Weird Science

Energy – How to Store It?

Polish ver­sion is here

The fol­lo­wing article was ori­gi­nally publi­shed in the quar­terly Eko­lo­gia (3/2024):

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Ples M., Ener­gia - jak ją maga­zy­no­wać? (eng. Energy – How to Store It?), Eko­lo­gia (eng. Eco­logy), Polish Cham­ber of Eco­logy, 3 (2024), pp. 33–34

Intro­duc­tion

Elec­tri­city sto­rage is one of the most impor­tant chal­len­ges in modern energy, espe­cially in light of the dyna­mic deve­lop­ment of rene­wa­ble energy sour­ces, such as solar and wind energy. This chal­lenge ari­ses from the insta­bi­lity of energy pro­duc­tion, which depends on chan­ging wea­ther con­di­tions. Sta­bi­li­zing the energy sys­tem, redu­cing reliance on fos­sil fuels, and cut­ting CO2 emis­sions are goals that drive efforts to find new, effec­tive energy sto­rage tech­no­lo­gies.

Howe­ver, the deve­lop­ment of energy sto­rage tech­no­lo­gies is not limi­ted to sta­bi­li­zing the use of rene­wa­ble energy. Over time, it has also become a key ele­ment for the elec­tri­fi­ca­tion of tran­s­port, espe­cially in the con­text of the gro­wing num­ber of elec­tric vehic­les. These vehic­les requ­ire incre­a­sin­gly effi­cient, safe, and high-capa­city bat­te­ries. The­re­fore, energy sto­rage impacts not only the energy indu­stry but also the tran­s­por­ta­tion sec­tor, heavy indu­stry, and, indi­rec­tly, even the hou­sing sec­tor.

The history of energy sto­rage tech­no­logy, espe­cially bat­te­ries, dates back deca­des, from sim­ple, tra­di­tio­nal lead-acid cells to today’s widely used lithium-ion bat­te­ries and simi­lar types. Chal­len­ges asso­cia­ted with pro­duc­tion costs, limi­ted ava­i­la­bi­lity of raw mate­rials, and recyc­ling dif­fi­cul­ties are promp­ting the search for alter­na­tive solu­tions.

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Image: sup­ple­men­tary mate­rial

Among these alter­na­ti­ves, fuel cells, par­ti­cu­larly hydro­gen ones, are begin­ning to play a signi­fi­cant role. Altho­ugh their deve­lop­ment faces cer­tain obstac­les, such as high pro­duc­tion costs (inc­lu­ding the use of pla­ti­num and other rare metals as cata­ly­sts), they offer pro­mi­sing pro­spects, par­ti­cu­larly in heavy and indu­strial tran­s­port. More­o­ver, other inno­va­tive con­cepts are emer­ging, which may domi­nate the mar­ket in the future. Over the years, I will intro­duce some of them.

Modern Energy Sto­rage Tech­no­lo­gies

Advan­ces in energy sto­rage rely on the deve­lop­ment of new, advan­ced tech­no­lo­gies that improve effi­ciency, safety, and energy ava­i­la­bi­lity across various sec­tors. A variety of sto­rage methods are cur­ren­tly used, each with uni­que advan­ta­ges and limi­ta­tions.

Lithium-Ion Bat­te­ries

Lithium-ion bat­te­ries are among the most widely used energy sto­rage tech­no­lo­gies for por­ta­ble devi­ces, elec­tric vehic­les, and energy sys­tems. Their popu­la­rity is due to their high energy den­sity, long life, and fast char­ging. Despite many advan­ta­ges, this tech­no­logy also has its limi­ta­tions. Raw mate­rials used in pro­duc­tion, such as lithium and cobalt, are expen­sive and scarce. Addi­tio­nally, the recyc­ling pro­cess for these bat­te­ries is com­pli­ca­ted and costly, rai­sing envi­ron­men­tal con­cerns.

Sodium-Ion Bat­te­ries

An alter­na­tive to lithium-ion tech­no­logy is sodium-ion bat­te­ries, which use sodium instead of lithium. Sodium is much more abun­dant (mainly in bound form, such as sodium chlo­ride NaCl), making the pro­duc­tion cost of these bat­te­ries lower. Altho­ugh their energy den­sity is also lower, their sca­la­bi­lity and redu­ced pro­duc­tion costs may make them a future solu­tion, espe­cially for sta­tio­nary appli­ca­tions.

