A resilient energy system requires a large number of renewable energy sources.
The real question is: how renewable are these resources?
How renewable are biofuels?
1. C02 neutrality
The CO2 neutrality of biofuel types depends in particular on which plants and/or waste materials are used for fuel production, e.g. grass, wood residues, paper residues, household waste or plastic waste (R-PET).
Logistics and the supply chain play a crucial role in determining the actual level of carbon emissions produced. The delivery route, transhipment and means of transport all play an important role.
2. Energy conversion process
The energy conversion ratio determines whether we use a particular material to produce biofuels.
The exact energy conversion ratio is determined by 2.1.) the technology and 2.2.) the source material. For inputs: We can divide this into further individual steps that influence the decomposition process of the material, such as material decomposition, anaerobic decomposition of plant material and starch.
There is a hierarchy of materials, as not all waste inputs are generated in the same way. In particular, the calorific value and consistency of the material determines whether it is worthwhile for the plant operator to convert such a feedstock into fuel. The consistency of the material should not vary too much.
At the lower end of the hierarchy we have input materials such as sewage sludge, wood, lignocellulosic materials and at the upper levels of the hierarchy recycled plastics (PET) etc.
Plastic waste is more suitable for energy conversion than sewage sludge and wood for fuel production due to the high calorific value and consistency of the plastic material. These are just two concrete examples.
3. Cost considerations
STEP 1: First and foremost, we consider how much it costs us to produce the fuel. In waste business, a fee is paid for the disposal of the waste. Based on the market price, market structure and costs, we derive the price how much the customer has to pay for the disposal of the waste.
STEP 2: If it is a commodity, the matter becomes more complicated. In this case we have to pay a price for the material input (tons). Once we have produced the fuel, we can earn money by selling the fuel on the market
STEP 3: 3.1.We determine the price we can charge for the fuel on the market, what it would cost customers without subsidies. 3.2 We calculate the price we can charge for the fuel, taking into account the price that the customer would have to pay with subsidies. At present, biofuels with and without state subsidies will be more expensive. This means that biofuels cannot currently compete with refined oil distillates without subsidies and regulatory measures. We see this most clearly in the gap between SAF (Sustainable Aviation Fuel) and conventional kerosene in the aviation industry.
4. Innovativeness and the ability to transform innovation into a product that is marketable
In recent years, a great many solutions have come onto the market that promise us the best approach. The idea is to free ourselves from our dependence on fossil fuels. So much for the idea. Significant sums of money have gone into research on waste fuels. Most of these novel ideas reach their high waste rate before they are commercially viable. We see this most clearly in approaches to the commercialisation of algae fuel. This leaves us enough room to investigate why many new approaches have not yet gained momentum. The most likely factors were a.) funding, b.) the lack of continuous government support and c.) sales.
Biofuels must be seen in this context with all other renewable energy options currently available on the energy market. In the transport sector, biofuels compete with electric vehicles. In the chemical sector, biofuels sometimes compete with other uses and applications of biomass, such as cellulosic materials, inter alia to convert them into valuable chemical products.
5. Agricultural land is currently used to produce biofuels
We can mention two important crops that compete with biofuel production for land use. One is sugar cane, which is grown in large quantities in southern and south-eastern Brazil. In Brazil, it makes an important contribution to the energy security and energy independence of the South American country. Sugar cane is mainly used in the transport sector. Another example is the considerable production of palm oil in Indonesia. Indonesia’s palm oil production is so large that large quotas are used for global export.
In view of the fact that the world population continues to grow considerably, it seems prudent to pay particular attention to linking energy, water and agricultural resources.
To answer the question of whether biofuels are 100% renewable, we would like to rephrase the question slightly: What makes a renewable energy source really renewable?
We should be brief anc concise about what we mean when we talk about renewal. A renewable energy source is not dependent on external inputs for its continued existence. This already excludes a number of conventional renewable energy sources from the renewable energy podium.
An example of this should be wind turbines that depend heavily on rare earth metals and other minerals mined in developing countries. Their maintenance requires spare parts that are kept in stock for use. Wind turbines require constant supervision, which can only be carried out partially irrespective of location. The complexity of maintenance as carried out by human hands. At this point we have not even considered the energy loss associated with the lack of energy storage options.
With regard to photovolatic installations, we see that they are even more dependent on mineral raw materials of rare earths. This may change over the years as more advanced photovoltaic installations replace old techniques. These changes include silicon waveguides and other technological breakthroughs.