Photovoltaic Energy
Photovoltaic energy generation is going to play an increasing part in the source of electricity in France. In fact, in western Europe the production of electricity from solar sources has risen dramatically in the last few years. This region has seen the fastest growth compared to the rest of world and by 2004 had overtaken the United States in terms of mega watts of electricity generated. When we look at the percentage of photovoltaic installations in the world in 2009, the US had a 7.5% share of the market whilst Germany had 54.7%.
In all, Europe accounts for 70% of the installations in the world, which expressed another way equates to 14 giga watts. Of course this is still a small percentage of the amount of electricity consumed world-wide, which in 2008 was 20 169 tera watt hours (a tera watt is one million million watts). The potential of energy from the sun is not endless but in terms of the known reserves of gas, oil, coal and uranium, it could be thought of as being so. The energy radiated by the sun each year is 11 250 times greater than the needs of the world's population, so whilst predictions have been made of how many years there are before we have consumed the accessible fossil fuels, no such estimate exists for solar. Despite the overwhelming availability of solar energy in 2008, it represented only 1.3% of the world-wide production of electricty from renewable sources.
Although solar does have significant advantages in that it is free, abundant and very practical for generating electricity in remote locations, it is not the complete panaçea. First of all it does not work at night; it is expensive to build solar power stations and solar cells are expensive to produce compared to the amount of electricity they produce in their lifetime, although the cost of both is reducing as technology advances.
Energy efficiency and greenhouse gas emissions
Energy efficiency and greenhouse gas emissions are two very hot topics (no pun intended) at the moment in France. Of course the two topics are very much the same thing, in that the less energy that is used, the less that there are emissions of greenhouse gases. These are the gases in the atmosphere that absorb and emit radiation in the infra-red spectrum and they include water vapour, carbon dioxide, methane, nitrous oxide and ozone. The second one in the list, carbon dioxide, is a by-product of energy generation and use, i.e. the combustion of fossil fuels and wood. In France, the government have launched the Grenelle de l’Environment. This is a state-backed drive towards the protection of the global environment and one of its targets is the reduction by 38% of the consumption of energy in existing buildings by 2020. To achieve this goal, it will require the intensive renovation of 400 000 homes each year from 2013 and the anticipated consequent increase of 120 000 jobs in the building renovation sector. So we have the initiate towards energy efficiency and the reduction of CO2 emissions, but what of today?
The intensive use by France of nuclear power for generating electrical energy means that this country has become the lowest emitter of CO2 when compared to all other developed countries. This the finding in a report published by the National Institute for Statistics and Economic Studies (INSEE). It found that France, which represents 1% of the world’s population and 3% of the gross domestic product, emitted 1.3% of the world-wide CO2 production. This figure is greater than the average figure per person in the world, but less than the percentage for comparable developed countries, most notably the United States and the developed countries of Western Europe. The global average is 4.2 tonnes of CO2 per 1000 people and for the France the figure is 5.99 per 1000 people.
The INSEE study found that France produces 90% of its electricity from non-CO2 emitting sources. The principal source is the nuclear plants, of which there are around 60, and these generate between 75 and 80% of the electricity, and then there is hydro-electricity, which accounts for between 11 and 13%. Another source of energy that is going to play an increasing part of France’s electrical generation network is photovoltaic, i.e. generation of electricity by solar radiation. The market for this product has evolved dramatically in the last year or so and it is likely to keep on growing, partly because of the availability of financial support from the state and the regions.
I mentioned before that the photovoltaic energy is going to play an increasing part in the source of electricity in France. In fact, in western Europe the production of electricity from solar sources has risen dramatically in the last few years. This region has seen the fastest growth compared to the rest of world and by 2004 had overtaken the United States in terms of mega watts of electricity generated. When we look at the percentage of photovoltaic installations in the world in 2009, the US had a 7.5% share of the market whilst Germany had 54.7%. In all, Europe accounts for 70% of the installations in the world, or expressed another way 14 giga watts. Of course this is still a small percentage of the amount of electricity consumed world-wide, which in 2008 was 20 169 tera watt hours (a tera watt is one million million watts).
The potential of energy from the sun is not endless but in terms of the known reserves of gas, oil, coal and uranium, it could be thought of as being so. The energy radiated by the sun year is 11 250 times greater than the needs of the world's population, so whilst predictions have been made of how many years there are before we have consumed the accessible fossil fuels, no such estimate exists for solar. Despite the overwhelming availability of solar energy in 2008, it represented only 1.3% of the production of electricty from renewable sources. Although solar does have significant advantages in that it is free, abundant and very practical for generating electricity in remote locations, it is not the complete panaçea. First of all it does not work at night; it is expensive to build solar power stations and solar cells are expensive to produce compared to the amount of electricity they produce in their lifetime although the cost of both is reducing as technology advances. Another criticism of solar electricity generation is the area required for the panels, but in fact more than 90% of the systems installed in France by the end of 2009 were less than 3 kilo watt peak and that takes up a south facing area of roof space of approximately 20 square meters. One final statistic is that by 2007, the surface area of solar panel installations was 9 km². All of the world's electricity requirement would be satisfied by solar arrays covering 380 km², or an area slightly larger than England.
