Renewable resources

21 June 2012

The magic word that promises to facilitate energy transition is "renewable resources". They seem like the perfect solution: environmentally neutral, versatile, and constantly replenishing themselves. But are they really a panacea? Dr. Ralf Omlor, custodian of the Botanic Garden at Johannes Gutenberg University Mainz (JGU), is using the occasion of the "Renewable Resources – Plants, Products, Perspectives" Week to put his case that we need to take a more critical approach to this complex aspect.

At present, the oil palm is only extending tiny fronds into the warm, humid air of the greenhouse, but in next to no time it will be unrecognizable. "In three, four years it will reach as far as the ceiling," says Dr. Ralf Omlor. "By then it will be bearing its first fruits." Each fruit will weigh 30 to 40 kilograms, as this palm is one of humanity's most efficient crop plants.

"We have placed the oil palm at the focus of our newly designed greenhouse for tropical economic plants," states the custodian of the Botanic Garden, "since it most clearly represents the conflict between human needs and ecological impact."

Controversial palm oil

The palm is thus the perfect emblem for the "Renewable Resources – Plants, Products, Perspectives" Week that is being hosted by botanic gardens all over Germany. In Mainz, displays on the beds will be providing information about this all important subject into September, while Omlor and his colleagues will be offering related guided tours. In addition, each crop plant has been labeled with a QR code so that visitors to the greenhouse can scan these to obtain the corresponding information.

But, let’s return for the moment to the oil palm. "Cheap palm oil killing orangutans," screams a Greenpeace headline. Omlor is aware of the fatal connection. "Large concerns are clearing tropical rain forests and replacing them with palm oil plantations." This process is resulting in the rapid depletion of the large hominid’s habitat in Malaysia and Indonesia.

The incredible oil palm

"On the other hand, oil palms are the most efficient oil plants in the world. Their yield is five times that of the oilseed rape plant." In addition, the oil extracted from the fibrous flesh is of a very high quality: "Just one tablespoonful is enough to meet a person's daily vitamin A and E requirements." The plant is thus a vital source of food and an important economic factor in the regions where it is grown.

"So we can't simply preach to people and tell them not to plant it. And anyway, it's us, the people who also want to use the oil plants, who are the real problem." The global demand for palm oil and palm fat derived from its fruit is enormous. "Every day we use palm oil," Omlor explains. "It is used in soaps, detergents, chocolate, and ice cream." Palm oil is present in almost everything that includes vegetable fats in its list of ingredients and it even plays an important role in the production of biodiesel.

Diverse renewable resources

"When it comes to plant usage, it is seldom possible to make a clear judgment for or against, there is no good or bad," emphasizes Omlor. He sees it as his job to identify the various aspects and tell visitors to the Botanic Garden about them.

This is particularly true when it comes to renewable resources, which are seen as the panacea when it comes to energy turnaround. "The benefits of renewable resources are many but they are not infinite," says Omlor, and goes on to ask: "What are the positive aspects and what are the more questionable ones? There are quite a few in the case of the latter."

Renewable plant resources are not used as food for humans or as feed for animals, but are employed by industry and for energy generation. "One particularly controversial aspect is the use of food plants as industrial raw materials." This applies not only to the oil palm, but also to rapeseed and maize.

Limited cultivation area

To make his case, Omlor begins to quote statistics: "Germany has more than 12 million hectares of agricultural land. From 1998 to 2011, the proportion of this used to grow renewable resources expanded from 400,000 hectares to 2.3 million hectares." Land used to grow oil plants for biodiesel tops the list (900,000 hectares), followed by plants for biogas (800,000 hectares) and for industrial usage (300,000 hectares). "However, the area of land used for agriculture is shrinking rather than expanding."

So supplies are not unlimited. Germany is only able to produce one to two percent of the bioethanol for super petrol. However, the E 10 vehicle fuel launched last year in Germany has a specified content of ten percent ethanol. So, to make up for the shortfall, ethanol has to be imported. This has consequences. "The economic, social, and ecological effects are closely intertwined," says Omlor. The problem is not merely the threat to the rain forests. In Latin America, people are taking to the streets because of the high maize prices – the demand for bioethanol is making maize unaffordable as a foodstuff.

Trash is treasured

Plants have an unbelievable range of uses. Omlor touches on some of the possibilities on a tour through the newly finished greenhouse. Almost every household has a product made from fibers of a relative of the banana, the abacá, although very few are aware of this. In the past, abacá fibers were used to make ropes for ships as they remain tear-resistant even when wet. Nowadays this characteristic is used in a completely different product: the tear-proof teabag, which means abacá is present in every teabag in the world.

And new opportunities can suddenly open up completely unexpectedly – for example, 1.6 billion tonnes of sugar cane are harvested every year. Once the sugar has been pressed from the cane, a lot of waste material is left; this is the fibrous material known as bagasse. "Disposable dishes made from this bagasse are a huge hit in China."

Nothing grows for ever

Potatoes are now being used on a small scale for the production of plastics in Germany, but there is again a conflict of interests when it comes to their use for this purpose. But the use of sugar cane waste is a completely different matter: "I think the use of this waste as a raw material to make products in China makes sense," concludes Omlor.

Omlor and his colleagues at the Botanic Garden on the JGU campus offer background information that provides a new slant on ideological and political buzzwords. The custodian sees this as an important duty, particularly in the current climate. "People get the impression that renewable resources always grow back," he warns. "However, we will not have them unrestrictedly."

As far as Omlor is concerned, the least complex advice is always the most useful: "Cut down our consumption."