Solar Status 11-03-24 and more

I have the controller and transfer switch mounted on a sheet of plywood as shown below. This may be a temporary location however I wanted it to look fairly good. The unit to the right is the back of the current circuit breaker box. That mess of wires is old trelephone wires and cable internet wires.

I had a neighbor help me mount the controller as it is 50 pounds and does not have keyhole type mounting holes, rather they are circular. A keyhole would allow me to place the screws in the board then lift the controller and push it through the scres and let it drop down then tighten the screws. The circulart holes requires you to hold the unit in place while someone screws the screws and tighten. Unless I could prop the unit in place, it takes 2 people.

With the controller in place now, I had to find something to place the batteries on. Without an expensive equipment rack that means some type of table. After lots of Internet searches and retail visits I decided upon a small metal scaffolding step which is about 30 feet long and perhaps 1 foot wide and two feet high; essentually a wide step stool. These batteries are approoximately 18 inches wide, 18 inch deep and 6 inches high. For now they will sit on top of each other. I also bought some grey PVC to hold some of the wires but the battery wi=res will just drop down from the controller to the batteries.

The breakers in my circuit breaker box were not properly labeled nd I added a number of circuits a couple years ago, I needed to verify each circuit. I purchased a device to plug into an outlet and identify which breaker it is on. I also used a clipon ammeter to measure how much current each connection is using at the breaker. Since all the lights in the house have been replaced with LED lights there are only a few circuits that use larger use. They are the stove, drier, computers and some fans. At the beginning I will not be using solar for the drier or stove even though the controller can handle their 220 volt needs. I will connect the critical lights and circuits through the transfer switch to begin with. That switch connects to each circuit like the refrigerator and allows me to decide at any given time whether it gets its power from solar or the electric utility. In a completely off-grid location where no utility is available, I would have all circuits just conencted to solar. If I had sufficient battery capacity and did not want to be conencted to the grip at all, the circuit breaker box would get all its power from the solor controller. I opted t ostill have a connection to the utility for now. If I have sufficient sun and battery storage I may not need the utility at all but a connection that allows me to use it, like during some equipment failure with the solar, will cost perhaps $15 a month as a standby cost. I’ll keep it for security.

Here is my block diagram.

Starting in the lower right is the utility feeding to my breaker box. Power only comes in. My utility is moving away from people being able to export power and get paid for it. Besides, that requires lots of permits and agreements and so on. Then power from those needed circuits like the light in my diagram will have it connection to its breaker broken and instead go through the transfer switch (which alaos has a breaker). One way connects the light to the breaker box and the other connects to my controller for power. Not shown is square in the lower right of the transfer switch. That panel could hold a conenction to a generator which I am not using but is often used instead of a connection to solar.

The controller/ batteries will have an emergency off button which will instantly shut things down in the event of issues.

Next I will connect the loads like the lights and so on to the transfer switch and throw those switches to the utility side since the solar controller is not yet producing power. When the battery table and wires are connected I can power up and configure the controller and battery parameters. At that time I can throw a swirch to a light and it will be powered from the controller and battery. That will work until I run the batties down since they are not yet being charged. At that point I’ll connect one of the breakers in the box to the utility input of the controller which will allow me to charge the batteries if the utility is working. Since no solar is yet connected, I essentually have a giant and expensive UPS (Uninterruptable Power Supply). Electric for my loads like lights would eaither come directly from the utility or from the utility through the batteries to the loads. That doesn’t save me any money but would allow me to have standby power if the electric company has issues and no power comes from them.

So I have the new panels in the yard but not yet connected. I have to orient them towards the south and if I do not have control of their angle, will set them at about 72 degrees which is the average of where the sun is at my location year round. I have calculated the actual sun altitude and have decided that every 3 months I could make an altitude adjustment to better follow the sun. Sume people track the sun in both altitude and direction but it is not cost-effective for me to do that especially if I had decided to use those twenty 100 watt panels mentioned in the last posting. However I bit the bullet and purchased eight 400 watt panels from a guy on island. They are bi-facial panels wich, if mounted above the ground some, can increase power output by collecting light that bounces up from the ground to the underside. In steak of the original 2,000 watts from the original panels I will have 3,200 watts from the new panels. I could use a mixture of old and new panels if configured properly but I have a different use for those oher panels.

