Qu'est ce qui est réellement écologiquement durable ? Les vélos électriques (pedelecs et e-bikes) peuvent permettre une réduction drastique en terme d'énergie consommée, nécessaire pour le passage à une transition énergétique basée sur les énergies renouvelables.
The term “sustainability” comes originally from the forestry sector, but its use has since snowballed, and it has also altered in many aspects of what it means. In contrast to the increasingly popular meaning of “sustainable”, the concept of “energy self-sufficiency” has in recent years increased in appeal and acceptance. Pedelecs can be an important building block for mobility in individual or communal self-sufficiency concepts. But please note that sustainable energy is basically just renewable energy, and on this aspect too it’s worth taking a closer look.
The ‘creeping softening’ of the term sustainability, which should in itself be easy to understand intuitively, was described wonderfully by the late leading German politician and energy expert Hermann Scheer. Wherever you see the words “sustainability” or “sustainable” bandied about in any “Sustainability Report” from a company or institution, you should consider very carefully what they are actually saying.
Is there a need for a scientific definition? Doesn’t everyone have their own idea of what sustainable means anyway?
Activities are sustainable when they can be carried out over (in human terms) very long timescales, without limiting resources for following generations.
So in the energy sector 'sustainable' fundamentally means renewable energy, and then only in those forms where its production can actually be sustained over the long term. This is not the case, and has not been in the past, for many types of current biofuel production methods.
Is wider use of pedelecs a contribution to sustainability?
The question of sustainable energy production is neither unique to pedelecs nor to the transport sector: it is a fundamental problem. Hermann Scheer described the so-called “Energy transition”, in other words the changeover to supply fully from renewable energy (100 %), as potentially the greatest human cultural achievement since the industrial revolution. There are numerous technical options to make useful energy available from renewable sources, depending on local availability. With the exception of geothermal, all renewable energy can be traced directly or indirectly to the energy from the sun. So in future the problem of providing renewable energy is on one hand a technical problem (how efficient can solar energy, or its indirect forms such as wind, wave or biomass, become in providing useful energy with minimal losses) and on the other a question of area (how much area do we need to fulfil the necessary demand for energy via solar energy).
Whichever form of energy generation is chosen for renewable energy, it is clear that demand for energy must be dramatically reduced to make possible full supply from renewables.
It is just such a dramatic reduction in demand which pedelecs offer in comparison to internal combustion engines. If we examine a distance of 15,000 kilometres covered by one household by car per year, and further assume that 2,000 of them could be covered by a pedelec instead, this in approximate terms means a saving of at least 20 × 49 = 980 Kilowatt hours of end user energy per car per year.
The main reason for the positive outcome in favour of the pedelec, which also applies for a comparison of CO2 emissions per kilometre against the car, is the trivial fact that the pedelec is essentially a bicycle which is only minimally motor assisted. Another contributory factor is that an electric motor has a considerably higher efficiency than an internal combustion engine.
Even minimal energy use needs a sustainable source
A pedelec needs only minimal amounts of energy, but to be truly sustainable on the move it’s necessary to
ensure that this comes from sustainable, that is renewable, sources. The simplest way is to sign up with a supplier who provides exclusively electricity from renewable sources. But this only has the desired effect when the pedelec is only ever charged at locations where such an electricity supply contract applies, for example in a private house or at your employer’s company premises.
Care should also be taken to distinguish carefully between so-called “Eco electricity suppliers”. Does the company really supply all of its customers with 100% ‘eco’ energy, or are distinctions made, for example between industrial customers who are shunted onto fossil fuel energy supplies, and private customers who are sold the renewable electricity?
One should select an electricity supplier who provides nothing but eco electricity and who sells this to all of their customers.
In Austria there is a useful websi- te from the national regulator at www.e-control.at which publishes the electricity mix of approved electrici- ty suppliers in Austria. No such overview is known in Germany, but most supply companies do publish their mix on their websites, as publication is required accor- ding to an EU Directive(1).
How eco is eco electricity?