Lightning
Since 2002, the French wiring regulations, NF C15-100, has defined the situations in which it is obligatory or strongly recommended to have a parafoudre in the installation. The requirement for a parafoudre is determined by the niveau kéraunique, or Nk level, for a particular department. This is the thunderstorm severity and it is calculated by the number of days that lightning is observed in a given department per year. If the resultant Nk figure is greater than 25 a parafoudre is obligatory on all domestic electrical installations unless the supply cabling is entirely underground, i.e. right back to the sub-station. In our region, the Dordogne (24) is the only department where the Nk figure is greater 25, whereas the Creuse (23) and the Haute Vienne (87) have a value of 23 and the Charente (16) has 21. This is not to say that a parafoudre is unnecessary in those areas, but it is not obligatory.
A parafoudre may be installed into the household wiring system either in series or parallel. However, the crucial factor is that the connection to the earth is as a short as possible and never in excess of 50 cm and that this length is much shorter than the earth wires of any of the other circuits because the purpose of the device is to direct any excessive tension to earth before the sensitive appliances receive the surcharge. However, it is also important that the distance between the parafoudre and the equipment to be protected is not greater than 30 metres. If this is the case, then an additional parafoudre should be placed in the proximity of the equipment.
This is where the multiblock extension leads with incorporated surge protectors have a role to play. As a stand alone device, they cannot be relied upon to give a satisfactory level of protection, but their function down the line in front of the equipment will ameliorate the risk created by the voltage drop and residual tension from the parafoudre at the head of the installation. A parafoudre for use in the consumer unit should cost in the order of 140 € plus the cost of fitting.
Lightning Protection
After the long cold winter and all of the difficulties that caused, i.e. burst pipes, split radiators and frozen boilers, we are moving into a different period of climatic problem. That is the time of year when the thunderstorms come in from the Bay of Biscay and move across our part of France in a north-eastward direction towards the mountains. Each year, the territory of France is struck by lightning around 2 million times. The majority of these strikes are harmless and cause no damage to either people or property, but it is a different story for those that find their way into our electrical and telecommunications equipment. The lightning starts between two highly charged storm clouds, or between a cloud and the ground.
The clap of thunder is the sound of the lightning striking and discharging its energy. At this point, a current of several million amps flows between the cloud and the earth via the ionised channel that has been created. The effects of this are well known and for electrical, electronic and telecommunications equipment the outcome is usually disastrous. There are two forms of protection against lightning damage. The first is by using a lightning conductor, or paratonnerre, to prevent the direct effects and these are used on exposed sites and high buildings. The other method is with a surge protection device and these are known as parafoudres. The indirect effects of the lightning are the consequences of a direct strike on or close to the electrical or telecommunication distribution system and then carried by the network of lines to our apparatus. The effects of the voltage surge can also be created by lightning strikes in the vicinity of buildings, or by the discharge of energy through a lightning conductor. The strength of the surge will depend on the intensity of the strike and the distance from the point where the electrical equipment is installed.
The parafoudres are categorised in three groups dependent on the level of risk, the expected strength of the surge and method of installation. A type 1 parafoudre is used where there is a high risk, such as where the building has a lightning conductor and where the strength of the strike would be consistent with a direct impact. They are fitted to buildings on exposed sites, or high buildings such as apartment blocks and churches. Type 2 parafoudres are installed at the head of the electrical panels where the risk is only likely to be through an indirect effect. Type 3 parafoudres are used as a supplementary protection adjacent to a specific piece of equipment.
Smoke detectors
Five years after the law was originally proposed, the text to make the use of smoke alarms obligatory in all places of habitation has been published in the Journal Officiel. The law from 9 March 2010 means that at least one smoke detector must be fitted in all flats and houses, whether it is new or existing, within 5 years of the publication of this law. The text of the law is precise in that it is the responsibility of the occupant and not the owner to fit, maintain and ensure the good working order of the smoke detector. The law also requires that the occupant must notify their insurance company that they have fitted the device in their home and that the insurance company should make a reduction in the premium for the policy as a consequence. The publication of this law brings to an end a marathon of the legislative process, as it has been 5 years in development.
