Tag Archives: solar array

Ballasted Solar PV Mounting System for Flat Roof – Part II

We have finished our ballasted roof project from earlier this summer.
(This is continuation of Ballasted Part I.)

Before getting too far along, we realized we needed to replace the building paper with Colbond Enkadrain mat  that allows the roof to drain under the entire racking system.  Roofer Stan Howard specked this product, and this is the proper way to do any ballasted system.  In this picture, the guys are using a table saw to cut this stuff – funny – sometimes you need to pull a MacGyver move on the job.

In this scenario we made sure to request information from UNI-Rac on how to attach the Enphase M-215 microinverters to the Unirac G10 rapidrac ballasted racking and attached them as specified to the brackets.  From now on we will use WEEBs to bond the Enphase microinverters to our racking saving a lot of 6 gauge copper bonding wire.

Overall our team liked the rapidrac system and it went together surprisingly quickly.  Hopefully we will have a chance to install it on a future job before the river rock ballast is put down. Learning Moment: having to manage existing rock is a large portion of the job.

This system is (4) separate arrays of 9 modules combined on the roof producing up to 8.4 amps at 240 volts AC each for a total of 8.1 kW AC.  The system size is 8.64 kw – (36) 240 watt modules.  The owner will need to install his internet service before we are able to monitor the system online.  The system has already passed inspection and the Net Meter Agreement is signed and in the line up for having it installed.  It should be activated when the net meter is installed so they can use the electricity produced from the array while they are finishing construction on the home.

SBS Solar Customer Testimonial for MT Audubon

What follows is a great Q&A with a recent install for Bert Lindler and Kristi DuBois:

1.  Why did you decide to install solar panels?

When we first bought our home, we realized that the south-facing roof offered an opportunity for solar photovoltaic panels and solar hot water.  We want to minimize our environmental impact and installing solar panels is one of the easiest ways to do so.

Kristi feels strongly that every south-facing roof is wasted space that should be generating electricity.  Industrial forms of “green” energy like commercial wind and solar farms impact a lot of habitat for wildlife, or in the case of solar farms, replace the habitat completely with solar panels.  Rooftop solar units have no effect on natural habitat, so they are a much greener way to meet our energy needs than industrial energy facilities.

We were considering refinancing our home to take advantage of low-interest rates at about the time we were reminded of the subsidies available for installing solar photovoltaic panels.  Once we had the roof evaluated for solar power potential and had received a bid for the installation (along with an estimate of the subsidies), we knew we wanted panels.

DuBois Home - Solar PV - Sprin 2012

8-panel, 2kW Solar PV system

2.  Did you encounter any challenges during the installation process?

The first challenge for us was approval from the homeowners association for our installation. Our installer prepared drawings showing the appearance of the eight panels mounted on our roof. We took to the drawings to our immediate neighbors and discussed our plans. All but one of the neighbors were supportive and the remaining neighbor said that while he didn’t want to look at solar panels on our roof, he understood why we wished to install them and would respect whatever decision the homeowners association reached. The association’s architectural review board approved our request.

The next challenge was a couple of tall non-native trees growing in our yard. We were considering having them removed anyway, but did so promptly after we learned that they would shade the panels. We still have some shading in winter from our aspen trees, but the effects on our power production are minimal. We left the trunk of one of the trees standing as a wildlife snag.

3. How long will it take for your system to pay for itself?

If the price of electricity stays in the range of 10 cents per kilowatt-hour and our photovoltaic system produces 2,289 kilowatt-hours of electricity each year as estimated, the system should pay for our cost of installation in 15 years (the system has a 25-year warranty).  If the price of electricity goes up, the recovery period may be much shorter. If the price of electricity goes down, we may never recover the cost of installation.

Our cost was much less than the system’s total cost of $12,629. We received a subsidy of $6,000 from Northwestern Energy for our 2-kilowatt installation and federal (almost S2,000) and state income tax refunds ($1,000).

