Solar Power - More panels on the garage roof

The SolarCity installation team arrives.

Product specification on a panel, 210W peak output, Silicon by Kyocera made in Mexico.

Fronius inverter installed inside the garage, wired to the distribution panel shown next to it.

Mounting rails on the garage roof.

Closeup of how the rails mount on the shingles.

All the panels in place, four rows of nine panels, 36 x 210W = 7560W DC, after the inverter this works out to about 6.5KW delivered AC power.

View from the front of the garage early in the morning.

It's all wired in, we are waiting for inspection and approval before we can turn it on. The same monitoring system is used as was installed for my previous solar installation on the house roof. This time we leased the panels, there are several options, from no money down to buying the whole thing up front. I've opted for an initial payment of $10K, and $90/month fixed for the duration of the lease (20 years). I don't pay anything until its turned on.

We currently generate about two thirds of our usage of electricity. The extra panels should triple the generated capacity, so we will generate about twice what we use in the short term. That evens out when we start charging a Nissan Leaf (delivery due in April), and change out our propane furnace for a heat pump and air conditioner (hopefully in time to cool us this summer).

A useful side effect is that the garage itself will be a lot cooler inside during the summer, as the panels shade the roof.

Solar Power - The Year in Review

For our full story on solar click here.

We installed Solar panels in August 2009, and they were turned on during September. We have now had a whole year of power which is shown below. The time-of-use metering means that we get paid much more for the power we generate in the afternoon than the power we use overnight, so the "zero point" for billing is different than that for power consumption. PG&E recently sent us our annual bill, which was about $500. Added to the monthly bills for basic service this comes to about $700 for the whole year. Our previous electricity bill was about $2000 a year. Since we changed our hot water, clothes dryer and range from propane to electric, we saved over $1000 in propane cost as well. That puts payback at around ten years at todays prices, given the likelihood of increased propane and electricity prices over time, actual payback would be earlier than that.

The panels have got a lot of dust on them (the roof is too high to get at easily to clean them), so aren't running at peak efficiency, the best day we saw was around 28KWh, with a lot of days of 26-27 KWh through the summer. The totals for each month are shown in the screenshots below.






Since we have built a new garage, we now have a lot more roof area. So we are now looking to add another 4KW of panels, and to swap out our propane furnace for a heat pump that will give us heating and cooling (yay - its hot today...) sometime next spring. Then the only use for propane will be the emergency generator. It should also make the garage a bit cooler in the summer by shading half of the roof with panels.

Garage Structure Completed

After lots of stops and starts, all that is left to do is some exterior paint and to fit the main doors. Work has already started on the electrical installation and water for fire sprinklers. Since the walls got so wet, they warped and parts of the siding had to be replaced. For some reason Tuffshed did other jobs on days where the weather was nice, and turned up to work on this one whenever it rained. We had what was probably the last rain of the winter on Sunday and Monday, but the roof was already tiled by then. The last video was the trusses being installed, here is the rest of the sequence.











Moving the viewpoint to catch trench digging around the back of the garage.

Garage Trusses Video

On Tuesday a big truck had some difficulty delivering a 40ft trailer containing the roof framing trusses, but it was raining so that is all that happened.

On Wednesday 21st April it started out dry, rained for a while then cleared up, but they did manage to put up all the trusses, and I made another stop-motion video of the work.

Tuffshed aren't great at letting us know what is going to happen next, we have to call them or ask the workers. I think the next step is to put plywood sheeting on the roof, then get an inspector up to check that the nailing pattern is correct, then they can put the doors and windows in, tile the roof add the external trim and paint it. It should be much warmer and sunny for the next few days.

garage - roof and rain on Tuesday

the roof trusses will be delivered tomorrow and rain is forecast for Tuesday and Wednesday - so we will see how they deal with that... it sucks that we don't have a roof before the rain.

[Posted with iBlogger from my iPhone]

Garage Framing Walkaround

The walls are up, but the trusses for the roof aren't ready, so it will be finished off next week. Luckily the weather looks good for the next week or so.

Garage Framing - first day of construction

Tuffshed turned up with their pre-built sections, assembled them and added some siding and the main door frame. Another stop-motion video on YouTube. It was wet over the weekend, and the ground is very soft, but we have a few dry and warm days in a row forecast, so I'm hoping it will dry out now.

Garage - Pouring and Finishing the Foundation

Last Friday we poured concrete, and then it poured rain. Here's a stop-motion video of the work. Six concrete trucks came, we are high on the mountain, so they may not have been carrying a full load each time. The foundation is very deep on the downhill side, and the slab is 6" deep rather than the 4" minimum used for the walkway down the side and the parking apron.

