Sagebrush

[This is the second in a series of articles describing installation of a solar hot water system.]

The solar panel was not in stock at AAASolar, so we had to wait a couple of weeks for it to be freighted to the shop. We have access to a truck, so we could pick up the goodies at the shop and not have it delivered.

We could have transported the solar panel and storage tank in one trip, but decided to truck them separately to avoid any possibility of damaging the panel. Cracked glazing would have made me very sad.

Here is the storage tank protected for the trip:

The solar panel is solid and heavy, approximately 150lbs, too massive for one or two people to carry up a ladder. In retrospect, the easiest way to get this panel onto a flat roof is crowd-sourcing: get six good friends or family members with ropes pulling and pushing the panel together. Sadly this particular day I was (almost) friendless, so cleverness was in order. Phil and I fastened a 4×4 crossbar between two ladders, affixed a pulley in the middle, and tied a rope harness around the panel. We parked Phil’s jeep with electric winch in the garage underneath the ladders (barely seen in this photo because the dark-colored vehicle is in shadow).

The winch and pulley pulled the panel up to the roof, while one person on the roof steadied the panel using ropes. Again, this technique worked but is overly complex– use crowd-sourcing instead.

I could not work out how the mounting hardware fastened to the panel, and no documentation was included. AAASolar had no instructions for this particular model, and recommended we contact the panel manufacturer SunEarth. No instructions were found on the web site– a helpful person on the phone faxed us the drawings we needed.

One thing apparent from the drawings is that the panel is mounted  with the shorter side along the roof, unlike most panels we see installed in this part of the country: Good to know!

We needed to bolt the panel mounting hardware to the roof with long lag bolts sunk into roof joists. The problem was finding the roof joists! Two different stud finders gave no consistent readings on the roof (and yes, we did try the trick of using cardboard over this rough surface), and we drilled two or three holes that totally missed a joist. It’s bad enough to be drilling into a perfectly nice roof, but to miss the timber beneath and have to patch the hole is most embarrassing.

Finally, we hit upon the trick of drilling a test hole at a shallow angle, and then using a coat hanger wire as a probe to test for where the joist is located.

Once we know where one joist is, we should be able to find the next one, assuming the joist spacing is the same as over the garage, where joists are visible. One final indignity: the joist spacing was different on this section of the roof, so we had to drill another shallow angle test hole as before and patch it afterward. We used 2×4 boards as footers to help spread the weight on the roof surface, and screwed long lag bolts through the metal mounting block, the wood footer, and into the roof joist.

Albuquerque has a 35 degree latitude. We elevated the panel to 55 degrees, to give more sun in the winter when the panel needs it most.

Related Posts: Solar 1, Power to the Programmers

Sagebrush Systems “world headquarters” is fortunate to be located in a building with passive solar heating. A large expanse of south-facing windows direct sunlight onto adobe walls and bare brick floors for heat storage.

The furnace hasn’t been turned on for over a decade, so we save a good deal on heating costs. (In full disclosure, the solar adobe construction of our building does not provide complete warmth at our latitude at 5000 feet elevation, but we throw on an extra sweater and become accustomed to somewhat lower temperatures than the 70 degree F office workers expect. For a couple of weeks each year we get consecutive days of overcast weather, requiring the fireplace to be used.)

We plan further energy independence, with solar hot water, possibly a supplemental solar hot air heater, and eventually a grid-tied photovoltaic system to supply all electricity needed by Sagebrush.

Our latest energy project was to install a solar hot water heating system. The area is blessed with plenty of solar exposure, averaging over 300 days of sunshine a year. A few periods in winter might have cloudy days extending for a solid week or two. We do have hard freezes, so a glycol system is necessary. (A drain-back system might work here, but based on the number of burst water lines we needed to fix in supposedly drained water lines running up to our evaporative cooler, we decided to use a glycol system.)

Active glycol systems can use an electronic controller to monitor temperatures and turn the circulating pump on and off, or use a pump connected to a photo-voltaic (PV) panel which runs the pump only when the sun shines. We wanted a PV system, based on the experience of a friend with a system installed a few decades ago, whose original manufacturer no longer exists and has difficulty getting the controller serviced. We also confess to a pyschological satisfaction of using no utility energy, even the minimal amount needed to run a circulating pump.

We wanted a kit-based system, so we could participate in installation and learn better how to maintain and use the equipment– and because it’s a challenge. Someday perhaps one could go to a big-box “home improvement” store and buy a solar hot water system in kit form or completely installed, but that day is not here, so we have to shop on the Internet. This system from SolarRoofs.com looks well-engineered for do-it-yourselfers, with a complete step-by-step installation manual and no soldering required. Their solar panels are also extremely light-weight, which should be an advantage for high slanted rooftop installations. Ultimately we decided against this system because of the plastic glazing: We get a LOT of UV radiation here, hard on plastics, and we recently replaced an acrylic sun roof that was thoroughly destroyed after twenty years of sun exposure. Perhaps these solar panel glazings have superior UV resistance, but how can a buyer prove that?

Ultimately we purchased a solar kit with tempered glass panel glazing, ordered from the venerable AAASolar, located in nearby Albuquerque. It doesn’t come with a complete install manual like the system above, but they did offer to provide reprints of articles from Home Power magazine dealing with installation. The article “DWHW Installation Basics Part 2” from June 2003 was particularly helpful. We also save on shipping charges, since they are so close, allow local pickup, and we have a truck available. The kit includes solar panel, storage tank, PV panel, pump, assorted valves and gauges. You supply plumbing available from your local hardware store. Propylene glycol and pipe insulation are extra.

In future posts we document our adventures (and minor missteps) in installing the system:

Solar 2: Installing the panel.
Solar 3: Connecting everything.
Solar 4: Starting up and running, lesson, and future.

Related Posts: Power to the Programmers

Sheep help trim grass on Village of Corrales soccer fields in a sustainable manner.

Related post: What We Graze

RecAll-PRO version 1.0 was released ten years ago today.

A spin-off from standard RecAll with many advanced features, PRO became our best-selling public software product within a few months, and has remained so to this day.

Related Posts: Happy Birthday First Product

Noism: the practice of referring to oneself in the
plural as “we”.

“Only kings, presidents, editors, and people with tapeworms have
the right to use the editorial ‘we’.” Mark Twain

(image courtesy Wikimedia Commons)

We do this a lot when blogging…