PhotoVoltaic (PV) Mount and Work Structure
Last Updated: March 6, 2013
Most recent images first; plan drawings, text and additional references at bottom...

The completed and operational hydro at the tail works (sorry about the lack of intervening photos!). We used an ESD Stream Engine Turbine, 2 nozzle, producing ~18KWhr/day with ~140gpm delivered through 340' of 3" PVC pipe.

 

The finished hydro head works (at the pond).

 

The finished hydro tail works (downstream).

 

Adding the outpour rocks.

 

After the formwork was removed.

 

Forming and pouring the hydro tail works.

 

During the winter, we periodically get torrential storms that last several days. Although the PV design takes this into account, we realized that the outpour of the pond had a lot of untapped energy potential. Tapping such potential would allow us to better endure these low solar energy periods as well as to reduce the erosion caused in the natural stream courses downstream from the pond.

To address this potential, we designed a hydro electric system that became part of the PV structure. It 'kicks in' during peak winter storms, first charging the PV batteries as is needed, then the excess energy is used to heat the house's potable water.

 

Cutting a communications cable trench down to the PV & house sites.

 

...and laundry!

 

We're using the storage room for cold storage until the house (and root cellar) is built

 

...and I added a workbench to be able to work during the winter rains!

 

The solar electronics and batteries -- first power October 24, 2006 (no more generator)!

 

 

A view from the front

 

The solar array is complete & wired!

 

 

 

Installing the solar panels

 

Roofing completed!

 

 

 

Starting the other side

 

Note that the solar jacks are installed as we go, giving good support for the roof work in progress

 

 

 

 

 

 

 

Moving the roofing panels (28' long)

 

Installing the insulation

 

 

Installing the roof (metal, paneled). Note solar combiner in place on stub wall

 

'Sun sculpture' finished (yellow fresco) and finishing remaining plaster work

 

Plastering around the 'sun sculpture'

 

Applying the finish plaster coat (lime plaster, colored with Tempera -- aka 'fresco', ~1/8-1/4" thick)

 

 

Applying the base plaster coat (natural cement plaster with straw reinforcement, ~1/2" thick)

 

Chopping straw for the base coat plaster (reinforcement)

 

Slaking the lime for the finish plaster

 

 

Ready to plaster

 

Masking in preparation for plastering

 

Getting the last sheet of sheathing in place

 

The first sheathing panels in place (Hardibacker 1/2" Cellulose-reinforced concrete panels)!

 

 

The double-wide (pocket) door completed (fabricated by yours truly) and doors painted. Cross braces are in (2 sets, center wall and roof). All stud wall infill is completed. Structure is wired and plumbed!

 

Starting the stud wall infill. Single-wide door in place.

 

Candy threading the cross bracing rods

 

 

Installing the peak cross pieces

 

Welding the tabs for the beams.

 

In case you are wondering, this is the trusty (and quiet) generator we have been using to build everything (as well as to live by). [Honda EU3000, ~3 gallons/20 hours, super quiet]

 

The batteries get delivered! (~3300lbs & ~40kwhr storage each)

 

From the PV face

 

Erecting the Superstructure

 

The Steel has Arrived (columns set into place)

 

The finished foundation slab, the next day.

 

The 'crew' working finishing the concrete (a huge thank you to Richard, Jenny and Dean!).

 

Due to the position and size of the slab, we needed to have the concrete pumped into place. Here the pumper is just starting to place the concrete.

 

Mixing and pouring the piers (here I'm tamping). We had hoped to do a monolitic pour (piers and slab as one) but the weather has only gotten worse. Continued fears of the sonotubes collapsing (we are now having to pump them regularly) as well as another week of forecasted rains, led us to make the decision to mix and pour the piers ourselves rather than to wait for the 4 dry days the concrete company needs to be able to get in and deliver. Due to the flooding of the tubes, an 8-sack mix was used. Note the foundation structural work is complete with the remesh in, the utilities set to the proper heights and the column bolts in place.

 

Tying in the rebar reinforcement (rain again!). Note the doubling of bars near the edge for extra strength (24" OC normal + remesh).

 

Candy cutting rebar for the foundation reinforcement

 

The pier column in place and tied to cross bars

 

Setting the pier column in place in the compacted, leveled and framed foundation

 

Fabricating the pier columns

 

Cutting and bending the rebar for the pier columns

 

Delaminating sonotubes and the 6x6x10 mesh used to prolong their integrity. We were away for a week and it has rained ever since we returned. Faced with having to redig and pack the foundation, this measure at least allowed us the possibility of saving the tubes (and foundation).

