Brian, My comments were drawn from the referenced Rocky Mountain Institute report comparing German and US "Soft Costs" which include installation labor. The report offers several points where US NEC requirements are not recognized. For example, no screws or threaded connection or continuous bonding conductor is required to ground/bond the modules and the racks to the system ground. Rooftop cables can be laid loose under the modules on the roof, they also show a cable support method of a few UV resistant Ty-Raps (which last about 10 years in service). The report cites rooftop conduit and temperature rated cables as an unnecessary material and labor expense. As an electrician I will claim that roof tops are hostile environments for many electrical products. The NEC suggests that the design ambient temperature is >150F and I have physically measured even higher surface temperatures on low slope asphalt and composition roofs. Cable insulation degrades, conductors short out and arc, sparks ignite asphalt. The last step will not happen on clay tile.
The tone of my comment is that the focus seems to be eliminating installer jobs as a way for the PV industry to survive the challenge of reduced subsidies. I also object to calling labor a soft cost like sales , engineering, procurement and profit. Labor can be more or less efficient, even from day-to-day. A good business person can also negotiate better prices on components, so module costs are a little soft too.
Job creation (in the US) was the core reason for the subsidies.
For the next 20 years, a PV module installed in Bangladesh has a greater value to the planet than the same module installed in Los Angeles.
Continuous efficiency improvements in all electrical devices will continue to reduce baseload needs, in the U.S.
Efficiency is the true and implacable enemy of coal.
The war on efficiency will be hard for utilities to wage with a straight face.
Wind may kill birds, solar may kill tortoises but efficiency kills utility profits! Oh, the horror.
What do we care about efficiency if our power is cheap and brown?
Which, regrettably, it is and will be for many years into the future.
Cheap is what most people want. If you can convince them that green is cheap, they will love it.
Electric motors deliver high torque at low RPM, gasoline engines require high RPM to deliver high torque. The performance curve is reversed in the two types of drive systems. Electric dragsters could win every race but produce little of the tire smoke and engine noise necessary to the motor sport experience. Three of the first five in the latest Peak's Peak race were electric; higher torque at lower speeds.
The first couple of years of the Prius demonstrated the extraordinary torque delivered by electric motors. Drivers who tried to accelerate the Prius in its unnamed "insane mode" aka "foot-to-the-floorboard", occasionally snapped the drive shaft. Customers were not impressed. Manufacturers quickly built in torque control to prevent the negative outcome. Tesla engineered a physical solution in a more robust drive train and allowed the driver to intentionally over ride torque control, a feature that is probably used mostly during the sales process and occasionally to show off to your envious friends
Fifty plus years ago the Beatles wrote a somewhat relevant lyric.
"Sitting in an English garden, waiting for the sun
If the sun don't come, you get a tan standing in the English rain."
At that time the industrial world was becoming aware of the link between industrial pollution and health. We have made great strides at reducing visible pollutants and some toxins from our collective air and water resources. We continue to ignore invisible dangers such as GHGs. Can't see or smell or taste so why worry. All we have are slow changes in observable conditions such as small changes in "heat content" (Donovan) or atmospheric chemistry which are revealed by measuring temperature and CO2 content of the oceans and atmosphere. Both measurements are "handy indexes" (Hallinan) and do not identify a cause of the incremental increases in heat content.
Personally, I "believe" that excess CO2 emissions are the culprit in the increasing heat content aka entropy. The interaction of the CO2 molecule with reflected infrared light energy has been demonstrated in controlled lab experiments. Of course methane, volcanic eruptions and water vapor are also contributors. It appears that we humans are performing a global scale experiment. Hope the experiment does not destroy the laboratory.
Another report on this website described the employment mix for the solar PV industry in the US. Approximately 175,000 FTE total with @95,000 installation, @ 23,000 manufacturing, some R&D, marketing and other non-installation jobs. These positive results show about as many PV installers as blue collar coal miners, both above and underground, in the US job market. An interesting inflection point.
Another report analyzed average installation costs by component and revealed an "unsustainable" cost of sales at $0.48/Watt. Efficiency in the PV market will require drastic reduction in cost of sales, especially when the tax credits expire.
New microinverter and racking systems will make the installations more homeowner friendly and further reduce installer job growth numbers.
