Bimini with Solar Panels
Sept 10, 2009 12:55:58 GMT
Post by sailingpages on Sept 10, 2009 12:55:58 GMT
Hi,
One of the things we always had in mind with our 36i was to install a bimini and solar panels that are in line with the styling of the boat. i.e. Complementary or an enhancement, not detractive. Last year we approached Dave Elliot from Daves Trimmers Brisbane, Qld, AU with a rough plan of what we wanted to achieve. He come up with a great design and we had the bimini installed during our commissioning but with all the outlay we left the panels until now. The following is a summary of what we did in the hope that it might be useful for others.
The alternative power solution for us was to be completely solar. Our preference, but we do not really like wind generators for a few different reasons, and solar is ideal given the amount of sunshine in Australia.
The power solution I designed consists of
4x Kyocera KD95 95 Watt solar panels
1x Blue Sky Energy 3024DiL Maximum Power Point Tracking regulator
1x Blue Sky Energy IPN Pro Remote Display
2x Lifeline GPL-31T AGM Deep Cycle Batteries (@ 105 Ah each).
1x Lifeline GPL-1400T AGM Marine starting battery
8m AWG 6 for both positive and negative array feeders
Using the modelling software that I also use for my Oceanographic work www.homerenergy.com, this solution (i.e. balance of PV power and battery capacity) will provide just surplus to our load requirements whether on passage or at anchor all year round.
1. The mounting of the panels
From the photos you can see how the bimini was designed to incorporate the solar panels. To mount the panels, brackets to suit 25 mm stainless tube were mounted with longer bolts to protrude up through the aluminium extrusion of the panels. A custom made delrin spacer was sat into an 8 mm hole in the panel extrusion to isolate the stainless bolts and the aluminium.
2. Wiring
Two panels on port are wired in series to give +24V. Two panels on starboard are wired in series to give +24V. 3x Schottky diodes are then used between the positive terminal of each +24V array to connect to positive feeder. The negative of each +24V pair is connected directly to the negative feeder.
3. Regulator - MPPT
Basically if you want the best value for money out of a larger array, you need to use a maximum power point tracking regulator. Why is this? Solar panels are constant current devices meaning that they produce the same current regardless of the voltage the terminals are held at. For instance, the KD-95 panels we have used produce maximum power at 17.9 Volts with a current output of 5.31 A (under 1000 Watts / sq. metre insolation). Power = Voltage x Current = 17.9V x 5.31A = 95.05 Watts
If we were to place this panel on a standard solar regulator which will hold the solar array at the battery charging voltage (typically +14.4 V for bulk charge), the Power Output = Voltage x Current = 14.4V x 5.31A = 76.46 Watts which is 20% less than at maximum power. With four panels, you would nearly be losing the equivalent of an entire panel by using a standard regulator. A MPPT regulator uses switchmode power conversion to keep the panel voltage at maximum power, and to charge the battery at a different voltage level.
The regulator we chose provides +12V battery charging from a +24V array, battery temperature compensation, auxillary charging (for engine start battery) and a remote panel with information such as state of charge (%), array current, charge current, temperature, Ah from full etc.
4. Batteries.
We chose Lifeline AGM batteries mainly because of my background in using these for remote oceanographic monitoring applications. Not the cheapest but by limiting the depth of discharge to around 70% / 80%, we expect to get 6 - 8 years of life out of them. The biggest advantages of AGMs are that they are genuinely non-spillable, require no maintenance, they have very low internal resistance and thus much greater efficiencies (around 99%, not 80% for most lead-acid batteries) and consequently faster charging.
Solar Regulator in Bottom left corner.
In summary, I have built this solar system using the same design philosophy used for a remote oceanographic deployments that only get visited every 2 years. It is what I consider an 'ideal' solar system for our use, with no compromise. Not cheap, but reliable with a long life expectancy and no maintenance. Best of all, it is very transparent in the way it is installed and will be even more transparent to us using it as liveaboards.
