Although the Braden’s new green home features so much more, all visitors on tours through the Braden home want to know about one thing – the solar array and photovoltaic system.  This is, after all, the backbone of the “off-the-grid” philosophy.  Most visitors have a hard time believing that all of the standard electrical needs of a household are met by an off-the-grid system, but they are.

The Bradens didn’t go into this whole venture blind.  Dave Braden had family members who had been off-the-grid for many years.  In addition, he subscribed to “Home Power” magazine before building his green dream home, and the couple attended seminars at the Kortright Conservation Centre, near Toronto.  This centre gives in-depth classes on various aspects of off-the-grid living for the curious. 

The usual approach of most people who want to set up a solar energy system for their house in Canada is to research the various components needed, then either order them over the internet or drive down and pick them up in the US.  It isn’t that the items aren’t available in Canada – I personally know of three major dealers that I could call right now to order components from.  It is just that the cost is often lower in the States, due to the fact that most manufacturers (not dealers) have not yet properly adjusted for the increase in the Canadian dollar.

Braden decided in the end that he needed an expert, and even after years of reading “Home Power” and attending the classes, he was not that person.  The photovoltaic system was simply too important to leave up to anything less than an expert consultant.  Luckily enough, he found his guru in the person of Mike Morse, owner of Nith Valley Solar.  Mike sat down with Braden and worked out the details of the necessary system, and in the end the bill for everything was $43,000.  This included the photovoltaic system, batteries, inverters, control panels, and a small backup windmill should the photovoltaic system fail to store sufficient power in the iffy months from October to April.

Direct current comes in to the house from the PV system via two separate mechanisms, the main one being the inverters.  The power is then stored in a large battery bank, and then changed from DC to AC to accommodate the needs of a “regular” household.  While DC appliances are available, they are often more expensive and their use would go against Braden’s philosophy of providing a demonstration home.  The only exception that Braden is considering making to this rule is a Sun Frost refrigerator, which would greatly reduce the load on the system. 

Despite the fact that solar is a tried and true technology, visitors still have a hard time believing that the Braden home is truly “off-the-grid”.  Not only is it off the grid, but it operates so efficiently that I’m sure that many others will want Braden to build their homes to the same specifications.

Technical Specifications

PV Array

• 12 of 165 watt solar modules for 1,980 watts at 72 Volts DC, future expansion to 2,640 watts.
• fixed pole mounts
• modules guaranteed for twenty years under mfr warranty

Controller

• Outback MX60 - converts incoming 72 VDC to 48 VDC to the battery bank.

Battery Bank

• configured for 48 VDC
• 2 banks of 8 Surette S460 deep cycle batteries in series
• 1,050 amp-hr capacity or 50 kwh.

Power Board

• Dual Outback FX3648 inverters convert 48 VDC to 120 VAC series configured to 240 VAC.

Metering

• Outback Mate and remote Trimetric meter on the main floor

System designed to meet all electrical requirements of Dave's house when PV array is expanded to 2,640 watts and a 1 kw wind generator is to be installed to supplement solar PV generation during the winter.

References

• Interview & Tour with Dave Braden
• Article on Braden’s Home in the Star
• http://www.thestar.com/sciencetech/article/290351
• System Specifications from Mike Morse, Nith Valley Solar