Once I find a cheap way to mount and orient the new panels I’ll connect them into the controller and configure it to use solar and that solar power during the day will charge the batteries and supply me with electric. The system will switch to the utility if the batteries run low.

• Daytime when I get sunlight, my batteries will charge and I will use electricity from the sun.
• Nightime after the sun goes down I will use power from the batteries.
• Overnight if the batteries deplete, the system will switch to the electric company.

All the time to start, the drier and stove will still be connected to the electric company as they are now.

There are some limiting factors as to how you configure things. Those constraingts are the number of solar panels you have, how much sun you get and when, the size of your batteries anbd the amount of the load your house presents.

You can have massive numbers of solar panels and pretty much power anything you want… during the day. If you don’t have storage like batteries, then after the sun goes down you are in the dark. Alternatively, you can have all the batteries in the world but without a way to charge or keep them charged, once they are discharged you are out of power. If you have a large load with minimal batteries and minimal solar panels, you will not be able to run many things.

If you consider solar you would need to consult websites that tell you how much solar your area gets. This may be city data or might actally use satellite data to determine your roof size and whether you have trees in the way, In my case that didn’t help me because those sites often condider that you are limited to roof size wher I am putting the panels on the ground and have plenty of area to place them.

Once you determine how much sunlight you receive, you can then look at how much power you need. Your electric bill is a good resource there. Newer digital electric meters are sending your usage to the utility which in my case has a website where I can look at data in 15 minute increments if I want. I can see the minimum, average and maximum power I have received from the utility. They are now going to be charging based upon time of day so leaving the drier and stove on the utility is fine to begin with as long as I use them when the utility costs are low. I may need a third battery to offset their use if I want to run them off solar.They might work now directly off solar during a bright sunny day, but I will have to see when everything is up and running and tune things.

Here in Hawaii on my island, we have afternoon clouds and sometime smoke from the volcano which can reduce available sunlight. Also trees grow quite fast and some incredibly fast and can block the sun, so I also have to place the panels in the best location. I do save considerable time, money and effort by not drilling holes in the roof to put panels there. That appears to be a major cost in some peoples installation of solar. Also hevaing to rely upon other people to build your system adds to cost.

The particular system I chose, the EG4 6000XP and associated 48 volt Lithium Ion Phosphate batteries are designed to work together. You simply with the batteries together and t othe controller. The solar panels are sized for current and voltage and just connect to the controller. You could, in a simple setup then take the output of the controller and run your house. Almost every item that you need, like DC circuit breakers for the batteries, AC breakers for the output and all built into the controller which saves you a lot of extra work and cost. Then you just have to bring in outside power like a utility or generator if you find that you need to augment the system with extra power.

My Sisters have a slightly different system which has a controlelr, a couple of batteries and some panels. They are a bit short on battery power and since totally off grid, if the batteries run down they start a gas generator ro suppliment power and charge the batteries. Extra panels don’t help them as they are running out of power overnight. If they add more battery capacity they can run a lot longer even if they have no sun for a couple of days. It is always a tradeoff in cost and capacity. ALternatively they could add a windmill as they get LOTS of wind where they are. It seems the wind blows at night too so if it blows after sunset they would use wind power and battery power over night.

There are lots of ways to power your house from things like wind, solar and yes even a stream or river if you have the right equipment.

By the way, the batteries in my system hold considerable power so I purchased the sign below. Depending upon your configuration, you could have lethal voltages or currents available on terminals. Just as opening the circuit breaker box and exposing connections. you must know what you are doing and how to properly act around open accessable circuits. If you do not have electrical background, I advise you to contact an electrician.