General
About 3 years ago I put in a bunch of solar panels as part of the whole green thing and to cut down on power costs. Now that it’s been about three years (actually about 2 years 8 months) I’ve got enough notes that I can share some of the lessons learned that may not be so apparent.
Getting Ready
Plan out what you want from your electrical system in the longer term when you start this. If you want to install a backup generator at some point, make sure the engineering team that does the solar panel design knows this. It will save you a host of issues in the longer term.
The peak production months along the shore seem to run from May to July, which should not surprise people. Two factors come together for this. The first involves how many hours of sunlight you have. The second involves the weather. Very cloudy days along the shore will cut your production significantly.
On that note, consider installing a reasonable weather station in roughly the same location as the panels (but not casting a shadow on where the panels would go). The reason for this is simple: you want value for the money. A good weather station will measure temperature, wind, rain, solar energy, and other factors. The engineers that design the systems do so off of averages and the like. This gives you some data to work with.
You can also take a look at sites like “Wunderground” that list weather stations in your area for historical data. Mine, for example, had about two years’ worth of data last time I checked. To do that, visit their site, click on one of the stations and you’ll see a station identifier. Click on that and look for the graphs.
Finally, make sure that any work that you need to do on your shingling or the like is done before the system goes on. Replacing shingling is fun. Replacing shingling under a solar panel system is even more fun.
The General Activities You Can Expect
Installing a solar power system has four major activities.
First, make sure the contractor handles the design but also the permits and rebate paperwork. Some of these programs are faster than others so ideally, if the contractor can just chop the rebate off the bill it would be ideal. Most of these activities will involve a person coming out to take a look at the site, take some pictures, and such. Make sure you have your plan (from above) together for that step and make sure that person knows that you expect them to pass that onto the engineers as well.
Second comes the installation phase. This will begin with the rails being installed (or the ground mount system). This generally needs an inspection before panels can go on or the system can be turned on. Expect a couple of days for this as there’s a fair bit of work that needs to be done.
This is what the rail system, power lines, and grounding lines look like before the panels. Be sure that they leave you a route to get to your chimney (annual sweep outs) and such.
Third, they will install panels and make sure all the connections are good. Your system won’t be active at this point. It will still need the NS Power folks to come out and take a look at things at the end before it can actually connect to things.
Finally, you get to turn the thing on. When this happens, get them to write down the order that things need to be shut down in (what breakers are turned off first and in what order) and then turned back on again.
Selecting a Contractor
I took my time in selecting a contractor and am pretty sure I drove their sales people to near distraction (they didn’t show it, but I am a bit of an organization nut). It’s pretty simple, remember three things when you talk with them.
- You are making a significant investment in the system (regardless of the return on investment) and the onus is on them to show you why they are the best option.
- You are making an investment that should have a useful life of 20 years to 25 years. That means you want a stable company that’s going to be around and will be able to do any maintenance that comes along.
- Scheduling is a two way street. Get them to commit to dates when they are going to show up then make sure they know that you’ll be expecting them on those dates.
The other side is looking at who handles the administration. Oddly enough, you may want the contractor to handle all the permits. If they do, you will want to know when they submit the permits and get estimates on when they should be received. You may need to follow up with them if you don’t hear anything back for a bit.
Do all of this stuff “above board.” Don’t get pulled into anything where somebody offers “work for cash.” While that may look tempting, you’re going to want to include the system on your insurance and, depending on your work from home arrangements, you may want to make sure your accountant (if you have one) knows and factors in the appropriate amounts on your taxes (if you can claim it–I’m not a tax lawyer guy so this is where you have a chat with the accountant or CRA).
Expectations on Performance
Make sure that you speak with the contractor so you know how many Watts your system is actually supposed to produce. This can save you a bit of stress in the future.
Performance comes in three parts: generating, transmission, and use.
Generation involves your panel converting sunlight to power. Winter months (with shorter days) generate less power than summer days. Snow covering the panels over an inch or so will vastly reduce your generation. Some may argue this but I’m going with what I see with mine. The same thing goes for cloudy days. Generating credits during the summer months that offset the demand and lower production in the winter is the balancing act.
Watch your design for distribution issues. Panels are installed on circuits. These circuits include breakers that allow them to be isolated, etc. A panel, when it first starts, may have a peak Amperage of slightly over 2 Amps. Now count the number of panels. If the number of panels multiplied by those 2 Amps equals or is higher than the breaker tripping point, expect challenges on particularly sunny days. Catch this early and inform the engineers doing design that you want to avoid those situations.
