Solar vs wind vs hydro

[Pete7]

Bergius, for summer sailing in the Baltic, lots more solar must win hands down. Three reasons for this. Firstly long day light hours during the summer which shows in your graph figures, noting the drop in September. Secondly, the air temperatures are much lower than say the Caribbean.

I measured our previous 300w solar panel mid day in June last year. Clear skies so full sunshine. Top glass surface was 28'c, backside was 38'c. I suspect that if we had been further south, those temperatures would be much higher and therefore reduce the effectiveness of any solar panel.

Large over 250w solar panels are cheap in Europe at the moment, even if the choice has reduced over the last couple of years. Sadly LG and Panasonic in Europe producing high quality panels have pulled out of the market.

We spent November upgrading from 300w to 600w. This means we should see an increase from 1.3kWh each day to 2.4kWh in sunny conditions.

Wind wasn't even a consideration due to the risk of shading the solar.

However, one of your fellow countrymen fitted an alternative to the Watt and Sea hydro and produced an YT video about it. 5A at 12v whilst travelling at 5 knots isn't too bad. Whether its worth the E1800 price tag is debatable. https://sailnsea.1a-shops.eu/ Interesting if you were doing long passages, otherwise its solar.

Pete

https://www.youtube.com/watch?v=gfAf...channel=MJambo

[Networker]

I have 1200ah LiFePO4 and 1450w solar, and it’s not nearly enough. Will be getting a hydro generator to help with the autopilot (it seems to use 6-8ah or more!) and wind to help give energy while sailing or anchored. I find that redundant energy supplies to keep boat happy is critical since solar is good, but not sufficient.

[noelex 77]

For those struggling with energy, don’t forget the option of reducing your energy demand.

This need not mean doing without comforts and conveniences, but rather installing systems and using practices that use electrical energy efficiently.

[Pete7]

Guilty of boiling too much water at home, the solution is a 0.8L kettle half full which makes two mugs of tea. Since we drink a lot of tea there are some real savings here.

Pete

[SailingHarmonie]

For those installing wind generators, avoid the common mistake I see ALL the time of mounting them above the solar panels!

I see many, many installations where on an average not-very-windy day the wind generator shade reduces solar output by more than the wind generator makes. A very costly mistake.

[bergius]

Originally Posted by Adelie

I assume the average daily consumption you indicate in Watts is actually Whr or should we multiply by 24hr to get Whr?

The graph you quoted is just using variable names. What’s indicated as “Watts” is actually Wh-per-day. So average consumption 1.2kWh per day, and production either slightly below or above that.

[bergius]

Originally Posted by noelex 77

For those struggling with energy, don’t forget the option of reducing your energy demand.

That’s of course the ideal. Then you need less generating capability, and less energy storage.

There are some places where we could probably cut… turn the fridge off, and get a self-steering wind vane to complement the current electric autopilot (we generally only hand steer for harbour manoeuvres).

However, the lion’s share of our power consumption is laptops and internet. Being able to do “boat office” is what enables us to spend the whole summer in the Baltic. So that’s sadly not something we can cut. Hence, the search for alternatives.

[bergius]

Originally Posted by Pete7

Bergius, for summer sailing in the Baltic, lots more solar must win hands down. Three reasons for this. Firstly long day light hours during the summer which shows in your graph figures, noting the drop in September. Secondly, the air temperatures are much lower than say the Caribbean.

Absolutely! It was fun seeing the panels produce something already at 5am in the summer. Though of course this means we get practically nothing from solar now in the winter, meaning that we can only anchor out for 2-3 days before having to head back into a marina to plug in.

There isn’t a lot of space for panels on our boat. We will likely get a bigger panel for the stern arch. Around 350W might fit, but I haven’t found panels with the correct geometry yet. So far the best bet seems to be going from the current 150W mono to a 200W PERC.
We might try to fit something on the sides of the push pit as well, but that can’t be big because this boat has curves.

Here’s the boat with its full current solar array deployed:


The FLINsail generally produces enough electricity for our needs. The problem with it is the two situations where it isn’t working - when we are sailing, or the wind is above 18kt. Last summer we sailed on 2/3 of the days of our five month cruise, so the deployable panels didn’t quite get a chance to shine. Let’s see how it will be in the coming summer. If we spend more time at anchor, the equation looks quite different.

Originally Posted by Pete7

However, one of your fellow countrymen fitted an alternative to the Watt and Sea hydro and produced an YT video about it. 5A at 12v whilst travelling at 5 knots isn't too bad. Whether it’s worth the E1800 price tag is debatable. https://sailnsea.1a-shops.eu/ Interesting if you were doing long passages, otherwise it’s solar.

