Note: This is another entry in the 'Solar on a Strata' blog series <https:bcsea.org/solar-on-strata It chronicles the planning, installation, and ongoing experience with a 60-module solar PV installation on Central Park Strata, a 63-unit condominium in downtown Victoria. HES-PV supplied the hardware such as Fronius Inverters and Solar Panels in June 2015. I was the Strata President and led the project to install them, and continue as a volunteer adviser to the Strata Council.
Bottom line: There isn't much to report in the last year and a half. The system continues to produce electricity every day, without maintenance. I asked the current Strata President if they would like me to come to their next AGM to answer any questions, and her response was:
“We have asked around about the solar panels, and nobody really showed much interest in learning more about them. I think that overall, people are just happy that they will eventually pay for themselves and generate power, but that's the extent of their interest. Unfortunately, I think that by coming and doing a presentation would be a waste of your time.”
Here are some details:
As of the end of January 2018, the system has produced 45 MWh (Megawatt hours) of electricity. This is AC power delivered out to the building, as measured by the inverter. It's about 5% over what we expected from the most accurate pre-installation prediction - http://pvwatts.nrel.gov
The initial analysis predicted it would supply about 1/3 of the electricity used by the strata common area. As reported in the last blog, the strata replaced the High Pressure Sodium exterior lights on the building with LEDs, reducing the overnight demand by about a kilowatt. In the 12 months since that change, the solar panels supplied about 47% of the electricity used by the strata common area.
I have done my best to calculate $$ saved and it looks like $5,780 from June 11, 2015 to the end of January, 2018. Any calculations for solar should be done on a full 12-month period to account for the huge seasonal variation. Those run from June 2015 to June 2017. The best estimates I can provide show that the system saved $4,654 in electricity costs during those two years, a 4.95% annual return on the $47,000 invested.
BC Hydro Invoices
The August invoices show the most change, of course. August 2014 was $707.46, August 2016 was $39.96 and August 2017 was $64.06
No magic here, but it's easy to see the eclipse cutting production from 08:50 to 11:05 on August 21. The loss was about 8 kWh, costing about $1.13.
The Strata Council was very supportive in having tours of the system on September 23 as part of Green Energy Doors Open <https://www.bcsea.org/green-energy-doors-open> Ten people showed up for three tour times.
The ventilation fan installed in the electrical room worked fine over the summer, and the room has been cooler. I had a recorder there until the end of June, and it was almost always under 30, with a couple of bumps to 32.
The Inverter continues to report its output and condition through the Fronius website <http://bit.ly/central-park-pv>. I receive weekly and monthly emails with output summaries, and also if there is a problem in the system - to this point only with the Internet connectivity.
Fronius changed its public website so that we can now only see two days of previous output profiles, although monthly and annual summaries are still available.
As usual, the only trouble from the system was from the lobby display. This time the LCD panel that shows the production failed. I purchased a replacement at the Sally Ann for $10. It's a bit different shape than the last one, so I had to modify the wood frame it hangs in a bit. Again, this display has no effect on the actual electricity production which continues uninterrupted since June 2015.
Too Much Power ?
This is the one for geeks. As mentioned in my last blog entry, some of the electricity the panels produce in the summer displaces 'Step 1' electricity, which isn't as expensive as 'Step 2'. When we designed the system, the goal was to NOT generate enough to displace 'Step 1'. However, with the LED lights, it turns out that for the July and September billing cycles, the solar panels have cut into the Step 1 rate. But I have done the calculation and this has only reduced the cost savings by $127 in the last two years. Not a big deal in the big picture.
I rinsed the panels in spring of 2016, when they just had a bit of grit along the bottom edge. They didn't seem to need any cleaning in May 2017 after our very wet spring. I checked them closely again in mid September 2017 ahead of the tours, and they had a bit of grit at the bottom again, but also a very thin layer of find brown dust which I thought might be from this summer's forest fires. I gave them a better cleaning this time
- used a bit of soap in two buckets of water, and a soft broom again. It took about an hour.
However, there was been a lot of rain this fall and a month later I didn't find any grit left. I think my rinse was unnecessary - the October rains would have cleaned them.
The Strata chose to replace the 'dog dish' CFL corridor lighting with new LED fixtures. I don't know what this cost, but I saw a comment on Facebook that the hallways are brighter. I can't detect any difference in the power consumption on MyHydro. The 6" fluorescent U-tubes draw 13 watts (plus a magnetic ballast), and the LED lights are rated at 14 watts, so I wouldn't expect to see a change.
I remain happy to talk to anyone who is interested in following Central Park's lead. My email address is on the 'Solar on a Strata - Join Us?' page. I have spoken/emailed with about 13 people. I don't know of any who have gone beyond the investigation stage.