5.2.2 Adverse Weather Conditions

The main types of uncertainties in the operation of marine networks are illustrated as above. As above, how to obtain the range of uncertain variables, i.e., the probability distribution function or uncertainty set of ξ, is the basic problem of the optimization model.

Fig. 5.5 Adverse weather conditions and the two-stage adjustment

Typical Problems

Energy Management for Photovoltaic (PV) Uncertainties in AES

In the day-ahead window, i.e., in the first stage, the on/off states of the DGs and the cruise speed, which cannot immediately respond to uncertainties, are optimized based on the day-ahead forecasts PV generation. During the half-hour-ahead online operation time period, i.e., in the second phase, the load factor of the DGs and ESS is re-dispatched based on the half-hour-ahead forecasts of PV generation.

Fig. 5.11 Definition of the angle of solar ray and the tilt angle. Reprinted from [52], with permission from IEEE

Energy Management for Navigation Uncertainties in AES

The worst speed loss and the corresponding on-time rates under different θ with or without wind are shown in Fig.5.22. The reason for securing the rates on time for the proposed approach can be deduced from fig.

Fig. 5.19 On-time rates of different voyage schedules. Reprinted from [57], with permission from Elsevier

Li, J., Ou, N., Lin, G., et al.: Compression-based stochastic economic transmission with high penetration of renewables. Hu, Z., Xu, Y., Korkali, M., et al.: Uncertainty quantification in stochastic economic dispatch using Gaussian process emulation.

Energy Storage Management of Maritime Grids

Introduction to Energy Storage Technologies

Then in [4], energy storage is used to supply the energy consumption for the onboard gas collection system. Later [12,13] use energy storage to recover the energy when lowering harbor cranes.

Fig. 6.1 Primary and secondary energy [1]

Characteristics of Different Energy Storage Technologies

Classifications of Current Energy Storage Technologies
Battery
Flywheel
Ultracapacitor

In the following context, some energy storage technologies used in maritime grids are described in detail to show their applications. The main advantages of supercapacitors are higher power density, faster charging and discharging, longer life cycles compared to other energy storage technologies.

Table 6.2 Characteristics of different energy storage [14, 15]

Applications of Energy Storage in Maritime Grids .1 Roles of Energy Storage in Maritime Grids

Navigation Uncertainties and Demand Response
Renewable Energy Integration
Energy Recovery for Equipment

When integrating energy storage, the main energy source and energy storage can share the total power demand, shown in Figure 6.8b. The charging/discharging of the energy storage can balance the energy demand and ensure that the main energy source operates in a stable state, and.

Fig. 6.7 Schematic of an electric propulsion system with ultracapacitor

Typical Problems

Energy Storage Management in AES for Navigation Uncertainties
Energy Storage Management in AES for Extending Lifetime

In the time window within the journey, i.e. second phase, the navigation uncertainties are treated as realized. To analyze the effects of energy storage on the navigation uncertainties, the total battery power and SOC in the first and second stages are shown in Fig.6.16. In fact, DoD and MSOC are two main factors we considered in the battery breakdown.

In the following, we use a vector to denote the MSOC-DoD combination hereafter, i.e. (S OCbmean,i ,dib). 2) Impacts of DoD and MSOC on battery life. As shown in the dataset, the battery with higher MSOC suffers from higher battery degradation. In the proposed model (method C), the DoD and MSOC are considered as two factors for battery life.

Then, in the next journey, the battery groups change their roles for the iterative applications.

Fig. 6.13 Relation between the first and second stage of proposed model, reprinted from [33], with permission from IEEE

Multi-energy Management of Maritime Grids

Concept of Multi-energy Management .1 Motivation and Background

Classification of Multi-energy Systems

Since the above three main advantages, research on multi-energy management is essential for future energy systems. Multienergy systems can be classified from different perspectives, and there are mainly four perspectives to characterize MES. Such as services provided by MAS, including electricity supply, water supply, heating service, EV charging services, gas filling services, etc.

The fourth perspective discusses the coordinations between different energy systems, especially the coordination between different networks, such as electricity, gas, district heating/cooling networks, in terms of facilitating the development of multi-energy management methods and their interactions. In this perspective, MESs can be classified as building MES, district MES, region MES and so on. In general, MES can provide several services to customers, such as electricity supply, heating and cooling power, and even some transportation services, such as charging/discharging electric vehicles.

In this sense, the fuel type can also classify the MESs, such as the coal-gas MES, gas-hydrogen MES, or even ammonia MES since ammonia is a new type of carbon-free fuel [23].

Future Multi-energy Maritime Grids .1 Multi-energy Nature of Maritime Grids

Multi-energy Cruise Ships
Multi-energy Seaport

Port microgrids cover the port territory and energy sources include offshore wind farm, onshore photovoltaic plant, oil pipelines and electricity supply from the port city. In summary, maritime networks have a very wide range of system scales, from the smallest to a ferry or a building and the largest to a port city, which includes all energy sources within a conventional MES. Various maritime grids are closely connected with energy links, and current multi-microgrid coordination methods can be applied to maritime grids to achieve better system characteristics.

This is the main difference between the currently studied MES (land MES) and maritime networks. In Figure 7.2, a rig can pump crude oil or natural gas and transport it to an island or port. The thermal load on a cruise ship includes cooling and heating loads, swimming pool and cooking.

The CCHP supplies both the electrical current and the thermal current, and the PTC uses electricity to produce thermal current.

Fig. 7.3 Topology of a multi-energy cruise ship

General Model and Solving Method .1 Compact Form Model

A Decomposed Solving Method

This chapter proposes a decomposed method for solving this type of problem, which is given by the following Theorem 7.1. Note that gi(yi)+τi·Gi(yi) is a constant when minimizing x, so it is eliminated for simplification. The set U T(x) of the optimal multiplier vector for (7.3) is nonempty for all x in X and uniformly bounded.

