Many people have asked us why we are installing solar photovoltaic panels on our roof.  They believe that solar thermal panels are superior since solar thermal can provide hot water for (1) domestic hot water; (2) radiant heating inside the house; and (3) heating the swimming pool.

Since we will have geothermal energy available for our domestic hot water, heating in the house, and even to heat our swimming pool, we have a greater need to generate electricity. 

Our geothermal heat exchange uses multiple pumps.  These pumps need electricity to operate, so we will be using renewable energy from our photovoltaic panels to obtain renewable energy from the earth.

Our stated objectives include being zero net energy and zero carbon.  We intend to meet these objectives is through renewable resources, including geothermal heat exchange and solar photovoltaic generation.

Increasing Use of Electricity

Generally, our household has been an early adopter of new technologies.  These technologies often require electricity to operate.  Thus, our household may use more electricity that others so we want to be ‘hedged’ against the rising cost of electricity.

In an article today entitled, ‘Plugged-In Age Feeds a Hunger for Electricity ‘ the New York Times reported that:

Worldwide, consumer electronics now represent 15 percent of household power demand, and that is expected to triple over the next two decades, according to the International Energy Agency, making it more difficult to tackle the greenhouse gas emissions responsible for global warming.

To satisfy the demand from gadgets will require building the equivalent of 560 coal-fired power plants, or 230 nuclear plants, according to the agency.

To reduce the burden that our household will put on the grid, we’re going to to two things. 

First, we will do our best to anticipate where ‘always on’ devices will be and have ‘on/off’ switches in those locations.  These switches may be connected to our home automation system so the switches can be turned off automatically when required.

Second, we’re going to have solar photovoltaic panels on our roof.

Sizing Our Photovoltaic Panels

We designed our house so we could fit up to 48 solar photovoltaic panels on the roof.  However, due to the current legislation in California, we can only generate as much electricity as we use.  We cannot be net generators of electricity.  Frankly, we can’t understand this legislation and we believe the legislation needs to change.  This issue is in front of the California senate, with AB 560 (to raise the limit on net metering from 2.5% to 10%) and AB 920, which would allow homes to be net generators of electricity.

Existing law provides that where the electricity generated by the eligible customer-generator exceeds the electricity supplied by the electric distribution utility or cooperative during a 12-month period, the eligible customer generator is a net electricity producer and the electric distribution utility or cooperative retains any excess kilowatthours generated and the customer-generator is not owed compensation for those excess kilowatthours unless the electric distribution utility or cooperative enters into a purchase agreement with the eligible customer-generator for those excess kilowatthours.

Given the size of our house and usage patterns, Akeena Solar estimated that we should install 32 photovoltaic panels and that will drive our consumption to zero.  Given that the cost of photovoltaic panels is dropping and the performance is increasing (and, we simply can’t generate a financial return on additional photovoltaic panels), we’re limiting our installation to 32 photovoltaic panels.

We will, however, have all the infrastructure in place to support 48 photovoltaic panels so when the legislation changes and we can be a net generator of electricity or, if our power consumption is greater than expected and we need more panels to drop our net consumption of electricity to zero, we can simply bolt in the additional photovoltaic panels as and when required.

Future Capability for Electric Vehicles

Although we do have electric vehicles today, we are going to have our garage wired for charging electric vehiclces.  If we have electric vehicles in the future (Tesla?) then our consumption will increase.  And we’ll simply bolt in those additional photovoltaic panels.

Other Thoughts

To help heat our swimming pool, we plan to put PEX tubing in the concrete decking around the pool.  Thus, the warm pool deck will pre-heat the water circulating in the pool, which will heat the pool and cool the deck.  With appropriate valves and controls, this should be a win/win.

Monday will be a big day.  The two bridges and the stairs are loaded on Larson Steel’s truck in Gilroy and will be delivered to the project site by 8:00 am on Monday morning.  Our friends from Summit Crane will have a 45 ton crane at the project site to put the stairs and bridges in place.  And, HP Inspections will be verifying the welding at 1:00 pm on Monday afternoon.

It’s good.  All good.

Completed Bridges

Hector showed me the bridges are loaded on their truck.  Very cool.

Larson Steel's truck, with the two bridges and stairs loaded and ready for delivery and installation on Monday morning.

Bryan climbed on the truck for some close up photos. Here is the landing on the stairs.

Hector waiting patiently as Bryan reviews the stairs and bridges.

Everything looks good. Note the HSS 4x4x 3/8 column tucked in the bridge. This is one of two structural columns that will be visible in th house.

