A study from Hungary, Egypt, Japan, Afghanistan and Germany compared the efficiency and cost-effectiveness of renewable energy hybrid systems featuring either horizontal axis wind turbines (HAWTs) or vertical axis wind turbines (VAWTs) in terms of energy, economics, and environmental performance.
The findings indicate that for systems incorporating HAWTs, the cost of energy, net present cost (NPC), and total system cost are £0.016/kWh, £67,866, and £262,470, respectively. In contrast, for systems with VAWTs, these values are £0.048/kWh, £102,648, and £397,983, respectively. The renewable fraction and CO2 emission savings are 80.5% and 73.2% for cases involving HAWTs and VAWTs, respectively.
The results demonstrate that HAWT-based hybrid renewable energy systems (HRES) are more cost-effective and efficient for rural electrification. This research provides a foundation for further exploration of wind turbine types in HRES designs.
Wind and solar power are the most prevalent energy sources worldwide, yet their sporadic nature poses challenges for network operators. Combining these sources can stabilise production, reduce risk, and enhance reliability. Hybrid systems, which integrate green energy sources with grids and storage, present an effective solution with lower installation costs compared to conventional energy sources. However, sustainable energy systems face limitations in consistently meeting demand due to variability in energy generation. Hybrid renewable energy systems (HRES) mitigate this by combining multiple sources, typically PV and wind, often supplemented with battery storage. Optimising the components and design of these systems involves various economic and performance criteria, including multi-criteria decision-making techniques such as genetic algorithms and particle swarm optimisation.
This study used the Multi-Objective Genetic Algorithm (MOGA) in MATLAB for sizing HRES incorporating horizontal and vertical axis wind turbines, solar PV, and grid connections. The economic viability is assessed using metrics such as cost of energy (COE) and NPC. The energy demand assessment includes detailed evaluation of electrical equipment, their power ratings, and operating hours.
HAWT and VAWT:
- HAWT: Features a rotor, nacelle, and tail vane, effective in regions with consistent wind direction. Requires spacing to avoid turbulence.
- VAWT: Features an axis parallel to the ground, effective in turbulent wind conditions. Ideal for rooftops, beaches, and urban areas due to lower start-up wind speeds and omnidirectional capability.
The study optimised HRES for two scenarios: one with HAWTs and one with VAWTs.
Case 1: HRES with HAWT
- Components: PV panels, HAWT at 30m hub height, grid, inverter, and load.
- Results: 18 optimal systems identified, with the best configuration having a COE of £0.016/kWh, NPC of £67,866, and total cost of £262,470. Renewable sources cover most of the load during all seasons, significantly reducing grid reliance and costs.
Case 2: HRES with VAWT
- Components: PV panels, VAWT at 10m hub height, grid, inverter, and load.
- Results: 18 optimal systems identified, with the best configuration having a COE of £0.048/kWh, NPC of £102,648, and total cost of £397,983. Renewable sources cover less of the load compared to HAWT systems, leading to higher grid reliance and costs.
CO2 Emission and Renewable Fraction:
- HAWT systems achieve an 80.5% reduction in CO2 emissions and a 70% share of wind energy.
- VAWT systems achieve a 53.2% reduction in CO2 emissions and a 17% share of wind energy.
- Grid reliance is significantly lower in HAWT systems (19%) compared to VAWT systems (47%).
The study demonstrates that HAWT-based HRESs are more cost-effective and efficient than VAWT-based systems for the specified location. The optimal configuration for the HAWT system has a significantly lower COE and NPC, making it a more viable option for rural electrification. The findings advocate for prioritising HAWT technology in hybrid renewable energy projects to maximise energy output, minimise costs, and enhance environmental sustainability.
Source
Techno-economic evaluation and comparison of the optimal PV/Wind and grid hybrid system with horizontal and vertical axis wind turbines, Energy Conversion and Management: X, 2024-05-28
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