1. Introduction
Due to perpetual decline in solar photovoltaic (PV) systems costs [
1,
2], the least expensive sustainable source of electricity generation is now solar energy [
3]. The cost reductions have become substantial enough that PV-generated electricity can be utilized to subsidize heat pumps, which enables the profitable electrification of natural gas-based [
4] or propane-based residential heating in Canada [
5]. In addition, the current operational cost of electric vehicles (EVs) warrants electrification of transport [
6], which has the potential to be a major economic engine in Canada [
7,
8,
9]. Lower-cost solar electricity only further incentivizes this transition. Currently, solar based electricity constitutes less than 1% of total electricity generation [
10]; however, there is clearly an economic demand for a massive growth in PV to offset fossil fuel electricity generation, heating fuel, and transportation fuel.
Residence in cities has increased worldwide [
11], and Canada also has followed this trend with its four largest urban regions (the Calgary—Edmonton corridor, Lower Mainland, Southern Vancouver Island, and all of the Extended Golden Horseshoe in Ontario) currently comprising more than half (51%) of the population [
12]. As the cost of PV systems continues to decline, more land is needed for the installation of utility-scale PV systems to power densely populated localities with sustainable electricity. Such PV systems are generally situated in rural agricultural areas [
13]. This has the potential to become an issue with rural residents like those observed with wind power siting conflicts [
14,
15] and, thus, a stepping stone to conflicts over large-scale PV deployment due to apprehensions of possible impedance of agricultural production [
16,
17,
18,
19,
20]. As the world population continues to increase (1.15%/year) [
21], such land use conflicts could intensify as the requirement for food production increases [
22]. Historic approaches to convert farmland to a source of energy (i.e., ethanol fuel [
23,
24]) have proven counterproductive, as they increased food costs as well as global hunger [
25]. With a population growth rate of 0.86% per year [
26], Canada is already under intense pressure to convert farmland into housing [
27,
28]. There is a long list of studies that indicate a solution to the energy–land use issue could be through agrivoltaics: the dual use of land for both electricity generation via solar photovoltaic systems and farming [
29,
30,
31,
32,
33]. An increase in PV system deployment in Canada is beneficial for both local and global environments as solar energy is a sustainable energy source [
34]. It shows particular promise in Canada when applied as a dual use on agricultural land [
29]. Photovoltaics is a net energy producer, which means the energy consumed during its production is generated multiple times over its warranty lifespan of 25 to 30 years [
35], with its technical lifetime being much longer than this [
36,
37,
38]. The environmental returns become even more favorable as the efficiency of PV systems continues its rise [
39] and the energy payback period for PV is now less than a year [
40].
Canada is committed to playing its role in the reduction in greenhouse gases (GHGs) and has committed to increase its share of electricity generation through non-emitting sources to 90% by 2030 [
41]. Agrivoltaics deployment would solve the issue of land use conflicts on agricultural lands and has the potential to substantially reduce national GHG emissions and help Canada move to renewable energy for electricity, heating, and transport. Previous research has quantified the agrivoltaic potential in the province of Ontario [
29] and reviewed agrivoltaic-related policy for the province of Alberta [
42]. However, no comprehensive investigation has been undertaken for the sustainable power potential of large-scale agrivoltaics deployment in Canada. To fill this knowledge gap, this paper first reviews the benefits of agrivoltaics and previous agrivoltaic crop studies that could be relevant to Canada. Then, it quantifies the potential of agrivoltaics in Canada. Geographic information systems (GIS) analysis of farming areas in each province of Canada is integrated with PV simulations to achieve this. Sensitivity runs are performed for vertical-mounted and single-axis tracking PV systems. The energy output aggregated for each province and territory through agrivoltaics is compared with the current electricity requirement in Canada. Finally, methods to enable large-scale agrivoltaics are reviewed from policy pathways identified globally.
