Electric vehicle (EV) charging is an important aspect of EV ownership. With power rating, connector type, cabling requirements and vehicle specification to consider, Zap-Map has created a series of step-by-step guides that cover the key issues related to EV charging.
EV charging explained
There are three main types of EV charging – rapid, fast, and slow. These represent the power outputs, and therefore charging speeds, available to charge an EV. Note that power is measured in kilowatts (kW).
Rapid chargers are one of two types – AC or DC [Alternating or Direct Current]. Current Rapid AC chargers are rated at 43 kW, while most Rapid DC units are at least 50 kW. Both will charge the majority of EVs to 80% in around 30-60 minutes (depending a battery capacity). Tesla Superchargers are also Rapid DC and charge at around 120 kW. Rapid AC devices use a tethered Type 2 connector, and Rapid DC chargers are fitted with a CCS, CHAdeMO or Tesla Type 2.
Fast chargers include those which provide power from 7 kW to 22 kW, which typically fully charge an EV in 3-4 hours. Common fast connectors are a tethered Type 1 or a Type 2 socket (via a connector cable supplied with the vehicle).
Slow units (up to 3 kW) are best used for overnight charging and usually take between 6 and 12 hours for a pure-EV, or 2-4 hours for a PHEV. EVs charge on slow devices using a cable which connects the vehicle to a 3-pin or Type 2 socket.
Charging on public networks
The UK has a large number of public EV charging networks, with some offering national coverage and others only found in a specific region. The major UK-wide networks include BP Chargemaster (Polar), Ecotricity, Pod Point and Charge Your Car.
Regional networks usually cover well defined areas such as the Midlands or the South West. Since a number of these are operated by or have links with national networks, it is often possible to use the points within these regional networks with a national account. However, the level of access depends on the network and specific charge point.
Payment and access methods across networks vary widely, with some networks providing an RFID card and others a smartphone app to use their services. While most require an account to be set up before use, some rapid units with contactless PAYG card readers are starting to be installed.
Although many EV charge points are free to use, the majority of fast and rapid chargers require payment. Charging tariffs tend to comprise a flat connection fee, a cost per charging time (pence per hour) and/or a cost per energy consumed (pence per kWh).
How to charge an EV at home
Charging at home is often the most convenient and cost effective way to recharge an EV. Government grants are available for the installation of home EV charge points, and a large number of companies offer a fully installed charge point for a fixed price.
Most home chargers are either rated at 3 kW or 7 kW. The higher powered wall-mounted units normally cost more than the slower 3 kW option, and halve the time required to fully charge an EV. Many plug-in car manufacturers have deals or partnerships with charge point suppliers, and in some cases provide a free home charge point as part of a new car purchase.
In most cases, home-based charging requires off-street parking to avoid trailing cables across public footpaths and public areas. All EV charging units are wired directly to the central metering unit, usually on its own circuit for safety and to enable monitoring separate from other electrical loads. While less common, on-street residential charging units are becoming available in some local authority areas.
How to charge an EV at work
An increasing number of companies are installing workplace EV charging units for use by employees and visitors. As with home-based charging, plugging-in an EV at the workplace charging makes sense as an employee vehicle will typically be stationary for most of the day when it can be conveniently charged. Work-based chargers can also play a role in attracting customers to visit a commercial or retail site.
While workplace charge points are similar to home-based units, power-ratings tend to be higher with more 7 kW and 22 kW units installed. More business units are double socket allowing them to charge two cars at the same time. The higher power units also enable plug-in company fleets to ‘opportunity’ charge in the middle of the day to increase the effective number of business miles driven per day without having to use more expensive charging on the public rapid network.
Company benefits in the form of grants and enhanced capital allowances are available for workplace charging units. Company owners can decide whether to provide free charging or top charge a fee to use the facilities, many opting for zero or low cost to incentive EV usage within the company and by customers and visitors.
Charging your electric car
A key issue when choosing which EV to buy or use is the type of charging inlets on the vehicle. For full EVs, car manufacturers tend to favour one of three charging inlet options: (1) Type 2 and CCS, an option offered by most of the European car makers who include a Type 2 for slow/fast charging, and a Type 2 Combo (also known as ‘CCS’) for rapid charging; (2) Type 1 and CHAdeMO, for slow/fast and rapid charging respectively; and (3) Tesla Type 2 which can be found on all current EU Tesla models.
