The volatility in energy trades is a factor that also plays out in the renewable-energy sector: Solar, wind and nuclear stocks don't tend to go straight up for long, even if they've been going up this year. Four of the clean energy ETFs, including two solar ETFs, had huge losses last year before regaining ground in 2017. Even this year's big winner, PBW, has a three-year annualized return of –13 percent (5-year annualized is –1 percent). And that was under climate-friendly President Obama.
The Global X Uranium ETF (URA), up near-15 percent this year, has a five-year track record even worse than coal's, with an annualized loss of 20 percent, according to Morningstar. The Guggenheim Solar Energy ETF (TAN) has a three-year annualized return of –23 percent.
PowerShares' strategist Bloom said, "Renewable-energy trends are moving in the right direction, especially if you look at the opportunities in China where many of their larger cities have hit toxicity thresholds. Economic growth continues to accelerate clean-energy adoption around the world, and with rapidly expanding economies of scale, we may see performance smooth out going forward."
Bottom line: Elections may ultimately sort out domestic priorities, but economics — and recent stock-sector performance — matter a lot more to investing than political promises.
— By Tim Mullaney, special to CNBC.com