No, it is not a remake of a song of Serge Gainsbourg (See, sex & Sun) nor a reshuffling of a jazz band (Earth, Wind and Fire), but the title of a document (https://ecolo.be/terre-mer-soleil-10-mensonges-nuclearistes-et-3-scenarios-verts/) written by the Green (environmentalists political party) in Belgium, I read a couple of months ago.
Despite its title, this document is not the nth writing against nuclear power plants, however the nuclear energy is the one on which the major part of the generated electricity in Belgium is relying as of today. The document’s broad technical and economic survey had caught my attention and stimulated me to write the following.
Let me be very clear about myself. I’m neither a nuclearist nor an anti-nuclearist. From my point of view an opinion is rather relying on arguments and facts than on a polarized position. To illustrate this I will use the following example: there exists no European scale treatment for (the whole European) nuclear waste (cons.), but the electricity generated by nuclear base unit plants has the lowest marginal cost (pro.), taking both into account I’m rather pro/cons (to be chosen in function of your own assessment of the balance).
Of course, much more elements are necessary to enable this assessment. It was just an illustrative example to emphasize that I will not give you (only) my own conclusions, but rather develop arguments leading to them, so that you can build your own one. And I strongly encourage you to do so.
From my point of view, the document suffers too much from a kind of repeated negative associations to some named protagonists, which gives a taste of revenge towards them and so harms the document’s credibility. Of course it is my own perception of the writing. On the other hand, I have been impressed by the broad and detailed economic as well as technical approach, where also leading edge energy technologies (like methanation) are examined.
Several chapters are dedicated to the analyse of the actual Belgian power generation units fleet, getting out the nuclear ones, and replacing them to ensure the sourcing of the electricity demand on the short and long term, placing the sourcing in a constantly more renewable generation trajectory.
Comparisons are made between scenarios and also between several analysis of similar scenarios, which not all lead to the same conclusion, showing that making projection to the future (or prospective) is always relying on hypothesis, so that the result is often more the consequence of these hypothesis than depending on the scenarios themselves. I will thus definitively not add an extra layer on top of them but rather advise you to examine them along your principles, or conversely to challenge your own hypothesis with the one developed.
In the fifth chapter, 8 major ideas are presented among which the 4 first are ‘classical’, or at least expected from an environmentalist and the 4 last ones are more innovative. A lot of topics are addressed, sometimes in an original way. I would grant several stars to the document if I had to give a global feedback. But, of course there are always ‘buts’, I have been disappointed by the so classical new>replace>old and top>down approach for 2 major topics, the mobility and the sourcing. I will now focus on these 2 subjects.
Concerning the mobility, I’ve been disappointed by the lack of deepness in the analysis. Public transportation is good from big city to big city and for mass commuting travels, but, from my experience, they are neither adapted to a flexible, social active live (like bringing the children to their afterschool activity) nor to cover the last kilometres from/to (big city) station to/from home or work. So, I will focus on the vehicle for individual/family mobility.
It should be clear for everybody that the electric vehicles (EV), which have a yield exceeding 90% in any circumstance, will surely supplant the internal combustion engine (ICE) powered ones, which in practice show an effective yield laying between 10% to 20 % (short distances, traffic jam, …).
However, the yield of EV itself is already very interesting, factor 2 to 3 in comparison with the ICE when making use of electricity generated by the existing park of power plants (mix of nuclear, coal, gas, renewable, figuring a global average yield which lays above 45% in Belgium), it will only deliver its full advantage when the used electricity will come from (100%) renewable generation, but this is precisely one of the goal of the proposed scenarios.
A further and more careful reflection about vehicles would also have highlighted the nonsense of making still heavier and more powerful cars … to be stuck in traffic jams. From my point of view, instead of aiming a world without individual cars, a more constructive approach would have led to promote reasonable and well-suited vehicles (which will in a not yet determined future also be shared).
We could reduce the tax on vehicles fulfilling e.g. the following characteristics: 5 seats (4 passengers + driver), 100% electric powered, a maximal weight of 850 kg, a maximal power of 50 kW, external sizes fitting within a rectangular box of (for instance) 1,7 m (W) x 1,5m (H) x 4,2m (L) and providing a drag factor (Cx) lower than 0,30, a WLTP autonomy of at least 500 km and the possibility to be charged with a T2/3,7kW plug as well as with a common 16A/230V plug (and optionally other plugs, the 2 mentioned ones being required). However realistic, these figures could be tuned, after dedicated (truly) independent studies.