To complicate matters, different EV models can charge at different slow and rapid speeds depending on what on-board charger has been fitted, with some plug-in hybrids unable to rapid charge. Battery capacities also have a significant influence on charging speeds, the larger EV batteries more likely to require rapid charging.
To help you understand the strengths of each particular EV model, we’ve created a number of EV charging guides for the UK’s best selling electric vehicles. These guides cover all aspects of charging an EV, and include models from the likes of BMW, Nissan, Renault, Tesla, and Volkswagen.
How Does a Generator Create Electricity? How Generators Work
|Generators are useful appliances that supply electrical power during a power outage and prevent discontinuity of daily activities or disruption of business operations. Generators are available in different electrical and physical configurations for use in different applications. In the following sections, we will look at how a generator functions, the main components of a generator, and how a generator operates as a secondary source of electrical power in residential and industrial applications.
How does a generator work?
It is important to understand that a generator does not actually ‘create’ electrical energy. Instead, it uses the mechanical energy supplied to it to force the movement of electric charges present in the wire of its windings through an external electric circuit. This flow of electric charges constitutes the output electric current supplied by the generator. This mechanism can be understood by considering the generator to be analogous to a water pump, which causes the flow of water but does not actually ‘create’ the water flowing through it.
The modern-day generator works on the principle of electromagnetic induction discovered by Michael Faraday in 1831-32. Faraday discovered that the above flow of electric charges could be induced by moving an electrical conductor, such as a wire that contains electric charges, in a magnetic field. This movement creates a voltage difference between the two ends of the wire or electrical conductor, which in turn causes the electric charges to flow, thus generating electric current.
Main components of a generator
A description of the main components of a generator is given below.
(a) Type of Fuel Used – Generator engines operate on a variety of fuels such as diesel, gasoline, propane (in liquefied or gaseous form), or natural gas. Smaller engines usually operate on gasoline while larger engines run on diesel, liquid propane, propane gas, or natural gas. Certain engines can also operate on a dual feed of both diesel and gas in a bi-fuel operation mode.
(b) Overhead Valve (OHV) Engines versus non-OHV Engines – OHV engines differ from other engines in that the intake and exhaust valves of the engine are located in the head of the engine’s cylinder as opposed to being mounted on the engine block. OHV engines have several advantages over other engines such as:
• Compact design
However, OHV-engines are also more expensive than other engines.
(c) Cast Iron Sleeve (CIS) in Engine Cylinder – The CIS is a lining in the cylinder of the engine. It reduces wear and tear, and ensures durability of the engine. Most OHV-engines are equipped with CIS but it is essential to check for this feature in the engine of a generator. The CIS is not an expensive feature but it plays an important role in engine durability especially if you need to use your generator often or for long durations.
(a) Stator – This is the stationary component. It contains a set of electrical conductors wound in coils over an iron core.
(b) Rotor / Armature – This is the moving component that produces a rotating magnetic field in any one of the following three ways:
(i) By induction – These are known as brushless alternators and are usually used in large generators.
The rotor generates a moving magnetic field around the stator, which induces a voltage difference between the windings of the stator. This produces the alternating current (AC) output of the generator.
The following are the factors that you need to keep in mind while assessing the alternator of a generator:
(a) Metal versus Plastic Housing – An all-metal design ensures durability of the alternator. Plastic housings get deformed with time and cause the moving parts of the alternator to be exposed. This increases wear and tear and more importantly, is hazardous to the user.
(b) Ball Bearings versus Needle Bearings – Ball bearings are preferred and last longer.
(c) Brushless Design – An alternator that does not use brushes requires less maintenance and also produces cleaner power.
Common features of the fuel system include the following:
(a) Pipe connection from fuel tank to engine – The supply line directs fuel from the tank to the engine and the return line directs fuel from the engine to the tank.
(b) Ventilation pipe for fuel tank – The fuel tank has a ventilation pipe to prevent the build-up of pressure or vacuum during refilling and drainage of the tank. When you refill the fuel tank, ensure metal-to-metal contact between the filler nozzle and the fuel tank to avoid sparks.
