Here's an odd question; I work for a company that sells and installs renewable energy equipment. We've sold a few electric car owners solar-topped carports for their chargers, but it got me to wondering what car-lite and/or car-free folks might want in solar powered stuff.
Obviously a solar shade for an electric bike would be just a couple of 280W modules, (3'x6.5', roughly) maybe 4 at most, (1120W peak production would pretty much need to be grid tied to have something to do with the extra power.) which would be relatively pricey if we actually did the fabrication work, since our projects usually start at 10-12 of those modules. We might offer something as a kit. Shipping sucks on bulky stuff, but even still we've been able to beat other vendors on prices with shipping when we find a good deal ourselves.
At the moment, we generally don't buy any modules under 230W, because the smaller ones cost more per watt. If there was enough interest, we might work up something based on panels that will fit on a typical pannier rack, but we're probably not ever going to be interested in trying to compete with mass-produced solar phone chargers and such. Our business model is more based on finding an unmet need and looking for ways to fill it. So, what needs are there that solar could meet, but that nobody's trying to meet?
(Come to think of it, there might be some demand for just some sort of pannier attachment that would carry one or more midsize 12V modules and double as a stand. Easy to carry on a bike, and freestanding to charge your stuff while camping or picnicking. One of my homebuilt panniers just bit the dust, and I tend to be Captain Dashboard anyway.)