The following hardware and software-based tools or components were used to achieve the research objectives, as seen in Table 1.

The methodology proposed for this study includes the following:

I. Detailed procedure for conducting a load audit in Akwa Ibom State Polytechnic.

II. A comprehensive approach for developing a hydro pump storage model for improving the electric power supply at Akwa Ibom State Polytechnic using HOMER.

In order to effectively conduct a load audit of electrical power demand in a Polytechnic, a step-by-step methodology must be followed. This process is crucial for identifying areas of inefficiency and potential cost savings, as well as ensuring the overall reliability and safety of the electrical system. The following steps outline a comprehensive approach to conducting a load audit in Akwa Ibom State Polytechnic.

I. Data collection: The first step in conducting a load audit is to gather all relevant data related to the electrical power demand in the Polytechnic. Data includes information on the size and layout of the facility, as well as historical data on energy consumption and demand patterns. It is also essential to collect data on the types and quantities of electrical equipment and appliances in use, as well as any recent changes or upgrades to the electrical system.

II. Power quality analysis: Once the data has been collected, the next step is to conduct a power quality analysis to assess the overall health and efficiency of the electrical system. Power quality analysis involves measuring parameters such as voltage, current, power factor, and harmonic distortion, and identifying any issues that may be affecting the quality of the power supply. This analysis can help to pinpoint areas of inefficiency and potential sources of energy waste.

III. Load profiling: After conducting a power quality analysis, the next step is to create a load profile for the Polytechnic. Load profiling involves analysing the energy consumption patterns of different areas of the facility, such as classrooms, laboratories, offices, and common areas. By identifying peak demand periods and load profiles, it is possible to optimize the operation of the electrical system and reduce energy costs.

IV. Energy audit: Once the load profiling has been completed, the next step is to conduct an energy audit to identify opportunities for energy savings and efficiency improvements. An energy audit involves assessing the performance of electrical equipment and systems, as well as identifying potential upgrades or retrofits that could reduce energy consumption. An energy audit can also help to identify any maintenance issues or operational practices that may be contributing to energy waste.

V. Recommendations and implementation: Based on the findings of the load audit, recommendations can be made for improving the efficiency and reliability of the electrical system in the Polytechnic. These recommendations may include upgrading to more energy-efficient equipment, implementing energy management strategies, or making changes to operational practices. It is crucial to prioritize recommendations based on their potential impact and feasibility, and to develop a plan for implementing them in a timely manner.

Conducting a load audit of electrical power demand in Akwa Ibom State Polytechnic requires a systematic and thorough approach. By following the steps outlined in this methodology, it is possible to identify opportunities for energy savings, improve the reliability of the electrical system, and ensure the overall sustainability of the facility.

By taking a proactive approach to managing electrical power demand, Akwa Ibom State Polytechnics can reduce costs, enhance operational efficiency, and contribute to a more sustainable future.

To assess the current electricity requirement in Nigerian higher institutions, for example, Akwa Ibom State Polytechnic. To achieve that, the approach employed involved identifying the facilities, systems and processes for which energy needs to be determined, as well as the time period for the analysis.

It included gathering information for electrical equipment and appliances such as power ratings, operating hours, and efficiency. Having done that, the major electrical facilities identified include lighting (LED) desk top computer, AC units, fan, printer, photocopier, water pump (1.2 Hp), water pump (1.5 Hp) and iron. The ratings as specified on each facility were applied to the load audit for effective determination of power requirement in Akwa Ibom State Polytechnic. For the simulation, the load profile on the HOMER interface is presented in Fig. 3.

The proposed methodology for the research project on the development of a pump model for improving electric power supply at Akwa Ibom State Polytechnic using HOMER technology involves several key steps. These steps outline the process of designing, implementing, and evaluating the pump model to optimize the utilization of renewable energy sources and improve the power supply reliability. The proposed methodology is as in Fig. 4.

The capital cost is broken down as shown in Table 2.

Based on the system model and simulation results, the pump model for energy storage and distribution will be designed as seen in Fig. 5.

The pump model will be responsible for capturing and storing excess renewable energy during periods of high generation and supplying stored energy during periods of low generation or high demand.

The design of the pump model will consider factors such as energy storage capacity, efficiency, reliability, and cost-effectiveness. The goal is to develop a pump model that maximizes renewable energy utilization and ensures a reliable power supply.

An optimized Pump as a Turbine (PAT) suitable for the above-mentioned scenario was selected from the HOMER Library and has the following specifications.

I. Design flow rate-32l/s.

II. Available head-16m.

III. Minimum flow ratio-50%.

IV. Maximum flow ratio-150%.

V. Pipe head loss-15%.

VI. Nominal capacity: 4018 kW.

VII. O&M cost/yr-$600.

VIII. Capital cost-$6,000.

IX. Replacement Cost-$2000.

X. Life span.-25yrs

Considering the design of the pumped hydroelectric system, a uniform flow rate of 32l/s (0.03m3/s) was assumed since the system is not affected by rainfall. The availability of water at the lower reservoir was also to be regular across the seasons (see Fig. 6 and Fig. 7).

Using the HOMER software tool, a detailed system model will be created to simulate the hybrid renewable energy system for Akwa Ibom State Polytechnic (See Fig. 8 and Fig. 9). The model will include the renewable energy sources such as solar and hydro power, the existing power infrastructure, and the proposed pump model for energy storage and distribution. The HOMER software will allow for the optimization of system parameters, considering factors such as energy generation, consumption, storage capacity, and cost.

