constant (avoiding the formation of mold and humidity inside). To achieve this, it is necessary to build walls, floors and roofs in order to minimize dispersion, increase performance and to adopt fixtures that minimize the passage of cold and heat, as well as noise. 

These homes often turn out to be healthy also due to the use of materials of natural origin, according to the dictates of green building and green architecture. 

A strong help in minimizing consumption is given by home automation systems, both inside homes and in common condominium spaces: the simplest example is that of sensors that detect movement and determine the switching on of the lights of the stairs and of the hallways. 

CAN PASSIVE HOUSES BE SELF-SUFFICIENT? 

These homes can now be almost completely self-sufficient, with the installation of solar thermal panels for the production of hot water (but also for heating), photovoltaic panels for the production of electricity and storage systems. In a house that has photovoltaic panels, it is possible to cook without gas, as well as heating; with adequate insulation, heat pumps get used more efficiently. In some cases, the use of small-scale geothermal which, using the water from the heating system, exploits the temperature difference between the atmosphere and the ground, allows for the integration of these systems to be maximized. 

In Italy, the forerunner with a consolidated experience CasaClima Agency in Bolzano. 

Undoubtedly, it is easier to transform an independent house into a passive house, but in Italy and Europe there are examples of energy efficiency and green building also applied to condominiums and also to social housing. And the green systems on the walls and roofs are widespread in many urban experiences: in the roofs of buildings in different cities around the world there are already gardens but also condominium gardens to ensure food supply and better control of the temperature of the houses. 

WHAT ARE THE COSTS OF A SELF-SUFFICIENT PASSIVE HOUSE? 

The cost of building a passive house is only 10-20% (2000 euros per square meter), in the face of energy savings of at least 85% compared to a traditional house. This makes the building of a passive house absolutely competitive. 

If throwing down the house to make it passive can be problematic and expensive, it is easier to equip it with a photovoltaic system with storage, the price of which has gone down from year to year and today is much below the price of a small car, net of the total cost of the works. And even lower than the cost of a solar thermal system. And if we talk about small cars, today, with petrol at around 2 euros per liter, the hybrid becomes more and more convenient and the electric one could be, with a constantly growing demand, if the infrastructure for recharging were more capillary in the distribution and suitable for different technologies. 

The only way to weaken war scenarios with the current Russian-Ukrainian one, in fact, is to make the European Union less and less dependent on foreign, through greater investments towards the reduction of energy consumption, favoring the production of renewable energy. 

But if it's all so beautiful and easy, why are we still talking about the energy transition as something futuristic after 20 years? 

Read the previous episode on 22 tips on how to reduce energy consumption. 

 

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Vania Statzu

Environmental Economist MEDSEA

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