Lithium Iron Phosphate Battery

The lithium iron phosphate battery (LiFePO₄ battery) or LFP battery (lithium Ferro phosphate), is a type of rechargeable battery, specifically a lithium-ion battery, using LiFePO₄ as the cathode material, and a graphitic carbon electrode with a metallic backing as the anode. The specific capacity of LiFePO₄ is higher than that of the related lithium cobalt oxide (LiCoO₂) chemistry, but its density is less due to its lower operating voltage. The main drawback of LiFePO₄ is its low electrical conductivity. Therefore, all the LiFePO₄ cathodes under consideration are actually LiFePO₄/C. Because of low cost, low toxicity, well-defined performance, long-term stability, etc. LiFePO₄ is finding a number of roles in vehicle use, utility scale stationary applications, and backup power.

Lithium Iron Phosphate LiFePO4, each Cells 700 Ah Amp Hours 3.25 Volts. Two cells are wired in parallel to create a single 3.25V 1400Ah cell, with a capacity of 4,550 Watt hours or 4.55 kWh. Note the multi-layer copper bus bar designed to carry more electrons on the surface of multiple plates rather than using a single solid connector between cells. Higher discharge rates needed for acceleration, lower weight and longer life makes this battery type ideal for bicycles and electric cars. 12V LiFePO₄ batteries are also getting popularity as a second (house) battery for a caravan, motor-home or boat.

LiFePO₄-powered solar lamps are visibly brighter than ubiquitous outdoor solar lights, and performance overall is considered more reliable. Many home EV conversions use the large format versions as the car's traction pack. With the efficient power-to-weight ratios, high safety features and the chemistry's resistance to thermal runaway, there are few barriers for use by amateur home "makers". Motorhomes are often converted to lithium iron phosphate because of the high draw. Some electronic cigarettes use these types of batteries. Other applications include flashlights, radio-controlled models, portable motor-driven equipment, industrial sensor systems and emergency lighting. 

Home Fuel Cell

A home fuel cell or a residential fuel cell is a scaled down version of industrial stationary fuel cell for primary or backup power generation. These fuel cells are usually based on combined heat and power-CHP or micro combined heat and power MicroCHP technology, generating both power and heated water or air. A commercially working cell is called Ene-Farm in Japan and is supported by the regional government which uses natural gas to power up the fuel cell to produce electricity and heated water. Most home fuel cells fit either inside a mechanical room or outside a home or business, and can be discreetly sited to fit within a building's design.

            Some of the newer home fuel cells can generate anywhere between 1–5 kW—optimal for larger homes (370 square metres [4,000 sq ft] or more), especially if pools, spas, and radiant floor heating are in plans. Other uses include sourcing of back-up power for essential loads like refrigerator/freezers and electronics/computers. Deploying the system's heat energy efficiently to a home or business' hot water applications displaces the electricity or gas otherwise burned to create that heat, which further reduces overall energy bills. Retail outlets like fast food chains, coffee bars, and health clubs gain operational savings from hot water heating.

Since it is in general not possible for a fuel cell to produce at all times exactly the needed amount of both electricity and heat, home fuel cells are typically not standalone installations. Instead they may rely on the grid when the electricity production is above or below what is needed. Additionally, a home fuel cell may be combined with a traditional furnace that produces only heat. For example, the German company Viessmann produces a home fuel cell with an electric power of 0.75 kW and a thermal power of 1 kW, integrated with a traditional 19 kW heat producing furnace, using the grid for electricity need below and above the fuel cell production.

Radio-Frequency Identification

Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. The tags contain electronically stored information. Passive tags collect energy from a nearby RFID reader's interrogating radio waves. Active tags have a local power source (such as a battery) and may operate hundreds of meters from the RFID reader. Unlike a barcode, the tag need not be within the line of sight of the reader, so it may be embedded in the tracked object. RFID is one method of automatic identification and data capture (AIDC).  RFID tags are used in many industries.

