Quality electrical components help make all the electricity you need.
But for quality electrical components, generating solar, wind and hydro electricity would be neigh on to impossible. In a sense, these components are like glue. Putting them together in a practical way produces clean usable electrical power.
This is sort-a like putting a bunch of electrical parts together to build a really handy widget. When the price of glue goes down, more widgets are built and pretty soon everyone wants one.
With the advent of thin film solar, the cost of PV cells going down, and wind generator costs being reduced, wouldn’t you say generating power with one or the other makes really-really good sense.
Serious power generation needs precision electronic control elements especially if the electricity you’re making is intended to be intertied with the Grid. If not, at the very least, as an emergency alternate energy supply to feed the home’s AC electrical system. Without all the electrical elements; impossible.
Besides, quality electrical components are a must if you wish to avoid destroying that new plasma wide screen. Of course, off grid living is the ultimate goal.
DC electricity from photovoltaics wind generators and hydro turbines, must be converted to 60 cycle AC in order to be utilized in the homes standard utility system. But there’s a lot more to controlling electricity than reorganizing a few electrons.
A variety of electrical components is needed to produce the kind of energy that’s usable. The principles are really not rocket science, but they are important, so let’s move ahead.
Please note; the typical system electrical components illustrations on this page are not exact, but they do closely resemble the actual electrical part for your benefit.
We’ll start this with the two most important electrical components without which, no electricity could be produced from wind, hydro or solar.
Wind Turbine Generator Wind turbines AKA Wind Systems for private power generation usually produce DC electricity. However it really depends on the type of generator one builds or purchases. Some home built systems produce AC. It's then rectified to DC for further use.
The ultimate goal with any home power system is to become energy independent and perhaps connect to the grid. And electrical components provide a means to do that. Special constituent parts such as controllers and inverters convert DC electricity to AC.
Special electrical devices prepare the generated electricity to match the utilities 60 cycle single phase power delivered to your home by the utility.
Installing a wind power system is recommended only for experienced DIY home owners, otherwise an experienced contractor should be consulted.
Even then, an experienced diy’er may find such a project challenging. Careful attention to every detail for such a project is a must. For example, erecting the tower should only be done with lot’s of help for it's safe and precise placement.
Unfortunately, the initial cost of quality systems may be a deterrent to such a project. However, remember the initial cost may be offset by renewable energy installation tax incentives. Such incentives are becoming more and more popular as the cost of energy rises and electrical components costs are becoming more economical.
Low Voltage Disconnects Not to be confused with the array dc disconnect (the ordinary switch), a desirable attribute included in premium controllers is low voltage disconnect (LVD). Basically, whatever is connected to the load terminals will be shut off to keep the batteries from discharging to harmful low levels.
Some units may incorporate a timer to allow a grace period elapsing before shutting down. However this feature can be bypassed and the reset time extended in case of emergencies. Small non-essential loads like lights and radios are often connected to such outputs.
Low Voltage Reconnects When the battery voltage is above the Low Voltage Reconnect, the controller reconnects the load. Basically, this is the LVd’s exact opposite.
Reverse Polarity Protection Quality units provide reverse polarity protection. That is, they will not allow passage of an incorrect polarity to damage sensitive parts in other electrical components. Basically, processor controlled high current solid state transistors block current flow in the wrong direction. Older units used diodes and silicon controlled switches (SCS) for protection.
Ideally a solar array should be allowed to operate at its maximum voltage all of the time. Electrical components like MPPT charge controllers make that possible.
These switching wonders work at relatively low frequencies compared to the 5 to 10 mega hertz range that their digital cousin’s operate in. However the frequency they operate in is sufficient.
One of the secrets of this design is that it wider control loop bandwidth which is five to ten times its switching frequency. This means fewer and smaller parts – which means lower cost. But this also means an almost negligible loading of the array or generator. So at 50 to 90 kilo hertz, loading the source is almost nil.
This means 92 to 97% conversion of the output from the array or generator can be used. Therefore, during winter months, charge controller efficiency gain is 20 to 45% and 10 to 15% in the summer. Better yet, MPPT’s conversion rate for grid tie systems is between 94 to 96%.
Another advantage of this electrical component is that its MPPT feature will match any size PV array to the charge controller’s load. For example, you can charge a 24 volt battery with a 60 volt PV array.
The MPPT performs all this with a micro-controller or microprocessor that continually monitors and calculates the optimum voltage the solar array is able to deliver. Because of the higher voltage, smaller gage wire can also be used. Smaller wire will also save you $$$.
The array’s higher input voltage is converted to a lower output voltage through the converter. The output voltage constantly shifts matching the batteries voltage moment by moment.
