Wind, solar, dams and wave. They may not replace coal and other fossil fuels today but we can substitute a lot of our energy needs with a concerted effort into those renewables.

I've got some bad news about hydro dams for you.

https://en.wikipedia.org/wiki/List_of_hydroelectric_power_st...

> 1,917 deaths

> 26,000 dead from flooding, 145,000 dead from subsequent famine and epidemics, 11 million homeless.

> 1800 - 25000 people killed

> 75 fatalities, due to turbine failure

There's also the part where we have tapped out the Earth's exploitable hydro capacity. Hydro output is expected to grow by ~20% by 2050. [1]

Unfortunately, it needs to grow by ~200%, if we want it to replace even half of the electricity currently generated by coal.

https://en.wikipedia.org/wiki/Hydroelectricity#Future_potent...

Hydro is also terrible for river ecology. Egypt gained a multi-billion dollar fertiliser industry (that didn't exist before) after they added dams to the Nile.

Dams hold back silt and sediment essential to farm land and despite everything you learned about fish ladders and salmon, they don't really work as well as the power companies say.

A large part of hydro actually is storage rather than production though. It's most valuable as a stabiliser for the electricity network.

Yes, but it also doubles up as a fairly reliable source of baseline power.

It's a great energy source. It's also incredibly dangerous, and cannot replace coal.

Nuclear is actually one of the safest energy sources. http://i.imgur.com/EkYYLRh.png

Plus carbon pollutants are known to be carcinogenic.

Put another way: coal kills about as many people each year as nuclear has in its entire history if you include the bombs dropped on Japan.

That is brilliantly put and I'm totally using it next time I have the energy conversation, and if it works as well as I suspect then just about every time after that too!