To start, he purchased a portable saw mill and began clearing the lot.  Using trees he cut down on site, he built this temporary power shed to house the inverter, charge controller and batteries:

We used a bit of left over rubber roof membrane to water proof the roof prior to installing the PV panels.  The PV panels are Sharp NU-235F1 mounted on Unirac rails.

The inverter is a Xantrex XW-6048 with a XW-MMPT solar charge controller.  Also used are the XW power distribution panel, the XW control panel and generator start panel.  Since this system is going to be used in the finished house, we choose the larger inverter.  This house has a well that is 380 feet deep and uses a Goulds 1 1/2 HP submersible pump.  This pump is the largest single draw in the entire system, starting surge of about 5,000 watts and using 2,100 watts when running.  The 6 KW inverter is able to handle this without problem.

The batteries are  16 Surrette S-530 flooded cells.

The wall between the batteries and the inverter has 30 pound roof felt to act as a corrosive barrier between the batteries and the electronics.  Ventilation is copious.  The tarp is placed over the opening when the system is not in use.

The house itself is in progress, with the foundation completed and the floor slab being prepared for pouring soon.

Being certified as a NABCEP PV installer opens up several state sponsored incentive programs which opens up more business possibilities.

This is not the end all for PV installers, continued education and learning is always required.  Keeping up with the latest technology can be a chore, especially in a developing technology like PV.

In September, I intend to take the Solar Thermal Certification for all the reasons noted above.

The downside to TFPV is lower efficiencies, on the order of 7-9% for most commercially available modules.  This adds to the array area and adds expense and labor to a PV installation.

XsunX, Inc., manufacture of Thin Film Photovoltaics is working on boosting TFPV efficiencies to 19-20%.  Several development laboratories have seen efficiencies of 19% or greater in lab testing.  The difference between lab tests of specific PV modules made in tightly controlled conditions and mass manufactured modules is the purity of the substrate materials.  In conventional TFPV manufacturing, substrate is manufactured in a continuous roll process, making large quantities of low grade material.  These rolls are then cut up into 125 x 125 mm cells and installed in modules.  What XsunX is proposing is using a proven automated manufacturing process very similar to that used in the making of computer hard drives.  Smaller 125 x 125 mm solar cells will be manufactured individually instead of in large rolls.  Other parts of the process include a proprietary co-evaporation chamber which will speed the process and minimize contamination.

According to CEO Tom Djokovich, the cross industry system has the capability of making 600 million CIGS units per year, which equals 3 GW of solar cells.  With a 12% efficiency, the cost per watt will be about $0.80 wholesale.   Currently XsunX is developing the manufacturing machinery for this process as well as building their own thin film manufacturing plant.  They expect the first small production run in the end of 2010.

The aims of the smart grid are:

• Self-healing from power disturbance events
• Enabling active participation by consumers in demand response
• Operating resiliently against physical and cyber attack
• Providing power quality for 21st century needs
• Accommodating all generation and storage options
• Enabling new products, services, and markets
• Optimizing assets and operating efficiently

According the the US Department of Energy website.

Renewable energy critics often cite the very small percentages that renewables currently contribute to electrical generation in the US.  The other argument against installing photovoltaics is their low efficiency, between 14-16 percent in most commercially manufactured silicone modules.  Others argue that the cost is too high and the reliability is low.  All of those statements are true in the context of the artificially low prices we are paying for energy today.  If the real costs of energy were reflected in one’s electric bill, the cost per kWh would be in the $0.25 to $0.40 range.  Currently, unsubsidized photovoltaic electricity is $0.218 per kWh ($7.31 per watt installed, over 25 year life span).  Our current utility electric rates are about $0.15 per kWh.  If only the Federal income tax refund were taken (30% of the installed system cost), that brings the cost down to $0.152 per kWh.

Behind the meter solar generation is much more efficient than conventionally produced power.  A coal, oil or natural gas fired power plant dumps about half the energy consumed into the environment as waste heat.  Another 10 percent or so is consumed as resistive losses in transmission lines, then there is the energy required to produce the fuel, mining, pumping, transportation, etc.  That is what is required to use whatever fossil fuel the power plant is burning.  The amount of original energy from the sun needed to produce a unit of fossil fuel (e.g. gallon of oil, cubic foot of natural gas, ton of coal, etc)  is almost incalculable.  If we were to compare solar energy inputs, photovoltaic panels are far more efficient than any fossil fuel could ever be.

