Mooring in tropical place with 28-30C during the day time and 24-27 at night.

In our previous artile we discussed cold, winter mooring and energy needed to live on board.
Lets's look at energy we need for mooring in tropical place with 28-30C during the day time and 24-27 at night.
Case study:
Boat around 11m long, two people on board, 30C air temperature outside and 24C water temperature.

Let's estimate how much energy or fuel we need.

1. On board we will need energy to cook food. In our previous study I used kerosene fueled cookers as of example. It is better to use diesel cooker to avoid carrying different types of fuels. But if you don't mind to store editionally LPG/Propain/Acohol it is ok.  Also we established 0.1L per day for an avarage cookng habits. We came to  this number from the following:

All liquid fuels has approximately the same amount of energy density (+/- 15%) so in assumption of 45MJ/kg we could derive to needed amount of fuel to store for 1 month of cooking.  I estimated at around 5KW per day but this was including all electric needs. For cooking alone it will be about 1200Watt per day total. if  we convert this to Joule, it will be 4.3Mj or about 100gr of fuel or about 0.1L per hour of diesel. If you cook for 1hr per day, this is your dayly consumption. This is wonderful estimate as it completely proven by my practical living in autonomous mode. I used 8L LPG per 3 months in the kitchen by cooking every day 3 meals and making tea. That is 8L for 90 days and 0.09L per day. Or about 2.7L LPG gas for a month.
2. Fridge or frizer or both. Fridge takes around 320Kw  per year or about 1KW per day or about 40W per hour.  This valid for medium size fridge. Smaller fridges on ultra small 24v compressors can do 35Wh, if ambient temperature is 24C the duty cycle is 50%. Let's assume it is 6hrs 50% duty cycle and the rest it is 90%. Then our dayly consumption will be 672W. With both Fridge and frizer you need to double that.
3.-Two way radio or transceiver or "walkie-talkie" or "communication radio".  Most of time it is used in receive or listening mode. Per hour it consumes 0.1W or about 24W per day or about 700W per month. In transmit mode radio use way more energy. So let's say you only use 15W transmit mode for only a few hours per month. That will be about 27W per day.

-Cell tower communication in a form of modem or a cell phone. If you near cell phone tower and can have signal, you will always want to be connected. A simple (small screen old Nokia) phone will take about 100 to 300mW per day or about 5W per month. But most people like to use digital phones or modems or both-old phone and modem at the same time. Modem takes about 4W per day.


-large screen cell phone will take aroud 9W per day.

-Laptop or Tablet. Assume it is smaller size, 10in screen. Modern tablets use from 30W per hour on  smaller Android, 10in screens to 200Watt per hour on faster models and 17in screens.
Let's say it is 50W per hour, non video editing tablet for reading and typing purposes. 8hour usage will bring 400W per day for entertainment purposes. If you have video editing laptop this number will be around 600W per day for non engineering usage.

-Lights. Very important to use signal lights for safety to avoid collisions. Two bright 3W led for parking is 6W per hour or about 36W per day on 6hr night and this could come up higer in fog. Plus lights inside. I would estimate this around 2watt per hour in 5hours of period or 10 more watts per day. Total lights would take about 50W per day. If we just use very dim 0.5W parking light and will bevery savery with reading during dark hours, this number can be redused to 15watt per day.

-On-board computer or equipment to keep board alive. 2W per hour or 50W per day

-Pumps. Bilge pump for taking out seeping water is around 30W and it is used very seldom. But even 30min per day it is 15W per day. Water pumps for kitchen:20W or with 45min total usage it is about 15W per day. Sewer pump:100W or for 10min usage per day it is 15W per day. Please note: we are talking about absolutely small pumps. In real life 5 times larger pumps are used.So in asumption small pumps and no distiller it is around 45W per day per person.

-In humid environment fans are important. Small 2W fan and two of them on boat would take about 80-100W per day. 2W is very small propeller. In real life, I would say it is more like 5-10Wh. But assume you will use them only at nightand 6 hrs per at day time, this could be about 40W per day.
-I didn't mention about satilite dish.They are about 30W per hour to receive and 200W per hour to transmit.
Let's take 150 Watt as an estimate. Then per day in 8hr usage it is  1200W per day!
-Air condicioning. I've seen a smaller 400wh units. So this will be 2000W per day if you use it in 50% duty cycle and only 10hr dayly.

5. If boat is moving with electric engines, electric conumpton is huge.  It might take 20minutes to get your boat moored. Let's say 30min. Let's assume it is only 5KW motor will have 2.5KW for 30min run.   If I have 24V batteries, it is 416A current for 20min-which is 1/3 of hour. Using this calculator https://visbis.com/newsinfo/about-batteries/all-about-lead-acid/calculator3.html would give me 450Ah, 24V battery bank. I just used different numbers of battery capacity to come up with 0.3hour in the calculator. I will let you think about that on what it means in terms of weight and cost.
If we add all together only bare minimum, excuding satilite equpment it is 1200W/day for 1 person or 1600W/day for two people.
With AC it is 3300W per day.

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