Fridge and watermaker on 27' mono?

[Pete7]

Originally Posted by Don C L

This a great thread. I don't yet foresee a time when I could afford all the power generation, power storage, refrigeration and watermaking technology, along with all the infrastructure to support them, but thanks to y'all I see it may just be possible on our little boats!

Don, I concur. It has taken us a decade to add new sails, fridge and 180w of solar. Though I have just sprung for one of these which appeared on UK e bay for £73. At that sort of price they are almost expendable.

https://www.aliexpress.com/item/Doki...819234645.html

The rest of the budget goes on updating stuff like the loo, fire ext and guard rails and this week new Trojan FLA batteries.

I don't see a freezer in the power or £ budget and thankfully don't need a watermaker. Maintaining the heater is important though, along with dodgers and a sprayhood, fairly essential kit in England.

However, it is coming together, slowly.

Pete

[Pizzazz]

Originally Posted by witzgall

We only started the engine twice in four months for the sole purpose of charging. We did take advantage of opportunistic charging while motoring or motorsailing. We used one, 33 gallon tank of water a week.

Get the Ventura 150. Don't even consider the 40e. You will not want to have it running while off the boat, and at 1.X gallons an hour, you will be a prisoner on your own boat otherwise.
Chris

You have a great setup. It is difficult for us to judge what share of your power generation came from the alternator since you motored opportunistically. With the setup you have one hour engine time will give you close to 120AHrs at any time, so my guess is that the solar and wind was just a nice add on in the big picture.

Regarding the watermaker, you say you would not want to run it while off the boat. There is no reason for this limitation, do you let your fridge run when you are off the boat? Same principle here. I would often switch on the PS35 when I go the islands and come back 10 hours later.

Again if buying new, Spectra probably makes sense but if you factor in the cost vs. a used PS35 (15x difference) and the noise difference, then the PS35 has it's uses. It is not for everyone, I agree.

[Gene Neill]

Originally Posted by peter loveridge

have you considered collecting rainwater?

Absolutely yes. I just don't want to factor it in since it cannot be relied on. I have been told (??) rainwater can be tough to collect in the tradewind belts.

[Gene Neill]

Originally Posted by witzgall

Upgrade the Beta with the 75 amp alternator w serpentine belt that Beta Marine NC offers. Regulate it externally with an MC-614 (Note, I work for Balmar) Install a Balmar SG200 to monitor your batteries, so you really know what is going on with them.

Chris

Thank you sir. I will follow this advice.

[Gene Neill]

Originally Posted by Don C L

This a great thread.

It IS! I am amazed and humbled and grateful to everyone who has posted. I thank you all.

A couple pieces of good news! One, I have found a suitable place to install a Ventura 150! So, bye bye PS40E, hello more water, faster, and for less energy. 4Ah saved daily.

And, I found more data on the Engel, which I will post below. I had previously only seen the figure of "0.7 - 2.5 Amps", and had to take a very wild guess on the actual consumption. According to the chart below, at 35C (95F) ambient temperature, and 5C (41F) in the fridge, the power draw is 0.96A with a 40% run time.

Of course, I realize every time we open the fridge or add a can of warm beer, we completely blow that all away. But even if the fridge ran 24 hours a day at 1 amp, that would be a 12Ah savings from the 36 I had budgeted. So ... I think I will deduct six. To be safe. This also puts me at the high end of what Liaka reported on the previous page.

Does this sound reasonable?

These two factors combined would mean a savings of 10Ah daily (14 percent!), bringing my planned energy budget down to 61Ah/day.

[witzgall]

Originally Posted by Pizzazz

You have a great setup. It is difficult for us to judge what share of your power generation came from the alternator since you motored opportunistically. With the setup you have one hour engine time will give you close to 120AHrs at any time, so my guess is that the solar and wind was just a nice add on in the big picture.

Regarding the watermaker, you say you would not want to run it while off the boat. There is no reason for this limitation, do you let your fridge run when you are off the boat? Same principle here. I would often switch on the PS35 when I go the islands and come back 10 hours later.