2. Agrivoltaics Benefits
Agrivoltaics is the dual use of land for both agriculture and PV electricity generation. It is a relatively new technology that overcomes some previous criticisms of large-scale solar PV farms as it ensures agricultural operations continue on farmland. Agrivoltaics provides multiple benefits and services, which are summarized in
Figure 1:
Renewable and sustainable electricity generation;
Decreased greenhouse gas emissions from offsetting fossil fuel power generation;
Reduced climate change from reduced carbon emissions;
Water conservation;
Increased agricultural crop yields;
Plant protection on farm from excess solar energy;
Plant protection on farm from excess wind;
Plant protection on farm from hail;
Prevents soil erosion;
Reverses desertification;
Maintains agricultural employment;
Enables production of local food;
Improved health from the impacts of pollution;
Increased revenue from the sale of energy for farmers;
A continued source of income that can acts as a hedge against inflation;
Energy for servers and cryptocurrency miners;
Potential for integrated greenhouses;
Potential to produce on-farm-generated nitrogen fertilizer;
On-farm production of renewable fuels including hydrogen and anhydrous ammonia;
Renewable electricity generation to charge EVs for both on- and off-farm use.
The first two agrivoltaic benefits come directly from the fact that solar photovoltaic systems generate renewable and sustainable electricity and that when this green electricity offsets electricity from fossil-fuel-generated sources, GHG emissions are reduced [
43]. This, in turn, reduces global climate destabilization and the long list of adverse effects on the economy, human health, and the environment [
44]. Agrivoltaics also has the potential to benefit water systems by improving farm water efficiency and water conservation [
45,
46,
47,
48]. Agrivoltaic arrays can be used to power both drip irrigation [
49], which is far more efficient than spraying, and vertical farming [
50], which uses a small fraction of the water resources demanded by field-based crops.
Most importantly, many studies on a wide variety of food crops have now demonstrated that agrivoltaics increases crop yield, which include:
Due to the modest or even substantial positive impacts on yield of the wide variety of produce summarized above, the land use efficiency increases for agrivoltaics over side-by-side farming and PV [
63], and, thus, the land productivity could increase by 35–73% globally [
64]. Agrivoltaic arrays generate microclimates beneath the solar PV arrays that alter several factors including the relative humidity, air temperature, both wind speed and direction, and moisture of the soil [
61]. This microclimate is often beneficial to food crops because the solar PV array acts as a shield to protect crops from excess solar energy. Agrivoltaic systems also acts as wind shields and protect plants/cultivars from heavy wind loads [
65]. This same PV shield concept can protect crops from hail, while simultaneously increasing PV performance due to lower operating temperatures created by the crops beneath the modules [
30,
54,
66]. Agrivoltaic microclimates also can mitigate soil erosion [
67] and can even be used to rehabilitate deserts [
68] and barren land [
67] to grow plants there.
Agrivoltaics, when designed appropriately, can minimize agricultural displacement for energy [
33,
64,
69]. It maintains local agricultural employment and continues to enable local food production, which provides the environmental and health benefits of reducing the distance food travels [
70,
71,
72,
73]. Along with the known health benefits from fresh food, agrivoltaics decreases the many health problems associated with fossil fuel combustion by displacing these fuels [
73]. Thus, agrivoltaics can both directly and indirectly improve human health and prevent premature deaths [
74]. Agrivoltaics also helps to mitigate Scope 1, 2, and 3 emissions [
75]. Scope 1 emissions reduction is due to the reduced travel/commute of products that traditionally need to be remotely produced and brought onto farms for cultivation such as fuel, electricity, and fertilizers—agrivoltaics enables the on-farm production of these products. Scope 2 emissions reduction is achieved as farming operations can use electric vehicles which can be charged from electricity generated on-farm via agrivoltaic technology. The same electricity can be used for other farming operations. Scope 3 emissions reduction is possible if electric vehicles are used to transport the produce from the farm, which can, again, be charged using on-farm-generated electricity, thus alleviating the emissions generated by vehicles during travel. Scope 3 GHGs are indirect emissions that are released in the supply chain of goods and services. Agrivoltaics also increases the crop revenue for a given acre [
76], which can help farmers economically. In addition, as the solar PV system is a capital asset that generates economic value that increases with inflation, it can be viewed as a financial means to hedge against inflation during times of high inflation [
77]. Agrivoltaics can be coupled to large loads from computing facilities such as those running AI, server farms, and cryptocurrency miners [
78]. There is a particularly good potential symbiosis between server waste heat, greenhouses, and agrivoltaics for powering both systems [
79]. Partially transparent PV can be integrated into greenhouse glazing itself, providing further coupling between solar electricity generation and food production [
80,
81,
82].
