just want to add a few notes to this topic. Using solar to charge and using battery to power your systems is a wonderful idea. My only concerns here is how are you going to regulate that power so that you can use it. Dc is great but dc do fluctuate at a certain voltage. Your regulator has to provide constant voltage and amperage. Just my opinion.
Using Solar battery for DAC and Pre-amp
I did a minor science project yeasterday. I used Solar panel to charge my solar pure sine wave inverter battery at day time. Then I used the battery to power my Oppo 205 anb Sennheiser earphone amp. The result is super. A day sun shine will charge 100% of battery. Then I have 5 hr of of energy to power my audio equipments. The 12V to 110V pure sine wave inverter battery gives much clean power source (no noise for power grid) and it's 100% carbon free clean energy. I urge audiophile to explorer this option of new energy source: clean and pure.