Introduction
In the face of climate change, growing energy demand, and the depletion of fossil
fuels, the global energy landscape is undergoing a critical transformation. Renewable energy
sources such as solar, wind, hydro, and biogas are now recognized as essential for a
sustainable future. However, the intermittent and site-specific nature of these resources
presents significant challenges to reliability and consistency in energy supply. This is where
hybrid renewable energy systems (HRES) come in. A hybrid system combines two or more
renewable sources often supported by energy storage or backup systems to create a more
stable and efficient energy solution. These systems offer improved reliability, better energy
security, and lower environmental impacts compared to single-source setups. By integrating
various forms of clean energy, hybrid systems capitalize on the strengths of each source
while minimizing their limitations. This makes them especially suitable for off-grid areas, rural
communities, and regions with variable weather conditions. As the world moves toward
decarbonization, hybrid renewable energy systems represent a flexible and innovative
approach to meeting energy needs sustainably and reliably. There are multiple renewable
resources we could use from like solar, hydro, wind and biogas.
Solar energy is derived from the sun’s radiation and is one of the most widely used
renewable energy sources globally. Through technologies such as photovoltaic (PV) cells
and concentrated solar power (CSP), sunlight is converted directly into electricity. PV panels
are commonly installed on rooftops, in solar farms, or integrated into hybrid systems.
According to the National Grid, solar power is advantageous because it is abundant, silent,
and produces no emissions during operation. However, its main limitation is intermittency:
solar panels only produce electricity when there is sunlight, making energy storage a key
component in solar systems. In hybrid configurations, solar energy is often paired with other
sources like wind or diesel backup to ensure a continuous supply.
Wind energy harnesses the kinetic energy of air movement using wind turbines,
which convert the wind's motion into mechanical power and then into electricity. The U.S.
Department of Energy’s WindExchange platform explains that wind turbines can range from
small, residential systems to large-scale commercial wind farms. Wind energy is clean and
renewable, with no fuel costs or emissions. However, like solar, it is variable dependent on
wind speed and weather conditions. In hybrid systems, wind is often used in combination
with solar or hydropower to compensate for periods of low generation in one resource. For
instance, wind tends to be stronger at night, complementing solar energy’s daytime
generation.
Hydropower uses the flow of water often from rivers, dams, or pumped storage
facilities to generate electricity. It is one of the oldest and most reliable forms of renewable
energy. The U.S. Department of Energy notes that hydropower offers flexible output and can
be adjusted quickly to meet demand, making it highly compatible with other intermittent
renewables. Hydropower systems range from large-scale dams to small-scale micro-hydro
systems used in rural or mountainous areas. When incorporated into hybrid energy systems,
hydro can provide the base load power or serve as a backup to intermittent sources, thereby
enhancing system stability.
Biogas is produced through the anaerobic digestion of organic matter such as
agricultural waste, manure, food scraps, and sewage. This process generates methane-rich
gas that can be used for heating, electricity generation, or even as a vehicle fuel. According
to the Environmental and Energy Study Institute (EESI), biogas offers a sustainable way to
manage waste while generating energy. Unlike solar and wind, biogas is not weather-
dependent, making it a reliable component in hybrid systems. It can also contribute to
circular economy practices by turning waste into a valuable resource, reducing landfill use
and methane emissions
Configurations of Hybrid Energy System
HRES integrates multiple renewable energy technologies such as solar photovoltaic,
wind turbines, micro-hydropower, and biogas systems with energy storage and backup
generators to provide a more consistent and efficient electricity supply. Typically, a hybrid
system consists of renewable energy generators, battery storage units, power conversion
devices (including inverters and charge controllers), and a centralized energy management
system that optimizes power distribution and system performance. Solar and wind power
remain the most widely used renewable sources due to their accessibility and scalability,
while micro-hydropower and biogas are implemented in locations with suitable natural
resources. Energy storage plays a critical role in addressing the intermittent nature of
renewables, and backup generators improve reliability during periods of low renewable
output.