The first few seconds of each video look messy, this was introduced when youtube encoded it, my original video is fine.



On Saturday, the weather was better, and the team came back to finish the surface and tidy up.



Final bill was about $25K, and I would recommend Amaya Concrete of Morgan Hill, they did a good job.

This week, we let the concrete cure, wait for the ground to dry out and do some basic grading of the ground levels and slopes. Next week the building will be delivered and installed.

Garage - Inspected and delayed

We passed inspection by the county this morning, but the weather has turned too bad to pour concrete tomorrow, so we are postponing until after Wednesday's storm has passed, and will resume work on Friday. Today the electrician finished his work on the pipe that carries the power, and the Tuffshed foreman Mike visited to inspect the site and check and adjust the position of the hold-down bolts that are set into the foundation.

Garage - Working on Saturday

The concrete team were back today, putting in more rebar and tidying everything up. Chris Ramoutar the Electrician was also here putting in a 2-inch pipe to carry power to the garage. I'm having a high spec 220V and 200Amps dedicated circuit configured so that it's ready to recharge electric cars in the future. I got a work-out clearing up the felled fir tree and chipping the small branches, and collecting large rocks that had been dug up, and arranging them around the pond.

Here's a view from the deck, you can see the apron on the right, and the garage foundation on the left, and Chris working in the trench that takes the power line.



Here's a view from where the driveway will be as it joins the apron, you can see the walkway to the left of the garage.



Later that evening some very confused deer wandered over the foundations, since it has been built over their usual path from the forest out to the front yard.

Garage Site - rebar ready

Another stop motion video at 30s intervals shows most of the day's work. The tree that was falling over was pushed back the other way and cut up, and they added the parking "apron" in front of the garage.

There is a 4ft wide walkway along the side of the garage by the house, so the main pad is 36 by 36ft. It slopes to the right by three inches over that width so it will drain. The walkway slopes away from the garage by one inch. The apron is 26ft deep, 36ft wide and slopes by 12 inches (4%). The driveway will connect to the side of the apron that is nearest the house.

Garage Site - digging the foundations

Today the new leach-field pipe was inspected, and the foundations were dug, I did a stop-motion video using iStopMotion on an old MacOS laptop looking down from the house, and most of the day's work is compressed into one minute.



Tomorrow they will do the detailed preparations for the pour on Monday of the garage slab itself (6" thick), perimeter foundation (at least 18" deep, more on the downhill side where it is on in-fill), a walkway down the side of the garage, an "apron" in front of the garage to park on, and pads for the propane tank and generator.

Garage Site - full speed ahead

Pictures taken this morning, before digging started for the new leach field pipe that's getting inspected and filled back in on Thursday. The foundation layout and trenching will be done on Thursday and Friday, hopefully pouring concrete Monday and inspections on Tuesday. Everything just went from glacially slow to full speed....

In the first picture, taken from a window in the house, the white blob is the propane tank, and you can see the leaning tree.



The second picture is looking back from by the tree. The two low black things by the house are the caps for the septic tank.



I'm setting up a stop motion camera, will try to capture the building process. The MacOS iStopMotion app seems to work fine and has a five day free trial, so we will see how that goes.

Garage Permit - now the fun starts

I went into the county office and picked up the permit, paid them some more money to cover their costs of inspecting the work as we do it. They gave me back one of the marked up copies of the final site and building plans, and the permit sheet, and I stopped off at a Fedex office to get several copies made. Next stop is Tuffshed, to talk to the foreman who gets it built, and the concrete contractor (Jose Amaya Concrete of Morgan Hill) who normally works with Tuffshed. Jose is available immediately so we may actually get going fairly quickly. First step is to mark out the foundation and pour it.

The new septic tank connection pipe is going in today and being inspected tomorrow.

Garage Plan Resubmitted

This morning I took the requested clarifications on the building design into the county offices. We should hear back in a week or two, it's minor stuff so I hope this is the last step. We already have our permit for the leach field repair, so I'm starting on that work. We got the septic tank pumped and inspected (it was in good condition) this week, and filed the inspection results with the county, so the next step is to put in a new re-routed pipe and diversion valve between the tank and the leach field.

Garage Plan Detail

To get everything approved we had to survey the land and get a detailed plan drawn up by a Civil Engineer - we used Terry Szewczyk and he was helpful, competent and kept the costs to a minimum. The picture below is a detail from one of the drawings, which were produced at 1inch to 20ft scale, and shows the important part where the garage goes. For some reason the contour lines altitude is shown based around 2000ft, whereas the real altitude is about 2400ft, but no-one seems to care if that aspect of it is accurate.



