News about Solar, Wind and alternative green power technologies

Skepticism abounds where solar energy is concerned and such cynicism leads to a many untruths and unreliable information. One fable that exists despite its being dispelled often is the one concerning the safety of utility workers. It concerns how that safety is at risk when they are called upon to operate in contact with grid – tied photovoltaic systems. It is a pervasive myth but a fable nonetheless.
 
What Constitutes The Danger?

When the debate about line worker safety is broached, what specifically seems to be at issue is the inverter or the apparatus that changes the direct current [DC] electricity generated by the solar panels into residential alternating current [AC] electricity.
 
The use of alternating current is the most popular type of electricity due to it being simpler to transfer for long ranges, and because of this, the majority of today’s appliances and electrical devices are built to work with alternating current or AC.

Direct current [AC] and DC, direct current are actually incompatible, so a way of switching DC to AC is required to connect the two, therefore an inverter is used.

What Makes Up The Inverter?

Why is it called an inverter and not a converter? A reasonable question and really that is what the job of an inverter is, converting DC power to AC power and that is the precise reason why it is named an inverter rather than converter. The IEEE or [Institute of Electrical and Electronics Engineers] defined the inverter as meaning a system, machine or device that changes direct current into alternating current electricity. The inverter then has a basic functionality of converting DC power from a PV system and battery array [to store only the DC power] used to store off – grid power and grid – tied units with battery backup energy. This AC power can then be sent back to the grid or used for energizing AC loads.

Varieties Of Inverters

There are three kinds of inverters available. The square wave, modified square wave and sine wave. Square wave inverters supply very limited power for small uses. Modified square wave inverters can supply bigger transfers and can easily handle a broad range of loads but can mean certain issues arise with various devices like clocks and microwaves that use digital timing units – they operate fast or slow – as well as the battery packs of cordless tools.

Sine wave inverters wind up as the most popular choice for inverters and are used frequently in home solar power units. This is because they generate negligible amounts of harmonic distortion and will operate with the most delicate bits of equipment. This is also the lone inverter variety that can be utilized with grid-tied systems.

Safety First

Inverters are provided with the most safeguards of any piece of apparatus in the entire home solar power system. They must undergo certification by most of the identical organizations responsible for regulating many appliances. They are obligated by the IEEE, UL and NEC to automatically disengage from the grid when under particular conditions, like an inverter break down, power outages, voltage irregularities, and the like. The inverters do not simply come with built in safety controls but when operating near PV electric arrays utility workers are taught to be quite safety conscious. As well, when line workers conduct their line maintenance they are called upon to ground any conductors that are located in the inverters, thus supplying an extra covering of security while working with inverters.

There are numerous homes that utilize generators to supply electricity into homes during a blackout. When they are not equipped with the right transfer switch, the generator could send electricity back into the grid causing very high voltage surges. When this occurs, the result can be fatal for line workers and is the primary reason why the line workers have such intensive training in safety precautions.

The Record Says It All

The record of safety where inverters are concerned is optimal in the industry so it is a safe bet that in ensuing years they will become an established and typical bit of the residential electrical units. The line workers and utility personnel  come face to face with many hazardous situations as a part of their job description but the inverters and grid – tied photovoltaics certainly is not part of that dangerous work. The perceived danger is a myth!