Hybrid systems can be configured as stand-alone setups, designed for off-grid
communities where grid access is unavailable, or as grid-connected systems that allow
excess power to be fed back into the utility network. Moreover, configurations can be
categorized based on electrical coupling: DC-coupled systems offer greater efficiency in
battery integration, whereas AC-coupled systems provide flexibility in expanding existing
infrastructure. A typical small-scale hybrid system may include solar panels, a wind turbine,
a lithium-ion battery bank, a diesel generator for backup, and an energy management
controller. The system prioritizes renewable sources to supply the load and charge the
battery, activating the backup generator only when renewable generation and stored energy
are insufficient.
In addition, hybrid systems blend grid connection with energy storage, ensuring a
continuous power supply and remain powered through outages, nighttime, or cloudy days
thanks to battery backups. They maximize renewable energy usage, storing excess daytime
production instead of wasting it, and can feed surplus back to the grid via net metering. Over
time, the efficiency and cost-effectiveness of hybrid systems shine: lower long-term
maintenance, no fuel costs for generators, and intelligent load management that adapts
output to demand . They also offer energy independence, reducing reliance on the utility grid
and often benefiting from subsidies or increased property value.
On the other hand, these systems bring high initial cost due to the added complexity
of batteries, inverters, and controls and increases installation expenses compared to grid-
tied setups. They are also more complex to install and manage, requiring specialized
equipment and expertise to balance energy flows among panels, batteries, and the grid.
Overall, hybrid renewable energy systems demonstrate significant advantages,
including enhanced reliability, reduced environmental impact, optimized energy efficiency,
and potential cost savings over time. These attributes position HRES as a vital component in
advancing sustainable energy solutions worldwide.
1. PROJECT OVERVIEW
This document presents the complete system design and justification for selecting a
solar and on-grid based hybrid energy solution tailored for a rural household in the
Philippines. The system is built around the PowMr POW-HVM1.5K-24V hybrid inverter,
capable of delivering clean, continuous power by combining solar photovoltaic input and an
AC biogas generator backup. The system ensures a minimum of 24-hour backup power with
48-hour autonomy using a reliable battery storage setup.
2. LOAD DEMAND ESTIMATION
The following table lists the maximum loads with highest daily energy requirement based on
residential appliance use.
Appliance Quantity Power Rating Usage/Day (hrs) Daily Energy
(W) (Wh)
LED Light Bulbs 2 10 5 100
Electric Fans 2 100 8 1600
Phone Chargers 2 18 3 108
MW Oven 1 1750 1 1750
Television 1 150 8 1200
Total Daily Load 4758 Wh
Safety Margin: 25% inefficiency buffer
Adjusted Daily Load: 4758 Wh × 1.25 = 5947.5 Wh/day
3. BATTERY BANK SIZING
● Target Backup Duration: 24 hours
● System Voltage: 24V
● Battery Capacity: 144 Ah
○ Use 1 pcs of 12V 100Ah and 1 pcs of 12V 44Ah LiFePO₄ batteries, arranged
in series, to form a 24V, 144Ah battery bank.
● Autonomy Period: 12 hours (0.46 or 0.5 days)
○ 144Ah x 24V = 3456 Wh
○ (3456 Wh x 0.80) / 5947.5 = 0.46 days or 12 hours
● Battery Type: LiFePO₄ (80% Depth of Discharge used for calculation)
Conclusion:
The selected 2-battery configuration provides approximately 0.46 days of autonomy
under typical daily load conditions. This meets the 12-hour backup target with a buffer and
also ensures longer battery lifespan by limiting discharge to 80%.