Flow Bat­te­ries

Flow bat­te­ries have an unu­sual design: their elec­tro­des are in the form of a suspen­sion in a solu­tion. This tech­no­logy is sca­la­ble and is used in large instal­la­tions, such as sto­ring energy from wind and solar farms. Altho­ugh flow bat­te­ries are cha­rac­te­ri­zed by a lon­ger life­span and easier sca­la­bi­lity, their com­pli­ca­ted infra­struc­ture and lower energy den­sity pre­sent chal­len­ges that may limit their wider deploy­ment.

Solid-State Bat­te­ries

These bat­te­ries eli­mi­nate the need for liquid elec­tro­ly­tes, incre­a­sing their safety and sta­bi­lity. They offer higher capa­city and faster char­ging com­pa­red to lithium-ion bat­te­ries. Cur­ren­tly, this tech­no­logy is still in the early sta­ges of deve­lop­ment, but it has the poten­tial to domi­nate the mar­ket in the future, espe­cially in elec­tric tran­s­port, where safety and bat­tery lon­ge­vity are cru­cial.

Fuel Cells

Fuel cells, espe­cially hydro­gen ones, are ano­ther pro­mi­sing solu­tion in the energy sto­rage mar­ket. Their ope­ra­tion is based on the direct che­mi­cal conver­sion of hydro­gen and oxy­gen into elec­tri­city, with water being the only by-pro­duct. These cells have poten­tial appli­ca­tions in tran­s­port as well as in large energy instal­la­tions, tho­ugh their imple­men­ta­tion is cur­ren­tly limi­ted by high pro­duc­tion costs and a lack of infra­struc­ture for hydro­gen sto­rage and tran­s­por­ta­tion.

Com­pres­sed Air Energy Sto­rage (CAES)

Com­pres­sed Air Energy Sto­rage (CAES) invo­lves com­pres­sing air during periods of sur­plus energy and then rele­a­sing it when nee­ded to power tur­bi­nes that gene­rate elec­tri­city. While CAES effi­ciency is not as high as that of bat­te­ries, it can be a use­ful com­ple­ment to other sto­rage tech­no­lo­gies, par­ti­cu­larly for sta­bi­li­zing the power grid.

Ther­mal Energy Sto­rage (TES)

Ther­mal Energy Sto­rage (TES) tech­no­logy invo­lves sto­ring energy in the form of heat, which can later be reco­ve­red and conver­ted into elec­tri­city or other forms of energy. This energy can be sto­red by hea­ting sub­stan­ces like water, salt, or mate­rials with high ther­mal capa­city. TES is mainly used in solar power plants and buil­ding hea­ting/coo­ling sys­tems. An exam­ple is Con­cen­tra­ted Solar Power (CSP), which ena­bles the sto­rage of ther­mal energy for later use, even at night. While TES methods are tech­no­lo­gi­cally advan­ced, effi­ciency and sca­la­bi­lity remain chal­len­ges com­pa­red to other sto­rage methods, as the cost-effec­ti­ve­ness thre­shold is rea­ched only for rela­ti­vely large instal­la­tions, making minia­tu­ri­za­tion a chal­lenge.

Chal­len­ges and Limi­ta­tions of Energy Sto­rage Tech­no­lo­gies

Altho­ugh the deve­lop­ment of energy sto­rage tech­no­lo­gies cre­a­tes many oppor­tu­ni­ties, there are also signi­fi­cant chal­len­ges that must be addres­sed for these tech­no­lo­gies to sup­port a broad energy tran­s­i­tion.

Raw Mate­rial and Pro­duc­tion Costs

One of the main chal­len­ges rema­ins the cost asso­cia­ted with raw mate­rials used in the pro­duc­tion of bat­te­ries and other rever­si­ble power sour­ces. Mate­rials such as lithium, cobalt, and nic­kel have limi­ted ava­i­la­bi­lity, which incre­a­ses pro­duc­tion costs. Fur­ther­more, the extrac­tion of these mate­rials has envi­ron­men­tal con­se­qu­en­ces and invo­lves chal­len­ges rela­ted to respon­si­ble sour­cing, par­ti­cu­larly in deve­lo­ping coun­tries.

