This is the way of the future: a street lamp powered by solar panels and a small wind turbine, with a battery to store power for when there's been neither sun nor wind, which is still 20% cheaper than a street lamp connected to the grid.
I particularly like the nifty little turbine and can imagine a strip of them sited on the ridge of my roof.
The key point to take away though is that this is the future: the costs of wind, solar and batteries are going to keep on falling and ultimately no fossil fuel will be competitive. Especially if a carbon tax becomes a widespread reality.
Disclaimer. After nearly 40 years managing money for some of the largest life offices and investment managers in the world, I think I have something to offer. These days I'm retired, and I can't by law give you advice. While I do make mistakes, I try hard to do my analysis thoroughly, and to make sure my data are correct (old habits die hard!) Also, don't ask me why I called it "Volewica". It's too late, now.
BTW, clicking on most charts will produce the original-sized, i.e., bigger version.