The Problem with Renewable Energy Systems…

Renewable energy systems are certainly the way forward globally- they are much cleaner alternatives to petroleum, coal, oil shale and other fossil fuels, and as their name implies, they won’t run out since they are capable of being replenished. However, the big gloomy “but” is this: renewable energy systems (solar, wind, tidal, bioenergy) are irregular. For example, wind energy's frequency and speed is dependent on several factors including the nature of the location (e.g.‘roughness’ factors- the presence of buildings or trees affects wind turbulence), rotation of the earth (Coriolis effect). Furthermore, the ongoing debate of ‘cassava/corn/sugar cane for belle (stomach) or cassava/corn/sugar cane for moto (automobile)?’ has made the concept of generating electricity from biomass a lot less attractive.Basically, the world is in a tight spot- keep using fossil fuels and watch carbon dioxide emissions climb beyond 390 ppm, leading to more trapped heat within our immediate atmosphere, leading to increased drought in some parts of the world, increased flooding in other parts, leading to starvation and death. On the other hand, implement bioenergy systems on a global scale and watch the price of garri* rise to ridiculous amounts as farmers hurry to farm the good stuff that will fetch them more money than they possibly thought… I can already imagine an edition of Inside Africa which covers it:

“…this week our very own Janet Doe brings you exclusive footage of one of the major exporters of cassava, the crop that literally saved our planet from destruction. Janet, over to you.” Janet then proceeds to tell all about the successful cultivation of cassava at Ibadan, Oyo State Nigeria, with impressive shots of vast, green cassava plantations and heavy-duty machinery busy at work harvesting ripe crops. Cut to the distinguished owner of the plantation, a Mr. Oluwallahchukwu who smiles to the camera and responds to Janet’s refined congratulations: “A marvellous accomplishment, Mr. Oluwallahchukwu. So tell me, how did you manage it? How do you balance the food needs of your country folk with global energy needs?” Mr. Oluwallahchukwu smiles a wizened but pained smile as he replies, “my daughter, the needs of the many overtake the needs of the few...”

Yes, bioenergy systems are a very touchy subject at the moment. This is why researchers are considering other options such as hydrogen economies and renewable urea—that is, energy systems run by sustainably produced hydrogen and possibly urea, which are more stable than the previously mentioned renewable energy systems and do not compete with food. This does not mean that research is veering away from bioenergy, solar, wind and tidal energy systems (not at all!), but it is in our best interest to explore all options. You might have heard about energy crops like miscanthus and willow which are under a great deal of research, as is municipal solid waste matter such as old tyres, waste cooking oil, forestry residue and others. Geothermal energy is also looking good (this is the subject of discussion in June’s edition of The Chemical Engineer (IChemE).
So what do you think- which renewable energy system could make a significant contribution to our growing energy demands? 

*Garri is grated, dried cassava which forms a major part of the diet in African countries like Nigeria.

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