Solar pv panels
Photovoltaics (often shortened as PV) gets its name from the process of converting light (photons) to electricity (voltage), which is called the photovoltaic effect. This phenomenon was first exploited in 1954 by scientists at Bell Laboratories who created a working solar cell made from silicon that generated an electric current when exposed to sunlight. Solar cells were soon being used to power space satellites and smaller items such as calculators and watches. Today, electricity from solar cells has become cost competitive in many regions and photovoltaic systems are being deployed at large scales to help power the electric grid.
Silicon Solar Cells
The vast majority of today’s solar cells are made from silicon and offer both reasonable prices and good efficiency (the rate at which the solar cell converts sunlight into electricity). These cells are usually assembled into larger modules that can be installed on the roofs of residential or commercial buildings or deployed on ground-mounted racks to create huge, utility-scale systems.
What Does CCTV Stand For?
CCTV stands for closed-circuit television.
So how does a modern CCTV system work?
The answer depends on the type of system involved. The systems are best defined by the types of cameras used. There are two common types of cameras in use today: Analog and IP-based cameras.
CCTV systems that use analog cameras have been around for years. They are still the most common type of camera installed in the field, experts say. Picture a camera or series of cameras with a dedicated set of wires fed into a recording device and series of monitors. Video is recorded and stored on site.
High-resolution, global quantification of fossil fuel CO2 emissions is emerging as a critical need in carbon cycle science and climate policy. The fossil fuel data assimilation system (FFDAS) estimates global high-resolution fossil fuel CO2 emissions. Originally created by Dr. Peter Rayner, collaboration with Dr. Kevin Gurney has advanced and improved the FFDAS product. Current results cover the years 1997 to 2015 at a spatial resolution of 0.1°. Stay tuned for a new version at 1 km2 for more recent years.
Electricity is the set of physical phenomena associated with the presence and motion of matter that has the property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell’s equations. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others.
The presence of an electric charge, which can be either positive or negative, produces an electric field. The movement of electric charges is an electric current and produces a magnetic field.
When a charge is placed in a location with a non-zero electric field, a force will act on it. The magnitude of this force is given by Coulomb’s law. If the charge moves, the electric field would be doing work on the electric charge. Thus we can speak of electric potential at a certain point in space, which is equal to the work done by an external agent in carrying a unit of positive charge from an arbitrarily chosen reference point to that point without any acceleration and is typically measured in volts.