Agrivoltaic-generated electricity can also be used to provide direct farm inputs such as on-farm production of fertilizers (e.g., nitrogen fertilizer) [
83] and renewable fuels (e.g., (anhydrous ammonia [
84] and hydrogen fuel [
85,
86,
87]). Agrivoltaics can be used for EV charging for on-farm use or to sell as a commodity, particularly if a farm is located next to a major road that is appropriate for an EV charging park, which, in turn, would help to accelerate the electrification of transport by reducing range anxiety.
Agrivoltaic systems are appropriate over a vast array of different scales. Generally, agrivoltaics are considered for large-scale (utility-scale) applications; however, even for a home planter, parametric open source cold-frame agrivoltaic systems are feasible [
88]. The technology can operate with a variety of shade tolerance in crops. For instance, full array density PV modules work well with shade-tolerant crops, while less dense PV systems are favorable for shade-intolerant crops [
89]. This is because the crops that are more sensitive to shading require more sunlight for growth. As the racking density is increased (full array density PV modules), less sunlight reaches the plants and this impacts their growth. However, cultivars that are tolerant to shading grow well even with high racking density systems. East/west-facing vertical bifacial photovoltaics can be a preferred scheme for agrivoltaics with field crops using conventional farm equipment [
89]. By increasing the installation height of PV arrays, more irradiance and bifacial gain is observed for bifacial modules [
90]. Another advantage of elevating the height of PV panels is the ease of operation of agricultural machinery. Increasing inter-row spacing between modules benefits ground irradiation; however, it also reduces electrical output for a given area [
90]. With agrivoltaics row spacing greater than conventional PV farms, the capacity factor would be increased due to freer air flow resulting in lower operating temperatures as well as radically reduced row-to-row shading. A small increase in the DC losses would be expected because of longer cable lengths, but, overall, the agrivoltaics system would provide economic advantages, enabling more land to be used in total. South-facing nearly conventional systems are beneficial for farming shade-tolerant crops, whereas some types of east–west vertical arrays are advantageous for permanent crops (e.g., species that are harvested over many seasons such as grapes) [
90].
Agrivoltaics technology is already used in Canada, with projects such as the Arnprio tri-part agrivoltaics project, which combines bee and honey production, monarch butterfly conservation, and solar grazing for vegetation control [
91]. At present, most agrivoltaics systems employed in Canada consist of traditional solar PV farms, which are also used for grazing sheep. Such systems are beneficial for the sheep as they provide thermal protection [
92] and improved quality grazing areas [
93], as well as for the PV systems as the sheep alleviate the cost of weed removal. Life cycle analysis of such agrivoltaic sheep operations show that they are environmentally beneficial [
94] but fail to reach the full potential of agrivoltaics that are designed around crop production.
Unfortunately, Canada is behind Asia, Europe, and the U.S. in agrivoltaic deployments. Nations that are more aggressive at deploying agrivoltaics are expected to gain a competitive advantage due to the benefits outlined in
Figure 1. Being the fifth largest agricultural exporter globally [
95], Canada’s motivation to keep up with novel agricultural technologies is high. As PV-generated electricity is already a low-cost option (i.e., Alberta PV is currently at CAD 47/MWh for a power purchase agreement (PPA) [
96]) and agrivoltaics has all the benefits summarized in
Figure 1, future utility-scale PV installations in Canada could favor agrivoltaics. The remainder of this article will determine the potential for agrivoltaics in Canada if such a policy were to be pursued.
