What aspects should I take into account when buying a new device?

Before purchasing a new device you should compare it with the most energy efficient device available in the market.

On comparing the two consider:

 the future savings in terms of energy consumption, evaluating these savings from both an economic and an environmental perspective;

 the possibility of the device perform more than one task with the same energy consumption;

♦ the prices of both devices and their expected life cycles.

Seek to see if there is a similar devices that use a renewable energy source, easily available locally, to produce the same task (for example a solar powered device) and perform the above comparison between the traditional device and the device powered by a renewable source.

Keeping in mind, in your analysis, the safety provided by the diversification and the proximity.

What can we, as an individual, do to be more sustainable from an energy point of view?

Star by placing the question to yourself and progressively implement the steps that you were able to identify as an answer.

Some tips in order to find the solution which suits you best:

1 – List by priority all you energy applications:

house heating and cooling;

 sanitary water heating:

♦ wash, dry and iron clothes;

 food confection;

♦ food refrigeration;

 electronic devices consumption


♦ dishwasher;

♦ electrical cars;


2 - Detail your daily energy needs by season and hour of the day

♦ list of equipment that are used

♦ number of days per season that are used

♦ number of hours per day that are used

3 – List by order of importance the sources of energy on which you are currently relying on:

 electricity provided by the existing network;

 natural gas provided by the existing network;

 gas bottle

 diesel, gasoline and other similar petroleum derivatives;

 solar thermal;

 electricity produced by solar photovoltaic;

 electricity generated by wind turbines;



 biomass (wood and pellets);

 liquid biofuels

 hydric electricity

 hydric mills and water mills;

 geothermal (passive);

4 – search for the optimal energy system for you. Try to diversify the energy sources and combine the ones that are mostly locally available with you energy needs;

5 – select the most energy efficient devices for each energy application and for each source of energy production.

6 – regularly redo the above analysis, to consider the technological developments on energy production and storage devices and the improvements of the energy efficiency offer by new devices and gadgets.

Energy savings can contribute to the global sustainability?


Energy consumption globally has grown exponentially, with no signs of slowing down, alarming increasing the pressure on our planet, largely due to the extraction of non-renewable energy sources (such as petroleum or coal, ...) and to the pollution and the carbon dioxide release generated during the extraction, transportation and consumption of these energy sources.

Renewable energy sources may help to increase the sustainability and the preservation of our planet non-renewable energy resources, but we need to reduce the overall energy demanding. To be sustainable we can’t continue to exponentially increase our energy demanding, even if the sources were 100% renewable, and that is why energy saving is essential.

To increase energy saving each individual may:

avoid energy wastes, create habits that reduce unnecessary consumption (such as turning off all equipment when not in use to avoid "parasite" consumption), adopt devices that allow to monitor and manage the energy consumption in a "smart and efficient" way;

♦ change the energy consumption habits to match as most as possible the production with the consumption, for example in the case of electricity generated by solar panels program the devices of higher consumption to operate during period of higher solar radiation and reduce the consumption out of this period;

♦ replace inefficient equipment, in terms of energy consumption, for devices with higher efficiency, that is, choose devices that require substantially less energy consumption in order to perform the same task;

 change the way buildings are designed and constructed in order to improve its energy efficiency and, for the existing ones, improve its thermal sealing and its overall energetic performance; for example by coating them with thermal insulation.

Energy savings should be a drive in any sustainability model, ideally the savings should be achieved without strongly compromise the comfort level and the productivity.

What should be consider when assessing the sustainability of a given energy source?

To measure the sustainability of an energy source the effects of its use, extraction/production, storage and transport needs to be consider from an environment, as economy and a social perspective taking a large time horizon.

Even when only renewable resources are used to produce, storage and transport the energy it is necessary to ensure a balance between the rate at which these renewable resources are consumed and the rate at which they are restored.

When selecting the energy sources to use it is relevant to compare the respective degree of sustainability, to ensure that the more sustainable energy source, for the specific purpose, is selected, which is very demanding and complex.

As a general rule, a renewable energy source will be more sustainable as:

lower the dependence on non-renewable natural resources;

 lower the dependence on non-renewable energy sources;

 lower its "carbon footprint";

 greater the proximity between production/storage and consumption;

  greater the use of renewable, recycled and local recycled resources:

 greater the positive effect on the local economy;

 greater the future security provide to consumers (especially taking the medium/long term).

Energy source

How can we take advantage of geothermal energy?

Geothermal energy can be obtained in two main ways:

Actively, by capturing underground heat at a very high temperature, a solution technically very challenging and only justifiable for large-scale installations, or capturing underground heat at a low-temperature, a solution obtained from pockets of heat usually found just a few meters below the ground and efficient for house heating.

Passively, by taking advantage of the thermal stability of the soil such as in partially submerged buildings as way to maximize the home thermal stability.

How can we use the Bioenergy?

Bioenergy (biofuel) can be used as a:

solid - biomass - wood and processed wood (mostly pellets);

♦ liquid - biofuels - biodiesel, bioethanol, ...;

♦ gaseous - biogas;


What are the most common renewable energy sources?

The most common renewable energy sources are:

♦ hydric energy - energy available in a water flow (produced by the flow and speed of the water), whether in an open system (the force of water from a river, stream, ...) or in a closed system (the force of a piped water flow - usually from a weir or a dam);

♦  solar energy - energy produced by solar radiation and heat. Can be an active solar energy such as the electricity produced by solar photovoltaic panels and solar water heating, or passive such as orienting the building towards the sun, applying materials with favorable thermal mass or design the space to naturally circulate the air heated;

♦  wind power - energy produced by the wind force. Can be an active wind energy such as the electricity produced by wind turbines or the mechanical energy produced by windmills and a passive wind energy such as air refrigeration of buildings;

♦  bioenergy - energy contained in the carbohydrates produced and stored by plants;

♦  geothermal energy - energy produced from the existing heat inside the earth.


The building architecture may play an important role on the future energy bills?


A building architecture that favors natural lighting, avoiding excessive exposure to solar radiation in the summer, consider building materials and construction solutions that promote thermal sealing, improve the energy efficiency of the building, allowing significant reductions on the energy demand without compromising on comfort, thus reducing substantially the future energy bills.

To be consider energy efficient a building architecture should also consider building materials and construction solutions with a small carbon footprint and be integrate on the landscaping in a way that promotes its energy efficiency.

The goal should be to combine passive techniques of energy capture (solar, geothermal, hydric,...) with construction techniques that allow the reduction of energy consumption.


Can the upgradation of an energy system to include renewable energy sources have economic advantages?

Yes it can.

To assess the economic value of the upgradation consider:

♦ the cost of adapting the current system. Consider the cost of new equipment and the cost of the installation;

♦  the maintenance costs of the new system vs the maintenance costs of the current system;

♦  the life cycle of the new equipment, the longer the life cycle the higher the potential value,

♦  the energy efficiency of the new system vs. the energy efficiency of the previous system;

♦  the cost of future energy bills of the new system vs the cost of future energy bills of the current system.

Although it is common to achieve economic benefits by adapting an energy systems to use renewable energy sources, the analysis should also consider the impacts on the sustainability and on the safety of the energy system.