Sustainable energy, I don't even have to think about it.
For me, FIRE has always been more about doing that than escaping my workplace per se.
Following.
Excellent! I have met many others that feel the same kind of burning passion around sustainable energy. What are your views on the various cleaner sources?
Well, for starters, the most economical energy investment is still in efficiency upgrades. From the standpoint of a utility (or of any energy producer), demand reduction can be modeled as a source that automatically synchronizes to demand... which is the best kind of source, in addition to being cheaper than new production capacity (all types). It's worth noting that electric vehicles represent a major reduction in overall energy demand, as well as lifetime cost of ownership (facts that get lost in the noise of emissions arguments and purchase prices, respectively), so I do spend some time advocating that as part of the big picture. Other than that, the highest-ROI items are much more mundane and have all been mentioned in MMM articles... efficient lights, insulation, air sealing, HVAC etc. My startup is heavily focused on retrofitting rentals to be as efficient as possible, via the above.
As far as production, I'm a big "all of the above" guy, including FFs to the extent they're needed as bridge fuels (though that's often wildly overstated../$.02).
I strongly support solar and wind, have invested heavily in both, and my local power mix is heavy in nuke and hydro, which I also think are great for what they are, though both have major barriers to expansion and are generally best left at their current deployment levels. Existing hydro in particular has great synergies with wind power... collocate new wind farm, use existing transmission lines (reducing cost of new wind) and use the dispatchable hydro whenever the wind doesn't blow. No batteries needed, and extremely high renewable penetration is possible.
My company also owns some shares in a company that makes compressed pellets from wood waste... if you heard about the UK recently having its first day in over a century with no coal burned for power, that was one of the gap-fillers that made it possible. Not the best source, but an interesting and profitable transitional fuel with less overall pollution and, aside from manufacturing and shipping, a closed carbon cycle.
I'm also looking at investing in storage technology and/or lithium production, but it's still too speculative at this time for me to commit.
What does 'Following' mean?
Following this thread, since I'm curious what others think about the concept.