4. SOLAR PV SIZING
● Target Contribution: 75% of daily energy demand
● Required Solar Energy: 5947.5 Wh/day × 0.75 = 4460.625 Wh/day
● Location Peak Sun Hours (PSH): 5 hrs/day
● System Efficiency: 80% (0.8)
Required Solar Capacity:
4460.625 Wh ÷ (5 hrs × 0.8) = 1115.156 W
Inverter PV Input Limit: 1500W x 0.80 = 1,200 W
Final Solar Array: 1 panels × 200W = 200 W
Actual Energy Harvested Daily: 200 W × 5 hrs × 0.8 = 800 Wh/day
Actual solar contribution: 13.45%
5. GRID CALCULATION
Grid Supply = Total Load - Solar Contribution
Grid Supply = 5947.5 Wh/day - 800 Wh/day
Grid Supply = 5147.5 Wh/day
6. SYSTEM INTEGRATION OVERVIEW
Figure 1 Flowchart of Solar-Grid Hybrid System Integration
Figure 2 Hybrid Power System Design with 1.5kW MPPT Solar Inverter Charger
7. COMPONENT SUMMARY TABLE
Component Rating / Spec Quantity / Capacity Remarks
Inverter PowMr POW- 1 Max PV: 1200W, 24V
Controller HVM1.5K-24V system
Solar Panels 300W 4 panels (1,200W Monocrystalline, 18V MPPT
total) compatible
Battery Bank 12V 250Ah LiFePo4 4 pcs (2S2P = 2 days autonomy
24V, 1,500Ah)
Miscellaneous Wires, Breakers, Lump Sum Includes BOS and
Mounts installation
8. COST ESTIMATE AND ROI
Component Unit Cost Quantity Total Cost
(Php) (Php)
Solar Panels 4,500 1 4,500
Batteries 5,000 2 10,000
Inverter 7,000 1 7,000
Miscellaneous - Lump 5,000
BOS Sum
Total ₱26,500
Monthly Energy Offset: 5947.5 Wh/day × 30 = 178.425 kWh/month
@ ₱12/kWh = ₱2,141.1/month
Payback Period:
₱26,500 ÷ (2,141.1) = 13 months = 1 year and 1 month
PRODUCT INFORMATION
The PowMr MPPT 1.5KW 24V Solar Hybrid Inverter 230Vac Built-in 80A MPPT Solar
Charge Controller 50/60Hz Automatic Pure Sine Wave Off Grid Inverter is a multi-function
inverter and charger which combines the functions of an MPPT solar charger, inverter, and
battery charger in order to provide uninterruptible power supply packed in a portable size.
The LCD display on the hybrid inverter has easy to access buttons for operations such as
AC load or solar charge priority, battery charging current, and input voltage which will be
based on its application which are user-configurable.
Main Features:
● 1,500 W Pure Sine Wave Inverter - Converts 230 VAC to 24 VDC and vice versa.
The surge power of the inverter of 3,000W in 5 seconds can be used for a range of
office and household appliances for uninterruptible supply of power.
● Built-In Solar Charge Controller - Supports a wide range of battery types such as
24V Lithium Batteries, Gel Batteries, Agm Batteries, Lifepo4 Batteries, Flooded
Batteries, and Sealed Lead Acid Batteries. The voltage range of the MPPT is 30-
150V which can power a variety of appliances while ensuring optimal charging
efficiency and reliable power supply for the solar energy system.
● Multiple Charging Modes - The solar inverter charger maximizes energy usage
through 4 charging modes: Solar First, Utility First, Solar and Utility, and Only Solar.
● Multiple Output Modes - It has Load Output Working modes: Utility First, Solar First,
and SBU First. Through its power-saving mode, no load consumption is reduced.
Basic System Architecture
Figure 1 shows the basic applications for this inverter/charger. Included in the
figure are the generator or utility and the PV modules to illustrate a complete
running system. Various appliances for households or offices can be powered by
the inverter including motor-type appliances.
Figure 3 Hybrid Power System
Product Overview
1. LCD Display
2. Status Indicator
3. Charging Indicator
4. Fault Indicator
5. Function Buttons
6. Power ON/ OFF Switch
7. AC Input
8. AC Output
9. PV Input
10. Battery Input
11. Circuit Breaker
12. RS232 Communication Port
13. Parallel Communication Port (only for parallel mode)
14. Dry Contact (Optional)
15. USB Communication Port
16. Grounding
Table 1 Line Mode Specifications
INVERTER MODEL 1.5KVA
Input Voltage Waveform Sinusoidal (utility or generator)
Nominal Input Voltage 230VAC
170Vac±7V (UPS)
Low Loss Voltage
90Vac±7V (Appliances)
180VAC±7V (UPS);
Low Loss Return Voltage
100VAC±7V (Appliances)
High Loss Voltage 280ACc±7V
High Loss Return Voltage 270VAC±7V
Max AC Input Voltage 300VAC
Nominal Input Frequency 50Hz / 60Hz (Auto detection)
Low Loss Frequency 40±1Hz
Low Loss Return Frequency 42±1Hz
High Loss Frequency 65±1Hz
High Loss Return Frequency 63±1Hz
Line mode: Circuit Breaker
Output Short Circuit Protection
Battery mode: Electronic Circuits
Efficiency (Line Mode) >95% ( Rated R load, battery full charged )
10ms typical (UPS)
Transfer Time 20ms typical (Appliances)
Output power derating:
When AC input voltage drops to
95V or 170V depending on
models, the output power will be
derated.
