Clean energy: seizing the power of green hydrogen

The war in Ukraine has super-charged the price of nat­ur­al gas, bring­ing seri­ous chal­lenges for gov­ern­ments, busi­ness­es and indi­vid­u­als. As nations look to the future of their ener­gy sup­plies, is it time to get seri­ous about green hydro­gen? 

Green hydro­gen is pro­duced by elec­trol­y­sis, pow­ered by renew­able ener­gy. Elec­trol­y­sis breaks water down into oxy­gen and hydro­gen, which can then be used as a clean ener­gy source. What’s more, burn­ing hydro­gen pro­duces water and no oth­er emis­sions. 

The renew­able fuel source is now cheap­er than nat­ur­al gas, so it may be time to seri­ous­ly con­sid­er its role in the future ener­gy mix. For some in the ener­gy indus­try, green hydro­gen holds vast poten­tial, not just in advanc­ing the glob­al ener­gy tran­si­tion and ener­gy secu­ri­ty but also con­tribut­ing to cli­mate goals and the race to net zero. 

Big ambitions

By 2050, 12% of the world’s ener­gy needs could come from hydro­gen, accord­ing to the Inter­na­tion­al Renew­able Ener­gy Agency. Green hydro­gen has the poten­tial to rewrite the ener­gy infra­struc­ture map for the net zero age, since ener­gy pro­duc­tion could shift to those nations that have both excess low-car­bon ener­gy and invest heav­i­ly in green hydro­gen infra­struc­ture. 

“We’re see­ing a strong increase in the num­ber of glob­al hydro­gen strate­gies, many cen­tred around green hydro­gen,” explains Dr Gra­ham Coo­ley, CEO of ITM Pow­er, which makes hydro­gen tech­nol­o­gy like elec­trol­y­sers. There are pro­found impli­ca­tions for the glob­al ener­gy mar­ket, Coo­ley says.

“As we are see­ing today, weapon­is­ing ener­gy sup­ply means ener­gy secu­ri­ty for almost all nations has risen to the top of agen­das. Green hydro­gen is the only zero-car­bon ener­gy gas and can be pro­duced any­where that has renew­able pow­er resources.”  

There’s already sig­nif­i­cant inter­est in hydro­gen. Accord­ing to the Hydro­gen Coun­cil, a pri­vate sec­tor-led organ­i­sa­tion backed by many tra­di­tion­al ener­gy firms, 520 projects and more than 90GW of capac­i­ty have been ear­marked world­wide, amount­ing to $160bn in invest­ment, though this is for all forms of renew­able and low-car­bon hydro­gen, includ­ing hydro­gen cre­at­ed from fos­sil fuels with car­bon cap­ture and seques­tra­tion. Funds are being allo­cat­ed across the world, from Sau­di Ara­bia to Aus­tralia and from Japan to Ger­many.   

“We are start­ing to see off­shore and onshore wind devel­op­ers bring­ing for­ward green hydro­gen projects at scale. But these green hydro­gen sup­pli­ers need to be con­fi­dent that they have cus­tomers who will offer them a route to mar­ket,” says Clare Lavelle, ener­gy con­sul­tan­cy leader at Arup. 

A nascent industry

The hydro­gen sec­tor is still in an ear­ly stage of devel­op­ment, with lim­it­ed infra­struc­ture and chal­lenges around scaled-up deploy­ment. The upfront tech­nol­o­gy devel­op­ment and cost required is sig­nif­i­cant, as is the invest­ment in bulk plant, stor­age and dis­tri­b­u­tion, as well as relat­ed safe­ty and secu­ri­ty ele­ments. 

What’s more, pro­duc­ing green hydro­gen from water is an ener­gy-inten­sive process. Where pos­si­ble, busi­ness­es and com­mu­ni­ties are bet­ter off using the elec­tric­i­ty gen­er­at­ed from renew­ables direct­ly, whether it’s for heat­ing via heat pumps or trans­port on elec­tric vehi­cles. Using elec­tric­i­ty from renew­able sources to cre­ate and then burn hydro­gen is rough­ly 30% effi­cient. In com­par­i­son, bat­ter­ies as an ener­gy store are more than 80% effi­cient.

“More evi­dence and research is need­ed to under­stand the opti­mal net-zero ener­gy sys­tem and the bal­ance of gas and elec­trons that can deliv­er an eco­nom­ic tran­si­tion,” says Lavelle.

