The hy­dro­gen econ­omy is tricky

Weekend Argus (Saturday Edition) - - COMMENT -

I DON’T un­der­stand Siegfried Berger’s ref­er­ence to har­vest­ing hy­dro­gen from the oceans, grav­ity and sun­light. (“Why do we ig­nore hy­dro­gen power”, Week­end Ar­gus, De­cem­ber 17).

Pro­duc­ing hy­dro­gen elec­trolyt­i­cally is a highly en­ergy-con­sum­ing process. It re­quires about five times as much en­ergy than can be ob­tained from a hy­dro­gen cell. Large so­lar plants could be con­structed to pro­duce the elec­tric­ity, on the ba­sis that sun power is free, but so­lar in­stal­la­tions aren’t free – they re­quire land and have to be main­tained; and there’s the mat­ter of safely trans­port­ing vast quan­ti­ties of com­pressed hy­dro­gen.

A chem­i­cal process can be used to pro­duce hy­dro­gen which only re­quires about twice the en­ergy that can be ob­tained from a hy­dro­gen cell – a con­sid­er­ably more eco­nom­i­cally vi­able propo­si­tion. But the process re­quires a tem­per­a­ture of around 1 000ºc. Us­ing coal or gas to get that tem­per­a­ture is out of the ques­tion.

A Peb­ble Bed Mod­u­lar Re­ac­tor (PBMR) would be one source of such heat, that be­ing its nor­mal op­er­at­ing tem­per­a­ture. An­other re­ac­tor which uses the transuranic nu­clides that re­main in used PWR fuel el­e­ments is the In­te­gral Fast (breeder) Re­ac­tor ( IFR) which op­er­ates at around 1 000ºc. While the PBMR is in limbo, four coun­tries have IFR de­signs in hand and/or un­der con­struc­tion – France, Rus­sia, China and Ja­pan.

Is South Africa ever likely to re­sus­ci­tate its PBMR project? Will it se­ri­ously con­sider an IFR in its nu­clear mix? I don’t know.

Although I agree about what is of­ten re­ferred to as the “hy­dro­gen econ­omy”, es­pe­cially for driv­ing mo­tor ve­hi­cles, the prac­ti­cal­ity of achiev­ing it would ap­pear to be a rather dis­tant ob­jec­tive.

Only when peo­ple en masse agree that the use of coal and gas must com­pletely cease is a change likely to oc­cur. And de­spite meet­ings such as the COP17, who is cam­paign­ing to get rid of our coal and gas-fired power sta­tions? Es­pe­cially when Eskom will soon have one of the largest out­put coal-fired power sta­tions in the world at around 4 GW?

How many or­gan­i­sa­tions are look­ing at hy­dro­gen-pro­pelled mo­tor ve­hi­cle de­signs? We can cyn­i­cally be­lieve that the petro­chem­i­cal con­glom­er­ates are re­sist­ing such de­vel­op­ments, but they aren’t im­mune from pub­lic opinion.

Who is go­ing to emerge from the wings with the power and in­flu­ence to con­vince peo­ple of the ne­ces­sity for the hy­dro­gen econ­omy?

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