mega factory vs solar powerplant?

Each adjacency gives +5%. So, for every adjacent manufacturing building, the Solar Plant gains 1 more bonus than the Mega Factory, which translates into a +5% advantage.

Since the Solar plant starts 8% behind the Mega Factory, you need to have at least 2 adjacencies for the Solar plant to be more beneficial than a Mega Factory in the same position.

You can only build 1 Solar.

Try aim for this to get maximum industry;

Hive/Durantium Refinery/Industrial Wonder in the centre, surrounded by 5 Mega and 1 Solar.

Will definitely give a big industry output when fully upgraded.

Even if you only build a single manufacturing improvement on a planet, allways do the (solar/fusion/quantum) power plant (since you are only allowed one) first.

The reason being the manufacturing you invest in it in comparison to the benefit you get. In case of no adjacency mega factory vs. solar pp, you are looking at 30+45+67 = 142 manufacturing for 33% vs. 45 manufacturing for 25% manfacturing. It takes quite a bit of time for the mega fac to pay of that deficit. Once you can upgrade to fusion pp, this discussion is obsolete anyways, since that one gives 50% manufacturing and is as good as the highest tier factory at lower manufacturing cost (45+67 = 112) than a mega factory.

OK similar question about Durantium Refinery? It gives s solid plus rather than precentage? so is SPF better than DR? (lets say surrounded by all base factories). If at some point when does it drop off?

There might be some special cases when you have very high pop planets with very low +% manufacturing, but apart from those:

DR (if you can spare the durantium) > powerplants > factories.

Thanks ZP - didn't know that.

Also remember the upgrades to the solar plant are much better then the factories (fusion +50%/+3 adj, quantum +100%/+5 adj).

If you've got decent adjacency (i.e. 3 or more buildings), it's even worse.

DR > (any of the special bonus buildings) > Manufacturing Capital > Power Plants > Factories

Well, if you put a manufacturing capital on a planet you should have the DR next to it in any case anyways. But lets take a look at what I wrote above:

So you have: 40 base manufacturing x3 because of the +200% so: 120.

If you put a DR on, which adds, lets say 12 manufacturing (4 from adjacency), you get 52 x3 = 156

If you use a manufacturing capital instead, you get +200% manufacturing (total of +400% manufacturing), you have 40 x5 = 200.

This is a rough estimate which mostly ignores adjacencies, but you get the idea: for high pop low +% manufacturing bonusses, the capital can be the better improvement.

But as I said before. If you can afford a DR, you should put it on the same planet as the capital anyways.

Except that you lose much of the bonus of having a MC on a world if you can't park it next to a bunch of factories or other improvements.  It seems silly to put a MC on a world all by itself. Not to mention that having a Raw Production of 100 is *extremely* difficult to do - you'd need 50 population/mining, 100% morale, and 7+ Economic starbases to get that.  Very few worlds are going to get a RP above 60 or so until late game; heck, most worlds won't crack 40 RP.  Basically, the MC only is superior to the DR when you have at least 40 Raw Production, AND less than 3% Manufacturing Bonus per point of allocated Manufacturing Output. The situations where an MC is better than a DR are so far outliers as to be completely irrelevant/ignorable.

It's like saying that there are some cases where you can use an Abrams' 120mm gun as a breathing tube for the crew. Sure, there are, but they're so extreme that no rational being is going to do that.

I suppose this discussion continues here now.