Solar systems

It seems arrogant to talk about man-made solar systems for generating electricity for home use off-grid, as if one were to elevate one's throne above the stars of heaven as Lucifer the bearer of light to do that. Not so. The "grid" itself is that beast, the natural intellect of man, given to the industrial revolution, with the arrogance to carry man-made electricity long distances over land.

However, the set-up of solar panels themselves does depend very much on their alignment with the sun, stars and planets, and the motions of the earth and moon. A common suggestion is that solar panels should face, say, due south in the northern hemisphere, inclined from the horizontal at an angle approximately equal to one's latitude.

Conditions of partial shade and/or high latitude dictate special engineering considerations with respect to adequate insolation for generating electricity.

The maximum energy intensity of sunlight hitting the earth on a clear day may be estimated as

I = 1350 W/m² × sin α × exp(–0.30 × p / sin α)

where α is the angle of elevation of the sun above the horizon, and p is the ratio of barometric pressure at the altitude of the site to that at sea level. The fist factor is the "outer space" intensity of sunlight at the Earth's distance from the Sun. The second factor accounts for the slant of the sun's rays, and the third factor accounts for the filtering and dimming of the sunlight through Earth's atmosphere.

The war against social objections to living off the grid

Solar panels are often considered a "green" or environmentally sensitive alternative for generating electricity, and we neither object to that consideration nor make a religion out of it.

Technology that enables "off-grid" living reduces the attack surface for secure computer systems, banks, broker houses, and even low-budget private homes etc. by enabling redundancy and reliability even if nothing else, and if the upfront capital and ongoing maintenance costs are reasonable for a reliable electric power system, should be welcomed by Christians living a simple rural lifestyle off the grid.

However, be warned that some "Christians" are married to the grid and to the assumptions of universal vaccinations etc. on which urban lifestyles have been based for millennia with or without Christ. "There's a lady" in the worst Mafia sense of the phrase, (guns are banned and please remove your hats, gentlemen,) so if you are a male "sovereign citizen" or "freeman on the land," then you are deemed to be risking her life and the lives of your children by your simple rural lifestyle.

It's a strange and unnatural situation of religious restrictions to urban white-collar employment and indoors-only entertainment where people with horses and cows etc. are suddenly deemed to be living lives of vice and heavy sin by a certain cadre of over-educated city-dwelling churchgoers, in whose presence hunting and fishing are deemed to be mortal and unforgivable sins.

City people are at always at law and if you give them an inch they take a mile, so don't even start with them.

Solar panels

As of 2026, typical solar panels are available in sizes of 100 to 400 watts, costing about one dollar per watt at the lowest bulk price available from major vendors in the United States.

These solar panels typically produce electricity at a nominal 18 volts, ranging from 16 volts at full load to 20 volts at no load in full direct sunlight, designed for charging 12 volt battery systems. Common automotive accessories may be powered directly or an inverter may be used to generate 110‒250VAC if desired.

Charge controller

Solar Cell System with Charge Controller and Battery (using TI TL5001AMJG)

Solar Cell System with Charge Controller and Battery (using TI LM51561HPWPR)

We find that off-the-shelf charge controllers are over-rated and overpriced, and we propose building one from scratch with adequate safety margins for high household power requirements.

A Buck-Boost Converter or Single-Ended Primary Inductor Converter (SEPIC) is typically used for this purpose.

An inductor, coil or transformer may be wound by hand using a adequate gauge of thinly insulated Tefzel or similar wire on a used or salvaged laminated or powdered iron core. The core of a transformer or inductor, if not powdered cerrite, must be made of thin layers of soft tempered malleable iron or mild steel that will swing the needle of a compass, and it should never be "quenched" or "saturated." The laminated iron core should be "tanned" with oak gall and waxed with beeswax and/or lacquered with boiled linseed oil to form insulative layers of oxide and wax or lacquer between the layers of steel, so that the transformer will not short out between the layers of steel and melt down under load. The windings of wire on a homemade transformer or inductor should be of the purest copper, smoothly drawn, carefully annealed to a soft temper, ductile, and flexible, with the best quality of insulation that is not too thick. Take care that wire windings are smooth and not bent or creased on sharp corners.

Power capacitors of several farads in capacity are widely available and inexpensive, mostly intended for car stereos and audio systems. We suggest using wire of adequate size for the intended current-carrying capacity, while over-provisioning and de-rating cheap power electronics parts, and installing fast-blow fuses at strategic locations, taking care not to overcharge a capacitor or induce a flyback voltage in a large coil. We are not certain about quality but there are audiophiles who listen to music and demand such quality.

High-power transistors, and even several transistors in parallel, may be used to control large electric currents.

Capacitance, inductance and transistor performance characteristics, etc. of all component parts should be carefully measured and verified with appropriate field or bench test equipment.

Component selection and Bill of Materials

The heart of the controller is a Pulse Width Modulation chip like the Texas Instruments TL5001AMJG . These particular integrated circuits operate in a wide range between 3 and 40 volts, and also come in radiation-hardened versions, which suggests that they were used for solar panels to power satellites launched into outer space decades ago, many of which are still in service today.

The Littelfuse/IXYS IXFN520N075T2 power MOSFET "trench gate" is essentially rated to handle 480A in the on state and 75V in the off state. The Vishay VS-FC420SA10 is another brand of power MOSFET rated to carry 435A when on or hold 100V when off. It comes in the same form factor, an SOT-227 which looks and acts like a miniature clothes iron, and requires an excellent heat sink rated for switching losses and forward voltage drop at the rated current. It would appear that if either of these devices functions as advertised, you could easily start an automobile with the electric current they are rated for handling if you wired one of them up in place of a solenoid for the starter motor. As far as we can tell, this can actually be done, except that the high power MOSFETS require 10V to drive the gate, and the drawdown on a 12V car battery from the starting current will reduce the voltage below the gate actuation level.

Insulated-Gate Bipolar Transistors (IGBTs) are another option for the high power current switching needed for the Buck-Boost or SEPIC controllers that need to be used for regulating the voltage from variably sunlit photovoltaic cells to a usable level.

Batteries

tbd ...