The development of solar cells has not stood still. Both cost reduction and performance enhancement have progressed substantially over the last 15 years. With efficiencies of 19-21%, and with the ability to adhere solar cells without of the use of traditional aluminum frames, we see the use of photovoltaic cells on boat cabins and decks as getting more and more attractive. You can get a lot more solar cells on a boat, than a car.
We are attracted to the simplicity of having the solar arrays adhered to the flat, or almost flat cabin tops, with some decking also possibly covered. To this end, most of the central plan area of the Trybrid is covered in solar cells, and with approximately 120 square meters of photovoltaic’s onboard before decking is used, there is a similar potential power source output as comparable 16,000 watt solar powered Sydney, and where we would expect a gentle hull speed of around 7 knots under sun and battery power alone, before the generator is deployed.
16,000 watts of sunshine fed solar power is enough to power maybe 8 regular homes, so at anchor, the Trybrid has a large amount of ‘domestic’ power for all the usual appliances of a normal home, including air-conditioning. This abundance of solar power would for example, be very useful for emergency desalination capacity. There is not enough solar power available to power the boat up to its 20 knot target, but there is enough for daytime cruising at around an anticipated 5-7 knots. With 2.4 tonnes of lithium batteries on board, there is plenty of storage available for night times or very cloudy days, but the weak link in terms of capacity is in the conventional battery bank, which would not be able to support full speed use for any length of time. Its this inability to store energy of any sizable amount by even the very best battery weighs on the mind of everyone in the hybrid design area. 2.4 tonnes of lithium battery will hold around 200kwh or electricity. This compares with 500kg of hydrogen , (in an unfortunate 7.7 tonnes of carbon wrapped cylinders), can hold over 10,000kWh. 10,000kWh of hydrogen vs 200kWh of lithium battery power says it all. Its for this reason that Trybrid looks to store half of its energy reserve in hydrogen, slowly made onboard through electrolysis. The electrolysis can and will be powered by the photovoltaic power source, but which will be topped up by shore power when faster fuel production is needed. Battery storage is an area well worthy of research and expenditure, as a better electrical storage system could obviously provide huge reductions in diesel or biofuel use. A boat can carry batteries much more easily than a can or an aeroplane. But even though nearly two thirds of the available electricity is lost converting both into and out of hydrogen, when you have a sizeable PV power stream, you might as well suffer the loses, as once the batteries are quickly charged, any residual power, for years to come, is looking for a use, and that use is hydrogen production. This makes TRYBRID one of the very first, if not the first mechanized means of transport to make its own hydrogen fuel source. This boat is one of the very first means of transport to close the loop on renewable use and its onboard manufacture. Just leave the boat alone, and eventually, it will refuel itself.
But the 50- 55kWh of electricity needed to make just one kilogram of hydrogen, (which is roughly the same as making the energy of one US gallon of petrol) has demanded more photovoltaic and wind turbine output, so a large new array of solar cells are designed to up production of power when the boat is at anchor or dock. With boats often idle for 90% of their life, there is logic in using the down time to make power….hydrogen power. This is an idea in its early days of development, but its an important first step into the new energy models of the future.
Below is a perspective of TRYBRID with its added ‘at anchor’ photovoltaic and wind turbine accessories, upping the power output from around 16kW to over 25kW, infact more:
Advancements in photovoltaic technology only bodes well for the future, as more cost effective ways to ‘slice’ the expensive silicon layers are advanced, and as other methods of tapping the energy of the non red spectrum light are researched. This is not an idle technology. And it is no longer a cost prohibitive technology, albeit at around maybe US$10/watt for the higher quality and higher efficiency solar cells, the raw photovoltaic costs for Trybrid are approaching US $160,000.