 For example, an RFID tag attached to an automobile during production can be used to track its progress through the assembly line; RFID-tagged pharmaceuticals can be tracked through warehouses; and implanting RFID microchips in livestock and pets enables positive identification of animals. Since RFID tags can be attached to cash, clothing, and possessions, or implanted in animals and people, the possibility of reading personally-linked information without consent has raised serious privacy concerns. These concerns resulted in standard specifications development addressing privacy and security issues. ISO/IEC 18000 and ISO/IEC 29167 use on chip cryptography methods for untraceability, tag and reader authentication, and over-the-air privacy. 

ISO/IEC 20248 specifies a digital signature data structure for RFID and barcodes providing data, source and read method authenticity. This work is done within ISO/IEC JTC 1/SC 31 Automatic identification and data capture techniques. Tags can also be used in shops to expedite checkout, and to prevent theft by customers and employees. In 2014, the world RFID market was worth US$8.89 billion, up from US$7.77 billion in 2013 and US$6.96 billion in 2012. This figure includes tags, readers, and software/services for RFID cards, labels, fobs, and all other form factors. The market value is expected to rise to US$18.68 billion by 2026.

Flywheel Storage

Mechanical inertia is the basis of this storage method. When the electric power flows into the device, an electric motor accelerates a heavy rotating disc. The motor acts as a generator when the flow of power is reversed, slowing down the disc and producing electricity. Electricity is stored as the kinetic energy of the disc. Friction must be kept to a minimum to prolong the storage time. This is often achieved by placing the flywheel in a vacuum and using magnetic bearings, tending to make the method expensive. Greater flywheel speeds allow greater storage capacity but require strong materials such as steel or composite materials to resist the centrifugal forces.

            The ranges of power and energy storage technology that make this method economic, however, tends to make flywheels unsuitable for general power system application; they are probably best suited to load-leveling applications on railway power systems and for improving power quality in renewable energysystems such as the 20MW system in Ireland.  Applications that use flywheel storage are those that require very high bursts of power for very short durations such as tokamak and lase rexperiments where a motor generator is spun up to operating speed and is partially slowed down during discharge.

 Flywheel storage is also currently used in the form of the Diesel rotary uninterruptible power supply to provide uninterruptible power supplysystems (such as those in large datacenters) for ride-through power necessary during transfer – that is, the relatively brief amount of time between a loss of power to the mains and the warm-up of an alternate source, such as a diesel generator. Powercorp in Australia have been developing applications using wind turbines, flywheels and low load diesel (LLD) technology to maximize the wind input to small grids. A system installed in Coral Bay, Western Australia, uses wind turbines coupled with a flywheel based control system and LLDs. The flywheel technology enables the wind turbines to supply up to 95 percent of Coral Bay's energy supply at times, with a total annual wind penetration of 45 percent.

Electric Vehicles

Companies are researching the possible use of electric vehicles to meet peak demand. A parked and plugged-in electric vehicle could sell the electricity from the battery during peak loads and charge either during night (at home) or during off-peak.Plug-in hybrid or electric cars could be used  for their energy storage capabilities. Vehicle-to-grid technology can be employed, turning each vehicle with its 20 to 50 kWh battery pack into a distributed load-balancing device or emergency power source.

This represents 2 to 5 days per vehicle of average household requirements of 10 kWh per day, assuming annual consumption of 3650 kWh. This quantity of energy is equivalent to between 40 and 300 miles (64 and 483 km) of range in such vehicles consuming 0.5 to 0.16 kWh per mile. These figures can be achieved even in home-made electric vehicle conversions. Some electric utilities plan to use old plug-in vehicle batteries (sometimes resulting in a giant battery) to store electricity However, a large disadvantage of using vehicle to grid energy storage would be if each storage cycle stressed the battery with one complete charge-discharge cycle. 