How­ev­er, in ener­gy-inten­sive indus­tries like chem­i­cal and steel pro­duc­tion where high-grade heat is need­ed, green hydro­gen could replace cok­ing coal to pro­vide a green­er alter­na­tive. In some trans­port sit­u­a­tions where bat­tery tech­nol­o­gy will strug­gle, such as in heavy goods vehi­cles or ship­ping, hydro­gen also comes into its own.

Hydro­gen can also be used to pro­duce ammo­nia via a well-known process called Haber-Bosch. Ammo­nia is a vital chem­i­cal used to pro­duce fer­tilis­ers, an area of con­cern while sup­plies from Ukraine and Rus­sia are in ques­tion.

Green ammo­nia can also be used as a fuel source. It’s eas­i­er to trans­port than hydro­gen and is more ener­gy inten­sive as a fuel, with the glob­al ship­ping indus­try look­ing to green ammo­nia to pow­er boats. 

“Hydro­gen is an excel­lent ener­gy vec­tor that has appli­ca­tions in a vari­ety of sec­tors and can be pro­duced when there is excess or cheap elec­tric­i­ty and stored as ammo­nia,” says Ben Saw­ford, vice pres­i­dent at KBR Glob­al Sus­tain­abil­i­ty Advi­so­ry. “It can then be utilised at anoth­er time, when demand is high and sup­ply is low. Addi­tion­al­ly, cogen­er­a­tion in nuclear pow­er plants offers mas­sive advan­tages not seen with oth­er tech­nolo­gies.” 

A question of cogeneration

What is cogen­er­a­tion? This is where excess heat, elec­tric­i­ty or oth­er forms of ener­gy are used to gen­er­ate anoth­er form of pow­er, prefer­ably one that can be stored or used imme­di­ate­ly.    

For exam­ple, typ­i­cal­ly 65% of the ener­gy gen­er­at­ed by nuclear pow­er plants is lost as waste heat, which is extreme­ly inef­fi­cient if it isn’t used. New advanced nuclear tech­nolo­gies are being devel­oped that will be able to oper­ate at sig­nif­i­cant­ly high­er tem­per­a­tures than exist­ing plants, which could be advan­ta­geous when it comes to gen­er­at­ing hydro­gen. 

“The process can utilise these high tem­per­a­tures along­side elec­trol­y­sis to pro­duce hydro­gen,” says Neil Leg­gatt, group busi­ness man­ag­er for nuclear at Fraz­er-Nash Con­sul­tan­cy. He notes that steam elec­trol­y­sis using nuclear heat and elec­tric­i­ty could pro­duce hydro­gen using 35% less elec­tric­i­ty, with an over­all effi­cien­cy of about 50%. 

Complex future

There are plans to locate hydro­gen plants next to nuclear reac­tors to pro­vide cogen­er­a­tion. There are also efforts to locate green hydro­gen plants along­side oth­er renew­ables such as wind farms, so that when excess elec­tric­i­ty is gen­er­at­ed it can be turned into anoth­er source of ener­gy. 

The com­plex­i­ty of the ener­gy tran­si­tion and future ener­gy mix demands a joined-up approach in gov­ern­ment pol­i­cy and ener­gy secu­ri­ty. A mix of low-car­bon ener­gy streams and infra­struc­ture will be need­ed to pro­vide a con­sis­tent sup­ply. Hydro­gen pro­duc­tion could ensure less ener­gy is wast­ed and help tack­le crit­i­cal, yet ener­gy-inten­sive indus­tries that have tra­di­tion­al­ly used fos­sil fuels. 

What’s more, nations with abun­dant solar or wind pow­er that pro­duce excess pow­er beyond their own demands will be able to export renew­able pow­er by ship­ping green hydro­gen or ammo­nia to where it’s need­ed.   

“Renew­able-rich nations will increas­ing­ly have the oppor­tu­ni­ty to sup­ply nations that do not meet their own ener­gy demands,” says Lavelle, point­ing to col­lab­o­ra­tion between Scot­land and Ger­many and between Japan and Aus­tralia. 

The future looks bright for green hydro­gen. How­ev­er, care­ful and con­sid­ered deploy­ment will be cru­cial if it is to be tru­ly val­ued in the future ener­gy mix.