Monday, March 2, 2026

Electric Vehicle

 OK so perhaps all my research into affordable energy and housing could be summarized in my latest purchase. Two days before Christmas 2025, I purchased a used Chevy Bolt. This car is spec'd at around 200 miles per full charge. Well the first thing to note as that you really get about 130 miles per charge during a sub zero (Fahrenheit) winter.

But the bigger breakthrough here is that an EV can charge off of your house electric outlets. Not only that, the electricity is cheaper than gas (below 50 cents USD per kWh). Not only that, but this can be thrown into reverse and you can use your EV car battery during a power outage to power your appliances.

That's all well and good, but here's the trick. Your house grid electricity fluctuates in price as the peak times of day are reached. As you can imagine, more people pull electricity in the mornings before work and around dinner time. This means the electric utility has to charge more for the electricity that is used during these times.

Out of the box, the car comes with a 110V AC charger. It says it's rated for up to 220V, but the plug is definitely a 110V plug. The trouble is it takes two days of charging to charge the Chevy bolt from empty to full from a 110V outlet. 

That means, that you would be charging your car most certainly during the peak electric price times of day. 

So to avoid this, use your 220V dryer outlet to charge your EV overnight. That way it can charge the car from empty to full at the target time of day for the best electric rates, which is overnight.

The other way to avoid this is to charge your EV using solar. But a 220V AC solar inverter is going to cost you well over $200 (not mentioning the battery array that would be strong enough to pull that kind of current).

Thursday, September 11, 2025

Opportunistic PV Charging

 What should be known is for PV, it's critical to capture energy at the exact time interval that it is being produced most abundantly within any given day.

So it's widely known that solar and wind renewable energy is intermittent. While that presents a challenge, it can be overcome with engineering and process changes.

The main consideration is that on a perfectly sunny day, PV will generate it's highest amount of electricity between 10AM and 2PM. A brief 4 hour window can stand between you and a comfortable night of sleep. On an overcast day, this issue is particularly known.

Therefore it behooves all of us to generate as much electricity as possible between these hours. But there are several things that will keep your PV system incapacitated during these hours:

  • Snow cover
  • Inadequate wiring gauge (fire hazard)
  • Inverter pulling more power than can be generated in the time window
  • Batteries already at full capacity
  • Break in the cloud cover comes earlier or later in the day (not between 10AM and 2PM)
If each of these things can be avoided or insulated against, it will be the difference of several kWhs on a 5 kW panel PV system.

Wednesday, September 3, 2025

Charging Batteries Outside

So there's plenty to say about adding more solar panels to my rooftop build. But summer really doesn't need a bunch of added solar panels since PV production is at it's highest. I will probably have more to say about how much solar and storage I have closer to winter.

This update is to say, while we still use lithium battery cells, we should probably be charging them outside. I've even heard that sodium ion cells also have a risk of shorting at the end of their cycle lifespan. So here's a picture of my outdoor enclosure I cobbled together. The batteries and inverter are in this same enclosure with electric lines coming in and going out:



Tuesday, February 25, 2025

Winter Solar

Since my last post, winter has come and gone, and I added another half a kWh of lithium ion battery storage. Here's the big surprise.

It's comparatively difficult to generate solar energy in the winter than the summer. I could easily charge a kWh battery in the summer months. But in the winter even on a sunny day, I would do well to generate .25 kWhs.

One of the problems is snow cover. It's right outside my window, so it's fairly easy for me to scrape snow and ice off the panels. But it was a cold winter and it's not pleasant scraping ice off solar panels in the wind chills of winter.

The sun does melt some of the snow off the panels. But the black color of the panels doesn't melt as much snow as you'd like. Essentially a small pocket of air forms off the surface of the glass which makes it an insulator from the heat that would normally melt the ice.

The moral of the story is to spec your solar array for 1/4 performance during the winter months.

Wednesday, April 10, 2024

12V DC Heating Elements

 This is a follow up on a previous post concerning survival level applications for PV and battery packs. The idea here is to find the lowest price to give people warmth and light using minimal circuitry.

I won't go into the weird sauce of how I connected my battery. But the big idea there is that I'm not using any inverters for me DC heaters. Inverters and even voltage regulators introduce inefficiencies and we want people to get as much bang for the buck as possible.

First of all, here is a picture of the heating elements for under 20 bucks on Amazon:


Second, these elements get very hot... like over 140 degrees F... enough to make food safe to eat.

With that out of the way, the logic of the system is this:

1. A 400 Watt solar array charges a .25 kWh battery pack in less than an hour in full sun (using a BMS circuit to step the voltage down)

2. The 12V 100W heating elements will then drain the battery overnight providing more than enough heat for a single person (not enough to heat a 12' x 12' room) for about 2.5 hours

So following this logic we could say 4, .25 kWh battery packs would be more than enough so that one person could sleep comfortably all night and even into the day (8 to 10 hours).

