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SPEC’s solar tour

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The PV panels on the roof of the MEC building

The PV panels on the roof of the MEC building

SPEC, the Society Promoting Environmental Conservation, and the oldest enviro group in Vancouver, organises “solar tours” every now and then. I joined one yesterday, on the roof the Mountain Equipment Co-op.

MEC has two arrays of panels, each pumping out about 1.5 kW on a sunny day. The first set is an ten-year old mono-crystalline unit that was originally on the roof of the old SPEC house; the panels went for about $10,000 then. I remember bringing a class to SPEC around that time, and the staff made it clear that these units were for learning; with the cheap price of BC Hydro power, these would never pay for themselves.

The unexpected beauty of poly-crystalline panel up close.

The unexpected beauty of poly-crystalline panel up close.

Fast forward ten years: the second array of a similar capacity was purchased for about $1,300. PV panels are now so cheap that our guide, who showed some solar water heaters, recommended against them. “It’s now cheaper and simpler to put up PV panels and use the electricity to heat up a water tank”, he said. Wow – just a few years ago it was gospel that hot water heaters could pay for themselves in between 5 and 10 years, PV cells, well – now it’s the reverse.

The panels at MEC are a funny angle, about 20% off the vertical. This is less than optimal, but our guide explained that this is the simplest option: the mounts for this flat roof are ballast-type, which means that they are not attached to the roof. A higher angle would risk the wind moving them.
It’s still not super cheap, but it’s getting there. Most systems, as this one is, are net-metered, which means that extra electricity is sold back to BC Hydro at around 7 cents per kilowatt hour. (You’re charged more like 10 cents, though, when you buy power – taxes and fees seem to run one-way.) In BC there is no feed-in-tariff for solar electricity, unfortunately. (A feed-in-tariff is a higher fee as an incentive for solar power producers; Germany successfully pioneered this approach with the twin objective of creating a market for the technology and reducing greenhouse gases emissions. But BC has clean hydro power.)

Where solar PVs are most appropriate is in remote locations. BC Hydro charges about $12,000 for each pole that they install to reach your property. An ordinary house may require about $10,000 worth of panels, half of that or less if energy efficiency measures are used. A solar installation is more than panels, of course; there’s the cost of installation, inverter, batteries, etc, so that may double or triple the overall cost. But even then, it may be cheaper than connecting to the grid. Most homes, though, usually connect directly to the grid, sparing the expenses of batteries.

Our small group around the panels at MEC

Our small group around the panels at MEC

I asked about power failures – in the extent of an extended blackout, would a house with PV panels be able to produce power, say to keep the freezer from thawing? Unfortunately, that’s not possible with most installations; they shut down if the grid goes down. That is done for safety reasons; if there were some PV juice running through the wires while a technician is trying to fix them, there would an obvious hazard. But I was glad to hear that there is a new system coming that has an automated kill-switch that would enable users to still derive power from their cells even when the local grid is down.

The new housing co-op on 33rd (near Victoria) will use solar PV as part of its power supply, and our guide said that this is typical of an increased demand.

Our guide (stupidly, I didn’t write his name down) is a system designer and installer, and had lots of savvy with respect to practical issues. No wonder: before getting a Master’s degree in Sustainability Studies, he was a practicing electrician.

SPEC’s next tour will be on May 10th.  These free tours are part of the Wild About Vancouver outdoor education festival, with a very cool line-up of events.

______________________________________________________________________

Addendum: Rob Baxter, of Vancouver Renewable Energy, mentioned to me that the name of our guide is Darren C Anderson.

 

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Written by enviropaul

April 19, 2015 at 1:36 pm

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