Today we had some gentlemen come and pour concrete into the giant hole we dug yesterday. You may recall that we had to dig a 24 inch wide hole 58 inches deep to the pole that will hold our solar panel array. The problem is that the amount of concrete needed to fill a hole that size requires mixing 26 80-lb bags of concrete. The solution is that Kate found some concrete ninjas who do this regularly.
I once worked construction with a guy who said: “Concrete waits for no man.” What this means is that concrete is a force of nature and does not negotiate. Once you get concrete wet a timer starts. If you don’t have the concrete where you want it to be when that timer goes off, then too bad.
The concrete ninjas showed up on time with the bags of concrete and their mixer. Within 45 minutes they were headed home, the hole was full, and the work space was clean. They had a perfect system setup with an open bag on the tailgate. One guy would grab the bag, turn around, and pour it into the mixer. That is the best way to have to handle an 80 lb bag. I would have not been that smart.
Once they had 7 bags poured in the mixer was full for that load. They would get the water ratio right and add some pure cement to increase the strength. Once everything was set they just rotated the mixer 190 degrees and everything poured into the hole. They did 4 loads and were done.
Manuel recommended that we let the pole sit for a week before putting the solar panels on top. By then the concrete will be halfway cured. It will take a month until it fully cures.
Now that the pole is up we will begin working on connecting the wiring from the pole to the solar charge controller in the cabin. Then we will be able to hook everything up and have 12v and 120v electricity in the cabin! This week we will spend time finishing the inside wiring and pull wire to my shed/workshop/man cave.
I dug trail for an hour then the 3 of us went on a 26 mile bike ride. We went north west into the wind. We stopped halfway in the town of Dolores and had some snacks at the local grocer. It was a beautiful day and the ride felt great.
One thing I briefly mentioned in my post about Solar Panels is that we are mounting them on a pole. We are doing this because we have a flat roof on the cabin that we may eventually build a deck on. Additionally since it is a flat roof the snow will accumulate and block the panels in the winter. A top of pole mount allows us to leave the roof clear, avoid having snow block the panels, and have the ability to adjust the angle of the panels seasonally.
When searching for top of pole solar mounts I learned a few things:
They are on the pricey side considering there is no electronics involved.
Wind is the biggest thing to be worried about but snowload is also a concern.
The pole used is big heavy and requires a really large hole.
The price is what it is and we ended up with a good deal.
The wind in our area is not too bad. We do not get tornado’s, yet, so nothing special needs to be done. The snowload for our area is on the bubble for the mount we purchased.
Top of pole solar mounts do not come with a pole. That is because they require a very large steel pole that would be really expensive to deliver. Instead we had to make a trip to a local steel shop to buy a 12′ 4″ 40 series steel pipe. Its big and heavy.
Next the mount manufacturer informed us that the pole needs to be set in a 58 inch deep 24 inch wide hole. Digging a hole that big by hand would be a difficult job. In our case digging that hole by hand is pretty much impossible because our soil is clay and compacted.
To dig this hole we need a mechanical auger. A 24 inch auger:
The hole now needs to be filled with concrete. The volume of concrete needed for a hole that size is about 2/3’s of a yard of concrete. That’s about 26 80-lb bags of concrete. Fortunately we found someone who can handle a load that size and are hoping to have it cemented in tomorrow.
The plan is to have the panels mounted and connected this week. Very exciting.
The wiring from the panels to the cabin are going to be buried. I dug the trench for that today. I am very tired now. Good night.
Holy moly we are halfway through the 100 days of blogging challenge! In some ways it feels like the time has flown by but I remember days where I scrambled to come up with something to write about. Also we are only halfway there so who knows what might happen.
What I do know is that this is the most consistent I have written for a long time. Probably since University or even longer. It has been great practice to sit here at the end of each day and spend time reflecting.
Part of this challenge was also to help distract me from the pandemonium that is the US today. Not only does writing about positive things help me stay positive. Spending time writing also means I have less time to read the news. There is only so much news that I need in a day to stay on top of things.
This blog started off focused on my cycling. It has progressed into being more about what is happening in my life in general. The cabin project is coming along. We almost have the solar finished. The wiring is pretty much done and we are digging the hole for the pole that the solar array sits on tomorrow. The trail building has grown into a new hobby for me and I am enjoying talking about it. Kate and I are designing a house so I will definitely start writing more about that process.
I am sure more will come up and I hope you stick around and keep reading.
