Monday 27 February 2012

Access to electricity to the entire world population

Ensuring access to electricity to the entire world population is one of the biggest challenges, and not coincidentally the year 2012 has been declared by the UN Secretary General Ban Ki-moon "the year of sustainable energy for all."

Even today, over 1.3 billion people lack access to electricity, while 2.7 billion can cook or simply heat with wood, charcoal and animal waste.

There is a lack of energy but not lacking in waste, some say. Because more and more often, initiatives arise when the energy comes from waste.

The most recent comes from Kenya, where Access: Energy, Energy Division of the Association Access: collective, is promoting the use of mini wind turbines, called Night Heron Turbines, providing people with the technical knowledge to achieve their wind turbine from scrap metal, car parts and electronic waste.

But, as we said, the combination of garbage and sustainable energy is not new. From Africa we move to Latin America, specifically in Brazil, where since 2007 Coelce has initiated the project Ecoelce, which provides discounts on the energy bill to customers who return the material to be sent for recycling at the collection points.

In other words: to promote sustainable energy, every idea is good. Garbage seems to give plenty.

Thursday 16 February 2012

Yet another post about global warming

Is almost a fact that on Mars we are not going to find crowded cities and suffocated by smog. And is gonna be pretty difficult to find oil refineries when we will go to explore the icy Pluto and Triton, icy moon of Neptune. Nor it is conceivable to expect to see on Jupiter highways crowded with cars wrapped in the fumes of the exhaust pipes. Yet these planets, like Earth, are heating up!

But if man, at least in this case, is not to blame, who is resposinble for the interplanetary warming?

The biggest culprit seems to be the Sun. In fact often mistakenly we are led to believe that the activities of our star are constant in time, or at least undergo changes only on a very long time, when in fact the energy it emits into the space in all directions over the years and decades undergoes periodic variations very small percentage, but still be able to influence the Earth's climate. The winds and all major weather phenomena thrive on the heat in the form of electromagnetic radiation coming from the Sun: the amount of energy in the amount that reaches our atmosphere is on average estimated at approximately 1367 watts per square meter.

Global warming would have serious consequences for all ecosystems, in particular, could cause the melting of polar ice caps and cause a sharp rise in average sea level.

The chief executive of RWE npower andrew duff talks global warming and nuclear power about this important and very actual topic of interest.

Tuesday 14 February 2012

How To Install Photovoltaic Systems

Within the scope of the following guide, the system voltage direct current (DC) should not exceed 1500V.

Technical Requirements

For the purposes of fire prevention in PV systems must be designed, constructed and maintained to perfection.

If the plants are run at the technical documents issued by the IEC (rules and guidelines) and / or intemational standardization bodies, they are made of the art.ln addition, all components must be in accordance with Community or national regulations. ln particular, the PV module must be in accordance with CEI EN 61730-1 and IEC 61730-2.

The installation must be executed so as to avoid the spread of a fire by the photovoltaic generator to the building in which it is embedded. This condition is considered fulfilled when the photovoltaic system, built-in construction, to be installed on structures and elements of coverage and / or façade incombustible (Class 0 or Class according to DM 26/06/1984 A1 according to the DM 10/03/2005).

Is also equivalent interposed between the photovoltaic modules and the support surface, a layer of material resistance to fire at least 30 and El incombustible (Class 0 according to DM 26/06/1984 or class A1 according to the MD 10 / 03/2005).

As an alternative may be a specific assessment of the risk of fire spread, taking into account the class of fire resistance of roofs and exteriors of the roof covering (according EN 13501-5:2009 UNl fire classification of products and building elements construction - Part 5: Classification according to the results of exposure of roofs to external fire a second ENV 1187:2 OO7) and the reaction to fire of the photovoltaic module certified in accordance with the procedures described in the decree of 10 March all'2 2005 on "reaction to fire classes for building products" to be used in the works for which this requirement of safety in case of fire.

The location of the modules and electrical conduit should also always ensure proper operation and maintenance of eventuari smoke and heat (EFC), and amendments take into account, based on the analysis of fire risk, the existence of possible routes of delivery of fire (skylights, chimneys, etc..).

At any rate modules, piping, drives, pictures and any other equipment must not be installed within 1 m from the EFC.Also, in the presence of vertical partitioning, fire places in the underlying asset to the support surface of the photovoltaic system, the same shall be at least 1 m from the projection thimbles element.

The PV system must also have the following characteristics:

• Be equipped with a control device for an emergency, located in and accessible position signaled that determines the disconnection of the electrical system, withincompartment / Building towards power sources, including the photovoltaic system.
• in the presence of gases, vapors, mists or dusts, in order to avoid electrical hazards determined from the start, you must install the part of the current system, including inverter, outside of areas classified according to D. Decree 81/2008 - Appendix XLIX;
• in areas with danger of explosion due to the presence of explosive material, the photovoltaic generator and all components in the atria current constituentspotential sources of ignition must be installed at distances of safety established by the applicable technical standards;
• The components must not be installed in areas known as "safe places" to DM 30/11/1983 sensidel, or be a hindrance to the escape routes;
• supporting structures, in order to meet the performance levels against the fire under MD 09/03/2007, must be verified and documented takingaccount the changed conditions of the structural loads on the roof, due to the presence of the photovoltaic generator, also with reference to DM 14/01/2008 "Technical standards for construction".Please note that for non-combustible canopies of service stations is no requirement for fire resistance.

Documentation

Will be acquired pursuant to the declaration of the whole photovoltaic system and not the individual parts, according to DM 37/2008. For systems with nominal power above 20 kW should be acquired documentation required by Circular Letter Ml Prot. P515/4101 subt. 72/E.6 of April 24, 2008 and subsequent amendments and additions.

Checks

Periodically and any change, extension or change in operation will be performed and documented inspections for fire risk of the photovoltaic system, with particular attention to joints and fastening systems.

Safety signs

The area where is located the generator and its accessories, if available, must be marked with appropriate signs conforming to D. Decree 81/2008. The aforementionedsignage must be marked:

WARNING: LIVE PHOTOVOLTAIC POWER DURING THE DAYTIME HOURS (XX Volts).

• The above-mentioned signs, resistant to ultraviolet rays, must be installed every 10 meters from the pipeline.
• In the case of photovoltaics on the roof of these buildings, such signs shall be installed at all access gates to thebuilding.
• The disconnecting the emergency will be identified with the provision of safety under Title V of D.Lgs.81/08.

Protection of operators

In regards the protection of operators Fire Department refer to what is stated in the note PROTEM 622/867 of 18/02/2011, regarding "Procedures in case of intervention in the presence of photovoltaic panels and operator safety fire."We note that has been taken into account the installation of devices for isolating groups of modules, operated from a distance, but to date it requires mandatory as it is not known reliability over time, or was issued a specific legislation that regulates the construction, operation and certification.

Existing systems

The photovoltaic systems, places in operation before the entry into force of this guide and service activity subject to fire prevention inspections, require,only, the obligations imposed by paragraph 6 of article. 4 of the DPR No 151 of August 1, 2011.ln general, such installations shall be provided for among other things:

• the presence and capabilities of the device of the emergency control;
• the application of safety signs and inspections referred to in the preceding paragraph.