Monday will be a big day.

One of our hollow core concrete panels is a bit too wide, so it needs to be trimmed.  Sounds easy, right?  Six inches thick and approximately 12 feet long.  Take 2-3/8 inches off.

A local Home Depot rents concrete saws.  For the 4 hour minimum, the charges are approximately $60 for the saw and $60 for the saw blade.  And $7 extra in case something breaks.

Dustin Barclay, from Teamwrkx, was available to help this morning.  He agreed to meet Bryan at the job site at 8:45 am, after Bryan picked up the concrete saw and blade from The Home Depot.

Pickup Up the Concrete Saw

At The Home Depot.

Concrete saw loaded and ready to go.

At the Job Site

Dustin met Bryan at the job site and helped unload the concrete saw and get it into position.  Clean the area, snap a chalkline, hook up the water hose, and start cutting!

Saw is unloaded and ready, job site is being cleaned up.

Snapped the chalk line. Measure twice, cut once.

Looks good, we're ready to start sawing.

Cut! Dustin and Bryan made two cuts, and the resulting cut was a bit more than expected. This will allow a good, wide, stong edge on the steel beam.

Completed the cut. Time to clean up now.

The cut piece at the front of the house. It was heavy!

.

Ute called me yesterday and mentioned that she saw our construction blog and was most interested in seeing our cistern.  She is completing a project in Los Altos and would like to include a rainwater catchment system, including a cistern.

Ute explained that she is a client of John Rider.

Hosting the Site Visit

Ute arrived at our site and Bryan took her on a full tour.

After the tour, Ute called John and he dropped by for a quick visit.

John Rider and Ute on site.

Lana Malloy and Don Perry Visit the Site, Too

Just as John and Ute were leaving, Bryan spotted Lana Malloy, one of the Council members with the City of Monte Sereno, walking on Via Sereno.  Lana was on VIa Sereno to review the sidewalk by Winchester Boulevard.  Given she had not seen our project site since construction started, Bryan took the opportunity to give Lana a quick tour.

Lana was on Monte Sereno’s Site and Architecture Commission before joining City Council in November 2008.  She was on the Site and Architecture Commission that approved our site development permit in July 2008.

Just as Lana was leaving, another Council member came by.  Don Perry had to review the same sidewalk area on Winchester so, after doing so, he was able to see our project site.

Monte Sereno council members Don Perry and Lana Malloy on Winchester Boulevard at Via Sereno.

We were very excited to see the bridges and stairs being fabricated at Larson Steel in Gilroy.  These will be extremely important features of our home so they need to be designed, engineered, fabricated and installed carefully.

HSS 5×5 with 1/2 inch Wall

Although we had some initial ideas regarding the bridge design, Hector Guerra of Larson Steel designed the structural steel components.  He recommended that we use two pieces of tube steel, 5 inches wide by 5 inches deep, with 1/2 walls.  Knowing we didn’t want any ‘bounce’ or movement in the bridges, he thought this basic structural design would work.

End of HSS 5x5, notched to sit on the W6x16 I-beam. Do you think it will be solid? Rock solid?

Bridge Foyer

This is the main bridge that goes from the foyer across the atrium to the living room.  It will be covered with Madrone hardwood flooring from the Santa Cruz Mountains.  We want this to be solid.  Rock solid.

Pete Larson inspecting the Bridge Foyer. Note the cross-pieces that will then support two layers of 3/4 inch plywood and then the 3/4 inch Madrone hardwood.

Bridge Hall

This bridge goes from the Living Room to the Master Suite.  The bridge decking will be made of glass, fritted for safety and frosted for privacy.  Importantly, using glass will allow light from the clerestory windows to go into the lower level, which will reduce the electricity required over the building’s life.

The Bridge Hall will have a separate aluminum frame in it that will hold the six pieces of 1-inch thck glass decking.

Stairs

Due to the narrow 38-1/2 inch opening between the steel column and the feature concrete wall, the stairs were a challenge to design.  We used HSS 2×8 with 3/16 wall for one stringer and, by the concrete wall, 3/8 inch plate. 

It was very rewarding to see the design coming together.

HSS 2x8 stringer components, ready for inspection prior to welding.

This is the bottom of the stairs, where the stringers will be attached together with a 3/8 inch plate. Yes, that plate will be attached securely to the concrete and then covered with 3 inches of concrete.

This is the stair stringer that goes against the feature concrete wall. The lower part (left hand side) is HSS 2x8 tube steel as we are not constrained for space at that location.