This is the 4th part of a multi part series covering the solar energy system we are building in our cabin. The 1st part discussed grid tie vs off grid systems. We are going to be off grid. The second part talked about AC vs DC and how an off grid system has to have at least DC because of the batteries. The third part covered batteries which we are going with AGM’s with 832 amp hours of power.
Today we are going to talk about solar panels, also knows as PV or photovoltaic panels. PV panels collect energy from the sun and convert it into electricity. When you think of solar electricity the panels are the first image that come to mind.
The cost of solar panels dropped significantly over the last 10 years. Kate and I added PV to our home in Phoenix in 2012. The renters haven’t paid a single electricity bill in 6 years. I haven’t priced our system again but I imagine its about 20% to 50% cheaper to do it now.
When it comes to solar panels there is a lot to consider. Watts generated, size, efficiency, and more. To me the panel is the least complicated item in the entire system. I want to set them up and never think about them again.
In this case since we have 832 amp hours of batteries to recharge we went with four 320 watt panels. This should be a little more solar panel than we need based on usage but its better to have too much than too little. For a cost comparison the solar panels all together cost about 30% of what the batteries cost.
We will mount the panels for the cabin on a top of pole mount. This is because we want to keep the roof clear for a possible future roof deck.
I did not manage to get up at 7am and get my workout in. There was a decent amount of smoke in the air from the nearby fires so I used that as part of my excuse. I have walked a little tonight and am going to get another lap in now.
Featured image is of the smoke from the East Canyon forest fire. It started around 1pm and is about 10 miles from us. We are not in any immediate danger except the smoke may blow our direction and be annoying. Welcome to Colorado in a dry summer.
Yesterday I did the second part of a multiple part series about building an off grid solar system for our cabin. The first part was about the differences of a grid tie system vs off grid. The second part was about AC vs DC. In this part we are talking about batteries.
Batteries are the most important part of an off grid system. You can have solar panels, a solar charge controller, an inverter, but if you don’t have batteries nothing else happens. The biggest surprise is that lithium ion is not necessarily the best option.
Electric batteries have been around since 1800 but we want batteries that can be recharged. The earliest rechargeable batteries were lead-acid, invented in 1859. Today rechargeable batteries are mostly associated with Lithium-Ion type batteries.
When choosing a battery for powering a home there are a few factors to consider:
1) Cost is always the first thing to consider when buying batteries. On the cheap end you can get Marine Deep Charge batteries from your local auto store. On the expensive end you are looking at Lithium. In the middle you have flooded lead acid and absorbed glass mat(AGM).
You want to spend a little more on batteries than the cheapest so that they last longer. The lead acid batteries we bought for the trailer were a little more but have lasted for six years at the point.
2) Voltage is important because that determines how your DC system runs. Recall from the last part of this series that DC electricity is the only type of electricity that can be stored in batteries. So by default when you have batteries you have a DC system.
Most DC systems are 12 volts as are most rechargeable batteries. However the longer lasting lead-acid based batteries come in 6 volt packages. This means we have to connect our batteries in series bring the voltage up to 12.
3) When you are talking about a batteries capacity, amp hours give you a way of comparing batteries. On the set of batteries that we chose for the cabin the amp hours are 416ah @ 20 hour rate. This means that they battery will deliver 20 amps of power over the course of 20 hours.
We are going big with this system though and are going to double it. We will get 4 of those batteries and tie them into 2 pairs in serial for 12 volts. Then we will connect those 2 pair in parallel to double the amp hours to 832 amp hours. The main goal here will be to run an electric refrigerator 24/7 in the cabin.
4) Maintenance is an important aspect of having deep state rechargeable batteries. If you take care of your batteries then they will last longer.
With flooded lead acid batteries, like what we have on the trailer, you have to check the water levels of the batteries at least once a month. If the water level gets too low, due to evaporation cause by usage of the batteries, the lead plates will corrode and stop working. AGM batteries do not have this issue as they are sealed.
The other maintenance of a battery is making sure it doesn’t run out of juice. Not only is it annoying when the power outage causes the lights to go out, but it is also damaging to the batteries to let them get too low.
The depth of discharge is usually defined as a percentage of how much of the battery’s capacity has been used. For lead-acid type batteries the depth of discharge that you should never go below is 50%. Ideally you want to avoid going below 80% if you want them to last the longest.