Let's talk money. The battery pack costs $35 for .25 kWh of energy. The heating elements cost $20. The solar panels cost roughly $250. So all in, this system cost me $310. If we wanted it to last all night, we're looking at more like $350.

So for $350 a person could sleep comfortably overnight every night for 5 years. Then it's just the cost of replacing the battery pack after that (maybe $40), for another 5 years of service.

But you may have noticed that the solar panels were only put to work for a single hour... so this person would have 7 more hours of daylight to use the panels for other systems. I'm thinking the heating elements could be plugged in directly to the solar panels during the day to provide daytime heat during colder months. Essentially this person could survive under a canopy in a sleeping bag in Yellowstone National Park all winter long... provided they had food for $350.



Tuesday, March 26, 2024

400 Watts of PV w/ Grid Inverter

 Something very news-worthy has happened in the past 6 months. There is a glut of PV panels manufactured and now the price has come down as retailers try to shed their inventory. I could at this moment go on the internet and find a 100 Watt PV panel listed for $50. So naturally I sprung for 3 new panels and put them on my roof.

As you scale up your home brew rooftop PV installation, there are problems to look out for. First of all, wires and connectors will get hot. But then the grid inverter itself will get hot. 

One thing to look out for is loose and frayed connectors. If the electrical contact surface area is small and a lot more current is pushed through that contact, it will heat up more than the rest of the wire. So essentially beef up your wires and connectors as you scale up your system.

Let's talk money. So the three new panels were a little over $180 and the first panel was $100. So $300 in and then another $200 for the grid inverter brings us to a total of $500 DIY rooftop solar installation. Now we could talk ROI which is something like 5 years, but that's a bit boring for a normal person's income.

Far more exciting is what doors 400 Watts (in the middle of the day) of electricity opens. Easily, this powers computers and laptops and TVs... but that's a 1st world problem and not very interesting. I've been looking into heated flooring and heated blankets and you can easily find a 100 Watt system like that.

What this means is to heat a room overnight, a 400 Watt system would easily charge a 1 kWh battery pack and that would heat a room for 10 hours overnight and have energy to spare to heat during the day. Presently I am working on a battery pack made from surplus cells costing $50 for a kWh and more to come on that.

Friday, July 7, 2023

Grid Tie Inverter

 The second most useful and readily available piece of equipment for those looking to generate their own electricity, is a grid tie inverter. The first most useful is just to get a couple 100 Watt solar panels.

The grid tie inverter I guess senses the frequency and phase of the AC current in your house or apartment and sends the current to the meter in reverse. Today I watched my meter go backwards after hooking one up.

Now the thing is, it will probably not be enough current to kick you back a check from the energy company. However, it will certainly reduce your electricity bill. Additionally, your account with the energy company would need to be enabled for net metering to be eligible for kick back checks. This usually comes at a monthly subscription cost. 

So up front, until you have 10 x 100 Watt solar panels or more, this piece of equipment can out of the box be used to reduce your electricity bill. The one I purchased was the "SolarEpic" 1300W grid tie inverter.

Tuesday, August 16, 2022

12V DC Water Pump and Solar

 One of the most visceral applications of solar power is when you watch a solar panel directly power an electric water pump. You can watch when the clouds come over and the flow lessens and then when the sunlight breaks again how it rushes the water with renewed vigor. As fun as it is to watch, let's talk about real world applications and how it might fit into your residential experience.

There are many reasons to pump water. Certainly in the more arid regions of the globe, it helps tremendously. But for the rest of us, it doesn't pay to sit there waiting on the sun to wash dishes or take a shower. Probably the most famous renewable energy application for pumping water is "pumped storage hydro". Again, this isn't on the residential level, but it can be scaled fairly easily.

Most likely, you may have a hydroponic system for growing indoor plants or perhaps an ornamental water fountain in your yard. But let's just take it from the perspective of water pressure and moving water from one elevation to another. 

New York City was famous for this issue as they would have water towers on top of the apartment buildings. This elevation of the water would allow the residents to have the water pressure they needed. In fact they still do use water pressure to move water from reservoirs into the city through underground tunnels.

Using a solar panel that produces ~40W (peak) of power at 12V, I can pump water for about 8-10 hours straight. With that much power I could move about 10 gallons of water every 30 minutes from 0 feet, to 10 feet of elevation. Let's say all that water is shower water. At the end of the day about 16 people could have water pressure for their shower they are going to take that night. And that is just running of 40 Watts of electricity. 

Now the next thing will be, "ok, having water pressure is great, but can it be warm/hot water". So then I have to get a 12V water heater and tell you how that works out and whether 40 Watts of solar panels is enough to provide enough water pressure and heat to take a comfortable shower at the end of the day.

Thursday, July 28, 2022

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).

Tuesday, December 15, 2020

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.

Wednesday, September 2, 2020

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.

Thursday, August 20, 2020

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.

Saturday, April 6, 2019

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.

Tuesday, June 12, 2018

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).