# Boat-to-Grid Electrical Energy Storage Potentials around the
## 3 Results  
### The Number of Sailing Marinas and Berths around Lake Balaton  
The numbers of the permanent and visitors' berths in the sailing marinas of each town or village at Lake Balaton were established. All around the lake, the number of permanent berths was 6542, while that of those for visitors was 349, i.e., altogether 6891 berths in total. Figure 5 presents the numbers of permanent and visitors' berths in each sailing marina in detail. The information concerning the 10 most important towns and villages in terms of berths is further highlighted in Table 2 and Figure 6. In these 10 major resorts (Balatonfured, Also\(\acute{\text{r}}\)s, Balatonkenese, Balatonfuzfo, Balatonhelle, Si\(\acute{\text{o}}\)fok, Keszthely, Fony\(\acute{\text{o}}\)d, Balatonfenyves, Balatonszemes, Balatonalm\(\acute{\text{a}}\)di) there are 4714 berths altogether, \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Year** & **2019** & **2025** & & & **2030** & \\ \hline Scenarios & - & A & B & C & A & B & C \\ PV power plants [GW] & 1.3 & 4 & 1.6 & 3.7 & 6.7 & 2.5 & 6.4 \\ Batteries, power capacity [GW] & 0 & 0.20 & 0.08 & 0.19 & 0.34 & 0.13 & 0.32 \\ Batteries, storage capacity [GWh] & 0 & 0.80 & 0.33 & 0.76 & 1.34 & 0.51 & 1.29 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Changes in the net installed capacities of PV power plants and energy storage systems in Hungary based on [65]. which is a significant proportion of all the berths at Lake Balaton at 68%. The geographical locations of these places around the lake are shown in Figure 6. As seen in the case of the 10 dominant resorts in Figure 6, there is a significant number of berths available all around the lake; however, it has to be noted here that at present, in 2021, all the marinas at Lake Balaton are operating with an occupancy of 100%, and there is a waiting list for those wanting berths. At lake Balaton, boat owners rent their berths, and the contracts are for one year, from 1 April till 31 March of the following year, everywhere. If the berth fee is received by 31 March, the client may keep their berth in the marina. The termination of the contract by the marina is subject to one year's notice. Long-term rents are not possible [62]. In terms of developments, it is a favorable situation that marinas suitable for accommodating small electric boats are available everywhere at the lake. Thus, regarding charging the boats or connecting them to the grid, it cannot be a problem if the boats use the marinas of different resorts according to the actual needs. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Resort** & **Total Number of Berths [pcs]** & **Share of the Total Number of Berths [\%]** \\ \hline Balatonfured & 785 & 11 \\ Also\(\circ\)rs & 678 & 10 \\ Balatonkenese & 520 & 8 \\ Balatonfürz6 & 425 & 6 \\ Balatonelle & 406 & 6 \\ Si\(\circ\)fok & 376 & 5 \\ Keszthely & 360 & 5 \\ Fonyöd & 306 & 4 \\ Balatonfenyves & 300 & 4 \\ Balatonszemes & 293 & 4 \\ Balatonalmádi & 265 & 4 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The 10 most significant resorts of Lake Balaton in terms of berths for sailboats, own results. Figure 5: The numbers of permanent and visitors’ berths in the sailing marinas of the resorts at Lake Balaton, own results. The Number of Small Electric Boats and Their Energy Storage Capacity at Lake Balaton--Present and Future  
The power and the storage capacity of the batteries of the small electric boats in the sailboat marinas of Lake Balaton in 2021 were established based on the data made available by the Government Agency of the City of Budapest [57], AQWIA Ltd. [59] and Stickl Yachts Ltd. [60]. The power of the electric boats varies, as shown below:  
* \(<\)6 kW, 4 kW on average;
* 6-10 kW, 8 kW on average;
* 11-20 kW, 16 kW on average;
* 21-40 kW, 31 kW on average;
* \(>\)40 kW, 46 kW on average. There are altogether 213 small electric boats in the sailing marinas of Lake Balaton. Figure 7 shows their distribution by the power of their electric motors.