A continual power system is a large-scale system for reliably supplying large amounts of uninterrupted power. Examples of a continual power system include uninterruptible power supply and an emergency power system. The need for a continual power system has risen over the last few decades because energy resources in the market are getting less and at a higher price as the industrial revolution progresses. This is due to several reasons such as the growth in global economy, depletion of energy resources, and the environmental impacts of energy production.
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The continual power system is one of many power systems that are being funded and used at this time because there is still no standard that exists that clearly defines the roles and responsibilities of the energy provider. As the modern world continues to progress, high-tech users are expected to demand a power supply that is high in security, quality, reliability, and availability. For businesses, reliability and quality is important because they rely on electrical services to provide lighting, general power, computer hardware and communications hardware. The key in reliable power systems is to avoid power disturbances, which are concerned with deviations of the voltage or current from the ideal single-frequency sine wave of constant amplitude and frequency
The desire for continuous and reliable power supply is not just within the business community. On a 2011 study done on Flemish households, the researchers found that only a relatively small share of them would be willing to switch to a lower reliability level if they would be compensated by a not too large bill discount. Computer power supplies have the AC/DC converter in which energy is lost when converted. By relying on a highly efficient dc only converter, instead of AC/DC, to store energy directly from a fuel cell the efficiency can be increased by up to 50%
Flywheel
An example of a continual power system is the flywheel-based type, which are common on colocation sites. These consist of an electric motor, a flywheel, a generator and a diesel engine. In normal operation, the electric motor, supplied from the grid, turns the flywheel which in turn turns the generator. In the event of power failure, the flywheel keeps the generator turning while the diesel engine starts. The flywheel is an effective way for governing the FESS for wind power smoothing. It is the range of 89-93% of mean state of charge which means as the blades on the flywheel turn, energy is being stored up between 89-93% of the given output. The idea is to use energy as optimally as possible by means of storing converted through the movement of the flywheel. The electric machine operates the flywheel and as it turns energy is stored.
Turbines
A turbine is a set of blades that are forced to turn from an external force. When the blades start turning, the shaft which this is connected to starts to spin, and the connecting generator then creates electricity. Examples of external forces that can be used to get the turbines going include wind, water, steam and gas. Turbines can be used in creating a continual power system because as long as the turbine blades turn, electricity is being created.
Currently, wind turbines are being heavily funded by the U.S. government. The U.S. Department of Energy (DOE) was allocated $88.2 million in the fiscal year 2014 towards the Wind Program and in 2015 the Wind Program's budget request is $115 million. The goal of the DOE is to develop and deploy a portfolio of innovative technologies for clean, domestic power generation and they are targeting to produce 20% of the nation's electricity by 2030. This type of turbine also increases the efficiency levels of electricity and power in homes and businesses in the U.S. Some drawbacks of this though includes that the different speeds of winds throughout the country makes this type of generator of continuous electricity uneconomical in some locations. Also, wind turbines can negatively impact wildlife by altering the surrounding habitat. The death of birds and bats in wind turbines is not uncommon.
The UK has begun looking for an alternate electric systems and wind generation is a solution they have started researching. Wind generation can displace a significant amount of energy by a large conventional plant, but the concern is weather this system can replace the capacity and flexibility of a conventional power plant. Another dilemma that they have with this system is that the majority of the wind is located in Scotland and the North of England; they need to have reinforcements for the transmission of north-south flow of energy. . The concern about wind generation being able to replace a power plant is important because wind power is variable, and the power will need to be retained to ensure that there is a supply of power under conditions of high demand and low wind. Since wind is not easy to predict additional reserves will be needed to maintain the balance of supply and demand. The obvious answer would be an energy storage system that has intermittency of renewable sources: during periods when wind exceeds the demand, the supply can be stored in a standing reserve or synchronized reserves. Standing reserve will increase the capability of the systems to incorporate wind power. Synchronized reserve will accommodate relatively frequent but comparatively small imbalances between generation and demand while standing reserve will be absorbing less frequent but relatively large reductions in wind power. This trade-off between reserves should balance out costs and wind power. It was found that this wind system would be able to accommodate, power with a small increase in overall cost, about 5% for consumers.
Over the last decade, tidal current turbine use has started to grow. This system has been around since Roman times, where tidal mills are placed in the water to harness energy by utilizing the elevation change of the tide. This technology has not been used much in the past however to extract energy because of its low efficiency and high environmental impact. While there is still being research done on the most effective tidal turbine, and how they can be made to minimize environmental impact, studies do show that due to the nature of the operationing conditions and the need for cost-effective power plants, the construction scheme for a tidal current turbine farm is expected to have turbines that are closely spaced. When these turbines are close to each other, there are hydrodynamic interactions affecting the performance of each turbine. Calculations on the efficiency level of these power systems find that a farm with hydrodynamic interactions between turbines may produce 30% more power output than that of the farm without hydrodynamic interactions.
Microbial Fuel Cells
Microbial fuel cells can create energy when bacteria breaks down organic material, this process a charge that is transferred to the anode. Taking something like human saliva, which has lots of organic material, can be used to power a micro-sized microbial fuel cell. This can produce a small amount of energy to run on-chip applications. This application can be used in things like biomedical devices and cell phones.
A study on the up flow of microbial fuel cell was developed to create electricity and treat wastewater at the same time. During a five-month time frame it was found that giving the system a sucrose solution continuously generated electricity of 170 mW/m2. The power density increased with increasing chemical oxygen demand up to 2.0 g COD/day but there was no increase in power density after that. This shows that while this system can continuously provide electricity it has its limitations.