You will probably wonder how I’ve defined these figures, and your question is worthwhile. So I give you below the fundaments behind them. First of all, the weight must be as slight as possible, because till 40-50 km/h the weight is the major component in the spent energy to move a car, however on the other hand batteries will remain heavy (I don’t expect less than 250 kg, for 65kWh in the coming years). Besides, the weight has also other aspects like: how heavier a car, how more raw material are needed to manufacture it, what can’t be good for our planet. Next, how heavier a car, how stronger the roads, streets, parkings must be to sustain its weight, thus once again more raw material, but also higher building and maintenance costs (for our society). While, the Renault Vesta II, a prototype which has been a champion in mpg (miles per gallon) challenges in the eighties, had a weight of ca. 500 kg (for a length of 3,3 m), so that taking into account the battery, necessary for our EV, and the upscaling in size (from 3,3 to 4,2 m length), a total maximal weight of 850 kg is a reasonable condition, without being eliminatory.
A maximal power of 50 kW could appear too limited, since we are used to drive cars having around the double of that, or still more. But, this maximum power is as good as never used in the practice. In normal circumstances, it is hard to use more than 20 to 25 kW of power, and this occurs only during very short time windows (less than 1 minute). What we need to accelerate is engine torque and, due to its construction, an electrical motor delivers much more torque at low speed than an ICE. With a weight of 850 kg, a maximal power of 35 kW is more than sufficient for the most of the situations experienced in the real life. Again, the Renault Vesta II had a maximal power of ca. 24 kW. The figure of 50 kW is just more than the double of that, leaving surely enough additional power for unforeseen circumstances.
The dimensions of a car play several roles, the cross section area (perpendicular to the movement) impacts the aerodynamic resistance to the movement and must thus be kept as small as possible. Of course the form of the bodywork is here also very important, but it is impossible to define it further than by its drag coefficient (or Cx, the factor multiplying the cross section area to give the actual air penetration resistant area). A Cx of 0,30 is good but not exceptional and a cross section fitting in rectangle of 1,7m (W) x 1,5 m (H) is sufficient to enable 3 persons to seat comfortably next to each other (commonly on the rear bank). The limit on the length is in turn related to the ground space required for each vehicle, how larger it is, how wider must be the roadways and, how longer how lengthier must be the parking areas. Globally said how bigger is this surface, how higher is our footprint (rather carprint) on our environment. On the other hand, a length of 4,2 m is more than enough for a 5 persons car and a roomy boot (at least 400l). The sizing, presented is roughly the one a VW Golf or a Renault Scenic, but with the space occupied by the motor nearly totally freed-up (totally when the electric motors are placed in or in the vicinity of the wheel).
An autonomy of 500 km (WLTP, which roughly will require some 65 kWh) can sound extreme when we know that the large majority of the daily (round)trips do not exceed 30 km. But, first this is an average, for which the standard deviation is not given and, the actual distribution is not documented, while we need to comply with at least 90% of the situations. We know, that in Belgium for instance, a not negligible part of the people drive between 100 and 250 km per day. Further, disposing of a surplus of energy, will make the car available for integration in the electricity grid (management), with a kind of remuneration (or rather an advantageous charging tariff), to absorb the (renewably generated) electricity in excess (e.g. by extra sunny or windy days) and re-inject it later (e.g. when the demand exceeds the production, or simply to feed the home).
Charging a battery set of 65 kWh in short time (let us say 1h or less), would require huge power capacity, the grid can’t offer. But a car sleeps in a garage each night during 10 to 12 h, and 8 to 10 h along the day during the time between the arrival and leave at/from work. Summed up on a daily basis, a car is moving no more than during 4 h, leaving 20 h for charging (and grid management participation). So a charging power of 3,7 kW is largely enough to restore the necessary energy for the next day (3,7 kW x 20 h = 74 kWh, of course the charging is not a linear phenomenon, I know, but a full discharge over several consecutive days is also not probable). A power of 3,7 kW is equivalent to 16A at 230V, which is deliverable by a common plug (with a bit heavier cable to sustain the delivery over a several hours) and will enable the connection of more than 2 million cars on the Belgian grid, without requiring any adaptation of it (for the details, see article: https://edenergy.be/will-ev-charging-overload-the-grid/?lang=en). Other charging power are not excluded (e.g. for people driving much and far, a 11kW of 22kW would be a plus), but the 3,7 kW T2 and 16A/230V ones must be required, to enable large diffusion of charging poles and societal sustainability.