That looks pretty interesting! The pricing is a lot more attractive than the around 5k for a Watt&Sea. Will reach out to the manufacturer to see how they thing they would fit on a double ender.

[Pete7]

Originally Posted by bergius

Absolutely! It was fun seeing the panels produce something already at 5am in the summer. Though of course this means we get practically nothing from solar now in the winter, meaning that we can only anchor out for 2-3 days before having to head back into a marina to plug in.

There isn’t a lot of space for panels on our boat. We will likely get a bigger panel for the stern arch. Around 350W might fit, but I haven’t found panels with the correct geometry yet. So far the best bet seems to be going from the current 150W mono to a 200W PERC.
We might try to fit something on the sides of the push pit as well, but that can’t be big because this boat has curves.

Bergius, I don't think its worth while going to 200w Perc, just not a big enough power increase for the cost and trouble. Hyundai have some 400-440w panels in Europe which look interesting. They are shingled like a tiled roof so don't have buss bars between each cell. Result slightly smaller panels. Andy from Off Grid Garage has installed a shed load of them on his roof. For him the small improvement isn't that important, but for us trying to maximise every inch of space, I think it would be worth looking at. Sadly all sold out in the UK when I looked in October / November or would have been very tempted.

https://www.youtube.com/watch?v=a_xx...Off-GridGarage

Pete

[Pete7]

Just looking at your frame, can't see why 400w shouldn't be fitted. This is my 300w panel before the upgrade, which I used 4 x 1" aluminium square tubing, plus some u bolts enabling the panel to sit with 10 deg forward slope in the normal position and lower to 45 deg facing backwards if needed. So if you fit a 400w panel or so, that would be a significant increase in solar.

Three photos, your A frame, second my 300w panel installation and shap shot of the output in June 2022 on a clear sunny mid day, southern UK. Might have generated more, but the MPPT dropped to float on the previous day with the batteries full.

Pete

[bergius]

Originally Posted by Pete7

Just looking at your frame, can't see why 400w shouldn't be fitted. This is my 300w panel before the upgrade, which I used 4 x 1" aluminium square tubing, plus some u bolts enabling the panel to sit with 10 deg forward slope in the normal position and lower to 45 deg facing backwards if needed. So if you fit a 400w panel or so, that would be a significant increase in solar.

Thanks! Current guidelines I’ve been given has been max 900x180cm of panels on the arch.

I just found a promising 120W shingle panel:
https://www.autobatterienbilliger.de...20s-solarmodul
We can fit two of those easily. And maybe three if my co-owner is willing to budge on the width of the panels…

Having 2-3 panels might be nice also in dealing with shading from the mast if I connect them to separate MPPTs.

[Pete7]

Certainly 3 of those would be nice or two larger ones. Assuming the panel strings are fitted with bypass diodes which is likely, mounting them in parallel means you could use one MPPT. If one or part of one was shaded, the rest of the panel and the others would work satisfactory. Keeps the wiring simpler.

3 x 120w would be a very good and then put the existing 150w on the guard rails perhaps with another on the opposite side.

Pete

[Pizzazz]

The first (and only) change I would suggest is to replace or bypass the 30A DC-DC charger. You should be able to get 50-60A continuously from that alternator and since you have lithium, the battery would take all of it. You will also get more heat and hot water that you will need along the winter months.

[bergius]

Originally Posted by Pizzazz

The first (and only) change I would suggest is to replace or bypass the 30A DC-DC charger. You should be able to get 50-60A continuously from that alternator and since you have lithium, the battery would take all of it. You will also get more heat and hot water that you will need along the winter months.

I think the LiFePO4 bank will be happier charged with the proper profile. When we had the original 35A alternator we used a LiFePO4-aware battery combiner to charge them, but went DC-DC with the bigger alternator.

We don't really consider the engine to be a charging source. This setup is just so that we don't deplete batteries when motoring (as we did with the original alternator). I felt a bit silly to motor for 10h (as we do for couple of days when coming from Berlin to the Baltic through the canals) and have to plug in immediately.

We burn enough diesel for heating already, I don't want to add the diesel cost, noise, and vibration from charging. I think so far we've run the engine to charge batteries only once, after an overcast week. And that was just because we didn't want to head offshore with <60% battery when we knew we'd be on autopilot the next 24h. Not something I want to repeat.

[Pete7]

Does the frame need to come down to go from wintering in Berlin to the Baltic? A single panel would be easier to take down out of the way of the mast.

Have been reading your website, that would be an interesting trip we could also do, if we ever retire

https://lille-oe.de/2022/

Pete