First, the sequence of optimal multipliers τv,uv will converge to a point denoted as (τ,¯ u) since the uniformly bounded assumption U T(x).

Typical Problems

Multi-energy Management for Cruise Ships
Multi-energy Management for Seaport Microgrids

From Fig.7.7a, the battery can coordinate with the speed adjustment to smooth the load profiles, facilitating the economy of vessels (the DGs can work better around their economic points). From Fig.7.7b, the battery can have much deeper charge/discharge events without the speed adjustment. From Fig.7.8a, the proposed two-stage scheduling model can meet the thermal load demand in a more accurate time scale by simply sending the load factor.

Expected internal temperature (second stage) First stage internal temperature. b) internal temperature and heat load in the first/second stage. From Figure 7.9, a BOS cruise ship will have much higher load requirements as the thermal load is provided by the PTC unit. Accordingly, the EEOI of the HES integrated cruise ship is also much lower than the BOS by 8.37%.

The electrical load profile, the heating load profile and the cooling load profile are shown in Fig. 7.11, all of which are given in 1000 scenarios.

Fig. 7.7 Onboard generation and battery SOC with/without speed variations, reprinted from [26], with permission from IEEE

Two-stage optimization is considered, meanwhile the joint constraints are considered

Only the first-stage optimization is considered

Wen, Y., Qu, X., Li, W., et al.: Synergistic operation of electricity and natural gas networks via ADMM. Qiao, Z., Guo, Q., Sun, H., et al.: An Interval Gas Flow Analysis in Natural Gas and Electricity. Chen, Y., Wei, W., Liu, F., et al.: A multi-lateral trade model for interconnected gas-heat-power energy networks.

Chen, Y., Wei, W., Liu, F., et al.: Energy trading and market equilibrium in integrated thermal energy distribution systems. Dai, Y., Chen, L., Min, Y., et al.: A cogeneration dispatch model considering the heat transfer process. Yao, S., Wang, P., Liu, X., et al.: Flow optimization of mobile energy storage fleets for resilient service recovery.

Li, Z., Xu, Y., Fang, S., et al.: Multi-objective coordinated energy transmission and voyage planning for a multi-energy ship microgrid.

Fig. 7.13 SOC of battery, reprinted from [28], open access

Multi-source Energy Management of Maritime Grids

Multiples Sources in Maritime Grids .1 Main Grid

Main Engines
Battery and Fuel Cell
Renewable Energy and Demand Response

In other smaller cases, the main engines act as the main power sources, especially in shipboard microgrids. Then, in the development of main engines, it enters the second phase, and this is the golden age of low-speed diesel engines. Then after 2000, the fourth stage, the main engines become smarter and various advanced control equipment is integrated to achieve automatic control.

Today, prime movers range in size from kilowatts to megawatts, using diesel, natural gas, ammonia, etc. Ships can charge or use cold ironing power while anchored in port, which can also be considered as using renewable energy for propulsion. In conventional operating patterns, the generation side must follow the trend of renewable energy or renewable energy must be limited [21].

In the energy market, demand-side management resources can be aggregated as a unit and act as a "virtual plant".

Table 8.1 Possible power sources for different equipment in a seaport (data from [1]) Diesel Petrol Natural gas Electricity

Coordination Between Multiple Sources in Maritime Grids

Some Representative Coordination Cases .1 Main Engine—Battery Coordination in AES

Main Engine-Fuel Cell Coordination in AES
Demand Response Coordination Within Seaports

Compared to the main engines, fuel cell has smaller capacity and scale, which is suitable for undertaking some small-scale cargo requirements. Compared to the battery, fuel cell does not need charging, which can undertake long-term load demand [28] studied this topic and compared two cases: (1) main engine; and (2) main engine fuel cell. The Elektra: Finland's first hybrid-electric ferry.https://ship.nridigital.com/ship_apr18/the_ele ktra_finland_s_first_hybrid-electric_ferry.

Available online: https://shipandbunker.com/news/emea/914341-fuel-cell-technology Successfully tested on two ships. Zhao, C., Wang, J., Watson, J.P., et al.: Multi-stage robust unit commitment accounting for wind and demand response uncertainties. Roh, G., Kim, H., Jeon, H., et al.: Fuel consumption and CO2 emission reductions of ships powered by a fuel cell-based hybrid powerplant.

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which prohibits any non-commercial use, sharing, modification, distribution and reproduction in any medium or format, so long as you properly credit the original author(s), the source, provide a link to the Creative Commons license, and indicate if changes have been made.

Fig. 8.4 Reason for propulsion system in demand response

The Ways Ahead

Future Maritime Grids
Data-Driven Technologies

Navigation Uncertainty Forecasting
States of Battery Energy Storage
Fuel Cell Degradation
Renewable Energy Forecasting

Siting and Sizing Problems .1 Energy Storage Integration

Fuel Cell Integration

Energy Management
Summary

In the future, more accurate uncertainty sets should be predicted to facilitate the operation of marine networks. Chapters 5–8 have highlighted the critical roles of battery energy storage in marine grids for load balancing and power quality issues. Chapter 6 has clarified the functions of energy conservation in the long-term operation of marine networks: (1) improving the economic and environmental characteristics of marine networks [5,12,34];.

In figure 9.9a, the main engines and energy storage share the strongly fluctuating power demand via maritime networks. In contrast to land-based applications, energy storage facilities in marine grids are usually installed in a distributed manner. Unlike conventional microgrids on land, maritime grids generally receive less support from the main grid.

At the moment, there are many practical cases and studies on the placement and dimensioning of fuel cells in maritime networks.