Renewable Energies
Frequently Asked Questions
1. Why choose green and renewable energies?
Security: Having access to readily available, green and renewable energy sources such as the wind and the sun is your right. By using technologies which let you benefit from these energy sources, you become more self-sufficient and acquire a certain level of energy independence.
Environmental protection: Energy produced from green and renewable sources produces less greenhouse gas (or none at all) and therefore decreases the level of negative impact on the environment. Your children and future generations will thank you!
Preservation of energy sources: Fossil energy sources are being steadily depleted. By choosing green and renewable energy alternatives, we can preserve what remains of these energy sources, all the while efficiently meeting our energy needs and requirements.
Energy saving: Energy is a precious resource that we must conserve. By owning our personal energy production system, we become aware of our power consumption, which in turn helps us use energy with efficiency and respect.
Responsibility: By choosing green and renewable energies, we show respect and responsibility towards the environment and the wider human society and we reach a level of energy independence from large centralized energy companies.
Local development:Local power production�systems do more than decentralize energy production; they also decentralize social or political power, create jobs at the local level, and promote regional economic development.
2. What is the greenhouse effect?
The greenhouse effect is a natural phenomenon linked to the presence of certain gases in the atmosphere, such as carbon dioxide and methane, which trap the earth’s infrared radiations. When there is no human interference, the greenhouse effect allows the atmosphere to maintain an average temperature of 15°C. Without this, the earth’s temperature would be around -18°C.
The evidence suggests strongly that the continually increasing concentration of greenhouse gases is due to human activity. For example, carbon dioxide is produced in large quantities when producing energy as in the burning of hydrocarbons in thermal power plants.
3. What are greenhouse gases?
These are gases with physical properties such that their presence in the earth’s atmosphere contributes to a greenhouse effect (warming process) at the earth’s surface. The main greenhouse gases are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and ozone (O3).
Since the beginning of the industrial revolution, the concentration of various greenhouse gases has continually been increasing because of human activities and in particular the use of fossil fuels. International efforts have succeeded in controlling the overproduction of certain of these gases, such as fluorocarbons, and in demonstrating the impact that individuals, businesses and national and international instances can have on environmental issues once they have been sensitized to the issues.
4. What are the consequences of an increase in greenhouse gas?
The main consequence is the earth’s warming. This in turn leads to important climate changes starting with the modification of ocean currents, diminished biodiversity and irreversible agricultural damage in the most affected regions.
More specifically, we see phenomena such as floods, increased precipitations or droughts (depending on the country’s latitude), decreased snow cover and the retreat of pack ice, the shrinking of glaciers and ice sheets, changes in agricultural yield, alterations in the range of distribution of various plant and animal species, etc.
5. What are some of the environmental advantages of using green and renewable energies?
Heat and electricity generated from green and renewable energy sources produces fewer greenhouse gases than if they were generated from fossil fuel. Also, renewables emits less air pollutants, including the following:
- Sulfur dioxide and nitrogen oxide, which are responsible for acid rain;
- The combination of particulate matter with ozone-creating smog on hot and sunny summer days;
- Mercury which can be transformed in the environment and become highly toxic to humans and animals.
6. What proportions of green and renewable energy are being used?
Today, renewable energies represent 13.5% of the total energy consumption registered worldwide and 18% of the global electricity production.
The production of renewable electricity originates mainly from hydro
dams (90%). The usage of other renewable energy sources is very
marginal: biomass 5,5%, geothermal 1,5%, wind 0,5% and solar 0,05%.
Source: Key World Energy Statistics 2005 Edition, © OECD/IEA
7. What are the different types of solar energies?
Solar thermal energy
With this system, solar radiation (about 40% to 80%) is transformed into thermal energy. The energy produced can be used directly, for example, for heating the domestic hot water used in a building. It can also be used indirectly, for example, for the production of steam used to run generators for the production of electrical energy.
Photovoltaic solar energy
This system involves producing electricity by transforming a portion of the solar radiation (about 15% to 25%) using a photovoltaic cell.
Passive solar energy
Passive solar techniques make use of the steady supply of solar energy by means of a building design that carefully balances the requirements for energy with the building's site and window orientation. The term "passive" indicates that no additional mechanical equipment is used, other than the normal building elements. All solar gains are brought in through windows and minimum use is made of pumps or fans to distribute heat or effect cooling.