This week, we visited METS in Amsterdam, one of Europe's largest marine trade shows. An opportunity to meet friends and suppliers in a single visit. It is simply huge so if you visit, take comfortable shoes.
Victron Energy solar input, forcing what we need
One such supplier present was Victron Energy who provide all our low voltage electrical equipment so it was a great opportunity to speak with their technical staff. Having switched the system live, we noticed a problem; it did not work as anticipated! The system takes 415 VAC 3 phase from our 2 by 60kW.H power batteries and feeds it to 220VAC and 24VDC power. It also takes input from our theoretical 6kW of DC power.
Victron MultiPlus controllers are "grid pass-through" devices. In other words, they use "Grid" power as their main source and "Solar" power as the backup. Batteries keep 100% topped up in the event of emergencies. That's not much use when your "grid" is a set of big batteries. We need to use Solar power preferentially and only draw from our propulsion batteries when the sun does not shine.
There are two potential solutions. Victron has an Energy Storage System (ESS) option for solar-based installations. It is pretty useful and function-packed but quite complicated in the implementation and still with a focus on an unlimited "grid" connection. More recently, they have updated the MultiPlus control software with a "Preferential Solar" option where the operator can force the system to take power from Solar to the maximum available and then draw Grid power only when batteries deplete to a predetermined level. It's a little more complex than that, but enough for now.
Does it work in practice? See the illustrations above. The first indicated Grid consumption at a specific moment in time over two days. Grid input = "0" Ha! The second showed solar input when we enabled the feature on day 2 (in the middle of the graph). We can see an increase in Solar input, which is still quite low, but also look at the (blue) line indicating the battery charge state. They are full by 14.00hrs that day so that the MPPT controllers will return to zero, and the system fully charges. Red columns are AC & DC loads. These have increased slightly as additional systems come on line day by day.
So, we can tick that box and move on.
DMS Magnusmaster Stabilisers
There followed some good news as we visited DMS Stabiliser in the Netherlands, in the form of Patrick Noor, his family, and company. Smart, innovative, and client-focused would be my takeaway. I'd also throw in genuine for good measure. We targeted our day at understanding how their Magnusmaster system worked in practice.
We selected Magnusmasters as they will fold away from damaging ice or logs and can break away in the event of impact without risking a hull breach. Two rotating cylinders, one on each side, generate a maximum of 4 tonnes of reaction force across our narrow 5.2m beam. That is a significant lever arm keeping us level.
A practical demonstration used a yacht owned by a client of DMS. Testing a stabilizer on a dead flat Dutch canal is not effective proof; they can, though, run them in antiphase to force a roll. Refer below to a video of what happened on a yacht of a similar beam to ours. Force the antiphase and the roll is both immediate and significant. Switch to "in phase," and it stops within 1 cycle.
We look forward to using these in anger as soon as the sea trial begins. For good measure, I've also included a video showing deployment time; for the forgetful among us, they will fold automatically when the transmission is set to neutral.
Keeping it light for this week, we also started both engines to connect the drives. For now, it's a wrap.