Our first step is to replace the pipe that goes from the septic tank to the diversion valve and the remaining leach field, so we start by getting the tank emptied (which needs to be done every few years anyway). The pipe has to dive down a bit then go across under the concrete "apron" that will lead up to the garage, and it won't be buried very deep, so we will be putting down a 4" pipe that is placed inside a 6" pipe for the part that goes under the driveway, to give it extra protection from being crushed.

The final detailed changes we need on the building design plan are now in hand (the layout plan shown above is already approved), so I'm back to the county office again next week to resubmit them and hopefully get the permit.

The other details you can see on the plan are the electrical connection, which will be a 220V -200Amp dedicated circuit capable of charging electric cars one day. The propane tank will be relocated, and hooked up to a generator and the house. There is also a water connection to a fire sprinkler system.

sketching the new garage

While figuring out what we wanted to build, I used Google Sketchup (the free version) to create a 3D model of the house and garage. Working with 3D takes a bit of getting used to, but it's very similar to the solid modeling I was doing to make custom 3D printed parts for my homebrew phone, and Sketchup is very good at getting these kind of artists-impression images created.

The house really is a box, and the full width deck with steps going back down the side doesn't exist yet, but I was able to get the relative position and size of the garage about right so we could see if it fitted in. We then went to TuffShed and got them to draw up plans for our oversized garage. If you get a garage custom "stick built" at the site, the cost is quite high, mostly labor. Tuffshed pre-fabricate the parts, ship them in, and put up the entire building in about three days. The cost (not including foundations) is about $30K for an 1150 square foot triple wide garage (32ft wide, 36ft deep), with a 16ft wide double door, 8ft wide single door, and 10ft high ceilings. The basic cost is more like $20K, but it cost extra to go from 8ft to 10ft ceilings, and we added a bunch of other extra options.

So far, we have had a few minor issues getting the Tuffshed plans approved by the county planning department. Really just clarifications of materials and codes on the drawings, but the first two tries have failed. Everything is now approved apart from the final tweaks to the drawings of the garage, so I'm hoping to get it taken care of next week.

the garage saga, it gets complicated

We live out of town, on top of the Santa Cruz mountains. This makes a few things easier, we only have Santa Clara County to deal with, no city rules. We also have more space. The downside is that it can be hard to find people to work on the house, and it can cost more to deliver heavy stuff like gravel than it costs to buy it.

The complications start with a scenic highway. We can't build anything within 100ft of the road, Then there is a well, we can't do things within a 100ft radius of that. Then there is a septic tank and leach field. The leach field is two banks of 250ft long buried perforated pipes which occupies a lot of space, including the space that we want to put a garage on. Then a driveway has to find it's way through and have a turn around area big enough to take a fire engine. All of a sudden, a few acres of land is full.

A few years ago we got a plan drawn up for a modified leach field layout. This removed the upper 250ft field so that we could put the garage there, and added a new 250ft field below. To comply with planning rules we had to show that we could on theory add another 500ft of leach field if the first one failed. So that took up almost all the space.

After all that the biggest possible garage we could fit is a free standing building 32ft wide and 36ft deep. It will have one single and one double door and sit alongside the house about 20ft away and slightly downhill.

To prove that the space existed I got my local ground moving specialist Bob Whalen to use an excavator to dig holes and locate the leach field pipes, and made a big flat area in the right place. Along the way we destroyed the upper leach field before I got permission, we got told off but since the rest of the plan made sense we got away with it and were able to move forward.

At some point the county realized that the plan they had for my driveway bore no relation to what had been put in by the people who built the house, this raised the spectre of a grading violation and possible grading permit, which would be needed if we had to move more than 150 cubic yards to get a driveway that conformed to code.

With a lot of help from Terry and crew at TS Civil Engineering we ended up with a plan for the driveway and leach field that met code, didnt raise a violation and didn't need over 100 cubic yards of grading. With a few tweaks the county finally approved the plan.

[Posted with iBlogger from my iPhone]

cars and a place to keep them...

I'm going to blog about cars over the coming months, partly because I'm about to start building a big garage to keep them in and I want to document the process.

We bought a house about 5 years ago that had a wooden shed as it's single garage. We had five cars at the time and there seemed to be enough space to build a big garage. However other priorities intervened and it wasn't until the middle of 2009 we finally got serious.

The first action was to make a large flat space, to see how big it could be, then we got bogged down in the planning process and this week we finally have the key approvals in place!

More details to come....

[Posted with iBlogger from my iPhone]