So in my last post on Introduction to generation I outlined the options and challenges for renewable energy generation and concluded that we were going to start with solar.
This video from Desiree and Jordan, Project Atticus, has been helpful. Like us they have a ketch (although smaller) which means a radar arch doesn’t work.
The simplest first step is going to be 4 x 40w solar panels on the top of our wheelhouse. It has a perspex “window” slot in the middle to allw you to see the mainsail when steering. That restricts things a bit but we can essentially fit one 40watt panel in each corner. Hopefully only one side at a time will be in shade from the boom & sail. So the panels will be connected in series along each side and then the two sides connected in parallel. That way the shaded side doesn’t affect the output of the other side. These will connect using a single Victron MPPT controller to the house battery bank.
The second step is to setup 4 large 175watt panels. They are approximately 1.5m long by 0.7m wide. We are starting with 2 controllers for these (one per side of the boat). The intention is to do some experimenting and end up with a variety of places they can be setup depending on whether we are at anchor or in a marina or sailing.
We are going to fit legs to the middle of the short sides. The bottom of the leg will be fixed just inside the edge of the boat. So the panel can be “stored” vertically or it can be swung out and the angle adjusted for maximum effect. They probably will need to tacked with the boat so that on the downwind side they don’t hit waves (ie we fold them away on the side we are heeling towards). At anchor they can be fully deployed and should get minimal shading. They will go from the back of the boat forward about 3m which should mean they are clear of where we get in and out of the dinghy as well as clear of sheets (the ropes that control the sails) when sailing. We probably won’t be able to use them when tied up in a marina as they will either overhang the dock where people walk or be in the way of other boats. We will make them reasonably quick for us to remove so that we can put them in other positions when that will be more effective.
When we are anchored or in a marina they should fit across the boat while resting in the middle of their length on the mizzen boom. Not quite sure what will be the easiest way to fasten them here as the legs won’t be quite as long as the boom is high.
I haven’t quite given up on putting panels off the back of the boat. It would require a “goal post” that is clear of the swinging boom (and sufficiently braced). I’m thinking the panels would need to be able to slide either behind the boat (when using the mizzen) or forward (blocking the mizzen but out of the way for docking).
I’m not sure if this can be made practical enough. I was wondering about fitting one long edge to the top side edge of the wheelhouse and then supporting the panel to stick out horizontally. They would not stick out much beyond the side of the boat but you would have to duck under them to walk forward and they might catch on ropes (particularly jib sheets).
The 4 x 40watt and 4 x 175watt panels we have at present should give us 860watts which is a good start, although we have to assume that due to shading we will be looking at more like 400watts effective at any particular time (depending on whether we move the big panels around when on anchor).
If tests show that all the places I’ve mentioned are possible then we might be able to get to over 1,500 watts which would be awesome (and enough to start considering an electric motor).
Beyond that if we can sort out storage when not in use we could potentially fit another 4 around the sides of the boat when at anchor.
By this time traditional conservative sailors are going to be horrified about what Vida will look like 🙂 To us though not needing fossil fuels is incredibly beautiful and very worthwhile.
To facilitate the flexibility we will end up with a variety of connection points around the boat supported by multiple MPPT boxes. Until then we will experiment using longer extension leads while we work out what works best.
One of the big challenges is that most of the examples (on YouTube that includes channels like Sailing Uma, Project Atticus, Beau and Brandy Sailing, Rigging Doctor) were at least started in the tropics where the experience of the sun is quite different to North Wales. We need more panels and we need to angle them more efficiently than they do.
We also need to focus a lot of attention on minimising the use. Having a large battery bank and big inverters needed for induction hob cooking could tempt us to be heavy electric users meaning we will never be able to generate enough renewable energy, I’ll be writing about that side of the equation too.