Our system includes microinverters that  convert the DC electricity produced at each panel to AC electricity we can use in our home or return to the grid for use by other Northwestern Energy customers. The microinverters reduce the risk that more than one panel will be affected by shading and are provide real-time monitoring of the power being produced by each panel.

Our account is credited if we produce more electricity than we use (only likely during the summer). This arrangement allows us to receive full benefit of all the power we produce without requiring us to buy a bank of batteries to store power.

We do expect that our home will be easier to sell and may command a higher price because of the panels.

4.  How do you see your solar panels contributing/fitting into the larger Missoula effort against climate change?

Our purchase reflects our personal values, greatly influenced by subsidies offered by the power company and federal and state governments. Even though Missoula’s solar energy potential is not as high as in areas with more sun, our community could reduce our environmental impact if more of us took advantage of the subsidies that turn roofs into power plants.

What sort of lessons has the process of installing your own solar panels taught you?

Snow melts quickly off our south-facing roof. We had expected the snow to melt just as quickly off the panels. It doesn’t. The panels, mounted an inch or so above the roof, have cold air beneath them.

We use a pole-mounted plastic snow rake to clear snow from the panels and onto our deck.  The deck never used to get shoveled, but it does now.

In general, we were extremely lucky. The cost of solar panels has dropped dramatically in recent years and the cost is still dropping. The installer handled the $6,000 reimbursement from Northwestern Energy so we didn’t have to pay that cost up front. The remaining up-front costs weren’t a problem because we refinanced our home loan when interest rates were at record lows.

The panels were installed on schedule at the agreed-upon cost.  Within a week after our panels were operating, Northwestern Energy installed the special meter that gives us credit for the electricity we produce.

During December, our solar panels produced just 18 percent of the electricity we used, but as the days became longer, the panels produced 30 percent of the electricity we used during January and 43 percent during February.

We enjoy having the panels and we’re happy to see them producing more electricity as the days keep getting longer.

Bert Lindler and Kristi DuBois

Green Blocks – Final Phase

SBS has had a wonderful and successful time on the side-order list for the City of Missoula’s Green Blocks energy saving program.

We began work back in the Fall of 2010 by getting 2-inters from the University of Montana’s COT Energy Program and got them fully trained on doing a basic solar site assessment.

Our Team ended up doing over 120 assessments over the course of 3-months last fall.  They braved blazing sun, side-ways rain and blowing snow from October – December.  But, it was well worth it.

This spring 2011 marked the final phase of this project.  The City added about 60-90 participants to get to their total count of 300.  We got ourselves another COT Energy intern for this past Spring and he went out and did about 48 more solar site assessments.

Half way through this phase we saw an 18% REDUCTION in the cost to install solar, plus the state and feds decided to KEEP the tax credits in place for renewable, Northwestern Energy gave us a dozen more $6k grants to hand out to customers in good standing, and the MT DEQ revolving loan fund keeps on chugging along (although they are 8-10 weeks out on funding).  To top it off, SBS starting taking credit cards for deposits.

The wet cold spring made for a slow start, and with the unseasonably cool summer, folks were not thinking about solar.  But with the aforementioned incentives, and a little 90 degree weather, we are in full swing.  Over half of the installs we’re doing in July and August came from Green Blocks leads and SBS is now booked out until September.

Thanks to the City of Missoula for this great opportunity!  We’d love to do it again.

If you’re interested in information about solar – get in touch: www.SBSlink.com or info@sbslink.com.

SBS Intalls Solar for Ravalli Co Habitat for Humanity

According to the Bitterroot Star, last week the the fifth home by Ravalli County Habitat for Humanity was completed and keys handed over to the owners. The new home is on Cherry Street in Hamilton and now belongs to Travis Sanderson and his family.

Much of the materials for the home were donating, including a Solar PV system – made possible through the work of Sustainable Building Systems (SBS) and Northwestern Energy’s Solar PV grant.  This system will reduce the family’s prior heating bill of $350/month in winter to around $80/month.