(c) Overflow connection from fuel tank to the drain pipe – This is required so that any overflow during refilling of the tank does not cause spillage of the liquid on the generator set.
(d) Fuel pump – This transfers fuel from the main storage tank to the day tank. The fuel pump is typically electrically operated.
(e) Fuel Water Separator / Fuel Filter – This separates water and foreign matter from the liquid fuel to protect other components of the generator from corrosion and contamination.
(f) Fuel Injector – This atomizes the liquid fuel and sprays the required amount of fuel into the combustion chamber of the engine.
(1) Voltage Regulator: Conversion of AC Voltage to DC Current – The voltage regulator takes up a small portion of the generator’s output of AC voltage and converts it into DC current. The voltage regulator then feeds this DC current to a set of secondary windings in the stator, known as exciter windings.
(2) Exciter Windings: Conversion of DC Current to AC Current – The exciter windings now function similar to the primary stator windings and generate a small AC current. The exciter windings are connected to units known as rotating rectifiers.
(3) Rotating Rectifiers: Conversion of AC Current to DC Current – These rectify the AC current generated by the exciter windings and convert it to DC current. This DC current is fed to the rotor / armature to create an electromagnetic field in addition to the rotating magnetic field of the rotor / armature.
(4) Rotor / Armature: Conversion of DC Current to AC Voltage – The rotor / armature now induces a larger AC voltage across the windings of the stator, which the generator now produces as a larger output AC voltage.
This cycle continues till the generator begins to produce output voltage equivalent to its full operating capacity. As the output of the generator increases, the voltage regulator produces less DC current. Once the generator reaches full operating capacity, the voltage regulator attains a state of equilibrium and produces just enough DC current to maintain the generator’s output at full operating level.
When you add a load to a generator, its output voltage dips a little. This prompts the voltage regulator into action and the above cycle begins. The cycle continues till the generator output ramps up to its original full operating capacity.
(5) Cooling & Exhaust Systems
Raw/fresh water is sometimes used as a coolant for generators, but these are mostly limited to specific situations like small generators in city applications or very large units over 2250 kW and above. Hydrogen is sometimes used as a coolant for the stator windings of large generator units since it is more efficient at absorbing heat than other coolants. Hydrogen removes heat from the generator and transfers it through a heat exchanger into a secondary cooling circuit that contains de-mineralized water as a coolant. This is why very large generators and small power plants often have large cooling towers next to them. For all other common applications, both residential and industrial, a standard radiator and fan is mounted on the generator and works as the primary cooling system.
It is essential to check the coolant levels of the generator on a daily basis. The cooling system and raw water pump should be flushed after every 600 hours and the heat exchanger should be cleaned after every 2,400 hours of generator operation. The generator should be placed in an open and ventilated area that has adequate supply of fresh air. The National Electric Code (NEC) mandates that a minimum space of 3 feet should be allowed on all sides of the generator to ensure free flow of cooling air.
(b) Exhaust System
Exhaust pipes are usually made of cast iron, wrought iron, or steel. These need to be freestanding and should not be supported by the engine of the generator. Exhaust pipes are usually attached to the engine using flexible connectors to minimize vibrations and prevent damage to the generator’s exhaust system. The exhaust pipe terminates outdoors and leads away from doors, windows and other openings to the house or building. You must ensure that the exhaust system of your generator is not connected to that of any other equipment. You should also consult the local city ordinances to determine whether your generator operation will need to obtain an approval from the local authorities to ensure you are conforming to local laws a protect against fines and other penalties.
(a) Electric start and shut-down – Auto start control panels automatically start your generator during a power outage, monitor the generator while in operation, and automatically shut down the unit when no longer required.
(b) Engine gauges – Different gauges indicate important parameters such as oil pressure, temperature of coolant, battery voltage, engine rotation speed, and duration of operation. Constant measurement and monitoring of these parameters enables built-in shut down of the generator when any of these cross their respective threshold levels.
(c) Generator gauges – The control panel also has meters for the measurement of output current and voltage, and operating frequency.
(d) Other controls – Phase selector switch, frequency switch, and engine control switch (manual mode, auto mode) among others.
