Do we have enough energy in the long run?

Yes.

This raises a lot of issues, including scalability, E-ROI, cost, capital expense, infrastructure, convenience, reliability, storage and portability. I believe it’s established that wind and solar are scalable, and have good E-ROI, and that the other issues can be handled in various ways.

The other measures are a long discussion. Here’s a quote from a source with credibility in this area: Kenneth Deffeyes, author of both "Hubbert's Peak: The Impending World Oil Shortage" and "Beyond Oil: The View From Hubbert's Peak," writes that "there are plenty of energy sources other than fossil fuels. Running out of energy in the long run is not the problem. The bind comes during the next 10 years: getting over our dependence on crude oil."

Mathew Simmons says: "I happen to think the world can make the transition into what we might call the post-Saudi oil era in some very rational way that will limit economic disruption. As a perpetual optimist, I believe the world still works beyond Peak Oil. While oil prices in this new world will obviously rise, this rise can be a blessing, not a curse. Far higher oil prices make all other forms of energy more competitive and spur on energy research programs that might discover some real long-term fixes."

I envision a grid powered by a complementary mix of sources in roughly the following proportions: 25% wind, 25% solar, 20% nuclear, 20% smaller renewables (hydro, geothermal, wave, etc) 10% various storeable fuels such as gasified biomass, synthetic hydrocarbons, hydrogen, ammonia, etc. Nuclear could be eliminated if desired, though at a significant price in transitional excess CO2 emissions, cost and reliability.