Double Measures

Our demand for electricity surpasses our ability to produce it often these days. Between the fridge, working from home,  kids growing up, and soon a water pump, we’ve expanded drastically but our solar setup has not. With Winter looming, it was time for an upgrade.

We can pick 2 strategies for an upgrade:

  • Beef up storage by buying batteries which can carry us through more cloudy days.
  • Beef up our panels to milk more amps out of cloudy days.

The former doesn’t make sense for us right now, battery lifetimes wouldn’t be in sync, and they freeze on the really cold days which is not advisable for their long term performance. Batteries are very expensive and we know that whatever we get will take a beating. In a few years, when we have a root cellar, we’ll also have an ideal place for batteries which won’t be subject to drastic temperature swings, then it will make sense to upgrade those. In the meantime, the only strategy left to to milk the cloudy days for more by buying more panels.

I couldn’t find the exact same panels so I bought some similar, and well, I had to get 9 for things to look symmetrical

I went vertical because I like where everything is now, I didn’t want to increase the panels’ footprint on the land.

I expanded on the existing frames made of pressure treated 2x4s. It looks a little eclectic and that’s ok, it works well :). We do get very high winds here so I have to build sturdy or I’ll be picking panels off the ground after a storm.

Now this is starting to be a serious array. I don’t think we’ll ever need more panels than this. Note that the top row looks a little different, as I said they aren’t the exact same panels.

Because we have more panels, everything downstream also needed to be upgraded. Truth be told, it needed to be upgraded a while back. I was definitely pushing the gauge of the wiring, and a lot of things I had done poorly as I was learning. I rewired everything with better gear, better knowledge, and dare I say better skills.

I started work on the control panel of my dreams inside. I’ve gotten to appreciate just how much time, and how much skill proper wiring takes.

Each solar panel now gets its own wiring, with an on/off switch and a diode to prevent electricity feedback. The panels have their own diode locally to prevent feedback damage, but between they and the control panel, there’s a lot of wire one could make mistakes with. Working together,  they can produce 100 Amps and so you really don’t want feedback. I soldered heavily (and uglily) any connection I could.

The solar on/off button casing is an fork from the previous on/off switch casing but with room for a diode and made so they can stack.

Download links here:
solar_on_off_button_casing.stl
solar_on_off_button_casing.dae
solar_on_off_button_casing.skp

I’m also making the control panel fully detachable, anything connected to it has a plug. It’ll make it easier to work on down the road.

Now we’re talking!

Long story short, it took several days of work to rewire all 18 solar panels and create this awesome control panel. There are still a few things I need to polish or position better. I “reverse-engineered” what powers our fiber ONT so I wouldn’t have to rely on an inverter to power a UPS to power it (ouch for efficiency). Turns out it just needs 12V, guess what I have plenty of in this solar shed? I got a 12V power cleaner (the aluminum radiator looking square to the right) to at least give it a very clean 12V, the other pins are optional signal pins to take various UPS actions based on power scenarios. It really didn’t make sense to jump through all these hoops to have a 12V battery backup when my whole system is essentially a 12V battery backup. We’ll see if anyone comes knocking on my door :).

The smarts for monitoring and hosting this very blog are mostly untouched but I did re-arrange them a bit. I tried to fit everything on the control panel but it made sense to separate by function.

Robin enjoyed playing with the switches, including the big catchunking one. We experimented with various scenarios, compared panel outputs et cetera. This was a nice unforeseen side effect this design.

All in all I still have a bit of work, but I knew exactly what I was doing and didn’t make a single wiring mistake which is really nice. I used to be way more puzzled by how to wire something much more basic than this. The charge controller stopped working mid-day, that’s because it stops at 80 Amps and the panels had reached this. Fortunately, it was very easy to turn off 4 panels and the system worked again. It’ll be just as easy to re-add them on a cloudy day. The real solution will be to upgrade the charge controller, this will be left for another time. With the Sun almost gone well behind the tree line, we were still making 2Amps, this is now definitely a nice setup :). “Legit Brah” as Robin would say.