Again if buying new, Spectra probably makes sense but if you factor in the cost vs. a used PS35 (15x difference) and the noise difference, then the PS35 has it's uses. It is not for everyone, I agree.

Actually it was the wind and solar first. The secret sauce to,it all was the lifepo4. When you are at 50% for a week with wet cells or agm, you are stressing about letting them sit there partially charged. Not so with lithium. Concerning leaving the wm unattended, I guess that is a judgement/comfort call. Some would leave the boat with a genset running, it could never do that. We also did not leave the boat with high winds, in case we drug anchor. Choices and risks.

Not ours anymore, we moved to a different boat.

Chris

[Pizzazz]

The beauty of the forum is that we can agree on the facts and then everyone makes his/her own trade-offs.

Regarding a fridge power draw of 1A x 12V x 24h = 288 WHr = 980 BTUs. A twelve pack of beer weighs 10 lb x 60F temperature difference = 600 BTUs. So, just to cool down a case of beer will cost you 2/3 of your daily power budget. Now, factor in the rest of the stuff and the heat losses and it should be obvious that the energy consumption would be much higher. Most boat fridges draw 3-5A average, I would budget on 2A at least, no matter what the spec sheet says.

[newhaul]

Originally Posted by Pizzazz

The beauty of the forum is that we can agree on the facts and then everyone makes his/her own trade-offs.

Regarding a fridge power draw of 1A x 12V x 24h = 288 WHr = 980 BTUs. A twelve pack of beer weighs 10 lb x 60F temperature difference = 600 BTUs. So, just to cool down a case of beer will cost you 2/3 of your daily power budget. Now, factor in the rest of the stuff and the heat losses and it should be obvious that the energy consumption would be much higher. Most boat fridges draw 3-5A average, I would budget on 2A at least, no matter what the spec sheet says.

not 60℉ temp difference unless you are starting with your beer at 100℉
The 60℉ starting point is just a 20℉ difference.
What I used to do was a pound of dry ice when I got the food at the store in my own cooler to take to the boat . On the meats and under the beverages. Would freeze the meats. Then put the dry ice in the top load fridge on the boat to help with the heat loading.

[cj88]

I am enjoying this thread because I am currently shopping for a new yacht that is sub-30'. Trying to work out how to make the systems I would like to have function while off-grid is pushing the power envelope so efficiency becomes king. Finding the best "value" options for an efficient extended-term off-grid sub-30' cruising yacht is certainly an interesting exercise. I would like to be as fossil-free and as simple as practicable. When you consider your refrigeration, tender, cooking, heating, water supply, nav, autopilot, etc. it certainly makes you look at every aspect in a new light.

[Copacabana]

Originally Posted by Gene Neill

It IS! I am amazed and humbled and grateful to everyone who has posted. I thank you all.

A couple pieces of good news! One, I have found a suitable place to install a Ventura 150! So, bye bye PS40E, hello more water, faster, and for less energy. 4Ah saved daily.

And, I found more data on the Engel, which I will post below. I had previously only seen the figure of "0.7 - 2.5 Amps", and had to take a very wild guess on the actual consumption. According to the chart below, at 35C (95F) ambient temperature, and 5C (41F) in the fridge, the power draw is 0.96A with a 40% run time.

Of course, I realize every time we open the fridge or add a can of warm beer, we completely blow that all away. But even if the fridge ran 24 hours a day at 1 amp, that would be a 12Ah savings from the 36 I had budgeted. So ... I think I will deduct six. To be safe. This also puts me at the high end of what Liaka reported on the previous page.

Does this sound reasonable?

These two factors combined would mean a savings of 10Ah daily (14 percent!), bringing my planned energy budget down to 61Ah/day.

Gene, I think you might be a bit optimistic about the power consumption of the Engel. They make a great little fridge, but in hot weather and normal use (putting stuff in and taking stuff out) the amp consumption numbers go way up. I have the Engel 40 (drop-in model) and in the Brazilian summer it runs pretty much all day long. I would budget 40 ah per day and be happy if it uses less.