The first step involves collecting relevant data related to the power supply infrastructure, energy consumption patterns, and renewable energy potential at Akwa Ibom State Polytechnic. This data would be obtained considering the following.

I. Reservoir (Inyang Anwankwo) II. Mini-hydro power turbine III. Electric pump IV. Generating the output module V. Energy controller And through site visits, interviews with relevant stakeholders, and existing reports and documentation. The collected data will be analyzed to identify the energy demand profile, assess the existing power infrastructure, and determine the potential renewable energy sources available for integration.

The institution currently uses electricity from PHEDC at the Band A tariff. The cost/kWh is at N250 ($0.167)

The reservoir is mounted at the top of a 4-storey building available in the study area.

The height of the building is measured as 16m. The volume of the reservoir was determined as follows: The flow rate Q is given by the equation below:

Q = . (1)

ρgηtH Where p denotes power measured in Watts, W, Q is the flow rate in cubic meters per second, ρ is the density of the fluid, g indicates the acceleration due to gravity, ηt represents the total efficiency of the system, and H denotes the Head or pressure (Usually measured in meters, m).

P = 4kW ηt = 0.8

ρ = 997Kg/m3 ( is the density of water in kg/m3 = 997 kg/m3) g = 9.8m/s2 H = 16m Q = .

997 × 9.8 × 0.8 × 16 Q = 0.032m3/s (32l/s) The volumetric flow rate Qv per day is given as:

Qv = Q × 86400.

Qv = 0.032 x 86400 Q = 2,763.39m3/s The minimum reservoir capacity is determined using Eq. (2).

V = 259200 × Q(m ). (2) V = 259200 x 0.032 V = 8294.44m3 Considering a sizing factor of 1.1 as et al. [21] recommended, V = 9123.84m3 Thus, the estimated volume of the upper reservoir is 10,000m3 The formula in Eq. (3) was used for calculating the power required by the pump:

P = ρ ∗ g ∗ Q ∗ h, (3) Where: P = power (In watts), ρ = density of water (Typically 1000 kg/m3), g = acceleration due to gravity (9.81 m/s2), Q = volumetric flow rate (0.032 m3/s and h = height of the reservoir (16 m).

Substituting the values:

P = 1000 ∗ 9.81 ∗ 0.032 ⋅ 16.

P = 5027.52W.

The power required by the pump is approximately 5027.52 watts or 5.03 kW.

To account for losses in the system, the term for head loss (HLH_LHL) was included in addition to the static head. The total head HtH_tHt can be expressed as:

Ht = H + Hl, (4) Where: H = static head (16 m) and Hl = head loss due to friction and other factors:

P = ρ ⋅ g ⋅ Q ⋅ Ht. (5)

Substitute the updated total head HtH_tHt into the power formula. For now, the head loss is denoted as HL. The updated power formula, Eq. (5), becomes:

P = 1000 ⋅ 9.81 ⋅ 0.032 ⋅ (16 + Hl).

If the head loss is 15% of the static head, Hl can be calculated as:

Hl = 0.15 × H. (6)

Substituting H = 16m

Hl = 0.15 × 16 = 2.4m.

Now, the total head Ht is:

Ht = H + Hl, (7)

= 16 + 2.4 = 18.4m.

Substituting this back into the power formula:

P = 1000 ⋅ 9.81 ⋅ 0.032 ⋅ 18.4.

P = 1000 ⋅ 9.81 ⋅ 0.5888 = 5772.53W.

So, the power required by the pump is approximately 5772.53 watts or 5.77 kW.

We need two pumps of 7.5hp at 250gpm each installed in parallel to achieve the required flow rate $3520.21 x 2 = $1104.0.

Installation Costs = 10% of purchase cost = $1104.0.

To calculate the power generated by a hydro turbine with a known head and outlet flow rate, the following formula is used:

P = η ∗ ρ ∗ g ∗ Q ∗ h, (8)

Where: P = power output (W), η\etaη = Efficiency of the turbine (Assume 0.9 or 90% as a typical value if not specified), ρ\rhoρ = density of water (Approximately 1000 kg/m³), g = acceleration due to gravity (9.81 m/s²), Q = flow rate (m³/s) and H = Head (m).

The system is designed to provide a reliable power supply to the Hostel (male and female), ICT and Research Centre of Akwa Ibom State Polytechnic, Ikot Osurua, where critical infrastructure such as Servers, data centre, and other digital resources are stored.

Fig. 10 shows the load profile of the building after a comprehensive load audit. The peak load is 3.61kW and the daily demand is 82kWh/day, with a load factor of 37%.

Considering the factor of safety and future equipment requirements, a 5kVA (4kW) system was designed.

Considering the upper reservoir of 10,000m3 derived from specific objective 2, the pump has a nominal rated capacity of 4.02 kW. The pump yielded an annual total production of 29,919 kWh/yr, with a mean output of 3.42 kW. The results shown in Table 3 were obtained from the simulation profile as presented in Fig. 11.

The simulation result shows a positive Net Present Value (NPV) of $11,757.14, indicating a good future value of the project in present times with a Levelized cost of Energy of $0.0304 (N51/kWh) and an annual maintenance cost of $600.

The monthly power generation by the pump energy storage system is presented in Figs. 11 and 12, respectively.