Tuesday, August 11, 2009

Hydroelectricity is the Best Renewable

Hydro power is the most desirable and cheapest way of generating electricity in a renewable fashion, therefore it should be used as much as possible. This is done well in NZ and Australia (Snowy Mountain Scheme and Tasmania.

There are pluses and minuses, though.

Plus #1
When combined with thermal plants in a high load (city) region you can operate base load supply with thermal plants at full steam ahead and use no hydropower. Twice a day or so, or during times of peak demand, or in summer when there is a heat wave and high demand, you can essentially "turn on the tap" at the hydroplant and immediately meet that extra electricity demand. (Not very likely with a wind farm!). With a spare thermal plant it takes along time to "stoke it up" and you would have to keep operating on standby to do this.

So the hydro dam storage of water represents stored energy available whenever you need it. This the problem with wind and solar energy, there is no easy way to store it and the supply is intermittant and unreliable anyway, and so is a nightmare to feed it into the national grid. Hydroelectricity is good to met those peak demands. Even a small hydroelectric plant is very useful.

Hydroelectricity supply is actually dependent on the weather or climate. Last summer the dams in NZ got down to 50% capacity and they were worried about the situation.

Plus #2:
Hydrodams can be stocked with trout and made into a valuable recreational region, as they are in New Zealand. Some of my best trout I have caught in hydrodams, or in the river oulet below.

Minus #1
Most of the best hydrodam sites are already being used. To get another one would require a huge battle with the Greens and environmental movement. Look at Brumby in Vic ignoring the alternative of daming the Mitchell River for water supply, but instead building a desalination plant costing 2 or 3 billion dollars. There is a lot of water there going to waste, but the Greens mean votes for Labor!

Hydroelectric plants are by far the best renewable source of electricity. The worst and least economic are windfarms, about which I will have more to say.