The Year of the Trench

The backhoe is really paying for itself this year, I just added conduit from the solar shed to the house for a much more legit electrical setup. I gave us 2 3″ conduits separated by a foot, the idea being that I want to have separation between AC and DC (a lot of the house is on 12V DC) to avoid interference. And I also need to pass some data. It’s all been in one bundle for years so I don’t think interference is a real issue but hey, now’s the time to give us options.

tractor time

Kids always love a hole in the dirt

Schedule 40 3″ pipe is MUCH harder to work with than 2.5″, it barely has any flexibility. Don’t forget the expansion coupling going from the ground to the house.

I’m still working on the wiring, all conduits end in the same spot with the idea that this solar shed will become more in the future, most likely a root cellar doubling as housing for the batteries.

Inside the house, things are about the be super legit.

Filling it all back up

A little dirt will really keep kids busy for hours

While the backhoe was on, I helped a neighbor dig holes for a pole barn assuring him a beer was all I needed for thanks. Little did I know that I would instead be introduced to a concept which was thus far foreign to me: the wheelbarrow full of beer & wine, which showed up at my doorstep the following day. I certainly love the abundance, but what really cracks me up, is the idea of Lou rolling around the neighborhood a wheelbarrow full of alcohol.

Cheating the Laws of the Universe – Le Bruit du Frigo

That’s it, after 4 years of slowly learning and ramping up our solar production, we figured out enough to run a fridge. In truth we’ve had capacity for a while now, but I had things wired sub-optimally in a way that prevented us from running anything requiring surge power (power tools, condensers). Silly me for wiring our load to the “load” port on the charge controller, this port is apparently only intended for small loads. It always blows my mind how incredibly disparate information is about solar installs online. There’s so much fuzziness, various understandings, theories, concepts which apply, or not, no one really knows. Most posts are a person asking some random simple question followed by 50 answers going deep in the weeds on some highly specific aspect, unrelated to the question, and that no one but its writer gives a crap about. In one of these random threads someone alluded to this fact, that the load port on the charge controller isn’t really meant for anything surging. Sure enough, after wiring the inverter straight to the batteries, I can power fridges, ACs and power tools. It’s a very nice step up.

Now of course because nothing is ever simple I had other issues with our inverter so I just got another nice one which is really the cat’s meow.  We now have a full backup solar system, extra panels, batteries, charge controllers and inverter. They just all suck a little more 🙂 but I’m sure they’ll be useful somewhere some time.

After 4 years of battling with various shitty refrigeration arrangements.

I added 2 batteries, the fridge is a power hog.

Oh and I used the opportunity to revamp the solar monitoring page, mainly I separated the 12VDC circuit from the 110VAC one and recalibrated the sensors.

We’ve been catching up on all the ice cream we missed on (note that we ate plenty in the past 4 years, just not as much as we would like, which is too much)

Now, having a fridge is really really nice. I joke that if I had remembered beer was so fresh in it, I would have solared us up enough to power one upon arrival. The reality is that I had to learn how things work and make plenty of mistakes along the way, and that the solar project competes for time against all the other projects.

We did question the need for a fridge for years, we were hoping to change our eating habits to not need one. The truth is that we didn’t (cheese is just too good), and that our eating habits “degraded” immediately after getting one. The fridge is always full and holds a lot of less healthy food we did with less of only a few weeks ago.

Our main concern however, and this may come as a surprise, is the noise that a fridge makes. Our house used to be extremely quiet, it’s something we noted when we moved in, just how eerily quiet the house was. Neither of us had experienced a house this quiet, and it’s something we appreciated. I thought the fridge noise would get on my nerves, but in reality I find it soothing because it makes me think about all the good stuff in there that’s being kept nice and fresh. Did I mention fresh beer is yummy? It looks like 4 years of not having a fridge made me appreciate how nice they are.

Now the coolest thing about this whole deal, is how we’re turning Sun heat into cold. It feels like cheating, and it’s elating. The hotter it gets, the more cold we can generate. How does that even make sense? I’m sure I can understand it but I choose not to, it’s just too good left as universe breaking supernatural magic.