Energy tech to watch

1. LOW-CARBON COOKER

Three bil­lion peo­ple around the world cook on an open fire or use “dirty”, unhealthy fuel and, accord­ing to the World Health Orga­ni­za­tion, about four mil­lion peo­ple die from indoor cook­ing smoke every year. African Clean Ener­gy (ACE) was found­ed to come up with a solu­tion to this prob­lem and its answer was the ACE 1 Ultra-Clean Bio­mass Cook­stove.

This uses gasi­fi­ca­tion to burn almost any type of bio­mass – wood blocks, wood chips, sticks, cow dung, corn cobs and oth­er sim­i­lar agri­cul­tur­al residues – smoke­less­ly. ACE claims the stove, which has a com­bus­tion cham­ber made of refrac­to­ry ceram­ic tiles, reduces fuel use by 70 per cent, cuts fuel costs by about 50 per cent and almost com­plete­ly elim­i­nates black car­bon emis­sions. The stove’s ceram­ic base has a bat­tery in it to pow­er the unit’s fan, as well as charge mobile phones and run LED lights through the inbuilt USB port and DC con­nec­tor.

2. FLYING WIND TURBINE

Wind tur­bines are con­tro­ver­sial. Whether they are off­shore or onshore, peo­ple tend to love them or hate them. But imag­ine if they were deployed high up in the sky, almost out of sight. The Altaeros Buoy­ant Air­borne Tur­bine (BAT) is raised into the sky on a teth­er, where it har­ness­es more pow­er­ful high-alti­tude winds. A heli­um-filled shell allows it to lift into the air and sta­bilise; inside is a light­weight con­ven­tion­al three-blade, hor­i­zon­tal axis wind tur­bine.

The advan­tage of tap­ping into these high-alti­tude winds is that they are more con­sis­tent and aver­age around twice the veloc­i­ty, with five to eight times the pow­er den­si­ty, than those found near ground lev­el. Because the tech­nol­o­gy can be deployed almost any­where, it can reduce the cost of gen­er­at­ing renew­able ener­gy in remote com­mu­ni­ties and at remote indus­tri­al sites. A portable ground sta­tion can be put into posi­tion from a ship­ping con­tain­er and includes an autonomous con­trol sys­tem.

3. ENERGY FROM SEAWEED

The Euro­pean EnAl­gae project, led by Swansea Uni­ver­si­ty, is test­ing a num­ber of tech­niques to grow sea­weed. Why sea­weed? Macroal­gae (sea­weed) have a high car­bo­hy­drate con­tent, which means they can be used to gen­er­ate bio­gas through anaer­o­bic diges­tion. The grow­ing tech­niques tri­aled so far include using com­bi­na­tions of long­lines (ropes), grids and tex­tiles. These are first “seed­ed” with young sea­weed gama­phytes grown in on-shore hatch­eries and then placed off­shore.

The length of time they are left to grow depends on the species, but it’s usu­al­ly months to a year before it is har­vest­ed by hand or by using barges. As well as ener­gy, a viable sea­weed indus­try has oth­er advan­tages, includ­ing alter­na­tive boat work for fish­er­men, addi­tion­al habi­tat for marine life and, when sea­weed is grown next to com­mer­cial fish farms, it grows faster, indi­cat­ing it can absorb the excess nutri­ents from the fish-farm­ing process.

4. HEATING AND COOLING WITH SEWAGE

Sewage is a great ener­gy resource. That’s the view of Huber, which uses spe­cial heat exchang­ers and heat pumps so waste­water can heat or cool build­ings above ground. Munic­i­pal sewage con­tains ther­mal ener­gy ¬– its tem­per­a­ture is usu­al­ly between 10 and 20C all year. Huber takes sewage from the sew­er, screens it, pumps it through spe­cial heat exchang­ers and then returns it back into the sew­er. The heat exchang­ers can either add this heat to the building’s own heat­ing sys­tems or take excess heat away from the build­ing, there­by help­ing to cool it.

The poten­tial is sub­stan­tial. Accord­ing to Huber’s own analy­sis, waste­water flow­ing under New York, Los Ange­les and Munich could pro­vide between 15 and 50 per cent of the ener­gy need­ed by com­mer­cial build­ings; in most oth­er cities the fig­ure is between 30 and 35 per cent. The tech­nol­o­gy is cur­rent­ly being used in 400 to 500 instal­la­tions across the world.

5. MAKING FUELS FROM THIN AIR

Sci­en­tists at Bath University’s Cen­tre for Sus­tain­able Chem­i­cal Tech­nol­o­gy are devel­op­ing a new cat­a­lyst pow­der, based on iron nanopar­ti­cles and car­bon nan­otubes, which can con­vert the green­house gas car­bon diox­ide from indus­tri­al flue gas into fuels and oth­er indus­tri­al­ly use­ful chem­i­cals. The tech­nol­o­gy pro­vides an eco­nom­ic incen­tive to large car­bon emit­ters to invest in expen­sive cap­ture equip­ment, reduc­ing indus­tri­al car­bon emis­sions and help­ing make a sig­nif­i­cant impact on cli­mate change.

The process can be tuned to pro­duce hydro­car­bons of choice with high selec­tiv­i­ty, includ­ing short-chain olefins, which are wide­ly used in indus­try as feed­stock to pro­duce chem­i­cals, and longer-chain hydro­car­bons that can be used as fuel com­po­nents in the place of fos­sil fuels. These could be used to run vehi­cles, for instance. Researchers hope to use waste heat from pow­er plants to dri­ve the process, cre­at­ing a car­bon-neu­tral method of mak­ing fuels.

1. LOW-CARBON COOKER

2. FLYING WIND TURBINE