Renewable energy such as sunlight, wind power, hydraulic power, etc. are natural energy that can be used again once and used without worry of exhaustion. However, this energy can not be said to be a power generation method that is efficient and economical, unless it raises power generation efficiency to prevent waste.
Energy conversion is done in various forms, such as a water heater that boils water using gas and electricity as an energy source, an air conditioner that heats a room, a heater, and so on. Power generation efficiency is one of the energy conversion efficiency and represents the ratio of converting renewable energy having light, thermal energy, and others, into electric energy.
To generate electricity using renewable energy, it is necessary to convert the energy of sunlight, wind power, hydraulic power or the like into electric energy. If all energy can be converted to electric energy without wasting it, the power generation efficiency will be 100%; if it can only be converted by half, it will be reduced to 50%. In other words, when generating electricity using facilities of the same cost, the higher the power generation efficiency, the ideal energy, which is an efficient facility.
The power generation efficiency of renewable energy varies depending on the power generation method. And these variations should be considered by a business when choosing an energy supplier. Let’s consider a list of them:
Photo voltaic power converts the light energy of the sunlight that arrives at the surface of the earth in the sunshine into electric energy with a solar power generation system. The power generation efficiency at that time is about 20% in general solar power generation system. In the photo voltaic power generation system used in artificial satellites, the power generation efficiency rises to about 40%, but because it increases production cost, it is not economical as a general facility, and it is not very popular.
It is said that wind power generation that turns a windmill with wind energy and converts it into electric energy with a generator is said to have power generation efficiency of about 60% at the maximum, but further improvement in efficiency is theoretically impossible to do. To convert the energy that the windmill is turning into electric energy, actual power generation efficiency decreases because loss such as friction occurs at power generation. Therefore, the generation efficiency of general wind power generation systems is about 45% at maximum, about 20 to 40% on average.
Hydro Power Generation:
Hydroelectric power generation utilizes the potential energy of water. Frictional loss when flowing into a waterway is small, most of it can be converted into kinetic energy, so even if loss generated in the power generation system is added, power generation efficiency is about 80%. Among renewable energy, it is the most power generation method with high power generation efficiency.
Geothermal Power Generation:
Geothermal power generation uses electricity generated by the underground magma heat to make water vapor, and it generates electricity by moving the generator. Although the principle of power generation is the same as thermal power generation and nuclear power generation, power generation efficiency is not so high as about 10 to 20% because the steam temperature is lower than thermal power and nuclear power.
Biomass Power Generation:
Biomass power generation generates electricity by turning a generator; burning organic fuels such as animals and plants. The combustion method includes a direct burning method and a method of generating gas to rotate a gas turbine, but the power generation efficiency is about 20% because the temperature is low like geothermal power generation.
Why Does Loss of Power Generation Occur?
To compare business energy supplier, a business should ask the above question and understand that power generation efficiency, of course, is ideally 100%. However, loss occurs in the process of converting energy, and power generation efficiency declines gradually. Why does power generation efficiency drop?
When energy transforms, it is dispersed in various kinds of energy. Therefore, no matter how advanced the technology, it is impossible to convert specific energy to different energy.
Energy loss is also occurring when solar power generation which is familiar renewable energy converts from light energy to electricity. One of the reasons for the energy loss of solar power generation is the electrical resistance of wiring and circuits inside the solar power generation system. Like incandescent light bulbs, electric energy becomes thermal energy and losses, so power generation efficiency decreases.
Also, solar panels can not absorb all light as energy. The reason is that sunlight contains light of various wavelengths such as ultraviolet ray, visible ray, infrared ray because there is the light of a wavelength that is not absorbed by a solar panel in it. Also, the losses that do not hit the solar panel are also lost, and energy is gradually dispersed, which reduces power generation efficiency.
Energy conversion efficiency is important to effectively utilize limited resources. If energy conversion efficiency is high, unnecessary energy loss is suppressed, and energy can be utilized to the utmost.
Equipment with high power generation efficiency is, of course, ideal, but economic benefits will be lost if equipment costs increase to increase power generation efficiency. It is necessary to compare the cost-effectiveness from the viewpoints of both high power generation efficiency and power generation equipment cost.