The real news here is a seriously large aircraft engine maker is looking at electric motors, albeit small motors as yet. Nevertheless RR is spending money on electricity solutions and development will follow.

The 2011 Nissan Leaf lithium batteries had an energy density of 90 Wh/kg. Now that's about 150 Wh/kg; or, a 55% increase in 10 years. Battery technology is advancing, albeit slowly. Hopefully, some company will double that production metric soon so we can start ridding the Earth of The Hundred Year Fossil Fuel Scourge.

The U.S. OEMs will switch to clean cars when they can't make their Wall Street numbers selling gassers.

The good thing about a hydrogen bus is it is after all an electric bus that uses a fuel cell generator instead of a battery pack. Not that difficult to replace the fuel cell later if the hydrogen doesn't work out. However, money and clean energy transition time will be wasted as the oil and gas companies, push to extend their profits by sell hydrogen made from a gross polluting fossil fuel reforming process.

After driving an BEV for 10 years with no costs other than state fees, utility company electrons for fuel, and replacing three sub-quality lead acid battery for maintenance, I'm sold on BEVs and wonder why one would pay the extra costs associated with driving a complicated PHEV. Unless you like visiting the great guys for maintenance at the dealership and hunting for the best price and pumping gas at the local gas stations. Or perhaps it's because one is a victim of habit and feels more secure shelling out ducats for inspections and receiving ongoing announcements of operational well being.

I find it interesting that wind energy is being built out over the oceans; but, little progress has been achieved advancing wave power...perhaps I don't understand the problems to be solved other than corrosion(ha).

Doesn't matter what you call it or if you make it from garbage or oil when carbon burns in a jet engine it pollutes grossly. I would like to see some progress in burning hydrogen in jets...then, you can call it clean and not lie.

There's little good to be found in coal mining except providing jobs...I would like to see a quick phase out of coal; but, with the creation of new clean energy industries and retraining for the workers.

A long way to go; but, a beginning. The difficult problem is launching an aircraft to altitude without great amounts of pollution, This may require jet engines burning hydrogen then using ducted fans for cruising,

2050? Not soon enough: https://www.youtube.com/watch?v=KjRDUlkEbu4&feature=emb_logo

Good example of 'Greenwashing.' By using the term 'Clean Tech' when there is nothing clean about an internal combustion engine, especially a 7 liter internal combustion engine. Every ICE bus they buy today will be around for decades puking out pollution and poisoning children on every run.

LFP batteries are a good drop in solution to replace the toxic lead acid starter batteries for internal combustion engines, Many race cars teams have used them for years because they have a much higher power density, are 50% lighter and are more reliable. I have used one for 5 years now in my riding lawn mower and it starts every time. Pricewise, LFP is now about at parity with L/A and hopefully as more are produced, LFP batteries will cost less.

sd: Agree. However, reality is the fossil fuel industry owns too many of our politicians and oil, gas and coal will be around for many years yet. Using reforming to create H2 until we can switch over to carbon free production will work to accelerate the amount of H2 we need to develop and to prove it's use as a CO2 free jet fuel.

Currently H2 doesn't work well in jet engines; developing H2 as a jet fuel instead of JP-X could lead to less upper atmosphere pollution and GHGs.

After driving a Nissan Leaf for the last 9 years; I bought another b/c once you drive EVs you will never go back to obsolete ICE cars...traction batteries have advanced to the point that internal combustion engine no longer makes sense for personal transportation.

Same old story; successful applications will depend on battery tech advancements to translate to economic gain. And, once implemented, economic savings and viability should multiply with each battery tech upgrade.

Scientists at MIT believe that to make commercial electric aircraft viable using batteries will take an energy density of about 1,500 Wh/kg; todays common energy density runs about 300Wh/kg which leaves the door wide open for H2 in this transportation segment.

The only reason it's a parity is the ongoing taxpayer direct subsidies of approximately 16 billion a year. Without this boost, U.S. drivers couldn't afford to drive their ICE cars.

Don't believe all you hear about H2: https://cleantechnica.com/2020/12/18/big-oil-is-fueling-the-hydrogen-rush/

@Davemart: I believe that the H2 will more likely be generated by reforming when there are oil companies involved, especially when using fossil fuel assets, i.e., gas pipelines, Also, I would greatly appreciate your points be made without the personal attacking. That way information can continued to be intelligently exchanged on a high level.

I don't see H2 as practical for ground transportation; however, the knowledge gained from real world usage in cars and trucks might help bring fuel cell powered electric aircraft and sea ships to market sooner.

So, the idea is to use energy to reform and compress natural gas into hydrogen and then mix it with natural gas and use the existing natural gas pipelines for distribution; then use electrical energy to separate the hydrogen back out. Looks as if the oil companies are pulling out all the stops to bring H2 to market.

So, serious aircraft FC development begins; very encouraging!

Why would one chose this complicated diesel with all the operation and maintenance headaches over the more simple VW BEV? After driving an EV for the past 10 years, I dismiss all ideas about buying any internal explosive engine vehicle.

Great! No more unhealthy diesel smoke!