Table 2 Inverter Mode Specifications
INVERTER MODEL 1.5KVA
Rated Output Power 1.5KVA/1.5KW
Output Voltage Waveform Pure Sine Wave
Output Voltage Regulation 230VAC±5%
Output Frequency 60Hz or 50Hz
Peak Efficiency 94%
Overload Protection 5s@≥150% load
10s@110%~150% load
Surge Capacity 2* rated power for 5
seconds
Nominal DC Input Voltage 24VDC
Cold Start Voltage 23.0VDC
Low DC Warning Voltage
@ load <20% 22.0VDC
@ 20% ≤ load < 50%
@ load ≥ 50% 21.4VDC
20.2VDC
Low DC Warning Return
Voltage
23.0VDC
@ load <20%
@ 20% ≤ load < 50% 22.4VDC
@ load ≥ 50% 21.2VDC
Low DC Cut-off Voltage
@ load <20% 21.0VDC
@ 20% ≤ load < 50%
@ load ≥ 50% 20.4VDC
19.2VDC
Table 3 Charge Mode Specifications
Utility Charging Mode
AC Charging Current (Max) 60 A (@VI/P = 230 VAC)
Bulk Charging Voltage Flooded Battery 29.2 VDC
AGM / Gel Battery 28.2 VDC
Floating Charging Voltage 27 VDC
Overcharge Protection 33 VDC
Charging Algorithm 3 - Step
Charging Curve
Solar Input
Rated Power 1,500W
Max. PV Array Open Circuit 500 VDC
Voltage
PV Array MPPT Voltage Range 30 VDC~ 150VDC
Max. Input Current 10A
Max. Charging Current 80A
Table 4 General Specifications
INVERTER MODEL 1.5KVA
Safety Certification CE
Operating Temperature
-10°C to 55°C
Range
Storage temperature -15°C~ 60°C
Humidity 5% to 95% Relative Humidity (Non-condensing)
Dimension
(D*W*H), mm 286*240*91mm
Net Weight, kg 3.5
CONCLUSION
The design and implementation of a hybrid renewable energy system combining
solar photovoltaic and biogas technologies for a rural household in the Philippines
demonstrates a highly practical and sustainable solution to the challenges of energy
reliability and accessibility. By integrating solar energy with a biogas generator and a well-
sized battery storage system, the proposed setup ensures consistent power supply,
optimized energy use, and significant cost savings over time. The project not only aligns with
global goals for clean energy transition but also addresses local energy demands with
context-specific solutions. This exemplifies how locally available renewable resources can
be harnessed in harmony to create resilient, off-grid power solutions. The integration of solar
and biogas technologies not only meets daily energy needs but also contributes to
environmental sustainability and energy self-sufficiency. This hybrid approach offers a
scalable and adaptable model for rural electrification, particularly in regions where energy
infrastructure is limited or unreliable.
Through a meticulous approach to load estimation, component sizing, and system
integration, the report validates the technical feasibility and economic viability of hybrid
systems in off-grid settings. The use of a modern hybrid inverter like the PowMr POW-
HVM1.5K-24V enhances system efficiency and flexibility, while the calculated payback
period of less than four years highlights the system’s affordability and long-term benefits.
Ultimately, this project underscores the potential of hybrid renewable energy systems as vital
tools for rural electrification and sustainable development.
Moreover, proper inverter sizing plays a critical role in the overall performance and
reliability of hybrid energy systems. An accurate sized inverter ensures that the systems can
handle the peak power demands of connected loads without overloading or shutting down. It
also optimizes energy conversion efficiency, reduces energy losses, and extends the
lifespan of both the inverter and the connected components. Undersized inverters can cause
system failure or limit its functionality, while oversized inverters can lead to unnecessary
costs and inefficiencies. Therefore, aligning inverter capacity with the system’s load profile
and renewable energy input is essential for achieving stable operation, energy efficiency,
and long-term cost-effectiveness in hybrid energy solutions.
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