Jag har läst igenom rätt mycket i det här dokumentet och just delen om vätgas är farsinerande! Det är många problem att överkomma!
Dokumentet:
https://www.transportenvironment.org/pu ... o-mobility
Ett långt avsnitt handlar om bränslecellsbilar.
Toyota has been marketing the Mirai since late 2014, 2,000 were sold in 2016, and Toyota is aiming at 3,000 in 2017.41 Vehicle costs remain high. FCEV prices have been set at around $60,000 during the early market introduction phase, i.e. about $20,000 more than the BEV Bolt model GM launched in 2016.
In Europe, the interest remains minimal. In 2016, only 134 FC-vehicles were sold, a 22 per cent drop compared to 2015.
Det mesta av vätgasen idag är gjort på fossil väg. Endast 4% görs med elektrolys.. Med tanke på energimixen i vissa länder är det kanske tur? Om det går åt 2-3 ggr så mkt energi som för en elbil bara med själva tillverkningen är det inte riktigt hållbart i länder med stor del fossil el.
Several methods can be used for hydrogen production. The dominating technology is steam reforming from hydrocarbons in natural gas, oil and coal. Around 48 per cent of current supply is produced from natural gas using steam methane reforming, 30 per cent arises as a fraction of petroleum during the refining process, 18 per cent is produced from coal, and 4 per cent is manufactured by electrolysis.
Tydligen är det metangas som är vanligast att man använder... metangas är tyvärr den värsta växthusgasen av alla. :/
Bästa effektiviteten i produktion ca 80%.
Production from natural gas is the cheapest source of hydrogen and can be made with approximately 80 per cent efficiency. In order to fit in a European scheme for reducing carbon emissions from road transport, producing hydrogen from natural gas for use in vehicles would require the production plants to be equipped with CCS, which would have a significant impact on the overall production cost.
CCS - Carbon Capture and Storage
Tyvärr är electrolys också den dyraste, och även mindre effektiva metoden för vätgas. Att det också drar väldigt mycket energi är inte heller någon fördel.
Electrolysis means using electricity to split water into hydrogen and oxygen and is the most expensive commercial method for hydrogen production.
The efficiency of the best performing PEM electrolysers (around 70%) is sufficiently close to the theoretical minimum value that further improvements are expected only to be marginal. Small electrolysers, suitable for local small-scale production, may have efficiencies well below 60 per cent (E4tech Sàrl and Element Energy, 2014).
Solceller eller tillfälligt överskott från vind för elektrolys är dom lite osäkra på om det kan bli hållbart rent ekonomiskt:
Electrolysers have significant investment costs, which mean that they will only be cost-effective if operated for a sufficient amount of time during the year. As power generation surplus will occur only during short periods, relying exclusively on such hours is likely to be insufficient to reach a satisfactory capacity factor (IEA, 2015).
Även distrubution har sina problem... antingen med långa transportsträckor som blir dyra, eller dyr produktion lokalt.
Creating an infrastructure for hydrogen distribution and delivery to thousands of future individual fueling stations presents additional challenges. It is more expensive on a per-liter-of-petrol-equivalent basis. Producing hydrogen in large centrally located plants minimizes the cost of production but raises the cost of distribution. Producing hydrogen at or close to the point of end-use cuts distribution costs but increases the cost of production.
Transporting hydrogen in tankers requires cryogenic liquefaction, which is a process that cools the hydrogen to a temperature where it becomes a liquid. The liquefaction is highly energy consuming compared to gaseous truck or pipeline transport.
Och man tappar en del om det inte används direkt..
If the liquefied hydrogen is not used sufficiently fast at the point of consumption, it boils off from its con-tainment vessels. Typically it will evaporate at a rate of 0.5-1 per cent per day.
Priset för tankstationer är nästa hinder... och att det per station inte finns speciellt hög kapacitet.
Ricardo (2016) estimates the current capital cost for a capacity of 200 kg/day in a low pressure system (350 bar) to be $1,250,000 when the hydrogen is delivered to the station in gaseous form and the capital cost recovery period is 10 years. The capital cost of a station based on liquid deliveries and with a daily capacity of 400 kg is set at $1,970,000, while the cost of a similar station with a capacity of 800 kg/day would be $2,100,100. Ricardo believes that by 2030 the capital cost of the largest of these three examples will have been reduced to $1,260,000.
Ricardo 2016. Economics of Hydrogen Refueling Stations. CaFCP Bus Team Meeting, August 30.
Alltså ca 10 miljoner kr för en station som endast klarar att ge ca 2000mil per dag. (blir billigare allt eftersom... men investeringarna om man ska få igång det är rätt stora.) Undrar om det är tänkt ska betalas av staten eller om det ska slås ut på de som tankar.
Står också kring effektiviteten med elektrolys:
Each conversion step on the way from electricity to hydrogen and back to electricity entails losses. When the hydrogen is produced by electrolysis, the FCEV consumes at least 130 per cent more electricity per vehicle-kilometer than an identical BEV model.
Alltså en bit mer än det dubbla i elförbrukning mot en elbil.
In order to compensate for a much higher fuel cost, including transport and delivery, the FCEV itself must become a lot cheaper to buy than a long-range BEV or a PHEV. Today the opposite is true, and according to BEUC (2016), FCEVs will suffer from a price premium of at least 12 per cent compared to EVs, even in 2030.
Svårt att se hur vätgasbilar ska kunna konkurrera med elbilar här.. kommer dom ner lite i pris möjligen att dom kan bli prismässigt konkurransmässiga mot ICE-bilar. Men med allt runomkring.. alltså, det skulle kännas tungt om man satsat allt sitt kapital i vätgasmarknaden.
Dom avslutar delen med vätgas med att summera lite:
The powertrain of a FCEV brings two benefits compared to EVs: swift refueling and a relatively long driving range, though still considerably shorter than of an efficient diesel car. However, three im-portant hurdles are not easily overcome: 1) higher capital cost per vehicle, 2) need for investments in a separate fueling infrastructure, and 3) less than half the well-to-wheel efficiency compared to battery electric vehicles. These disadvantages are the reasons for why the focus of this report is on battery electric vehicles.
)
Antagligen!