Because of the isolation (lack of loading), the solar array is able to operate at maximum voltage efficiency regardless of the batteries state. Hence, array power normally wasted can be harvested for use in the system.
The same electrical components digital MPPT system can match a high voltage PV arrays designed for grid tie applications to charging batteries.
Moreover, systems specifically designed for grid-tie applications using solar inverters with MPPTs on board will convert the PV arrays DC voltage to AC to sell back to the grid. Charge controllers with this feature are among the coolest electrical components available.
You may pay a little more for electrical components with all the bells and whistles, but in the long run, the system will last longer and provide the kind of performance you should expect.
Each of these electrical components types have both desirable and undesirable characteristics. Obviously price and performance are major factors in choosing a type. A little research will help you decide which one is best for your system.
Okay, so what’s a sinusoidal wave? Such a wave form can be best described as a projection on a plane of the path of a point moving around a circle at a constant speed. In the case of alternating electricity - 60 times a second.
A true sine wave will follow a predictable stable motion. A modified square wave may act in an unpredictable manner because of the non-linear residual of the switched components remaining. Whereas a pure sine wave will have been sufficiently filtered so that the rotation around the circle does not, say – wobble.
As computer controlled electrical components, true sine wave converters monitor for the slightest current drain. When a load is detected (refrigerator turns on, or a light turns on), the inverter automatically comes on line to supply power to the load. When the load disappears, the inverter drops off too. The micro processor tests for loading every 100 milliseconds or so.
In some cases, true sine wave inverters produce cleaner wave forms than the utility companies. This type of inverter is as you might expect – costy, in fact the most expensive.
But for quality electrical components, generating solar, wind and hydro electricity would be neigh on to impossible. In a sense, these components are like glue. Putting them together in a practical way produces clean usable electrical power.
Installing a wind power system is recommended only for experienced DIY home owners, otherwise an experienced contractor should be consulted.
The charge controller will divert the generators energy to a dummy load when the batteries cannot accept all of the electricity it produces. This component converts the kinetic energy of the spinning blades into heat.
As a matter of fact, with several groups, you'll have enough extra electricity send it to the grid. Then your system can be classified as utilityinteractive (UI).
Such a device; for our purposes, is called an array disconnect or an on-off switch or breaker large enough to handle solar panel currents. Of the electrical components, other than wire, this is the simplest.
Anyway, the switch is simply a DC rated electrical SPST switch, one per arrat in a metal box. Fuses can also be used if desired or deemed necessary, but personally, I prefer using breakers where required. It's easier to throw a switch than pull a fuse.
You will likely notice that breakers have a lower current trip point than fuses. The reason is that breakers do not trip as fast on a momentary surge.
The average controller will handle currents ranging from 6 to 40 ampere, while some will handle much more. Should greater current capacity be required, multiple units of the appropriate amperage may be wired in parallel.
Pre-programmed micro-controllers (processors) provide a unique charging technique called pulse width modulation or PWM. PWM works by providing a series of pulses of varying duty cycles. A long 90% duty cycle provides greater charge current, while short 10% duty cycles provide much less.
However when the system does auto equalization the voltage is increased to 14.6 volts. With the voltage increased and current limiting initiated, all cells become fully charged.
Okay, but how do they work? The MPPT provides increased battery charge current. The idea is to isolate the PV array or generator from the batteries. This is accomplished with a high frequency DC to DC converter. Why high (HF) frequency? Because, HF is easier to filter to turn into a pure DC voltage.
Depending on your systems the electrical components bells and whistles; you may wish to monitor individual batteries, read individual panels in a group of segments, read various temperatures, and so on. Or you may only want just the basics; it’s entirely up to you.
The disconnect breaker/switch is a large DC rated device mounted in single slot metal enclosure.
Then when the opposite transistor turns on, current is fed into the same transformer only on the opposite end of the same wire the first transistor fed. In other words, the transistors switch on and off, causing the DC voltage to rapidly change polarity in the transformer.
This form of AC was processed to resemble an AC sine-wave, but still retained some square wave components. These were called modified sine wave inverters.
The exception is that over time the square wave components of the sine wave will take their toll on some components in PC’s and other sensitive electronic equipment. Moreover, advances in consumer products requiring pure AC are on the increase.
Most people have some knowledge of this electrical components function. Each panel circuit breaker feeds a branch. These are usually labeled so you know what's what: hall lights, main bathroom, living room, refrigerator – dishwasher, and so on.
All homes and businesses tied to the grid, connect through their own power meter. Ironically, they're so obvious we generally ignore them, or completely overlook them.
Gensets range from just a few hundred watts to huge MW systems that are capable of running a small town. Purchasing a large gen-set strictly for family use is not however necessary and is usually a waste of money.
