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.