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.
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%
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.
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.
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.