But is ‘eco electricity; always really electricity from renewable energy? Basically it cannot currently be guaranteed at every instant that the power you are using comes exclusively from renewable energy, given today’s connection systems and current production and storage capacities. For pure ‘eco electricity’ it must be guaranteed and certified that the amount of electricity delivered over the course of a year as ‘eco electricity’ must matched in quantity by the amount of energy generated by facilities which convert renewable energy to electricity. This requirement is strictly monitored at frequent intervals by approved certification companies such as TÜV, Bureau Veritas and others. This involves for example comparing the dealer’s purchase contracts with sales contracts, and production facilities are also monitored.
In other words – if all electricity customers switched to eco electricity, no more electricity derived from fossil fuel sources would be sold.
Annual energy consumption of a pedelec
Real test rides, carried out annually by ExtraEnergy, have shown that a typical pedelec uses an average of 1 kWh per 100 km in electricity. To put that in context, in an electric kettle you need around one tenth of a kWh to bring one litre of water to the boil. Or a 100 W light bulb left on for 10 hours would need 1 kWh of electricity.
A car with internal combustion engine in contrast today requires around 5 l of fuel per 100 km, for a very economic model. 1 l of fuel contains around 10 kWh of energy, so it uses at least 50 kWh per 100 km.
Do pedelecs really lead to fewer car kilometres?
On this question a number of field studies have already been conducted, for example in Switzerland (2) and in Austria (3). Overall these studies have shown that between around 20 % and 50 % of all journeys conducted by pedelec were made instead of car journeys. In absolute numbers terms, in Switzerland and in the larger of the two Austrian studies it turned out to be around 800 km which was covered by the pedelec per year. It should be added that journeys carried out by conventional cycling and – to a lesser extent – journeys on public transport were also displaced by pedelec riding.
So the potential savings from pedelecs are huge, not just because of their own low emissions, but because of their positive repercussions.
To be commended: efforts to link use of pedelecs to the use of electricity from renewable energy
In Austria (as of 2011), a national subsidy for the purchase of company pedelecs was approved, so long as the company used only verifiably eco electricity.
In the Czech Republic, a collaboration between pedelec dealer ekolo and eco electricity dealer Nano operated until the end of 2011. When buying a pedelec from ekolo and an electricity supply contract from Nano, Nano provided the customer with a credit to the value of the cost (19.59 € or 500 CZK) of the average annual electricity use for a pedelec (over 10,000 km).
The Austrian retailer Elektrobiker declares on its website that only eco electricity is used.
How long someone who has been persuaded by a subsidy or a credit note to take eco electricity also stays with it is an open question. Electricity supply contracts can normally be changed after a year at most.
>> Key pedelec data on energy and sustainability
➢ buwal Bundesamt für Umwelt, Wald und Landschaft. Elektro-Zweiräder, Auswirkungen auf das Mobilitätsverhalten, Umwelt-Materialien Nr. 173, Luft, 2004.
➢ Thomas Drage & Robert Pressl. Pedelec-test (in Andritz) in the context of European Union project Active Access. Downloadable at www.active-access.eu
➢ European Commission. Directive 2003/54/EG of the European Parliament and Council of 26. Juni 2003 concerning general provisions for the internal electricity market & for annullment of Directive 96/92/EG. 2003.
➢ Kairos. Landrad, Neue Mobilität für den Alltagsverkehr in Vor- arlberg (Endbericht). 2010, A report on a project in which 500 pedelecs were tested and users surveyed.
➢ Thomas Lewis, Christiane Edegger & Ernst Schriefl. Pedelecs und Renewable Energy, 2011. Downloadable at www.gopedelec.eu
➢ Hermann Scheer. Energieautonomie – Eine neue Politik für - erneuerbare Energien. Kunstmann, 2005.
➢ Hermann Scheer & Carl Amery. Klimawechsel – Von der fossilen zur solaren Kultur. Kunstmann, 2001.
(1) European Commission 
(2) BUWAL Bundesamt für Umwelt, Wald und Landschaft 
(3) Kairos , Drage and Pressl
Copy: Thomas Lewis, prepared within the EU GoPedelec! project: GoPedelec! Handbook (German version), Go Pedelec! Handbook in Czech, Dutch, English, Hungarian, and Italian
Translation: Peter Eland (www.electricbikemag.co.uk)
Online release: Angela Budde
22 November 2012