(9) Main Assembly / Frame
Original Source: https://globalnews.ca/video/4559498/this-is-how-you-grow-it-at-home
The light-emitting diode (LED) is one of today’s most energy-efficient and rapidly-developing lighting technologies. Quality LED light bulbs last longer, are more durable, and offer comparable or better light quality than other types of lighting. Check out the top 8 things you didn’t know about LEDs to learn more.
LED is a highly energy efficient lighting technology, and has the potential to fundamentally change the future of lighting in the United States. Residential LEDs — especially ENERGY STAR rated products — use at least 75% less energy, and last 25 times longer, than incandescent lighting.
Widespread use of LED lighting has the greatest potential impact on energy savings in the United States. By 2027, widespread use of LEDs could save about 348 TWh (compared to no LED use) of electricity: This is the equivalent annual electrical output of 44 large electric power plants (1000 megawatts each), and a total savings of more than $30 billion at today’s electricity prices.
How LEDs are Different
LED lighting is very different from other lighting sources such as incandescent bulbs and CFLs. Key differences include the following:
- Light Source: LEDs are the size of a fleck of pepper, and a mix of red, green, and blue LEDs is typically used to make white light.
- Direction: LEDs emit light in a specific direction, reducing the need for reflectors and diffusers that can trap light. This feature makes LEDs more efficient for many uses such as recessed downlights and task lighting. With other types of lighting, the light must be reflected to the desired direction and more than half of the light may never leave the fixture.
- Heat: LEDs emit very little heat. In comparison, incandescent bulbs release 90% of their energy as heat and CFLs release about 80% of their energy as heat.
LED lighting is currently available in a wide variety of home and industrial products, and the list is growing every year. The rapid development of LED technology leads to more products and improved manufacturing efficiency, which also results in lower prices. Below are some of the most common types of LED products.
Industrial and Commercial Lighting
The high efficiency and directional nature of LEDs makes them ideal for many industrial uses. LEDs are increasingly common in street lights, parking garage lighting, walkway and other outdoor area lighting, refrigerated case lighting, modular lighting, and task lighting.
Kitchen Under-Cabinet Lighting
Because LEDs are small and directional, they are ideal for lighting countertops for cooking and reading recipes. The color can appear more cool or blue than is typically desirable in a kitchen, and there can be some excessive shadowing in some fixtures, so it is important to compare products to find the best fixture for your space.
Recessed downlights are commonly used in residential kitchens, hallways, and bathrooms, and in a number of office and commercial settings. DOE estimates there are at least 500 million recessed downlights installed in U.S. homes, and more than 20 million are sold each year. Both CFL and LED technology can decrease downlight wattage by 75% or more.
LED Replacement Bulbs
With performance improvements and dropping prices, LED lamps can replace 40, 60, and even 75 Watt incandescent bulbs. It’s important to read the Lighting Facts Label to make sure the product is the right brightness and color for the intended location. When chosen carefully, LED replacement products can be an excellent option.
LED Holiday Lights
LEDs consume far less electricity than incandescent bulbs, and decorative LED light strings such as Christmas tree lights are no different. Not only do LED holiday lights consume less electricity, they also have the following advantages:
- Safer: LEDs are much cooler than incandescent lights, reducing the risk of combustion or burnt fingers.
- Sturdier: LEDs are made with epoxy lenses, not glass, and are much more resistant to breakage.
- Longer lasting: The same LED string could still be in use 40 holiday seasons from now.
- Easier to install: Up to 25 strings of LEDs can be connected end-to-end without overloading a wall socket.
Estimated cost of electricity to light a six-foot tree for 12 hours a day for 40 days
|TYPE OF LIGHT||COST|
|Incandescent C-9 lights||$10.00|
|LED C-9 lights||$0.27|
Estimated cost* of buying and operating lights for 10 holiday seasons
|Type of Light||Cost|
|Incandescent C-9 lights||$122.19|
|LED C-9 lights||$17.99|
*Assumes 50 C-9 bulbs and 200 mini-lights per tree, with electricity at $0.119 per kilowatt-hour (kWh) (AEO 2012 Residential Average). Prices of lights based on quoted prices for low volume purchases from major home improvement retailers. All costs have been discounted at an annual rate of 5.6%. Life span assumed to be three seasons (1,500 hours) for non-LED lights.