The industry will continue to grow impressively but job growth can not track that project growth for much longer
Enphase is one microinverter manufacturer which uses proprietary interconnecting cables which are probably not plug and play interchangeable with another brand. In addition the microinverter connects to an AC combiner device and then feeds a 20A CB in a panel. It does not connect directly to a residential outlet.
A 25 year warranty on microinverters compared to 15 years for central inverters is an actuarial artifact rather than a definitive quality indicator. Warranties are corporate bets that future costs will happen long after current profits are absorbed. Corporate bets are often incorrect.
Brian, I was unaware of the direct plug-in PV systems and would like to know more.
Please suggest a brand that employs direct AC plug connection to a residential electrical system.
I do not consider warranties beyond the 15 year NEMA standard to be any more than a marketing technique.
The industry will mature into some form of an installation/service model that will maintain and renew system components at reduced future costs.
You are correct about concern about capacitors. In the 1970s the NEMA standard for voltage withstand rating of capacitors within HVAC equipment was reduced by about 20%. The modern HVAC service model was born.
A large number (maybe 50%) of residential HVAC service calls involve capacitor replacement. It is easy to diagnose, cheap to replace and provides the opportunity to upsell.
While PV cells/modules and PV inverters are both semiconductor devices. Solid state with no moving parts larger than electrons. The difference in expected /warranted life span is due to how those electrons are managed.. In the PV material, huge numbers of photons impart energy to an equal number of electrons. Each interaction involves an infinitesimally small quantity of energy which is collected to provide an output voltage and current. The inverter receives all this energy and delivers it in timed pulses to the AC output. Inverter outputs are typically high speed switches such as IGBTs which will operate at full power hundreds of times per second. In addition, every pulse of the inverter output produces a reflected voltage up to 3 times higher than the nominal output voltage. It performs these high energy switching actions up to two trillion times per year
Mr Coomber, when I search for " stage  Solar PV technology products " as noted in your comment, I have only found one document reference. A U of C Berkeley market analysis with five stages of technical product development. Stage (4) is Diffusion and Commercialization. I think you are referencing a different analysis, I would appreciate a link. Thanks
When you mention residential demand charges are you referring to the system where users are charged more per kilowatt-hour after a certain consumption level is met. It would be measured by a separate demand meter which looks for peak consumption for 15 minute intervals. The highest consumption in any 15 minute period sets the demand price for electrical service above the demand limit, for the entire month. Residential users will object vigorously. They will also recognize that efficient use and timer controls provide a better ROI than PV in this circumstance.
Perhaps you are suggesting a reverse demand charge where you pay more if you use less than the utility has specified. This would punish PV owners and reward utilities, which would be the motivation to establish such demand penalties. Those who do not own PV systems sometimes use the argument that PV owners are not paying their full share of utility infrastructure costs.
Demand charges are common with large industrial and commercial users where the infrastructure serves only a few facilities. These businesses spend a lot of money on efficient operations to avoid these charges, often reducing production for multi-hour periods. The charges can amount to thousands of dollars a month and can be triggered by a simple controller-operator error. Residential users will object to an identifiable charge on their bill because they had their clothes dryer, hot tub, plasma TV and heat pump on at the same time.
Most utilities already have a residential monthly minimum bill which ostensibly covers infrastructure costs
My daughter and her husband recently had a 10 kWp PV system installed on their home in Kiel, Germany. The cost was < US$2.50/Watt nominal. About half of the cost of the same system in the US. Homeowners can manage permitting, inspection and FIT registration online. Designs can be selected from a pre-approved set of block diagrams. Contractors are installers in overalls, not project developers, permit specialists, site analysts and certified designers. Most skilled electricians can assemble the components of a PV system and most of them also understand azimuth and elevation. Some systems require real engineering, most do not.
The "Solar Warriors" clinging to the ITC model should recognize that all that white collar overhead is only sustainable with very expensive products, like nuclear power plants and residential PV, 15 years ago. The German FIT model has many flaws but has succeeded in lowering the total cost of ownership and encouraged widespread adoption of residential PV.
The value added by the non-productive part of the US PV business model surely can not equal the total cost of physical installation in Germany, can it???