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Energy Basics
Published in Stan Harbuck, Donna Harbuck, Residential Energy Auditing and Improvement, 2021
It is good to distinguish energy from power. Power is units of energy used over a specific time frame; power is energy divided by time. Some examples of energy units include Btu, foot-pounds, and joules. Examples of power units include Btu per hour, foot-pounds per minute, joules per second or watts, kilowatts, horsepower, and tons of refrigeration. Some of these units do not show a time unit built because of the way they are defined–watts are defined as joules per second, horsepower is defined as 33,000 foot-pounds per minute, tons of refrigeration is defined as 12,000 Btu per hour. Thus, while it seems counterintuitive, watt-hours (wh), horsepower-minutes (hpmin), and ton-hours (tonhrs) of refrigeration are energy units because the time unit comes from the original definition of watts, horsepower, and tons of refrigeration. Table 2-2 compares different unite of energy with units of power.
Energy Efficiency and Conservation Technologies
Published in Swapan Kumar Dutta, Jitendra Saxena, Binoy Krishna Choudhury, Energy Efficiency and Conservation in Metal Industries, 2023
Jitendra Saxena, Binoy Krishna Choudhury
Let us take the case of overall end-use energy through various stages of coal burning in power plants, transmission of generated electricity to user and end-use as light by him/her (Figure 3.1). Generally, efficiency (E) is expressed as ratio of desired output to the necessary input—a non-dimensional number, both numerator and denominator are expressed in the same unit of energy, limiting its value between 0 and 1. In case of electricity being used to light our home, typical efficiency for LED lights would be about 0.25, or 25%. Whereas, that electricity is generated at, say, coal-based thermal power plant, received through transmission and distribution system with an average loss of 20%, i.e. efficiency 0.8 or 80%. If the thermal power plant is producing electricity from coal at an average efficiency of 0.35 or 35%, the overall efficiency or end-use energy efficiency of the entire process of producing light energy at home by burning coal at power plant can be calculated by multiplying the efficiency of these three systems which are connected in series (from coal to light) = 0.35 × 0.80 × 0.25 = 0.07, or 7%. This value is pretty low and practically could be even lower, depending on how effectively we are using the final product—in this case, light energy—which in turn, contributes to raise the GDP of the country, depending on the productive use of the final energy. This chapter also explains the effect and relevance of energy conservation (EC) vs. energy efficiency (EE), which are distinctly separate but related terms. It has been shown in this chapter that EC may not necessary improve thermodynamic EE, but would improve the EE calculated based on economic perspective.
Multi-objective optimization of a hybrid micro-grid system for reducing grid dependency in the automotive industry: a case study of Iran Khodro company
Published in International Journal of Modelling and Simulation, 2023
Samika Yousefikhah, E. Asgharizadeh, M.H. Jahangir
Cost Analysis – Cost of Electricity (): One of the most well-known indicators of the economic benefits of hybrid systems is electricity costs. This is calculated using the cost of electricity per unit of energy. Eq. (7) provides the formula for calculating this index. As shown in Eq. (8)represents the total cost of the system, which includes loading costs (), maintenance costs for power plants (), and system replacement costs () [16].
A memetic algorithm for energy-efficient scheduling of integrated production and shipping
Published in International Journal of Computer Integrated Manufacturing, 2022
Jian Chen, Tong Ning, Gangyan Xu, Yang Liu
Property 1. If, thus=0 for jobon machine, . Proof. Because job is released before the completion of job , the job is available for processing at any time when the machine is available. Because the unit reset energy consumption is larger than the unit standby energy consumption , thus the machine is inclined to prefer standby mode.
Cost effective energy consumption in a residential building by implementing demand side management in the presence of different classes of power loads
Published in Advances in Building Energy Research, 2022
G. R. Hemanth, S. Charles Raja, J. Jeslin Drusila Nesamalar, J. Senthil Kumar
In this paper, the problem of cost minimization has been focused for the real-time system considering the residential users of Nirmal Block in Agrini apartment. The non-linear objective function along with the constraints has been effectively handled by incorporating the load shifting strategy of DSM using BPSO and BGWO algorithms respectively. Also, the simulation results clearly indicate that for this problem, BGWO algorithm proves to be a suitable alternative when compared to the BPSO algorithm. In addition to electricity cost reduction, significant reduction in PAR and peak demand has also obtained as additional benefits by applying BGWO algorithm. This greatly reduces the burden on electric utility companies. Also, by implementing IULMS in our test system, the off-peak hours have been effectively used for meeting the energy demand of the consumer. It is easier to save a unit of energy than to generate the same. Hence our work has primarily focused on energy savings by altering the energy consumption. As future work, real-time scheduling of device types can be handled. Different types of pricing schemes such as real-time pricing, critical peak pricing and time of use pricing can also be included. Other approaches to demand-side management such as load building and strategic conservation can be applied. Also, a suitable hybrid algorithm can be formulated for DSM.