1. Biofuels are a substitute for oil. Wind and solar energy are not a substitute for oil.
Biodiesel has some major advantages over solar energy. Biofuel is stored solar energy, just like oil. From an energy perspective, the main difference between biofuel and oil is that oil has a higher energy density and a higher EROI (Energy Return on Energy Invested). Energy return on investment basically determines how much energy we put into getting an energy source and how much we get out. Ideally, the energy source we are aiming for has a high calorific value. This makes oil much more suitable as an energy source because the calorific value of a fuel determines its usefulness as an energy source. It is also the fact that oil can be easily converted into other energy sources and retains its calorific value over time.
Just as oil is biogenic in origin, so is biofuel. At least that is the conventional theory of how oil was formed over millions of years. The main difference is that oil, unlike biofuel, was accumulated over millions of years as energy-rich matter. In comparison, biodiesel, unlike sweet crude oil, must be processed. This is indeed an energy-intensive process. Biofuels consist of long-chain fatty acids. Through a process called transsequestration, we can produce diesel from these fatty acids. We obtain a fuel that is more resistant to cold and can be burned more efficiently. The combustion process is more odorless. The fuel is converted more effectively than vegetable oil. This also explains why bioethanol can be used to power cars. Let’s compare this to another fuel source. If we convert oil from plastics and use plastics as a fuel source, we already have a petroleum-based product as a feedstock. This can simplify the process. Recycled plastics still need to be processed and chemically digested.
Both biofuel and petroleum are unique because they are plant-based, in liquid form, and have a high energy density. There are very few energy sources that are in liquid form and sport a high calorific value. Besides petroleum, liquefied coal, and biofuels, LNG is the only significant source (to our knowledge) that we can use commercially. According to the Gas Exporting Countries Forum (2021), natural gas can be liquefied to a temperature slightly below -160°C. To achieve this state, some technical steps are required. Cooling natural gas is also very energy-intensive. This puts biofuels and petroleum in a separate category from other renewable or non-renewable energy sources. Solar and wind energy or electricity do not exist in liquid form. Liquid hydrogen would hardly be an alternative because it requires much lower temperatures for cooling than even LNG. The process would involve higher energy losses.
2. Electricity finds the path of least resistance.
Energy losses from solar and wind power are ubiquitous. The losses occur here and there, and from time to time. They accumulate because we have no intermediate storage. We either have too little power or too much power. Because of the fluctuating supply of electricity, the European power grid suffers from grid imbalances. Then fossil fuels and nuclear power have to step in to fill the gap. The government has decided to limit and eventually phase out their use. But that doesn’t solve the main problem we have, which is the lack of long-term storage for excess power. An efficient energy storage system would allow us to store wind energy for later use.
We could store surplus electricity underground. We can do this in salt ponds or brine underground. Former salt mines are best suited for this. There may be other solutions as well. We could use pumped storage power plants, of which there are not many. We need to transport electricity from offshore wind farms in northern Germany to the south of the country. In the south are most of the pumped storage power plants. But that’s an ineffective way to store electricity because of friction losses. Another hurdle is the connectivity of the European power grid. Excess electricity can strain the grid in the Netherlands and Benelux countries. Electricity can flow unimpeded and potentially reach Germany’s neighbors before it reaches southern Germany.
Transporting electricity from north to south would consume a lot of energy. How can we compensate for these losses? By growing to higher altitudes. Wind energy can be generated more easily at higher altitudes. Of course, that brings higher capital costs to build those wind turbines. Grid integration costs increase depending on how many wind turbines are built at a given site. It is not always clear who will bear the cost of grid integration of wind turbines. There is a tug of war, so to speak, between the grid operator and the wind farm operator.
Larger width and length of turbine blades enables higher kWh production. When the wind blows very strongly, a lot of electricity is fed into the grid. This can throw the grid out of balance. It can even cause blackouts if we can’t compensate for the losses. Electricity seeks the path of least resistance. In this case, the electricity is routed to other countries outside Germany. But what happens if these countries have also generated a surplus of electricity from wind power?
Biofuels have none of these problems. They are well suited as energy storage. They do not have to be converted into other forms of energy and can be used immediately. Nor is their use limited to electricity consumption. Their use goes far beyond what solar and wind energy can provide, and biofuels are a complement to wind and solar energy. Biofuels are also a nice addition to the refinery business. Almost any location within Germany that already has downstream business activities and oil refineries can benefit from biofuel production.
3. We can build a resilient energy system and ignite the individual strengths of each energy source.
The most important goal for us should be to achieve the continuous availability of energy for the population. This should be done in the most environmentally friendly way possible. We should be able to produce energy at the lowest possible price per kWh. The further we move away from energy-rich hydrocarbon energy sources, the more difficult it will be for us to combine all these aspects. With respect to the continued use of fossil fuels, the most important environmental goal is likely to be that oil consumption releases less CO2 into the atmosphere.
This CO2 can be captured and used by the chemical industry or in agriculture. The CO2 can be used in greenhouses. Plants thrive, grow faster and contain more nutrients when they grow in a CO2-enriched environment. In a greenhouse, we use the captured CO2 in a closed system. We achieve something magical. We grow food to feed the population. In this way, we create a cohesive agriculture-energy-water cycle that benefits everyone. The main problem is that carbon capture in itself is an energy-intensive process that significantly reduces EROI (Energy Return-on-Energy-Invested). This undermines the availability of energy and increases the energy cost per kWh.
We need to combine different energy technologies and include not only renewables but also nuclear power and hydrocarbons. Renewables alone will not get us where we want to go. We still need to rely on other energy sources with a much higher energy return on investment (EROI). We rely on solar energy to increase renewable energy production. But both solar and wind energy are dependent on the weather. This is especially true in Europe, which has fewer hours of sunshine in the winter. The weather is mostly cloudy, with significant cloud cover. But biofuels can be stored in the summer and used in the winter. They are still a renewable energy source and a substitute for oil. Biofuels are not dependent on specific weather phenomena, but they are dependent on seasonal variations and fluctuations.
This article focused on wind energy and biofuels. This is because solar energy has a much lower EROI (Energy Return-on-Energy-Invested) in Europe. This is not to say that solar energy has no role in our future energy mix. Europe needs a broad mix of energy sources to ensure energy security. But wind energy is the main force behind the growth in renewables we are seeing in Europe. Prices per kWh for wind energy have gradually fallen. They are almost on par with solar energy.
However, the potential output of wind turbines is much higher than the output of solar energy in the North Sea region. Biofuels compensate for the weaknesses of wind and solar. They are less dependent on weather and less vulnerable to weather events. This minimizes potential short circuits in the power grid.
Gas Exporting Countries Forum (2021), LNG/GTL, Liquefied Natural Gas and Gas to Liquids, available at: Liquefied Natural Gas and Gas to Liquids | GECF.