Solar panels are usable too far out and RTGs never become economical

[OdinYggd]

The practicality of RTGs depends on what you are doing too. Solar panels require large batteries to keep heavy loads operating at night, while an RTG bank enables those same loads to operate round the clock regardless of orientation.

Its a bit of a tradeoff- weight for reliability. RTGs don't break, don't wear out, and always produce the specified amount of power. In exchange they are heavier and bulkier for a given output than a solar panel and battery bank.

As such, I prefer using RTG power for surface craft, that way at night they never run 100% out of power even during long nighttimes. Of course high demand craft will usually have solar panels or kethane-burning generators for main power, and the RTG is just aux power so that it stays controllable.

At some point in the future we might see RTGs having a decay factor, but for most missions this would be irrelevant- the RTGs last longer than most of our save files.

[architeuthis]

It would be nice if solar insolation followed the inverse square law. I agree with the OP that RTGs could be made more useful; currently they are mostly advantageous only for planetary surface missions with large power requirements (i.e. rovers). For surface bases it is probably easier to just use large batteries (I imagine when economics are included RTGs will be very expensive if they follow reality as a guide). In general it would be nice if the electricity mechanic was a little more fleshed out. I made a graph a while ago showing power levels for several solar panels if insolation from Kerbol did follow the inverse square law. Just for kicks it looked like this:

*y-axis is to log scale.

*For reference Jool is about 5 KU away from Kerbol.

Edited January 26, 2014 by architeuthis

[Alchemist]

For RTG there also could be different types (or just tweakables) with different half-life, so that there could be light and powerful sources that decay in several weeks (useful fur Munar probes), a bit heavier that work for months (medium-range interplanetary probes) and something with completely terrible power to weight ratio, but works for years and decades... And imagine Eeloo mission when panels don't really work, but proper RTGs are also a bit too heavy...

[Djolox]

The solar panel generating as much as it does makes some sense, even as far away as eeloo. Why? because in real life, Earth would orbit out much farther then eeloo. also, the rtgs are meant more for base power (providing a constant supply), while the solar panels help with peak loads (when demand is higher than supply for a short time).

Kerbol is less "shiny" than sun has smaller radius and that means power supply for panels are the same as in Real World

[coolitic]

I dont want RTG's to decay. Time warp being one reason and also it would take out much of it's reliability (hence messing up it's role).

Until they make reasonable ion engines/uses for large power solar panels are useless. (non-tracking ones have the advantage of being extremely light though)

[WhiteWeasel]

In my opinion, the only time I use solar panels (beyond aesthetics) is for ships with ion engines. That said, nerfing solar panels to match the RTG (2 or 3 of which can power quite a few reaction wheels) would utterly screw over any ship that uses ion engines. If anything, we need more heavy power sinks beyond ion engines to justify the use of solar panels because frankly, RTG's are going to provide all the power you need in most cases.

Edited January 28, 2014 by WhiteWeasel

[Rusty6899]

At the moment, if anything, I would say that the RTG's are too advantageous.

Obviously they can't compete with the solar panels for e/t, but that isn't the biggest concern for most missions. A single RTG can provide enough power to operate any command module and an SAS module simultaneously, meaning that unless you are transmitting science data from a short encounter, you are unlikely to need to worry about the electric power in your vessel (even then, I think you may be able to spam the perform experiment/transmit data buttons and it will send data when power becomes available). Does anyone seriously use Ion engines?

The mass of the RTG is also unlikely to affect Delta-V in any significant way, even for very small probes.

The obvious advantage of the RTG is its ability to work in darkness, meaning that it can have a significant edge on solar panels depending on the mission.

I do, however, agree with the OP in certain ways.

In my opinion the RTG, in the final game, should be a very high cost item, to be used only when it is critical for the mission. This would be best implemented by allowing solar panels to be sufficient for electric power gathering for solar distances up to Duna/Dres. For Jool/Eeloo/new outer planets, the RTG should be a necessary investment (this also helps to develop a logical progression of exploration to new players).

A further use could be created by the ability to collect and transmit "night time" atmospheric conditions on bodies, where the RTG's would again be beneficial over panels.

I also think that a finite, albeit very long, lifespan for the RTG would help for game balance and realism.

In the future, if I am planning a Jool mission, I want to have to consider whether it is more cost effective to have 2 tonnes of Solar panels to sustain my electric power needs, meaning that I will need an extra ~25 tonnes of fuel/engines to conduct the mission, or use a hugely expensive RTG.