100 Watt Solar Panel (Real Life Experience)

 So I've got a residence now with access to roof space for solar panels. I put my one, 100W solar panel up and ran the wires to my laptop to see how it did.

On a slightly overcast day, a 100W solar panel is not enough to power a ~60W laptop. If the sun was shining directly overhead of the panel, yes, a 100W solar panel would be enough. But this is real life.

Then I hooked up 40 more Watts of solar panel on my roof for a total of 140W of solar panels. That still didn't keep the laptop afloat.

Then however the sun came out, and it wasn't direct sunlight, but it was brighter than before. That was enough to keep the laptop going.

So, what is my real life review? A 100W solar panel is not enough to power a laptop on an overcast day. A 200W panel (or combined panels) would be sufficient. So if you're ever wondering how much solar panel to take with you so you can work on your laptop anywhere (during the day), it will be almost too much for one person to carry (rigid glass enclosed panels).

Energy Currency

 People recently started investing in crypto currency around the world. The idea surrounds very complex tokens that are generated by complex algorithms. These tokens can be transmitted electronically and traced very easily. But what is the true value of something that essentially is a padlock. Not much unless we all agree on it's value.

But philosophy aside, what people started doing was buying high end PCs and higher end gaming graphics cards that could compute the algorithms much more quickly. The problem is the quicker people generated crypto currency, the more electricity these powerful computers consumed. Naturally then it became an optimization curve then to match energy consumption (in the area the computer was running) with crypto currency generated. Obviously it's a worthless endeavor if the costs of production are higher than the market value.

Then people started realizing they could use solar energy and battery banks to generate crypto currency. This brings us to our topic of this post. What if we skipped all the fancy crypto currency talk and removed it from the equation? What we have left is energy consumed and some sort of currency produced. Or what if the energy was the currency and it was just a matter of capturing it?

Now we're getting closer to a currency that really doesn't have a lot of transmission and transportation constraints because everybody has access to the sun and wind and it's just a matter of going to a person that has a surplus and is willing to sell some. And if you are somebody living in the middle of nowhere... chances are you don't consume more energy than you'd be able to produce from the wind and sun and storage.

OK so what is the value of one of these energy currency units you ask? Well maybe you didn't because I haven't set up the argument very well.

Consider that Lithium ion batteries are probably our most efficient way to store energy and the amount of energy that can be stored per weight of material is close to the theoretical limit. With current means of mass production we are just about at 1 kWh of battery capacity for $100. This battery will last let's say 2 years at daily 100% charge cycling. If charging this battery is free each time because of renewable resources, it means the cost of storage is the only expense which for a complete cycle computes to about 14 cents.

So what we could say is that the universal unit of energy currency is the kWh and 1 kWh is worth... let's round down to 10 cents (assuming batteries become a bit cheaper and last a little longer). To put that in perspective that is enough energy to turn 10 gallons of water 40 degrees hotter. Basically a dime would get you a hot shower if you had the water in a bucket.

The only flaw in this model is that unlike 10 cents, you really can't carry a kWh of energy in your pocket (you could carry it in backpack battery perhaps). But even if you could it wouldn't be worth toting it around. But maybe the middle ground is that you could reasonably carry around 100 Watts of solar panels, and if you were stationary and in the sun, it would passively generate a kWh of energy.

So the flaw in the energy currency model assumes a sedentary lifestyle and not nomadic.

Solar Panel Electricity Price Threshold

OK so in the news this week Portugal announced they could build a solar farm for some municipality at a cost of 1.3 cents (USD) per kWh to operate (Reuters). This is a huge nail in the coffin for nuclear and coal and natural gas.

Most of us in the US pay around 5 to 10 cents per kWh depending on the time of day. lot's of moving parts and regulations weigh down most energy companies. But solar is solid state technology (for the most part).

Now there is still the drawback of the land use, but what this suggests here is that as long as the manufacturing process and source materials are abundant and stay at their current cost. solar is beginning to be the lowest costing choice between all of the ways to generate electricity.

This doesn't take into account storage. These panels proposed in Portugal would undoubtedly be part of a larger grid including standard backup generators. However even if the cost of storage was factored it at utility scale it would still come to about 3 or 4 cents per kWh.

Presently I can get a solar array that can produce 4 kWs of electricity for about $5,200. A lithium ion battery pack that is 30 kWhs in capacity will cost about $15000. If I stretch that out across 20 years (life of the battery pack), then it comes to just under 10 cents per kWh. So the benefits of having something grid scale is that everybody shares the cost and the scale is large enough to get the price down to more like 3 cents.

The point is... what are we waiting for? Solar is the easiest way to produce consumer electricity. Now it's also the cheapest. The only think I could think of is the safety of battery storage. but other than that... anybody could run with this business model today.

Overpopulation: If All The World Lived In The Contiguous US

 If all the world lived in the lower 48 states of the United States, everyone on earth would have 11,569 square feet of property (assuming there are 7.5 billion of us). That is a piece of property that is 107.5 feet long and 107.5 wide.

Let's say you build a house on this property for yourself that is 30' by 30'. Let's say you also have a solar array that is 30' by 30'. Additionally the roof of the house could be covered in solar panels. 10 meters by 10 meters of solar panels is enough to produce 100 kW of electricity in direct sun. times two if the roof is covered, that is 200 kW during the day and assuming 5 hours of peak performance... that is 100 kWh of electricity (way more than one person could use heating, showering, cooking, and washing clothes). That would take up 1,800 square feet. That leaves 9,769 square feet left to grow food.

