A recent meta-analysis led by researchers at Lincoln University has shed new light on the potential of agrivoltaics—or agri-photovoltaics, the practice of combining solar photovoltaic (PV) panels with agricultural production on the same land—for New Zealand's farming sector. Published in Agronomy for Sustainable Development, the study titled "Climatic and design tipping points in agrivoltaic crop production systems: A meta-analysis" analyzes data from 90 global studies across 20 countries, revealing that success hinges on climate, crop type, and panel design.
This research comes at a pivotal time for New Zealand agriculture, where pastoral farming dominates—accounting for over 50% of land use, with sheep and beef farms covering 24 million hectares and dairy operations adding another six million. As the country pushes toward 100% renewable electricity by 2030, solar farms are proliferating, raising concerns about prime farmland loss. Agrivoltaics offers a dual-use solution, generating clean energy while sustaining food production, potentially boosting farm incomes by 30-50% through electricity sales.
The Lincoln team, including Dr. Pieter-Willem Hendriks, Dr. Wei Zhang, and colleagues from Colorado State University, emphasizes no one-size-fits-all approach. "There are no golden rules to design," Dr. Hendriks notes, highlighting how variables like crop height, shading levels, and regional weather interact uniquely.
🌱 Understanding Agrivoltaics: Definition and Global Context
Agrivoltaics, first conceptualized in Japan in the 1980s as "solar sharing," integrates elevated solar panels (typically 2-4 meters high) over crops or pasture, allowing farming below while capturing sunlight above. Configurations include fixed-tilt, vertical bifacial panels, or trackers that adjust for optimal shading. Globally, over 10 GW of agrivoltaic capacity exists, with Europe and Asia leading; France mandates 20% of new solar be agrivoltaic.
In New Zealand, adoption is nascent but accelerating. The Ministry for Primary Industries (MPI) report "Putting the Farm into Solar Farms" outlines how panels over pasture can support grazing without full displacement, crucial since most proposed solar sites are on flat, sunny farmland ideal for sheep. Benefits extend beyond land efficiency: panels reduce evaporation by 20-30%, cool soil by up to 5°C, and shield livestock from heatwaves, increasingly vital amid climate variability.
Key Findings from Lincoln University's Meta-Analysis
The study reviewed 320 experiments, focusing on horticultural crops like lettuce, potatoes, and berries. