We used the most advanced charge controller on the market (the Xantrex XW MPPT 80 600) capable of converting up to 550 volts DC from the array to battery bank voltages allowing us to use large strings of up to 12 modules in series. This was a huge benefit on this system allowing us to achieve less then 2% loss running four strings of 10 gauge wire on a 250′ home run instead of 12 strings of 4 gauge with a standard 150 volt max controller with a dramatic cost difference.
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.
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.
This is a great article from the NY Times Energy and Environment blog about Passive House trending, standards, technology and more. One of our Energy Technicians, Zandy Sievers, recently finished the Passive House training this summer with Katrin Klingenberg, the director of the Passive House Institute-U.S. based in Urbana, Ill.
The story concedes that while the upfront costs can be 15-50% higher, the lifetime energy consumption is roughly 80% less than a normal home. Even this Vermont home will need no furnace, with heat generation coming from radiant floor heat and a small wood stove. Their hot water will be heater with solar thermal tubes.
Read the entire story here and check out the video below.
The Montana Radio Company and Sustainable Building System’s have teamed up to bring Cool Green Home to Missoula, where over $135,000 in home renovations will be given to a few lucky Missoula homeowners.
The project was started with a simple idea, take an existing Missoula home and create a “showcase” for energy-efficient and sustainable products offered by local businesses. It has gained so much attraction that 24 area businesses have partnered with us on this unprecedented project, and each will contribute in their area of expertise.
Our goal is to show our community that sustainable and green homes are not only good for our planet but good for our bank accounts, and with planning, big improvements can be made with modest steps. We intend on setting an example as to what a sustainable green home could look like. We don’t intend on building one from ground level but getting an existing home started on the path to green. We will start the home remodel by completing an energy audit of the home to identify the best places to improve the energy efficiency. For the next year we will continue to monitor the Cool Green Home and track how much money the family saved in energy costs and how their lives improved.
We received over 180 applications from Missoula-area homeowners and paired them down to a set of 10. From here the winners were chosen. Congratulations to our winning homes:
- Elke Govertsen & Paul Donaldson
- Jana & Chuck Doyle
- Ross & Norma Nickerson
- James Dodge & Jenny Daniel
- Paula Raines & Michael Hoffer
Keep checking here and at www.CoolGreenHomeMissoula.com for updates and information on the progression at these five homes. And if you entered and were not a winner, do not fret, there are great tips and DIY projects associated with this year’s projects and we’re already looking to 2011 for another round.
This is a great, and short, video from TED U, the interactive learning component of The Energy Detective (TED) device.
Here Catherine Mohr shares some quick and valuable information on evaluating simple life choices as they relate to energy and water consumption… paper towels v sponge v washcloth all the way to building a new home.
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.
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. http://enlighten.enphaseenergy.com/public/systems/BxqT67#.
PS – don’t those snowy spring peaks just look great in the distance? It sure is nice to be working Solar in Montana.
SBS Solar guru
SBS purchased two of the TED 5000 devices to try out and see how well they functioned and whether they could be of service to our clients. The package came with two sets of current transformers, an MTU device, a gateway to route data to a home’s wireless network and a remote display. The current transformers (CTs) clip over wires delivering power to home electrical circuits and through the magic of magnetic induction register the current moving through the wires. The MTU sends information gathered to the remote display and to the gateway which allows it to be accessed through an intranet connection on a home computer.
The remote display is a great tool for checking on the instantaneous electrical consumption in the home at any point in time. You can use it to watch the draw of particular appliances as you turn them on and off while following the numbers on the live dashboard (expressed as kWs, dollars, and pounds of emitted CO2). It’s quite fascinating in a sort of morbid way. (Oh that clothes dryer sucks the juice more than I ever imagined!) The internet option that comes with the TED 5000 allows data collected about energy consumption to be logged and displayed as a series of graphs and tables. It has the ability to learn certain load profiles and keep a tally of the energy consumption of that particular load.
Long story short…I’ve learned some very revealing facts about how we use energy in our home. For instance, I used to fret considerably about the energy gobbled up by our well pump. What I’ve learned is that while it does draw significant power (1.5 to 2.2 kW) its run time is short enough that its overall energy consumption is small compared to other devices in the home. As mentioned earlier, the clothes dryer is an energy hog of grand proportion and now our outdoor clothes line is gaily festooned with laundry full time come rain or shine.
My load profile shows the steady staccato punctuation of our cycling refrigerator and has definitely sharpened my resolve to bite the bullet and purchase an Energy Star Rated appliance. More than ever we are careful with lights, the TV, even the coffee maker. It lends new significance to all the little energy services we tend to take for granted.
Another nice feature of the TED 5000 is its ability to export data to the internet and display it on the power gadget on my Google search page. I now know even when I’m at work when the dishwasher is running or laundry is being dried. It’s not my desire to become the “Big Brother” of my own household, but it is a nice feeling to look at the graph and see a nice flat profile.
Here’s a the graph from my Google power gadget showing our power consumption over the last 36 hours. The double humped peaks are our dishwasher (an Energy Star rated device by the way) and the tall spike at about 4 o’clock yesterday was a brief episode with the clothes dryer. See the teeth at the bottom of the graph? Our refrigerator takes a bite out of our energy budget.
So you can see the impact TED’s presence has on our awareness. Maybe ignorance is bliss, but knowledge is power- the power to conserve. Now I know that for us an 11 kWh day is a pretty good one while 17 kWhs feels pretty indulgent! TED is a good guy…but he’s brutally honest. If you decide to bring him into your house he’ll certainly give insights to the grid.