So I decided to add some solar panels to my 2008 430e.  The 4 panels and controller are from SunWare in Germany and were very easy to install.  The deck pass-through connections also came from SunWare.  The panels are only 38 Wp each and I may add more after I live with these for a while.  The panels are walk on and have a non skid surface, and the best part is no big ugly arch.   

We did an audit on our DC energy usage and at that time our average daily usage was about 250ah. We added 20% to that figure and therefore wanted a system that could deliver 300ah daily in "normal" conditions. Victron have a small APP on their website that helps you calculate the amount of solar yopu need for the area you are operating your boat - different areas = different average hours of usable sunlight per day. From memory the APP calculated we needed about 900watts of solar. We ended up fitting 1025 watts. Now after having the system for 18 months and adding more and more use of the DC onboard we now wished we could have fitted about 1400 watts but we get by with the 1025 watts on good solar days. Our normal daily DC usage now is about 400ah - this includes running 2 frigs, one freezer, runing the water maker for say 2 hours, running the water heater for showers, coffee maker, washing machine, TV, vacuum cleaner, toaster and hot water jug etc.    

Apart from having "enough" solar you also need to reduce shading and fit enough solar controllers so if one panel is shaded it does not effect the output of other panels - eg if you have two panels going to one controller and one panel is slightly shaded the output of both panels is drastically reduced. We have 3 panels with 3 MTTP controllers.  

Unfortunately it is very difficult to add enough solar to a monohull without a arch. We have other forumites here who have added flexible solar panels to their bimini which is another option. We have various other cruiser friends who have also done this but it seems the flexible panels (even the expensive ones) do not last all that long with some friends having these panels fail after 12-18 months. It seems although these panels are flexible they do not handle continous flexing. 

If solar is done right it is great, if not done right it is just an expensive way to make not much power. 

They are all custom jobs. I looked at a lot of other boats with arches before starting. You just need to be specific with what you want. The SS fabricators often just want to do the job that is easilest for them. As we line aboard 24/7 we would see this arch every day so it needed to be the best we could do. For us there were a few musts-

1. Follow the curve of the bimini.

2. 38mm tubing was a better size than 50mm which looked a bit too chunky.

3. The arch could not go outside the envelope of the boat on the sides so if/when we came up against a high wharf the arch would not hit.

4. Not hang out aft of the transom much.

5. Incorporate the pushpits and stanchions. Including the nicely tappered Hanse cable connections.

6. Land the legs on the existing stanchion backing plates in the fibreglass.

7. Run the cabling through the uprights so little cabling was visible.  

8. Fit a LED flood light to the arch over the transom. 

9. Material had to be 316SS Hipol

10. Panels to have minimal shading. 

11. The arch could not interfere with normal sailing or berthing - so bollards needed to stay uncluttered. 

Eventually we also braced the bimini off the arch which made the bimini more rigid and removed one more bracket from the original design. We found the panels provided more shade at the helm which was an advantage. The arch also provides something solid to hang onto when well heeled over. 

Photos of the bare arch before the panels were fitted but gives you the idea. The same fabricator has also now made a similar arch for a Oyster 485. 

An arch will not power all that lot on your list ... more for everyday consumption too.  So not really a fair statement.

Your picture shows the problem with one of the panels covered by part shadow - so that one will not provide any power.  Even worse any panel in series with it will not provide power either.   A separate regulator per panel would help this but maybe overkill for a small set of panels like this.   But yes you will get a small amount of power.

Here is my own contribution to this discussion. Now expanded our solar-glued-walk-on-flexible panels to 3, one on each side (60W each) and one in front of the mast (80W). I understand the comments about using an arch and avoiding panel shading, but we are not living aboard, and the panels are most designed to help with the power demands of the instruments and self steering when underway, and the big TV screen in the evenings. Fridge and diesel heater are noticeable draws, when away for a week or so. 

We have extra flexible panel provision for temporary install on the sprayhood (100W) and the bathing platform (200 watts). All these are connected to the same 30 amp MPPT in parallel, so substantial gauge wiring is used from the various panels to the MPPT. 

I note two interesting observations. 

1. In the latitudes we general sail in (57 degrees north), substantially more sunlight is received by the boat at a low angle, rather than a higher angle (>45 deg). So the 160 watts on external side of the stern bathing platform contributes significantly. 

2. Panels do produce most power when in the sun and unshaded, but all panels produce a few fractional amps, even when not in the direct sun. With enough panels and long daylight hours, this contribution is significant. Again, perhaps not enough to live aboard, but certainly enough for extended stays on anchor for a few days. 

Wiring all the panels in parallel (all panels are matched to have an unloaded voltage of 22 volts) relies on the blocking diode if a panel is in the dark. This seems to work well. Indeed one can go around the boat, covering up each panel and determine the fractional contribution in amps from each panel from the Victron MPPT Bluetooth app. In general each is additive, with even the panels on the shaded side of the boat making a noticeable contribution. Also noting it is impossible for all panels to be substantially in the sun at the same time, so no concerns about overloading the 30 amp MPPT. 

Some may dislike the look, but with all the focus on green energy, I suspect the trend will catch on. I like to be friendly to the environment, but I appreciate the cost savings in diesel too. 

I can check them just now remotely using the Victron VRM system and 12 v monitoring and an on board 4G modem. 

I think the panels I purchased were from Photonics Solar in the UK -