Photovoltaics also produce peak power during peak demand times, which can help reduce costs associated with Time Of Use (TOU) metering.  They are a distributed generation technology, which spreads the failure risk out over many points of generation, reducing transmission losses as well.  A battery backup couple with a solar and or wind system will keep power on indefinitely if properly sized.

Ground mounted PV array after blizzard

It helps that the panels are tilted to 40 degrees, roof mounted systems likely will not shed snow like this.  Still, on a roof mounted system, the snow will melt off, it might take a little longer.  The only system I would be careful of in this climate would be an evacuated tube collector.  Because the tubes have a vacuum, no heat is transfered to the glass envelope, which is really good for collecting heat, but not so good for melting accumulated snow off the collector.

Net metering allows the owner of an on-site renewable energy system to receive a credit on his or her utility bill for any unused power supplied to the electric grid by the system. The credit then offsets the power received from the grid when the customer consumes more energy than the system is generating. In addition to acting as a hedge against rising energy costs and reducing overall stress on the electric grid, on-site renewable energy sustmers provide numerous environmental, public health, and economic development benefits to local communities.

This is the basis for all grid connected PV systems.  It is good that the government of NY realizes the benefits of renewable energy and are taking steps to help implement it here.

The question is, will all of this renewable energy replace fossil fuel based generation, or will it merely increase the energy capacity and thus use in NY?  There are indications that the latter is normally the case, unless fossil fuel based energy becomes too expensive for the average person of business.   After the energy efficiency increases in the 1970’s and 80’s, many people began building larger houses because they could now afford it.  History will repeat itself unless the true costs of energy are passed on to the end consumer and not the taxpayer.

In the future, perhaps solar installation training will become part of electrical apprenticeship programs.  The main skill sets that a solar installer has, which an electrician does not, is the site analysis, system design and intimate knowledge of available incentives and grants.  System design is getting easier with the advent of microverters.  In new construction, at least some of the system design aspect should be up to the architect, e.g. a roof facing true south tilted at latitude.  In retrofitting existing buildings, however, compromise is often the case.  With performance based incentives, such as what is available in New York state, that can increase the system’s cost.

In general, green construction requires an integrated approach.  All of the various systems need to work together to reduce or eliminate traditional energy inputs.  Electrical contracting is but one part of that equation.  There are many other green technologies available to electricians, such as reduced power lighting, variable speed motor controllers, energy efficient appliances, smart building systems, etc.

The article is an interesting read and brings out many good points.

The electrical inspector was not familiar with the product or the concept.  I showed him the spec sheet from Unirac, which details how the grounding clip creates one electrical path through the mounting rails for the ground.  Basically, the ground clip pierces the aluminum finish on the panel frame and the aluminum surface of the mounting rail.  With that electrical connection established, a ground wire is run between all of the mounting rails and connected to the grounding electrode system.  Keep in mind, that systems should have a continuous grounding path back to the service panel ground bar and cannot be bonded to the neutral or negative conductor of the PV system.

Not all electrical inspectors would accept this method and it is not currently part of the NEC, so it is better to check with them first.  Otherwise, it saves a lot of time, effort and materials to use WEEB grounds.

This makes panel and inverter selection much easier.  Downloading then reading .pdf files from manufacture’s web sites takes time and clogs up a hard drive.  This way, you can find out all of the critical information ahead of time.  Of course, any installation will need to have spec sheets on hand for the electrical inspector, the utility company, etc.

What Prism Solar makes is a proprietary holographic planar concentrator™ (HPC) film that, when used in conjunction with conventional silicon photovoltaic cells, increases the cell efficiency by about 40%. According to their website, the increased efficiency allows for use of 30-50% less silicon during the manufacture process, making the the cost around $1/watt.

Here are the advantages of HPC technology:

• Less silicon reduces cost per watt
• Passive tracking from holographic effect produces more energy from diffuse and reflected light.
• Cooler operation than conventional PV module, most unusable light passes through module without being turned into heat.
• Bifacial PV cells can increase module performance when mounted over a reflective surface.
• Lower embodied energy, the energy required to manufacture the HPC film is much less than that required to mine and process silicon.

They have four prototype modules on line in Tucson, AZ connected to Enphase inverters. One can look at the module performance on the Enlighten website. There is also a specification sheet for a 160 watt module.

According to their latest press release, they are about to create 175 new jobs in the Hudson Valley (although there is nothing on the careers page yet). All of that is good news for the solar industry and I look foward to seeing their product out in the field. I must say, it certainly looks cool.

I previously wrote about them here.