Originally proposed in 2005 after a series of fatal domestic fire incidents, two of the most notable being those in apartment blocks in Paris, the proposition has had to overcome a series of hurdles. The proposal was completely rejected by the Conseil Constitutionnel last year. One of the deputies complained that if these devices were installed, one would not be able to smoke in one's own home.
However, there is still a lot of debate and conjecture on the effectiveness of smoke alarms. Of the 98 different models available on the market in France in February this year, only 41 carried the NF (Norme Française) symbol to guarantee that they were fit for purpose. The NF symbol, delivered by the Afnor certification authority is the french equivalent of the British Standard BS kite mark. It attests that in this case the smoke detector uses an optical detector, that it contains no radioactive substances and is sufficiently ergonomically constructed to withstand incorrect usage, such as not fitting the battery or putting it in the wrong way around. The NF marque also imposes on the manufacturer that the device should be delivered with a battery and there should be a clear and explicit notice to say how long the battery should last, either one, five or ten years. Although some smoke detectors may carry the CE mark to show that they meet the minimum standards of european legislation and may be sold in Europe, the NF marque goes further to cover the needs of the user and the installer of the device.
Thermal-Dynamic Water Heater
As an alternative to solar heating for hot water, the thermal-dynamic water heater, which uses either ambiant air or extracted air, is a very attractive option. There is an economy in the order of 70% on the cost of producing domestic hot water when compared to a traditional electric water heater, known in french as a ballon chauffe-eau. Nowadays, highly efficient central heating systems make ecologically sound houses a reality. As a result, the production of hot water has tended to be more demanding in energy than the central heating. Solar water heating is the answer most often associated as the alternative to the traditional boiler for producing domestic hot water, but there exists another very advantageous solution and as such the thermal dynamic water heater is certainly going to have a bright future, as apart from the enormous reduction in running costs, since the beginning of this year it has attracted a tax credit of 40%. The thermal dynamic water heater is a heat pump with a COP in the order of 4, that is to say that 1kW of electricity consumed will produce 4kW of heat, whereas a conventional water heater is only 75% efficient, i.e. 1kW of electricity produces 750W of heat.
The units can be installed in an unheated garage or laundry room and the heat pump will take in the air from these areas and by exchange extract the calories to heat the water. The operating range is from -5°C to 35°C, so even in winter, a basement will be able to provide enough heat for the unit to function. Normally, the unit would require a room of at least 8m² to operate effectively, but if the laundry room space is too small, ducts can be installed to draw in outside air and pass it through the unit. A beneficial side effect of the system is that it acts as a dehumidifier for the surrounding space, which is ideal in a laundry room. From the environmental standpoint, it produces ten times less CO2 in the production of hot water compared to a fossil fuel boiler, i.e. gas or oil. The system can be installed as a stand alone device, or it can be incorporated into a central heating system powered by an air source or ground heat pump.
Dim lights or blackouts?
If you felt a bit dim in December and again in mid-January, it probably wasn't your fault. In fact during those two periods of unseasonably low temperatures (7-8°C below the normal) EDF turned down the power. As a consequence of the wave of very cold air that passed over France, the demand for electricity increased and very nearly exceeded the capability of the network to satisfy the requirement. In order to avoid blackouts, the power output was reduced by 5%. On the evenings of the 6th and 7th of January, the consumption of electricity reached 91 000 MW, according to Réseau de Transport d'Electricité (RTE). They estimated that on the 11th, 12th and 13th of January the demand would set a new historic record, beating the 92 400MW consumed on 7 January 2009, but in fact the weather warmed slightly and demand fell back.
France is normally self-sufficient in electricity, generating 80% of its electricity requirement through the use of 58 nuclear reactors. By 2020 this will have increased to 60 when the new reactors at Flamanville and Penly become operational. Unfortunately, in early January, nine of the existing reactors were stopped for technical reasons, leaving the network under capacity. The configuration of the network means that France has the option to buy in up 9 000 MW of electricity from its European neighbours and on the 4th of January it imported 2 400 MW and 4 800 MW on the 5th and 6th. In mid-december, the importation exceeded 6 600 MW, which is the equivalent of 6 nuclear reactors. France's electricity generation has been called all-nuclear because of the almost exclusive use of nuclear reactors and therefore the electricity is low impact when it comes to greenhouse gas emissions, but the reactors are slow to respond to demand. Whilst improvements in the structure to allow greater levels of importation and improved levels of reactor availability will reduce the risk of shortfalls, the construction of 12 gas-fired generating plants to meet short-term demand, has been proposed by the Direction Générale de l'Energie et du Climat. In Germany, the majority of homes are heated by gas or oil and a drop in temperature there brings about a large increase in CO2 emissions. By comparison, in France, many households are equipped with electric heating and as a result a drop in temperature of 1°C will increase electricity demand by 2 100 MW, but the environmental impact is low.