3. Materials and Methods
This study was carried out to determine the agrivoltaics potential in Canada using 1% of the existing available farmland in Canada. First, the total solar potential across Canada was determined using a vector dataset that estimates the photovoltaic potential (in kWh/kWp, where ‘kWp’ is the peak power of PV panel) of south-facing, vertically oriented arrays across the country [
97]. This gives the energy output (kWh) for a solar PV system of 1 kW peak power installed within those regions annually. From this layer, the area representing the cropland in each province (Ontario, Alberta, Saskatchewan, Manitoba, British Columbia, Quebec, and the Maritimes combined) was extracted based on the 2015 Land Cover of Canada 30 m spatial resolution raster dataset [
98]. ArcGIS Pro 2.9.0 with the Spatial Analyst toolbox was used to achieve this. It should be pointed out that “pastureland” was excluded from the dataset although it could increase the agrivoltaic potential of Canada further. This consideration is left for future work. The total conventional PV potential area, A
p, for each province was then determined from the area of the cropland raster cells and average PV potential of each using:
where N is the number of raster cells per band per province, A
r is 900 m
2/raster cell, and B
PV is the average PV potential per band.
The GIS procedure started by extracting cropland raster cells from the 2015 Land Cover of Canada using the “Extract by Attributes” tool. Each cell was 30 × 30 m in size, resulting in a total area of 900 m2. The vector polygons of annual photovoltaic potential (kWh/kWp) in a south-facing, vertically oriented array from Natural Resources Canada were then converted to a raster using the “Polygon to Raster” tool with the same cell size as the Land Cover data. The value was reclassified to represent the average kWh/kWp of each solar band using the tool “Reclassify”. New polygon feature layers were created for the outlines of provinces and the “Clip Raster” tool was used to clip the raster to these provinces. The “Build Pyramids” tool was run on all raster layers to improve the ease of display. The count and value for each layer could then be viewed by right clicking on the layer and selecting “Attribute Table” and the above formula applied.
Locations in each major solar flux grouping were used to model agrivoltaic systems in the opensource System Advisor Model 2022 (SAM) [
99] using Heliene 144HC-460 bifacial PV modules [
100]. SAM is a technoeconomic, free, open-source tool that performs modelling of several renewable energy systems including photovoltaics. The program is easy to use and includes directories of PV panels, inverters, and other components available in the market, thus providing a close-to-realistic solution. Moreover, it incorporates MPPT controllers, which optimize the energy production of solar panels. Different types of systems could be chosen based on the application of work such as residential or commercial, single owner or third-party owner, etc. The software also allows parametric analyses for optimizing any renewable energy project.
For this study, one percent of agricultural land was calculated for each province in Canada as the area of interest. To determine the configuration of PV systems in this piece of land, the area was considered as a square and the length of one side was calculated by taking the square root. Two distinct agrivoltaics systems are considered for the analysis: (1) vertical (south-facing, tilt 90°) (
Figure 2a) and (2) single-axis tracking (horizontal, tilt 0°, which is the default setting in SAM for single-axis tracking modelling) (
Figure 2b). The vertical PV system allows easy access to agricultural land as well as convenience of operation of agricultural machinery. Moreover, the farmers do not need to be concerned about the height of their produce/plants and the PV arrays, which makes this type of system quite favorable for agrivoltaics applications on open fields. On the other hand, single-axis tracking systems are employed to extract the maximum solar energy on the electrical side per unit area. Tracking may also provide an option to orient the panels vertically so that the farmers can work conveniently on their farmland. The design of a single array of vertical PV takes up a width of 4.8 m with an installed PV capacity of 2700 W [
101]. The design of a single array of single-axis tracking system takes up a width of 23 m and depth of 4 m with an installed PV panel capacity of 15,000 W [
102].
The length of one side of square land area is divided by the width of the array (4.8 m for a vertical system and 23 m for a single-axis tracking system) to determine the total number of arrays in one row. To calculate the number of rows on the piece of land, the length of one side is divided by 20 m for both systems to ensure sufficient distance for farm equipment mobility—the inter-row spacing considered for agrivoltaics system. Once the number of rows is ascertained, then, using the number of vertical and single-axis tracking arrays in a single row, the total number of arrays in an area is determined. Next, the product of the total number of arrays and installed PV capacity on a single array (2700 W for vertical system and 15,000 W for single-axis tracking system) provides the total installed PV capacity on the agricultural land. The following locations were chosen for each province based on the energy yield potentials from GIS analysis:
Alberta (Edmonton, Drumheller);
British Columbia (Richmond, Dawson Creek);
Manitoba (Winnipeg, Brandon);
Maritimes (Cardigan, New Glasgow);
Ontario (London, Chatham, Gameland);
Quebec (Sherbrooke);
Saskatchewan (Northern Pine, Regina).
