Members of PMG Shipyard’s advisory board, Philippe Guénat, Raphaël Domjan and Michael Lopez-Alegria

Building a Luxury Solar Assisted Yacht is more than just adding solar panels to the roof. There’s no advantage in using green energy if managing the use of it isn’t optimized. We at PMG Shipyard had to completely rethink how we would gather, store, distribute and manage the green energy for use to its maximum potential. On top of this, we wanted to keep the use of Heliotrope as simple as possible for the owner. To this end, various high-end technologies had to be incorporated.

Gather Maximum Solar


With limited space on the roof for solar panels, we had to find the most efficient solar panels on the market. At the time when we built the Heliotrope 65, that was Sunpower’s E20 series panels, offering a then unmatched 22.5% Cell Efficiency (20.1% Panel Efficiency) for a commercially manufactured panel (Typical efficiencies range were from 14% to 18%). That enabled us to produce nearly 8000W of Solar Power at peak. This is enough power to have the air conditioner run in the day direct from Solar Power Only and still have surplus for charging the batteries! The panels are so efficient that we can charge the house battery bank from 40% to full by 10AM in the morning on a clear sunny day!

To make sure there is power when it’s needed, we had to install a bank of gel batteries to a capacity of 2000Ah @ 24V. This provides enough capacity for comfort at night without having to run a noisy generator. With gel, we found a cost effective battery that was maintenance free, had a long life cycle and was durable on a cruising yacht.
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Optimized Power Distribution and Management
Mastervolt C-Zone Digital Switching

The key to making it all work together was to implement a smart switching system (or digital switching) that could allow for reliability, flexibility and efficiency on board. After evaluating various products we decided on the Mastervolt C-Zone digital switching platform. C-Zone has in essence become the nerve centre on board Heliotrope. Imagine boarding Heliotrope and getting her ready for cruising. With the press of one button the boat will start up all systems required. No need to go to a circuit breaker panel and start all required systems manually. C-Zone does it by itself. It’s the same if you anchor at a beautiful bay; with the press of one button the boat will go to anchor mode, and you can relax. When back at dock you can press one button and Heliotrope will be in dock mode while keeping the essentials running when needed. With C-Zone we could do more than provide just comfort but also smart functions. With limited power on board, managing load shedding is often a complicated task on yachts of this scale. Doing it incorrectly can trip fuses unnecessary and cause other unwanted problems. With C-Zone this task is managed automatically via smart algorithms. For example: on board is a commercial dishwasher that uses nearly 7000W of power for washing dishes in less than 3 minutes. The problem is that using it along with the air conditioners could overload the system causing breakers to trip. With C-Zone if the owner switches the dishwasher on, the system automatically switches the Air conditioners off, allows the dishwasher to finish its cycle and when done, switches the Air Conditioner back on by itself. To the same extent, if the batteries get dangerously low, the system will warn the captain or can even limit the use of non-essential products on board so that the critical components can work for as long as possible.CZONECZONE-logo
Today C-Zone has become the only trusted Digital Switching system and was used as standard on all of the Volvo Ocean Race 2014-2015 yachts. In this race the yachts, crew and equipment get tested in the most extreme environments and conditions and C-Zone’s been performing perfectly!