Recyc­ling and Waste Mana­ge­ment

Recyc­ling issues pre­sent ano­ther serious chal­lenge. Bat­te­ries, espe­cially lithium-ion ones, pose pro­blems regar­ding safe dispo­sal and the reco­very of raw mate­rials after their life­cycle. These pro­ces­ses are costly and com­plex, requ­i­ring the deve­lop­ment of more effi­cient recyc­ling methods and the reuse of mate­rials. Inno­va­tions in this field are essen­tial to ensure the susta­i­na­ble deve­lop­ment of energy sto­rage tech­no­lo­gies.

Effi­ciency and Sca­la­bi­lity

Each energy sto­rage tech­no­logy has limi­ta­tions regar­ding effi­ciency and sca­la­bi­lity. Lithium-ion bat­te­ries, while widely used, have limi­ted energy den­sity and life­span, which makes them less effi­cient for long-term appli­ca­tions. Other solu­tions offer gre­a­ter sca­la­bi­lity, but their energy effi­ciency often does not match that of che­mi­cal bat­te­ries. Incre­a­sing the effi­ciency of these sys­tems, redu­cing costs, and impro­ving safety remain key rese­arch goals.

Infra­struc­ture and Imple­men­ta­tion

Ano­ther chal­lenge is the lack of appro­priate infra­struc­ture to sup­port the deve­lop­ment of some energy sto­rage tech­no­lo­gies, par­ti­cu­larly hydro­gen-based fuel cells. The infra­struc­ture for hydro­gen pro­duc­tion, sto­rage, tran­s­port, and distri­bu­tion requ­i­res signi­fi­cant inve­st­ment, and its absence is a major bar­rier to the wide­spread adop­tion of this tech­no­logy. Simi­larly, the imple­men­ta­tion of tech­no­lo­gies such as CAES or TES requ­i­res spe­cia­li­zed instal­la­tions, which may be dif­fi­cult to build in cer­tain regions.

The Future of Energy Sto­rage

The pro­spects for the deve­lop­ment of energy sto­rage tech­no­lo­gies are pro­mi­sing, tho­ugh the future of this field will depend on con­ti­nued inno­va­tion, impro­ved effi­ciency, and redu­ced costs. One of the key direc­tions for deve­lop­ment will be the pur­suit of more susta­i­na­ble and acces­si­ble mate­rials, which will reduce depen­dence on rare raw mate­rials. Long-term inno­va­tions may also invo­lve new methods of sto­ring energy, such as using gra­vi­ta­tio­nal energy (sto­ring energy as poten­tial energy by lifting mass) or employ­ing nano­tech­no­logy to improve bat­tery energy den­sity. It is expec­ted that the deve­lop­ment of energy sto­rage tech­no­lo­gies will be a key fac­tor dri­ving the glo­bal energy tran­s­i­tion, ena­bling more sta­ble and susta­i­na­ble use of rene­wa­ble energy sour­ces and sup­por­ting the elec­tri­fi­ca­tion of tran­s­port and indu­stry.

Conc­lu­sion

Energy sto­rage tech­no­lo­gies are one of the key pil­lars of the future susta­i­na­ble energy sys­tem. They offer solu­tions that not only sta­bi­lize energy sup­ply but also sup­port the deve­lop­ment of elec­tro­mo­bi­lity and indu­strial trans­for­ma­tion. Chal­len­ges rela­ted to costs, recyc­ling, effi­ciency, and infra­struc­ture still requ­ire inten­sive rese­arch and inno­va­tion. Howe­ver, the poten­tial of tech­no­lo­gies such as semi­con­duc­tor bat­te­ries, flow bat­te­ries, and fuel cells may bring a revo­lu­tion in how energy is sto­red and used in the coming years.


All pho­to­gra­phs and illu­stra­tions were cre­a­ted by the author.

This text has under­gone sli­ght edi­to­rial modi­fi­ca­tions com­pa­red to the ver­sion publi­shed in the jour­nal to bet­ter suit online pre­sen­ta­tion.

Marek Ples

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