In the image above, you see the situation this applies to. The panels on the detached garage feed the main system but have to go across a line protected by a breaker. That breaker would trip on very sunny mornings until we made some adjustments to limit the surge in Amps to below the tripping point.
Finally, you may need to adjust your usage. Reduce your usage in the summer (clothes lines, etc) to help you build the credits you’ll need in the winter. Figure out when your peak production occurs. If you need to use heavier draw appliances (stoves, driers, etc.), then that may be the time to do so.
Reading the Meter
NS Power will install a reversible meter as part of this. This provides some visibility into your system’s return on investment. Two sets of readings need to be looked at. Your “D” readings represent how much power you draw from the grid. Your “R” readings represent how much you push back onto the grid. Ideally, your “R” readings will exceed your “D” ratings by October.
A small arrow will also indicate how you are doing at that time. Where the arrow points towards the grid, your demand is exceeding your production. Where the arrow points towards away from the grid, you are pushing power onto the grid.
Applications
Your system will ideally come with an application that will tell you some useful things then some “other stuff.” The useful stuff includes things like module performance and productivity. Look for panels that are under-performing compared to their neighbours (could be coverage or a problem in the panel).
The application should generate reports that show how the system is doing on a daily, monthly, and annual level.
Finally, your application will provide “fun facts” like the amount of trees, lights, etc. that can be tied to the “green” parts of the system.
For mine, I can track performance through the desktop or phone on an application. Those take some time to set up but have been pretty reliable since.
Environmental Factors
You want to be aware of two factors: wind and how the panels respond to coverage.
Make sure that you get the certified wind rating (sustained and gusts) for the panels. A good contractor has this information on hand as part of the install and no issues communicating it (at least mine did).
The second is coverage. Snow coverage factors in three ways. First, how deep is it before it blocks generation. Second, how does the infrastructure respond to being covered in snow. How long does it take to “warm up” to peak production again? Finally, can you use a snow broom to remove snow or are the panels susceptible to scratching, etc.
Originally, I went with the guidance that “nothing should touch the panels.” The problem here is that when the snow settles on them, it blocks power generation and can put the panel in hibernation. I decided to get one of those “brooms” rated for panel clearing and just clear off the bulk of the snow speed up the melting process. That melting takes care of the last bit pretty quickly.
On that point, don’t use a “rake” on the panels. Invest the money in one of the snow brooms that is certified for “delicate” surfaces like panels. These look like big stiff sponges. Also consider the length of the pole and if you can reach the panels safely. Don’t pull a “Wile E. Coyote” move and pull the snow down on yourself either.
Key Lessons Learned
First, solar power should not be considered completely reliable by itself. Snow coverage, cloudy days, and other factors can affect performance. If you are going “off-grid” in this part of the world, consider a second source of renewable energy to hedge your bets.
You will find guidance telling you to do nothing like brushing snow off the panels because you may scratch them. Don’t ignore this. At the same time, check with your contractor to see if a properly rated snow broom (some are rated for delicate surfaces) is worth it.
The return on these brooms can be “hit or miss.” On average, my system over the winter can produce around 30 kWh to 40 kWh when completely sunny and clear. One inch of snow drops that to about 2 kWh to 3kWh. Your return on investment for the broom, therefore, needs to look at the number of winter days where you can recover those missing kWh. Check the NS Power “Time of Day rates” and you’ll see that you’re not paying more than $0.23 / kWh. In my case, this means that from December to February (months that involve sweeping), I am recovering about $8.30 per day. If a broom costs you $240 through whatever company, it will pay for itself after about 30 days as long as you don’t damage your panels.
Wrap Up
The panels can be a good return on investment. I am on a single heat pump and electric baseboard heating. During the spring, summer, and fall months I pay the power distribution but am generating credits. I have to be a bit careful in the winter months if the credits get lower but all-in-all, the return is pretty good in the short term.
The systems are supposed to last for 20 years to 25 years. Without getting into specific numbers, my panels will have paid for themselves after about 15 of those 20 years based on my current numbers.
Another factor to remember is that having solar panels does not mean you have power if the grid goes down unless you are completely off grid. You’ll still need a backup generator of some kind.