can you explain me what's the point of hydro plants?

[ColinTH]

. sorry but can someone explain me what's the advantage in building hydro plants?...

1 - Helps to build spaceships. (as mentioned)

2 - Helps to build Utopia Project.

3 - Helps to build much needed ANYTHING.

. oh yeah and i forgot that an hydro plant takes an aluminum...

Oh! You don't have alluminium - Trade for it then! You can trade for any resource you like as long as you are not continually pressing next turn!

 

[Maniac]

They're in some (few) cities a worthy investment if you only count the hammer cost of a Hydro Plant. But are they worth it if you also take into account the research cost of its prerequisite tech? Its prerequisite tech is kinda optional to research if you aren't going for a Diplomatic Victory. And as said the building is situational, so there are likely to be few cities to divide the theoretical research investment required per Hydro Plant built.

 

[ignite]

Looking at the numbers...

I have a city (not capital) with 17 base production and 35% modifier (10% workshop, 5% liberty policy, 20% golden age), so my production is 22.95. Adding a Hydro Plant would give me 11 extra hammers from the river tiles. Without golden age, but with railroad later on, I'd be netting 15.4 (11*1.4) hammers from the hydro plant. Converted to Wealth, that's 3.85 gold, covering the 3 maintenance cost. I'm also paying 2 for the Workshop though. Altogether my output would be 28 base, 39.2 after modifiers, 44.8 in golden age. The workshop pays for itself because it already gives 2 hammers, plus the 10%, and the GE slot. I'm 4 tiles from my capital, so railroad would be 8 gold for a 25% boost. Without the Hydro Plant, the railroad would be adding only 4.25 hammers. With the Hydro Plant, it adds 7, so except for the faster travel, the railroad doesn't pay for itself, while the hydro plant does.

In theory then, if the Hydro Plant adds enough hammers, it's worthwhile to build even if you're just converting the hammers.

 

[Hpuk]

This thread was before G&K, which revamped the tech tree completely when it comes to hydro plants.
Before G&K it was often somewhat of a waste to get (or at least hard build) hydro plants, not because they were bad, but because they resided in an inconvinient spot on the tech tree, and came too late to really pay back the hammers they would cost to hard build.

They were in Plastics (Modern Age) in Vanilla, and are in Electricity (Industrial) in G&K.
The whole Refrigeration tech line in Vanilla was pretty useless, it came way too late to pay back the investement for any victory type, except Diplo since it requires you to go through those techs.

 

[gozpel]

they used to be better before the GA nerf to production.

they would put 1 hammer onto every tile with a river beside it. Hit up a GA and all of those tiles now have 2 hammers. Made grassland riverside tiles very useful.

This is a very good point if you're going Space-win.

Even a fairly poor hammer city, can build one of those cheap boosters in 14 turns, while the others concentrate on the heavy-duty ones. Done this many times, you just have to time it.

And at this stage, of course you bought everything for these cities.

A saved Artist will certainly help here. Golden Age when it matters!

 

[joncnunn]

You have a city with 35 production (which is ok) and it takes 35 TURNS to build the hydro plant. the hydro plant cost 3 gold to maintain, takes x2.5 or so production time to complete compared to the windmill, cost x1.5 more to maintain than the windmill and yet give less than the windmill.. at best, the hydro plant only gives +5 hammers or maybe 6. sorry but can someone explain me what's the advantage in building hydro plants? oh yeah and i forgot that an hydro plant takes an aluminum...

For a city that can build build a Windmill and a Hydroplant, the Windmill would indeed be built first.

Hydroplant's benifit is dependent upon number of river hexes in the city. (+1 per tile); but any buildings that improve % production yields further improve it.

Things slow to build are often cash rushed.