Conceptual Illustration of Agrophotovoltaic technology in Farmlands
The world’s growing population creates a need for sustained increase in food production, that has now become a struggle due to droughts, floods, and heat waves brought about by climate change. To overcome this, it is of critical importance to understand and capitalize on the renewables for energy generation. However, the greatest prerequisite for solar production is land, which is currently occupied for agriculture and buildings. Farmlands have been optimized and placed for food production over thousands of years before photovoltaics was born. In the context of built environment in urban cities, limited space availability, need for land identification and its acquirement descend clean energy initiatives to a great extent. Hence, there is a growing conflict between agriculture, buildings, and solar plants.
In recent years, due to increasing land-use conflicts in several rapidly growing solar PV markets this concept has seen revived interest. While plants are considered as the cure to global warming, it is imperative to note that agriculture and buildings are also a major source of greenhouse gas emissions leading to global warming. Agriculture and Buildings are estimated to contribute about 10-14% and 39% of total global emissions. Rapid growth clubbed with economic inflation would cause global GHG emissions to rise further creating a global climate crisis.
Being versatile from other approaches, Agrophotovoltaic (APV) systems and Building Integrated photovoltaic (BIPV) technologies offer an innovative, practical, and alternate clean energy solution to such a crisis. The aim of such systems is to ensure adequate crop yield and quality of crops, while generating renewable energy at the same time. It resolves the conflict between agriculture, buildings, and solar plants by constructing above and help mitigate GHG emissions by bringing renewable energy into the agriculture system, cutting the energy related emission. But does it make sense to cover crop cultivation with solar panels?
To answer the above, the following lists out some of the benefits associated with these systems:
- Increased land productivity of up to 70% can be achieved through combined energy and crop production.
- Apart from enhanced agricultural productivity, APV also contributes to decentralized, off-grid electrification in rural and developing areas, thereby uplifting the economic values of farming.
- Recent innovations involve the deployment of solar trackers for dynamic positioning of PV modules to allow sufficient radiation for crop growth and also to maximize the energy yield, complimenting the overall productivity.
- Maximizing the food-energy-water synergistic outcomes between PV system and crop cultivation, thereby providing excellent resource management. The outcomes would exhibit that the shade under PV panels helps in evapotranspiration and irrigation water balance resulting in adequate conditions required for food production, while enhancing water use efficiency.
- Furthermore, the reduction in soil evaporation under the PV panels contributes to curtailed yield losses in dry years and enhances yield stability.
Hybrid APV + BIPV technologies in a building’s rooftop urban farming space
Uncertainties about microclimatic heterogeneities and their impact on final crop yield are one of the main challenges faced in this sector. The technical know-how to find a perfect balance between food cultivation and energy production is highly essential and significant. Suitable selection of APV and BIPV technology is not only important for farming in terms of crop cultivation but also, for agricultural practices. More importantly, several technical and mechanical alterations need to be implemented to maximize the energy and crop yield.
To aid with the complex nature of these systems and its challenges, SERIS provides a consultancy service to enable clients to plan, install and implement it. SERIS’s expert Consultancy team, provides a detailed capability analysis on crop growing with PV systems. Our methodology and approach involve the following:
1. Determine if the land/site area is suitable for the deployment of these systems, based on the geographical, climate, and crop data such as, the Light Saturation Point (LSP) and shade tolerance.
2. Determine the optimal tilt angle and orientation for the PV modules.
3. From the illuminance study, the ground-coverage ratios (GCR) and light distributions for the crop are determined. (SERIS runs Real-time simulation for better understanding of outcomes)
4. Determine, the energy yield, optimal GCR, ideal PV system to be deployed, numbers of PV panels, PV cell technology and installation capacity.
5. Map the associated costs required and provide an estimate along with the levelized cost of energy (LCOE).
Source: BIPV Centre of Competence, SERIS
APV and BIPV systems best imbibe the sustainable philosophy of ‘Live and Let Live’ forming a perfect partner between food production and solar energy. It helps negate the disadvantage of the independent entities and creates a symbiotic relationship that is beneficial for both. With the right demand, technology advancements of these systems could be the future of sustainable farming and renewable energy.
Feel free to contact our team via email veronika.shabunko@nus.edu.sg