Another point is that I’ve always been amazed by the amount of cars on the road with only one person on board. It is surely a waste of (road and then parking) space, generating traffic jams and causing over consumption of fuel, all in comparison with what a motorcycle achieves. So that, in parallel with the considerations about (electric powered) cars, 2-wheels (like streamlined motorcycle, eventually gyroscopically stabilized like the C-1 of Lit) should also be promoted, when figuring e.g: 2 seats, a maximal weight of 120 kg (not streamlined, 140 kg streamlined), external sizes fitting in a rectangular box of (for instance) 0,8 m (W) x 1,5m (H) x 2,1 m (L) and providing a drag factor (Cx) lower than 0,20, a maximal power of 15 kW, and an autonomy of minimum 250 km at 90km/h constant speed as well in urban use (thus let us say a battery set of around 20 kWh).
The 2 seats requirement will enable to bring a child to school or to an activity, or to travel as a couple. The reasons for the other figures are similar to the ones presented for the cars, but adapted to a 2-wheels vehicle.
All this, without forgetting the reconditioning/conversion of existing cars into EV, which could be promoted, provided that the reconditioned vehicle leads to a weight reduction by at least 50kg, is equipped with a battery set of at least 25 kWh, and the other figures similar to the ones described above for new cars.
Working that way, promoting all these 3 types of EV, will ensure a drastic reduction of primary energy consumption and of the related pollution, foster a leaner use of raw material, develop a better match between the actual (mobility) needs and the manufactured vehicles (inclusive an increased use of 2-wheels where and when possible) and the eviction of massive landfilling of ICE (when buying a new EV), without curtailing the mobility of the citizens.
Concerning the sourcing, I’ve been disappointed that the writers were so tied up by the centralized electricity production concept, where a reduced amount of large/huge power plants, build on predefined dedicated sites, must supply the whole demand through a top down designed grid. The propositions, presented in the document, fit in the same mould as the ones elaborated earlier by Elia (the high voltage grid management company in Belgium), impeding to see further and to deepen and broaden the analysis. Please, forget never that the yearly average global net losses of the whole Belgian grid, concerned by the national consumption (thus excluding the cross borders transmission), reach 10% of the Belgian offtake (thus net losses of ca. 7 TWh/year). Awful.
Do either not forget that the citizens, us, who are often only considered as electors by the politicians … but, O.K, I won’t follow this course (sorry, I could not help mentioning this). So, we, the citizens, pay electricity bills where the offtaken energy represents no more than 25% of the total, the distribution and transport costs capturing the lion’s share.
Nonetheless, there exists a way of balancing security of sourcing, environmental ambition and advantage for the citizens. Imagine a world where each home is equipped with a nano-cogeneration (let us of 500 We, thus 500W of electrical power), a battery set (let us say of 5 kWh) and a heat storage tank (let us say having a volume of 200 l, with a thermal storage of 15 kWh), based on natural gas fed fuel cell (providing an electrical yield in the range 35% to 40%, thus 1,25 to 1,4 kWth), we would directly benefit of a global 85 % yield (generated electricity + heat, reported to the consumed natural gas), a maximal resiliency for our sourcing (a synchronous disturbance of several millions of units is totally improbable) and, eliminate the grid losses concerned by the residential consumption (which represents roughly 50% of the total national consumption).
Further, if, in the medium term, the methane (natural gas is mainly methane) came from renewables (via methanation of renewably produced hydrogen), our distributed nano-cogeneration based sourcing would be zero carbon. In the meanwhile, the 85% global yield will enable a progress that is definitively unbeatable by even the best approach considered in the document ‘Terre-Mer-Soleil’.
Of course, once again, stimulating the development at industrial scale of the nano-cogeneration figured out above, e.g. via financial support mechanism (really guaranteed over the amortizing period, without possibility of giving with one hand and taking back with the other, as has been done with the photovoltaic), would ensure its commercial emergence and large scale implementation on a short term. And, once the energetic transition achieved, the renewable methane will replace seamlessly the fossil one which we will be used on the most efficient way till then.