What are we spelling out here? This is a formula for overpopulation if all the farm-able land in the world was the size of the contiguous US. In this calculation we will assume that everybody can live off eating algae (yes as if we were all fish).

A 275 gallon water container is 4' by 4' by 4'. In other words it takes up 16 square feet of surface area. Each of these tanks can produce 50 grams of dry algae every 2 weeks in perfect weather.

If a normal person eats a pound of dry food a meal, then it would take 15 of these tanks to feed a person for one day (3 meals). 15 of these tanks would take up 240 square feet of the remaining 9,769 square feet on this piece of property. We would need 14 days of these tanks to allow this to be a non-stop cycle of food growing so a person could eat continuously. 240 square feet, times 14, equals 3,360. 

What this means is that there would be enough property left over from feeding one person to grow enough algae, for just under two more people to eat continuously. What this means is that there's enough room on this 107' x 107' piece of property to feed a person perpetually and then enough for that person to export food and turn a profit.

This is not an exercise in isolationist self-sustainable thinking. Rather this is to highlight, it's not that earth is running out of space for all the people in it. It's that we're not using the resources correctly. We don't need to be building walls to protect our resources and way of life. We need to use the resources better (and we need God to show us how to do that).

Now you might argue there's no room for roads and infrastructure. But 11,569 square feet is enough to put in a well and small septic system for one person. If travel is necessary... an electric quadcopter drone should be capable of carrying a person and goods/materials.

18V 100W Panel Capability

I recently purchased a 100 Watt solar panel that at it's peak produces 18 Volts of electricity. Since I'm working on a small aquaponics system for my porch, it seemed like a good use for the panel.

The system works by pumping water like a fountain over a container of water (basically like a fish tank). On the water's way back down to the main container, it passes through the roots of plants of your choosing that thrive off the nutrients in the water. The water also on its way back down, splashes and generates dissolved air in the water that fish use to breathe.

So then the water pump needs solar electricity to operate. I set it out today in a slightly overcast sky and just hooked the panel up directly to a 12V  .35A water pump. In the early hours of the day, there was not enough electricity to run the pump. But shortly thereafter it started working. I then covered the solar panel just to test if it would shut off and it did.

What this means is that a 100W 18V solar panel produces enough electricity to pump a generous amount of water (about a gallon every 45 seconds) a few feet in the air.

Since this little experiment, I've also hooked up a charge controller and a 12V 12Ah battery to the system. The idea is it will generate enough electricity during the day to charge the battery and operate the pump so that the pump continues to operate overnight. More on this later.

Bottom/Entry Level PV System - $50 (parts)

OK we officially have an entry point for a PV system that a low-to-middle income person (such as myself) could start building. We'll start the bidding at a $50 kit that could charge your cell phone and operate an outdoor LED flood light about 4 hours of the night. Don't have $50? Well I'll include a bill of materials with pictures so you know what to buy one piece at a time.

First of all the panels you buy (most likely online) should have a peak voltage output of about 18V. This will keep the panels from producing (during mid day) some voltage below the 14.6 or so Volts that the panels will need to push in order to put anything into the lead acid batteries.

Secondly, you want to consider how much storage you will buy. I'd recommend a 12Ah 12V battery as a minimum ($25) because that will be enough to push a LED outdoor flood light for 4 hours. So if you were inside during a power outage and wanted enough light to eat a meal in a pretty large room and have 4 hours to do so, a battery this size would do. If you go with a 26Ah battery ($49) at the same voltage, of course that same light would last all night.

Lastly, there's the charge controller. It's hardly worth mentioning on  this system because they are so cheap and safe to use with lead acid batteries. The only thing worth considering is scale. You can get a 10A draw and charge rate controller for $10. The panels I'm listing have a 4.2W max power output at 18V. So you'd have to hook up about 45 of these panels in parallel before you blew the controller with your panels. For this build, I only have 2 in parallel for a total of .47 Amps of power at any given time.

So what I'm saying with this last point is you have plenty of room to scale this system with an entry level charge controller. You can add more panels and/or more batteries to this system, and the same charge controller will be appropriate.

On a rant-like note... scale is what makes this entry level system so attractive.  You might be saying, why don't I just buy a solar flood light with batteries already installed and bundled? The answer is, for all the small PV systems you can buy, they are limited to a pretty specific use-case such as a walkway light, or a radio, or a USB cell phone charging system. The room to use the juice from these cheaper systems for other applications is more limited than what I'm listing here. Here's the bill of materials with pictures. Everything can be purchased on Ebay or Amazon.

1. 12 Volt, 12 Amp Hour SLA battery.... $24
2. 4.2 Watt, 18 Volt solar panel (x2)....... $17
3. 10 Amp, 12V solar charge controller.. $8

*all these screen shots are for reference only and there's no guarantee these sellers are honest.









I've built this myself with the items listed here (just form other sellers) and I'm using it to charge my electric bike batteries. So I'll have more to say on performance of the system later, but you will have your own use for this system such as lighting or heaters or water pumps. The only other thing to make this almost universally usable is a 12V AC inverter so you can run computers, TVs and appliances. You can purchase a 2000 Watt AC inverter for around $40 (but I would add more batteries in parallel before attempting to pull 2000 Watts... and use appropriate wiring as wires can get hot).