That is correct, with lead acid batteries you are only getting half of the listed amp hours. Keep in mind that using them that much will make them last half as long as only using 20% of them.
Lithium Ion batteries have an almost 100% usable capacity with no ill effects for taking them down almost to 0%. You want to avoid completely draining them but even then it does not damage the battery.
This is an area where lithium ion batteries are on a different level of performance. The problem is that they are over twice as expensive and the technology is not nearly as proven.
For the cabin we chose AGM batteries for cost, and maintenance. We are getting more and spending less than with lithium.
We went on a beautiful ride around Mancos today. 22 miles in total.
A few posts back I talked about solar for our cabin. That was the start of a multi part series about how we designed the system and then may have parts of the installation of the system.
In the first part I talked about Grid Tie vs Off Grid and some of the ins and outs of the two types of solar systems. In this part I will talk a little about AC vs DC and why with off grid solar we need to have both.
AC stands for Alternating Current and it is how electricity comes from most wall outlets. AC power can be transmitted across long distances with little power lost. However it cannot be stored.
DC stands for Direct Current and it is how electricity is delivered from a battery. This means that in an off grid system you will at least have to deal with DC. This is fine for many electrical items: lights, charging phones, and anything with a USB cable.
Unfortunately we live in an AC world. For example while laptops run on DC batteries, their chargers only work off of AC outlets. So if you want to charge your laptop you will need AC power. Same goes for all modern appliances: blenders, toasters, instant pots, air fryers, etc.
In order to generate AC power from DC power you use an inverter. An inverter converts DC power into AC power with some power lost in the process. This means that AC power drains the batteries even faster than DC.
Inverters come in a variety of shapes and sizes. The basics that you need to consider are: pure sine wave and amount of watts. You want to get a pure sine wave inverter. Period. Modern electronics will emit a high pitch tone with any other types. The amount of watts is determined by your most powerful appliance in terms of watts. In our case that is our Vitamix blender. It tops out at 1800 watts so we went with a 2000 watt inverter. However I noticed that the 3000 watt inverter was only $75 more and we grabbed that up.
DC comes in a variety of voltages. 12volt is the most common and is what we use. In the next episode of the solar system series we will talk about batteries and why we ended up with what we did.
Today was a day of errands. We drove to my mom’s and picked up a washing machine. This is the first washing machine we have owned in 6 years. It had to run off the generator for its first run but it did great. All this is to say that I did not get much exercise in except for lifting a washing machine a few times.
We built a 320 sq ft cabin 2 years ago. It started life as a guest restroom/bath-house but quickly evolved into a larger structure. Last year the windows and insulation were finished. This year we are adding solar power which means we need to finish the drywall. This weekend Kate’s dad and I are hanging, taping, and mudding the drywall.
Today we hung the ceiling and half of the walls. We rented a drywall lift to make hanging the ceiling almost easy. If you ever need to drywall a ceiling be sure to rent a lift.
When we hit the road in 2014 we had already installed a solar system on our trailer. It allows us to park anywhere there is cell signal and do our computer work stuff. Overall its one of the best home improvements we have ever done. It has worked great for us and has improved our understanding and respect for electricity.
Now we have built a cabin on our land. We are planning to power it with solar power and have used our knowledge from the trailer to build a larger system. We are also getting great support from our supplier to ensure everything works safely.
This is going to be another multiple part series because there is a lot to talk about.
In this part I will talk about the 2 basic types of solar electric systems for a home
Most residential homes and businesses are grid tie solar systems. When we lived in Phoenix we put solar on our home and haven’t paid an electric bill in 8 years. These systems create electricity from the sun and then put it back into the larger electrical grid. Then as the home needs electricity it pulls from the grid. Laws called net Metering force the utilities to give you credit for the energy you give them.
Our trailer and the cabin are going to be off-grid solar systems. This means that we not only create the electricity, but we also have to build a storage system like the electrical grid. This is done with batteries. Because batteries have a limited amount of power the trick is buying enough batteries for what you need. This is done using a spreadsheet or any number of online solar calculators.
For the cabins system we are going to double the size of our solar production and battery storage capacity. This will allow us to have a residential refrigerator, a clothes washer, and a few appliances. The plan is to make it a killer guest house, and maybe we will spend some of the colder months in it.
In the next episode we will talk about batteries.
I am taking it easier this week and have cut back on the strength training. Its not my favorite workout right now and I have enjoyed sleeping in a little bit.