Do I need an inverter? ...Generally the answer is no if you are not running microwaves, hot plates, blenders, and coffee makers. Why have expensive and complicated electrical systems in your van that can cost well over $6,000? The need lots of power and your batteries will have to be located within 3 feet iof your inverter that converts 12v to 110v power and complicates layouts in vans. Adding an inverter and extra outlets isn't much different than adding a panel to the side of your house, that's not cheap is it?
If you have a lap top; a simple small pure sine wave inverter will do the trick and plug into a 12v outlet. Keeping things all 12v keeps costs way down, simplifies the build greatly, and keeps things really simple. A 12v auxiliary battery and solar depending on install location and type usually is under 5k, a aux battery system under 3k.
Solar-most don't need solar unless you are running a fridge and not driving your van for 3 days or more for an extended period. Solar alone doesn't run your electronics, it refills your battery bank, you need to start with that first...then add solar. Most make the mistake that they think by just adding solar you meet your electrical needs. Its actually the opposite, your battery bank meets your electrical needs, then you need to recharge your battery based on needs through your alternator and/or solar.
Solar is recommended when using fridges or parking for extended periods of time while camping keeping your aux batteries charged up because you are not driving
Larger Deepcell AGM aux battery increases ability to run larger items and go longer without recharging. Here is example of stock battery on right and upgraded battery on left. 2 x more available power.
Example of a simple inverter that will plug into a 12v outlet. Make sure you always use Pure Sine Wave Inverter for your electronics.