# Developments in Electric and Green Marine Ships
## 5 Qualitative Assessment of a Battery-Powered Maritime Industry  
The quantitative analysis above along with the state-of-the-art technologies show that a battery system propulsion is technically feasible. However, when it comes to commercial technologies that could disrupt an entire sector through bringing significant changes to it, technical feasibility is just a necessary precondition. Having reassured that, the most decisive factor is the economic viability of the technological solution at hand. The constantly growing market of batteries is surely coming along with huge costs. The very nature of batteries, the required raw material, the technology, and the manufacturing process are still considered affordable but relatively expensive. Nevertheless, recent technological developments and the market growth are driving these costs down, and as a result, batteries, along with renewable energy sources (RES) such as solar, wind etc., are becoming cheaper [73; 74; 75]. Despite the falling costs of batteries, the alternatives remain cheaper and hence more competitive. In addition, the maritime sector does have specific characteristics that affect the feasibility of different power sources. Starting with the high power output requirement as a result of a vessel's power needs, which are high compared to those of other electric vehicles such as bikes, scooters, or cars. Such power output requirements tend to be cheaper and more easily achieved by fuels instead of batteries, since the first have bigger energy density (MWh/kg fuel). However, the situation is more complex. As far as the concern is on reducing emissions, it is clear that in the maritime sector, alternative fuels might have an advantage. Yet, reducing emissions is not the long-term goal, but a short-term transitional stage toward zero emissions. Important players of the maritime industry such as the UK do already plan ahead for a zero-emission maritime industry by considering optimistic forecasts and imposing strict regulations. The latter cannot be achieved by fuels such as LNG, LPG, etc., or alternative fuels such as hydrogen, ammonia, or methanol, because although they do reduce the emissions, they still cannot reach absolute zero, apart from hydrogen, which could in the future become a totally zero-emission fuel. The only fuels that could still be in accordance with the upcoming regulation about zero emissions shipping would be bio-fuels. Even though these, similar to other fuels, do produce emissions when burnt, these emissions do not burden the atmosphere with additional CO\({}_{2}\) because they come from the atmosphere in the first place. Bio-fuels come from biomass that contains CO\({}_{2}\) captured by the plants through photosynthesis. In the short-term to mid-term future of the maritime industry, there exists a high possibility scenario of an emerging competition between batteries and bio-fuels. Both alternatives come with advantages and disadvantages, and it is worth mentioning the most important among them. Starting from the batteries, the continuous growth of the electrification of our society along with the growing penetration of RES into the energy mix facilitates the further penetration of batteries. Among the latest trends in the energy sector are smart grids, where RES play a significant role, and along with digitalization and distributed grids, require large-capacity, trustworthy storage battery systems, mostly for energy security reasons. The downside is that while electrification and RES both face growth, inevitably the same happens with electric energy demand. Incorporating batteries as the exclusive means of marine propulsion would dramatically increase the electricity demand, affecting the whole energy sector. Forecasts do provide some valuable insight, stating a possible increase in electricity demand around 1150.0% in a scenario where batteries will not become the main propulsion of the maritime industry, and an increase of 15,400.0% [76]. Satisfying such a demand is uncertain, and if possible, would require significant changes.