 

Placing the gravel base for the foundation. It is placed in layers and compacted, the level checked as we go. A layer of sand is placed on top for the fine leveling.

 

The foundation has been roughed out. Here we are running the utility lines. Note the sonotubes already dug and placed -- these are for the piers to provide additional strength and stability since the pad was built from fill (the piers extend into virgin soil).

 

Well, the parts on order so we just went with a temporary fix (note the vise-grips!).

 

Again! The forward/reverse shifter broke from metal fatigue. Here Brian's attempting to weld it in place...

 

Almost back up and running again!

 

But I was able to get it welded the next day...

 

Starting to dig the foundation and Oops!, -- this one's serious (the backhoe boom snapped)!

 

Marking out the PV structure's foundation

 

Using a Solar Pathfinder to evaluate potential solar energy (PV) sites

 

 

The plot for the PV Structure site showing a nearly perfect candidate with over 90% insolation (solar radiation) year-round!

 

The PV System & Structure

One of the reasons for developing the Skyview Project was to have more space to fabricate new alternative energy designs. In reviewing options for mounting the photovoltaic (PV) panels to be used to power the work and homesites, we realized traditional mounts (e.g. pole mounted arrays) basically took the ground beneath them out of use. We decided to design a structure that would serve to support the PV panels, house the power invertor and batteries, as well as to provide a work area for our alternative energy design & development.

Extending our philosophy for the house and other structures and facilities we are building (fire safe and longevity), we chose steel as the structure material built upon a monolithic slab concrete foundation. Steel is one of the most recycled materials on our planet (steel generally has a minimum of 25% recycled content). The steel framework (12 ga superstructure, G60) would be augmented by steel stud walls (18 ga min) for the invertor, battery and storage areas, sheathed with concrete board and finished with a lime plaster.

As for the large size of the PV array, our goal is to be able to not only generate sufficient power for our personal needs but also for the research work and for electric vehicles (personal transport as well as possible conversion of the tractor/backhoe). For those interested, the closest electricity is ~3 miles away and when we considered the cost of hookup (e.g. to gain access to renewable energy rebates), it turns out the hookup cost is about 3 times what our system will finally cost. Incidentally, the size, in watts, of the array cannot be considered by itself. One also needs to take into account the winter cloud persistance (as well as summer dust) and the resulting degradation of output. In our case, the panel tilt is optimized for winter sun angles and the batteries are sized for 5 days worth of nominal storage. Furthermore, the mount's (building's) angle (with respect to true south) takes into account the coastal fog impacts. The system is also designed to accomodate wind and hydro (both available on the property) for future growth.

An interesting consequence of our building a seperate structure for the solar: "Section 73 of the California Revenue and Taxation Code allows a property tax exemption for certain types of solar energy systems installed on or before December 31, 2009. (The original exemption was set to expire at the end of 2005 but has been extended through 2009.) Qualifying solar energy systems are defined as those that "are thermally isolated from living space or any other area where the energy is used, to provide for the collection, storage, or distribution of solar energy." These include active solar energy systems, solar process heating systems, photovoltaic (PV) systems and solar thermal electric systems." The exemption is 100%, or for a shared use facility (non-living), 75%.

For those that are interested, the company I contracted to fabricate & provide the steel -- and who provided the knowledge I needed to work with it -- was Steel Starts out of Lakeport, Ca.: Dock Factory / Steel Starts. Contact them (Paul Racine) if you would like a similar structure. The supplier of solar components was Advance Power of Calpella, CA (707.485.0588, Advance Power).

 

Plans
Adobe .pdf format

Structure, page 1
Structure, page 2
Structure, page 3
Structure, page 4
Structure, page 5
Structure, page 6

PV Electrical, page 1
PV Electrical, page 2
PV Electrical, page 3
PV Electrical, page 4
PV Electrical, page 5

 

Additional Reading for Those Interested:

Solar Living Source Book, Real Goods, Hopland, California
Backwoods Solar Electric Systems, Sandpoint, Idaho
Designing and Installing Code-Compliant PV Systems, Endecon Engineering
Steel Frame House Construction, Tim Waite, NAHB Research Center, Craftsman Book Company, 2000
Harnessing Water Power for Home Energy, Dermot McGuigan, Garden Way Publishing, 1978