However, one major study showed that used intelligently, vehicle-to-grid storage actually improved the batteries longevity. Conventional (cobalt-based) lithium ion batteries break down with the number of cycles – newer li-ion batteries do not break down significantly with each cycle, and so have much longer lives. One approach is to reuse unreliable vehicle batteries in dedicated grid storage as they are expected to be good in this role for ten years. If such storage is done on a large scale it becomes much easier to guarantee replacement of a vehicle battery degraded in mobile use, as the old battery has value and immediate use.

Lithium–Air Battery

The lithium–air battery (Li–air) is a metal–air electrochemical cell or battery chemistry the uses oxidation of lithium at the anode and reduction of oxygen at the cathode to induce a current flow. Pairing lithium and ambient oxygen can theoretically lead to electrochemical cells with the highest possible specific energy. Indeed, the theoretical specific energy of a non-aqueous Li–air battery, in the charged state with Li₂O₂ product and excluding the oxygen masks, is ~40.1 MJ/kg. This is comparable to the theoretical specific energy of gasoline, ~46.8 MJ/kg. In practice, Li–air batteries with a specific energy of ~6.12 MJ/kg at the cell level have been demonstrated. This is about 5 times greater than that of a commercial lithium-ion battery, and is sufficient to run a 2,000 kg EV for ~500 km (310 miles) on one charge using 60 kg of batteries.

 However, the practical power and life-cycle of Li–air batteries need significant improvements before they can find a market niche. Significant electrolyte advances are needed to develop a commercial implementation. Four approaches are active: aprotic, aqueous, solid state and mixed aqueous–aprotic. Metal–air batteries, specifically zinc–air, have received attention due to potentially high energy densities. The theoretical specific energy densities for metal–air batteries are higher than for ion-based methods. Lithium–air batteries can theoretically achieve 3840 mA·h/g.

A major market driver for batteries is the automotive sector. The energy density of gasoline is approximately 13 Kw h/kg, which corresponds to 1.7 kW·h/kg of energy provided to the wheels after losses. Theoretically, lithium–air can achieve 12 kW·h/kg (43.2 MJ/kg) excluding the oxygen mass. Accounting for the weight of the full battery pack (casing, air channels, lithium substrate), while lithium alone is very light, the energy density is considerably lower. A Li–air battery potentially had 5–15 times the specific energy of a Li-ion battery.

Pumped Water

In 2008 world pumped storage generating capacity was 104 GW, while other sources claim 127 GW, which comprises the vast majority of all types of grid electric storage – all other types combined are some hundreds of MW.  In many places, pumped storage hydroelectricity is used to even out the daily generating load, by pumping water to a high storage reservoir during off-peak hours and weekends, using the excess base-load capacity from coal or nuclear sources. During peak hours, this water can be used for hydroelectric generation, often as a high value rapid-response reserve to cover transient peaks in demand. Pumped storage recovers about 70% to 85% of the energy consumed, and is currently the most cost effective form of mass power storage. The chief problem with pumped storage is that it usually requires two nearby reservoirs at considerably different heights, and often requires considerable capital expenditure.

Pumped water systems have high dispatchability, meaning they can come on-line very quickly, typically within 15 seconds, which makes these systems very efficient at soaking up variability in electrical demand from consumers. There is over 90 GW of pumped storage in operation around the world, which is about 3% of instantaneous global generation capacity. Pumped water storage systems, such as the Dinorwig storage system in Britain, hold five or six hours of generating capacity, and are used to smooth out demand variations. Another example is the 1836 MW Tianhuangping Pumped-Storage Hydro Plant in China, which has a reservoir capacity of eight million cubic meters (2.1 billion U.S. gallons or the volume of water over Niagara Falls in 25 minutes) with a vertical distance of 600 m (1970 feet).

 The reservoir can provide about 13 GW·h of stored gravitational potential energy (convertible to electricity at about 80% efficiency), or about 2% of China's daily electricity consumption. A new concept in pumped-storage is utilizing wind energy or solar power to pump water. Wind turbines or solar cells that direct drive water pumps for an energy storing wind or solar dam can make this a more efficient process but are limited. Such systems can only increase kinetic water volume during windy and daylight periods.