Next, the cities inside each province that match these potentials were identified and selected for SAM analysis. British Columbia was an exception. Richmond was selected for energy yields of 650 kWh/kWp, 750 kWh/kWp, and 850 kWh/kWp as there was no identified location close to the areas of energy yield potentials of 650 kWh/kWp and 850 kWh/kWp to use in British Colombia. Richmond has an average energy yield potential of 750 kWh/kWp, which is the average for the region.
Using these locations, SAM models (
Table 1) were developed to determine the annual energy yield for one kW of PV system for both the configurations. Finally, using the total installed capacity for an area and annual energy yield of the system, the total agrivoltaics potential of the location was determined.
5. Discussion
From SAM models and simulations, it is estimated that the potential annual energy output by employing agrivoltaics on 1% of agricultural land is 175,267 GWh for vertical systems or 272,554 GWh for single-axis tracking systems in Canada.
Table 10 summarizes the electricity generation potential of agrivoltaics installation on 1% of agricultural land within the provinces of Canada.
Canada’s total electrical energy production in 2019 was 632,200 GWh [
114]. Thus, about 28% or 43% of Canada’s electricity needs can be catered for from vertical bifacial or single-axis trackers agrivoltaics systems, respectively. Considering Canada’s targets for renewable energy generation and reduced GHGs, agrivoltaics technology manifests immense potential.
Table 11 summarizes the percentage of agricultural land on which agrivoltaics needs to be deployed to eliminate fossil fuel-based electricity generation in Canada.
This study provides an in-depth evaluation of agrivoltaics potential in each province of Canada. The results could be used to formalize future policies and regulations, which will then help unlock the technology’s full potential.
5.1. Limitations
Although this investigation demonstrates capabilities of agrivoltaics technology in Canada, there are limitations to this study. Firstly, there is a need to experiment with on-ground agrivoltaics systems that provide experimental evidence for both the electrical output and the performance of crops under the system. Thus, future work is required to translate simulations and model-based study into practical applications. Additionally, this study did not include the Canadian territories (The Northwest Territories, the Yukon, and Nunavut), which could be investigated in the future. Moreover, there are several agrivoltaics configurations that need to be studied (for instance, vertical bifacial, single- and double-axis tracking, fixed and variable tilt, stilt-mounted systems or conventional systems, etc.) with a variety of crops. Studies are also needed to understand the technical challenges that may arise when such a large number of solar farms are connected to the electric grid (e.g., transmission and distribution system upgrades). Further, additional experimental studies are needed to determine the impact of farming debris on PV system production in the two configurations considered here. The cleaning requirements of solar PV systems needed to optimize output, especially for dust and snow, is an area which requires further investigation.
Currently, little research focuses on the quality of crops that will be harvested under agrivoltaics. Hence, detailed investigation is required to determine if agricultural produce via agrivoltaics improves or deteriorates the nutrient profile. Moreover, social acceptance of the technology is key to its diffusion on commercial scale. Hence, studies are required which focus on people’s perceptions (and misconceptions) about the technology and seek feedback from the main stakeholders, which will promote its adoption on mass-scale. Moreover, a detailed economic analysis is required to ascertain the total capital investment needed for agrivoltaics projects in each area and the expected rate of return for optimized systems (including increased crop values as well as electricity production). Such studies will serve as the foundation of financial models, which help farmers, financers, and policy makers to make informed decisions.