Read the entire coverage from the Bitterroot Star here.

Solar Prices drop up to 25%!

After a PV module industry wide cost reduction, sourcing a lower cost mount system and dealers giving better pricing on all balance of system components, SBS has new numbers for potential Solar PV customers in MT that represent up to a 25% reduction in installed costs for PV systems!

If you couple the new lower prices with a $6000 Northwestern Energy PV grant, the 30% Federal Tax credit for renewable energy and the $500/$1000 (single/couple) State Tax credit, the costs are lower than every before.

And here in Montana, we can add to that a 10-year, 4% financing option (oac) from the MT DEQ revolving loan fund for renewable energy.

For a 2kw, 9 module system, total cost to the customer is in the $12,000.00 range.

After incentives this is roughly 3,200.00 out of pocket.

This on average powers about 25-40% of the average Montana home.

Here is an example of plausible breakdown for that $12,000 system

$12,000 GROSS
– $1000 (deposit to SBS to begin work)
=$11,000 NET
-$6,000 (NWenergy PV grant)
=$5,000 – Financed w/ MT DEQ loan
120-months
4%
=$51/month

Yes, that is correct, for at little at $51/month for a 10-year period, you can cover up to 40% of your energy bill. Awesome.  Check out this PV for more information: SolarPVFinancing-Basics-final.

And, when you file your taxes at the end of the year on that system, you’ll still get the $1800 Federal credit and the $500/$1000 state credit back.  You can keep these to use however you’d like, or put that money into your DEQ loan for early pay off (there is not penalty for early pay).

For a free solar site assessment, or to learn more, contact us at SBS today: info@sbslink.com, www.sbslink.com, 406-541-8410.

To get a general estimate of your solar or other renewable energy needs, try our Solar Calculator here.

New SBS Solar PV Customer Profile

Customer Name, location, system size:
Keegan Eisenstadt, Rattlesnake Valley, Missoula, Montana, 3450 watt solar PV system

What turned you on to Solar?

My father was a solar energy engineer in the 70s-80s in New Mexico.  They have had water heating panels on their house since then.  Additionally, my own work at ClearSky Climate Solutions is related to changing the course of climate change – which is predominantly driven by human demands for energy.  The clear need for more distributed generation of power from renewable sources is the most important element to reducing the emissions of greenhouse gases, and leaving a more stable world to my children.  Solar is a great way for me to practice what I preach, and also get a great price on power for my house!

What brought you to SBS?

SBS is an innovative, Missoula company that is looking at a holistic approach to analyzing and reducing energy use (and greenhouse gas emissions) of planned and existing structures.  My company works to mitigate carbon footprints with its clients, and a linkage to SBS was a natural for us.  Once I started learning more about what SBS does, I realized that I needed them to install a system on my home.  The solar system install team at SBS proved to be smart, capable and thorough.  I also think they are genuinely as excited about my system as I am!!!  I know they log into my system’s internet monitoring pages to see how it is performing, not daily as I do (which is great fun!), but at least weekly.

Racking system in, panel get ready!

What were your goals for this system?

My goals for the system were threefold: 1) make my house a laboratory for how to mitigate climate change with distributed generation of renewable power (which is something I have thought about, talked about, and worked towards for years), 2) give me a better-than-market price on electricity – which it will certainly do, and 3) provide an educational/outreach opportunity for my community to see just how easy it is to make your own power!

The financial incentives available right now for installing domestic alternative energy systems are good: 30% federal tax credit, $500/tax payer state tax credit, NorthWestern Energy grants, and low interest loans available.  My system will be financially paid off in 10 years, using a 4% fixed loan from federal stimulus money.  The system payback, from the energy created will be between 8-12 years, depending upon how fast prices for energy rise, and the panels on my system have a 25 year warranty.  So, my house will make roughly 1/3 of it’s power for free from about year 10 until 25.  That’s a good power bill!

Josh setting the first panel. Check out the nice lines on those racks and micro-inverters.

What do you like best about your system?

Actually, I’m surprised by this answer.  I had no idea how much more aware of energy use in my house I would become.  I now see/feel the house using energy….literally with the real-time monitoring tools that are part of the installation.  I turn on the stove, microwave, the stereo and I can see the kilowatts used jump.  It is amazing……I know that the mot

or in my refrigerator uses about 95 kW, that a big light fixture in the living room is 225 kW, that the microwave and clothes dryer are huge energy HOGS.  Frankly, I wasn’t really aware of those things before.  I never really internalized the energy demand of things in my house that way.  Even being interested in these things, I hadn’t internalized them in a tangible way.  It is such a surprise, and I am really enjoying it.  I’m sure in time, I will be happier with the cost savings….but right now, I am learning a lot and feeling great about it!

We just finished installing a 3450 watt solar PV system in the Rattlesnake where we employed 16 Enphase micro inverters. Micro inverters offer several advantages over more conventional string inverters.

Micro-inverters, monitoring and mountains...

Each solar module power production is optimized individually so little module mismatching occurs.  As well, if one module is shaded from a nearby tree, this one module will have reduced output, not the entire series string of modules as with the larger string inverters.  This advantage alone makes a huge difference but the pluses don’t end here.

The Enphase engineers designed one of the coolest monitoring programs found in the PV world.  Each individual module reports its power output over the existing AC output wiring to your in home computer or with internet service, this data is directed to the company’s website where current and cumulative data is displayed and stored.

A good graphic says a thousand words so if you are interested check out this link to the Enphase monitoring examples.

For more information on Solar or to talk with Dan:

Dan Brandborg
NABCEP certified Solar installer dbrandbog@sbslink.com

Hamilton’s first Pole Mount Solar Array

The Moore’s of Hamilton, Montana completed installation this Fall 2010 of a 10 module photovoltaic system which will provide 40% of the electrical power used in their home.  The pole mount solar array is mounted on a tracking system which follows the sun from East to West through the day.  The electricity is run into their home where it powers any electrical appliances that are currently in use.

If more power is available from the array than can be used by the home, this excess power will then turn the electrical meter backwards creating a financial credit with the utility.  This credit can then be used at night or this winter when the power draw of the home exceeds the solar power production.  So you can see that a system can easily be designed to provide any portion of you power bill that a homeowner determines.

This PV system(short for photovoltaic’s) is one of several in downtown Hamilton that Dan Brandborg , a native Bitterrooter has been involved with since he started working with PV in the early 80’s.  He has worked with Sustainable Building Systems out of Missoula, since 2009.

Solar Guru times Two!

SBS is proud to announce that we now have two NABCEP certified installers in the house.  NABCEP is the North American Board of Certified Energy Practitioners.

Greg Guscio, our solar thermal expert, has just passed the NABCEP test. This means that both Dan Brandborg and Greg are NABCEP certified.

Congrats, Greg!

Solar Highways – The Horizon is Near

Now this is something I am excited about. My mom sent me the link to this video over the weekend and she is right on. Solar Highways. If we were able to construct a save road, parking lot, highway materials w/ photovoltaics under super strong glass we could harness enough energy to cover ALL USA ENERGY NEEDS PLUS 15%!!!

Let that resonate for a moment.

No oil based electricity.

No coal powered electricity.

All solar. ALL SOLAR.

They even go on to explain how post consumer waste, otherwise headed for landfills, would be the source, mixed with other organic materials, to form the base and structure for the panels.

And finally, from a safety perspective, they plan to include embedded LED lights, powered by the solar, that would be used for a myriad of reason like lighting up crosswalks, giving messages like “SLOW DOWN, CONSTRUCTION AHEAD,” changes in speed limit, etc…

Watch the entire video here.

As I was noodling around in related news, I came across another neat happening in the past year. The State of Oregon is putting together some of the first highway solar projects along the highway like the arrays along the autobahn in Germany.

You can view that video here.