I haven't had a chance to thoroughly look over the solarcoin project you mentioned. It's on my list though. I'm sure I'll have a lot of questions, but it sounds very intriguing so far.
All fiat currencies are subject to fading out of existence, but energy will always have value. SolarCoin is a proof of stake time coin that is backed by a team with solid economic and technical abilities and promotes the positive externality of solar energy generation.Happy to meet @lpninja and I look forward to reading more into the whole project the next few days :)