Wait to install photovoltaics

The perfect is the enemy of the good.
We need to figure out the 20% that we can do now that will capture 80% of the benefit, not be paralyzed doing nothing waiting for perfect solutions.

If you want to install photovoltaics, first wring every bit of energy efficiency out of the house.

New energy efficiency standards for refrigerators are coming online, so if your refrigerator is old, it might be worthwhile to replace it, depending on how much you pay for electricity and how hot it is where you live.
The warm white (sometimes labeled as 2700K) compact fluorescent bulbs are really cheap and good now, and if you replace a light that you have on all the time, like the light in the kitchen, it will pay for itself soon and then keep on paying. You will be astonished at how much more light is directed to where you want it by a spotlight. Even an 8 watt bulb can be quite adequate if the light is directed to where you want it. I replaced a 60 watt incandescent spotlight that we leave on all the time, so that the house is not pitch black at night, with a 11 watt warm white (2700K) compact fluorescent spotlight like these. http://www.1000bulbs.com/R20-PAR20-Compact-Fluorescent-Floods/ It paid for itself in less than two months, and has continued to save $50 a year in electricity. I mean, why throw away $2,000 over the rest of my life?
The water heater... Ah, the water heater... Probably the single biggest user of energy in your house. Have a plumber flush it out annually because any sediment in the tank reduces efficiency by blocking the heat from getting into the water. Turn down the temperature of the water heater... scalding water should not come out. If you can control the temperature of the water, I do not understand why you would want scalding water to come out and potentially scald a child or an elderly person (we lose the ability to judge temperature as we get older). Get a solar water heater. The freezing problem has been solved by using evacuated tubes. I have one that cost, in current dollars, 5,000, and has saved 30,000 over the last 30 years. It is a Solahart, and I have been very happy with it. There are all kinds of rebates and federal and state tax credits, so check around, and find out what may be expiring and what may be available in the years ahead. Sometimes, the tax credits have a limit to the total funds available, and when they run out, that is it! If person 8,765 uses up the last of the funds, and you are person 8,766 to apply, you will get nothing, nada, zip. This happened to many people in Florida, I think. Also, it might be possible to install half a system in December and the other half in January, and get the tax credit twice, once for each half of the system. That might make a big or a small difference, depending on the circumstances. Of course, you would have to ask a tax accountant about this before doing anything.
In general, if you install a solar water heater, you get the tax credit, and when you sell your home, the solar water heater generally increases your appraisal price, so it is a win-win for you.
If that is not practical, when you replace your water heater, look at a tankless one. They use half the energy because they don't have a tank full of hot water sitting there 24/7/365 losing heat to the environment. And they do not run out of hot water. Gas ones are better than electric... electric may require substantial rewiring.
That is much cheaper.

A number of issues with photovoltaics are about to be solved, and those solutions will make a huge difference in the performance of the system over its service life of 25 to 40 years.

It seems that the glass can absorb a lot of spectrum, especially IR, and can reduce the efficiency of the photovoltaics. Special glass that allows more of the spectrum through is very expensive. Perhaps the price can be reduced, or perhaps the increased efficiency would make this aspect of the upfront cost not very important.

There is also the matter of specular reflection. Perhaps Solyndra design minimizes this problem?

Currently, most photovoltaics are strung like Christmas lights... the old fashioned kind where if one bulb goes out, the whole string goes out.
There are two reasons this is a problem. One problem is that, if you have this type of panel, you must decide on the capacity of the DC/AC inverter, which is very expensive, for the overall system, before you start. If solar panels become really cheap in the future, you cannot simply tack more of them on to your system if that would exceed the capacity of the inverter. Another problem is that, because the cells are strung in line, if any one part of a panel is shaded, that is a bottleneck, and the output of the entire system drops.
The solution to both these problems is to provide an inverter for each panel separately. Since each panel has its own inverter, you do not need to size the whole system and can continue to tack on panels as the price drops, and this solves the problem of system output dropoff just because a small part is shaded. This is currently under development.

Then there is the problem of dust. If the panels are installed inclined, you may need to dust them off often. (There was a video of Bill Nye and Ed Begley dusting off their panels in an all out war to see who was greener, but I can't find the video online anymore. http://www.usatoday.com/tech/science/environment/2008-07-10-begley-nye-green-off_N.htm ) On the other hand, if something like the Sanyo HIT Double Bifacial Photovoltaic Module were installed vertically, presumably the panels would need to be cleaned much less frequently. If you don't think this is a serious problem, just ask the Mars rovers... http://www.theregister.co.uk/2007/09/10/rovers_ready_roving/

Then there is the problem of hail, baseballs, and golf balls.

Then there is the cost of the mounting, the weight, and the wind load. These problems are solved by Solyndra design.

Solyndra is now installing a lot of commercial systems, so we will see how well they perform, and I hope they start residential systems soon. Or maybe Sanyo HIT Double Bifacial Photovoltaic Module because I already have a white elastomeric fairly flat roof, and this bifacial module also collects light hitting it from the underside http://finchannel.com/index.php?option=com_content&task=view&id=37940&Itemid=8

It seems the Sanyo panels have been in production for ten years now, so presumably serious problems have been fixed.
See the vertical installation at the bottom of page 1.
http://us.sanyo.com/dynamic/LinkListingItems/Files/HIT%20Double%20190%20Data%20Shet-1.pdf

On the other hand, Solyndra design is fairly new and certainly has not been tested as long. Very large commercial customers have been ordering multimillion dollar installations from Solyndra, and I assume their engineers have checked the design and product quality carefully, so that is also reassuring.

Solar panel prices are expected to drop by half within two years, but the panels are typically only about 1/3 the cost of the system; 1/3 is the inverter (electrical regulator) and 1/3 is the installation, but again, this can vary substantially depending on the design.

So, what I think I want on my white elastomeric roof is:
Residential system kit, infinitely expandable
Solyndra design, or Sanyo HIT Double Bifacial Photovoltaic Modules installed vertically
Separate inverter for each panel
Glass that will allow maximum range of solar spectrum through