That said, I think 300w of solar will be plenty to keep everything running on your boat. I have a similar setup (355w of solar and 220ah of flooded batteries) and I make more power than I can use. One thing that helps is turning the fridge on to freezer mode (setting 4 or 5) during the later afternoon when you're making plenty of amps and the batteries are on float and accepting few amps. Then, at the end of the day, you can dial the fridge down or even turn it off for the night.

I can't comment on the watermaker question as I don't have one. I have a large water tank in the keel (500 liters) and I have a great rain catching system. I can fill the tank in a normal tropical downpower in about 20 minutes. Look into rain catchment, even if you get a watermaker (as a backup and for safety). Perhaps you can run a 12v watermaker during the hours you are making more power than the batteries can accept or when you are motoring.

[Pete7]

Gene, how are you going to mount 300w of solar? don't forget that it will probably weight 20kgs if you go for say a pair of rigid 150w panels. On a frame? that will be another 10kgs right on the stern.

Pete

[Delezynski]

Gene,


We cruise a Nor'Sea 27. Departed the San Francisco Bay area in 04 and went south. Cruised full time for over 4 years most in the Sea of Cortez, summer & winter.



Departed with 4 32 W Flexible panels. reefer & watermaker. Upgraded with an 85 W mounted on stern rail & 2 more 50 W panels that we flew at anchor. Had and still have 3 Group 31 AGM batteries with 105 Ah each. Allowed us to live at anchor for months at a time. Had and still have 3 Group 31 AGM batteries with 105 Ah each. AND only once did our batteries drop a small bit below 50% DoD. Just watch the battery monitor. See our web page & Youtube page for extensive info.....


Greg

[Gene Neill]

Originally Posted by Pete7

Gene, how are you going to mount 300w of solar? don't forget that it will probably weight 20kgs if you go for say a pair of rigid 150w panels. On a frame? that will be another 10kgs right on the stern.

Pete

I've been agonizing about that for a long time, and the jury is still out.

I suppose the best option, weight-wise, would be semi-rigid panels on a Bimini. This would also provide the most shelter in the cockpit. An arch at the stern would be sturdy and have less shading of the panels, but there is the weight issue.

I'm open to any suggestions!

If I did use an arch, I would mount it as far forward as possible, with the backstay passing between the panels, and just enough clearance for the sail luff to swing by the panels.

[Gene Neill]

Originally Posted by Delezynski

Gene,


We cruise a Nor'Sea 27. Departed the San Francisco Bay area in 04 and went south. Cruised full time for over 4 years most in the Sea of Cortez, summer & winter.



Departed with 4 32 W Flexible panels. reefer & watermaker. Upgraded with an 85 W mounted on stern rail & 2 more 50 W panels that we flew at anchor. Had and still have 3 Group 31 AGM batteries with 105 Ah each. Allowed us to live at anchor for months at a time. Had and still have 3 Group 31 AGM batteries with 105 Ah each. AND only once did our batteries drop a small bit below 50% DoD. Just watch the battery monitor. See our web page & Youtube page for extensive info.....


Greg

Greg, I'm a subscriber to your Youtube channel but had not seen your web page. I'm on my way out the door right now but I'll give it a look tonight. Love your NorSea!

[drcat]

three items or suggestions
1) consider adding 2 more solar panels of same size each on side rail near stern. They swing up using a support and can be set up at anchor and sometimes at sea. Several cruisers use - see youtube sailing sophisticated lady for an example
3) Consider a non compressor refrig called KECO It draws 35 watts when running can go as low as 81 deg F below water temp. It is not a thermo elect but draws seawater into a cpu costs around 400 euros, but you need to build the box See youtube sailing Uma for example 2 yrs ago
3) Watermaker - Seawater Pro $2800 12v, 8-12 gal/hr. see Adventures adrift youtube from about 2 yrs ago.
Good luck with your adventures.