Lets see the board feedback on who they think is the best:
* PV panel systems
* Wind
* Solar Water Heating
You need to specify whether you're talking about home installation or utility-scale.
Here are my thoughts. Proceeding from most expensive to least:
Household-scale PV can be pretty expensive, depending on the subsidies available. In my view, its main benefit vs. other household improvements (see below) is in making it possible for your home to have a carbon footprint of zero. It usually only helps your electric bills substantially if air-conditioning costs are the biggest component, or if electricity is just really expensive in your area (or, again, if the subsidies are good). Eventually, hopefully, PV costs will drop to the point of it being just a no-brainer, but that hasn't happened yet. But there's also the grid-level benefit of distributed power generation, reducing the loads on (and therefore efficiency costs of) transmission lines, though that may be countered somewhat by the fact that having many small installations means certain overhead costs and inefficiencies aren't minimized thru scaling (inverters, metering, installation costs, maintenance costs,...).
For utility-scale solar, having a system with moving parts/fluids is quite viable, so there's a choice between PV and Solar Thermal. Solar Thermal (and any other setup involving concentrating sunlight) requires a very cloud-free climate to be efficient -- but, in such a climate, can be more efficient and cheaper to build at large scale than current PV (and can use thermal storage to provide nighttime output). For cloudy climates (e.g. Germany), it really has to be just straight PV, as the output doesn't fall off nearly as sharply in overcast conditions.
At intermediate scales (e.g. PV arrays over parking lots), I think PV works very well -- the lack of moving parts is still a big benefit, yet the overheads that reduce with scale are reduced quite a bit, and it still has the benefits of distributed generation.
Wind is best at utility scale, because it's most efficient (and least likely to kill birds) when it's large and high up in the air (several hundred feet at least). Wind availability is even better offshore. For the home, it's generally a poor choice, unless you have special circumstances (say, you're next to a cliff that channels the wind past your house, and blocks the sun).
Now, when you start talking about solar water heating, you're really getting into another realm, one that deserves a lot of attention. (This of course is not utility-scale, since water and air heating are not usually a multi-household utility.) There are a variety of items in this category, including:
- Solar water heating for space heating
- Solar water heating for "Domestic Hot Water" (DHW)
- Air thermal panels
- Building design
- Efficiency
Note that I'm putting efficiency last, because I'm going from most to least expensive, and efficiency is by far the cheapest alternative, especially when it can be incorporated into the design of a structure to begin with. That can reduce your energy needs to a quarter or a tenth of what it might be otherwise, at least for space heating/cooling; only after addressing that to the extent possible should one start investing in various solar collectors.
Among these, solar DWH is probably the least impacted by structural efficiency upgrades (drain-heat reclamation can be very good, but only if your drain pipes are accessible; behavioral changes are probably more significant), so it could be installed as a first step, before any efficiency projects.
Anyways, to sum up, and rework your list a bit, I'd rank it like this, based on a vague notion of "good":
1. Efficiency upgrades
2. Solar DHW
3. Solar space heating
4. Utility-scale wind
5. Intermediate-scale PV
6. Utility-scale solar
7. Household PV
I'm kind of surprising myself by putting household PV last, actually. But I still intend to add PV to my house, after addressing the first three items.
I'm also leaving out the transmission component: distributed power generation helps reduce the need for transmission in some ways, but having a lot of long-run transmission available is still necessary to allow a totally sun- and wind-based supply to provide a reliable supply. In the absence of really effective mass storage for electricity, you need to be able to draw from other regions that may be experiencing better conditions, if your local sun and/or wind resources are coming up short at the moment.