I am more than happy to answer any questions about our setup or your own.
Kind regards,
Geoff.
One of the things we always had in mind with our 36i was to install a bimini and solar panels that are in line with the styling of the boat. i.e. Complementary or an enhancement, not detractive. Last year we approached Dave Elliot from Daves Trimmers Brisbane, Qld, AU with a rough plan of what we wanted to achieve. He come up with a great design and we had the bimini installed during our commissioning but with all the outlay we left the panels until now. The following is a summary of what we did in the hope that it might be useful for others.
The alternative power solution for us was to be completely solar. Our preference, but we do not really like wind generators for a few different reasons, and solar is ideal given the amount of sunshine in Australia.
The power solution I designed consists of
4x Kyocera KD95 95 Watt solar panels
1x Blue Sky Energy 3024DiL Maximum Power Point Tracking regulator
1x Blue Sky Energy IPN Pro Remote Display
2x Lifeline GPL-31T AGM Deep Cycle Batteries (@ 105 Ah each).
1x Lifeline GPL-1400T AGM Marine starting battery
8m AWG 6 for both positive and negative array feeders
Using the modelling software that I also use for my Oceanographic work www.homerenergy.com, this solution (i.e. balance of PV power and battery capacity) will provide just surplus to our load requirements whether on passage or at anchor all year round.
1. The mounting of the panels
From the photos you can see how the bimini was designed to incorporate the solar panels. To mount the panels, brackets to suit 25 mm stainless tube were mounted with longer bolts to protrude up through the aluminium extrusion of the panels. A custom made delrin spacer was sat into an 8 mm hole in the panel extrusion to isolate the stainless bolts and the aluminium.
2. Wiring
Two panels on port are wired in series to give +24V. Two panels on starboard are wired in series to give +24V. 3x Schottky diodes are then used between the positive terminal of each +24V array to connect to positive feeder. The negative of each +24V pair is connected directly to the negative feeder.
3. Regulator - MPPT
Basically if you want the best value for money out of a larger array, you need to use a maximum power point tracking regulator. Why is this? Solar panels are constant current devices meaning that they produce the same current regardless of the voltage the terminals are held at. For instance, the KD-95 panels we have used produce maximum power at 17.9 Volts with a current output of 5.31 A (under 1000 Watts / sq. metre insolation). Power = Voltage x Current = 17.9V x 5.31A = 95.05 Watts
If we were to place this panel on a standard solar regulator which will hold the solar array at the battery charging voltage (typically +14.4 V for bulk charge), the Power Output = Voltage x Current = 14.4V x 5.31A = 76.46 Watts which is 20% less than at maximum power. With four panels, you would nearly be losing the equivalent of an entire panel by using a standard regulator. A MPPT regulator uses switchmode power conversion to keep the panel voltage at maximum power, and to charge the battery at a different voltage level.
The regulator we chose provides +12V battery charging from a +24V array, battery temperature compensation, auxillary charging (for engine start battery) and a remote panel with information such as state of charge (%), array current, charge current, temperature, Ah from full etc.
4. Batteries.
We chose Lifeline AGM batteries mainly because of my background in using these for remote oceanographic monitoring applications. Not the cheapest but by limiting the depth of discharge to around 70% / 80%, we expect to get 6 - 8 years of life out of them. The biggest advantages of AGMs are that they are genuinely non-spillable, require no maintenance, they have very low internal resistance and thus much greater efficiencies (around 99%, not 80% for most lead-acid batteries) and consequently faster charging.
Solar Regulator in Bottom left corner.
In summary, I have built this solar system using the same design philosophy used for a remote oceanographic deployments that only get visited every 2 years. It is what I consider an 'ideal' solar system for our use, with no compromise. Not cheap, but reliable with a long life expectancy and no maintenance. Best of all, it is very transparent in the way it is installed and will be even more transparent to us using it as liveaboards.
I am more than happy to answer any questions about our setup or your own.
Kind regards,
Geoff.
