This page dedicated to the available methods, research into development of currently experimental areas which generate power independent of the grid.
The following is an excerpt from a write up on the introduction to self-reliant power production. My intentions are to go into further details in my podcasts found at swampfoxgreen.podbean.com
Basic Electrical Principles-
Parallel & Series battery connections: When wiring like batteries in parallel you maintain the Voltage while increasing the Amperage – when wiring like batteries in series you maintain the Amperage and increase the Voltage. This is important as you can choose to use different battery types to store your energy and set them up to be compatible with the charging power of the system you put in place.
|Term||Abbrevation||Unit of Measure||Definition||Formula|
|Voltage||V||Volts (V)||Similar to water pressure in plumbing|
|Current||I||Amps||Equal to the voltage divided by the resistance; similar to flow rate in plumbing||I = V/r|
|Resistance||r||Ohms||Similar to pipe size in plumbing|
|Electrical power is measured in Watts. In an electrical system power (P) is equal to the voltage multiplied by the current.||P = V*I|
|In an electrical system increasing either the current or the volage will result in higher power.|
|DC Power Systems|
|Battery connection schemes|
|Parallel||For each battery the negative terminals are connected to one another as are the positive terminals. The discharge connections are connected to the last battery in the sequence, positve to positive, negative to negative.|
|This scheme delivers the sum of each battery’s amperage while maintaining voltage.|
|Series||For each battery the first negative terminal is connected to the next positive terminal continuing on until the end of the sequence. The discharge positive is connected to the positive terminal of the first battery, the discharge negative attached to the last battery’s negative terminal.|
|This scheme delivers the sum of the battery’s voltage while maintaining the amperage.|
There are several key points when designing a system to produce your own power. Being familiar with OSHA requirements in industrial businesses, there are some of those rules that apply in private systems no matter what type you decide to put into place.
Safety – The first and foremost is SAFETY! Realize that if you do choose to go this path, electricity demands respect as it can kill if you do not give it the respect it deserves. Develop a solid lock out program, even if you consider yourself to be the only soul around the system. A lock out system allows you to shut the power down at each part of the system to allow for the safe repair or replacement without a complete system shut down. Once the lock out is in place, always physically attempt to energize the system again to ensure the lockout is properly in place. A lockout can be achieved by simply pulling a fuse from it’s holder to break the circuit, or closing out a breaker and placing a lock on the outer casing. Fuses placed on the positive lines on the system allows not only the protection of your system components, but you as well. I do suggest that you not only put these in place but do research on the gauge (size) of wire needed to carry the load the distances between your components. Here is a good table to refer to:
|Wire Loss Tables for Solar Electric Systems including 12,24, and 120 volt charts.|
|This is a five percent table which means at these amperage ratings at the listed distances, 5% of the power would be lost due to resistance. Five percent is normally acceptable in low voltage systems, but if you want a 2% figure, divide the given distances by 2.5. For a 10% loss multiply the distance by 2. For distances at 48 volts, double the 24 volt distances for a 5 percent loss figure. For 240 volt 5% loss, double the 120 volt distances. These distances include the NEC requirement for over sizing of 25%|
|Example: For a pump drawing 9 amperes at 24 volts, located 88 feet from the battery bank, look at the center table for 24 volts. In the far left column find the next number higher than 9(which is 10) and follow that line across the table until you find a distance figure greater than 99. At the top of the column find the gauge of wire (#8) that should be used. This method insures that wire losses are kept to an acceptable level without spending too much money on extra-heavy cable. Using a heavier wire than indicated, however, will result in even higher efficiencies and we do sometimes invest in the next larger gauge. Wire can get expensive, and it may not be worth the money to get that last 1% if you have to go to a much larger wire size.|
|Do not use any wire sizes that might fall into the zones near the bottom on #’s 14,12,10 where they are blank – this would exceed the amperage rating of the wire and it may overheat and burn.|
|120 Volt AC or DC Chart|
|Amps in Wire||Watts at 120V||#14||#12||#10||#8||#6||#4||#2||1/0||2/0||3/0|
|24 Volt DC Chart|
|Amps in Wire||Watts at 24V||#14||#12||#10||#8||#6||#4||#2||1/0||2/0||3/0|
|12 Volt DC Chart|
|Amps in Wire||Watts at 12V||#14||#12||#10||#8||#6||#4||#2||1/0||2/0||3/0|
|These are one-way distances, measured from point A to point B. The out and back nature of electrical circuits has already been included. For PV arrays, figure the entire run, from the panels to the charge controller to the batteries.|
The key issue in designing any system is to ask, “What am I asking this system to provide for me?”. Answering this question truthfully allows the proper design and construction of a system which will deliver within the proper parameters in a robust manner. A second issue is to incorporate during the design phase the ability to upgrade components as improved knowledge and/or technologies are available. The ability to expand the initial system in the future if further needs arise requiring demands above original system consceptions should be a third issue. I am of the opinion that as power production is on the form of direct current (DC), it is best to consider having only items that run via DC power. The majority of items in today’s home are set up to run via alternating current (AC) and this is not because it is a better method, but because such was the standard settled on as cheapest for power produced in a central location to be delivered broadly to the masses. The conversion of DC to AC power can be accomplished by the system with an additional piece of equipment known as an inverter but this device does so with estimated power losses of anywhere from 10-20%, depending on the quality of the component, the sizing of the component as current research shows the closer they are put to their maximum rated load the greater the efficiency.
When looking at installing a system, new studies using more comprehensive data allows for more informed decisions as to whether to stay on the grid or not.
System Types: There are basically three (3) different types of Solar power generation setups, broken down into further sub-groups.
Off-Grid (Solar Cell production): DC Only, AC Only, DC/AC Combo
Grid-Tie (Solar Cell production): AC Only, AC/DC Combo
Hybrid (Solar Cell production w/backup power generation): DC Only, AC Only, DC/AC Combo
With these in mind, I’ll be going over just how to integrate each of these sub-groups into the system of your choice.
A commonly overlooked part of developing a photovoltaic system is allowing your panels to have the optimum collection angle. The optimum alignment is to have the sun’s rays hitting your panels at a right angle. Sounds simple enough right? It becomes a bit more complicated once you start to consider the fact the sun travels from east to west throughout the day, and that it is at different angles across the horizon as the season’s change.
To find the proper angle your system needs to be oriented at, along with other pertinent information, the Solar Electricity Handbook website has some great tools.
The following information is from http://www.mpoweruk.com/solar_power.htm