5.2. International Competition in Agrivoltaics
The agrivoltaics projects employed in Canada thus far are relatively small in scale and consist primarily of traditional solar PV systems, which are used for livestock grazing. These projects have been shown to be helpful for both sheep grazing (benefits include protection from heat [
92] as well as provision of high-quality grazing land [
93]) and PV systems (advantages include alleviated maintenance costs associated with weed removal, etc.), and when combined, for the overall ecosystem/environment as well [
94]. The merits of agrivoltaics technology go far beyond these, as can be seen in
Figure 1, and the technology can offer better land use strategies. Canada needs more aggressive development and advancement in agrivoltaics to keep up with the rest of the world, especially Europe, China, Japan, and U.S., where the technology is rapidly expanding. In 2012, there was only 5 MW of agrivoltaics systems installed globally; this has expanded to a total global installed capacity reaching 14 GW in 2021 [
115]. In China, the largest agrivoltaic system has an installed capacity of 700 MW, whereas Japan has 1800 small agrivoltaic systems [
115]. This shows the scale at which agrivoltaic technology has progressed and the flexibility it has with deployment. Moreover, approximately 2800 MW of agrivoltaics systems have been installed in U.S. [
116]. The U.S. Department of Energy recently approved USD 8 million to support agrivoltaics research and supplement its development [
117]. Canada, being one of the largest exporters of agricultural products [
95], has substantial revenue at stake and needs to consider what appropriate actions are needed to stay competitive with other countries that are both deploying and researching agrivoltaics aggressively.
5.3. Potential Use of Agrivoltaic-Generated Electricity: Computation, Transportation, and Export
As the results in
Table 11 clearly show, augmenting even tiny fractions of the agricultural land in Canada with agrivoltaics would eliminate all carbon emissions from Canada’s electricity generation. This is important as Canada’s per capita historic GHG emissions are the highest in the world [
118] and the existence of the new agreement on “loss and damage fund” [
119,
120] can make further emissions a major liability. Canada should be aggressively seeking to reduce carbon emissions liabilities [
121,
122,
123,
124]. It is also clear that the agrivoltaic potential of all the provinces far exceeds what is needed to decarbonize the electric system (
Table 11). There are several applications of low-cost sustainable electricity generation that would benefit from a large influx of agrivoltaics deployments in Canada: (i) decarbonizing transportation by moving to electric vehicles [
125,
126] and hydrogen fuel (e.g., mirror the hub and spoke collection system developed by dairy producers for on-farm hydrogen production by agrivoltaics [
127]); (ii) decarbonizing heating using heat pumps that are already economical in Canada [
5], (iii) powering increased computing operations [
78,
128,
129], and (iv) exporting electricity to the fossil fuel-dependent U.S. [
130].
7. Conclusions
This study estimated the agrivoltaics potential in Canada using a combination of GIS analysis over agricultural areas of individual provinces and SAM simulations for bifacial PV modules for single-axis tracking and vertical system configurations. Depending on the agrivoltaics technology employed, about a quarter to over one third of Canada’s total electrical energy needs can be met by agrivoltaics alone using only 1% of agricultural land. These results show that agrivoltaics could be a major contributor to electricity generation and enable Canada to render the power generation sector free of GHG emissions. The fraction of agricultural land in each province that can be used to decarbonize the grid in the province is less than 1% for all provinces, with the exception of Alberta (1.4%), British Columbia (1.1%), and the Maritimes, which needs 4.1% using vertical agrivoltaics. If single-axis tracking were used, all provinces could be carbon-free with less than 1% of agricultural land dedicated to agrivoltaics, with the exception of the Maritimes (2.5%). All provinces other than Alberta, British Columbia, and the Maritimes need less than 0.5% of their agricultural land. Although a broad semi-quantitative analysis is presented in this study, and practical results might vary, it is clear that the potential of agrivoltaic-based solar energy production in Canada far outstrips current electric demand. Apart from making farming and electricity generation net zero in Canada, electricity generated from agrivoltaics can be used to decarbonize several sectors. First, agrivoltaics can provide electric vehicle charging and hydrogen production to decarbonize transportation in Canada. Second, it can be used to power heat pumps to decarbonize building heating. Third, agrivoltaic-generated electricity can be used to expand machine learning and AI applications, as well as cloud computing data centers, cryptocurrency miners, and servers in Canada to help accelerate economic opportunities. Finally, Canada can export green electricity to the U.S. to help Americans eliminate their dependence on fossil fuels. China and European countries are working aggressively to develop the technology and secure a competitive edge by leveraging agrivoltaics to improve agricultural economics. For Canada to remain internationally competitive and advance agrivoltaics technology on the commercial scale, policies are needed to support agrivoltaic research, define agrivoltaic standards, and modernize regulations. Further, by providing financial incentives and access to capital, agrivoltaics development in Canada can be accelerated to economically decarbonize the entire country.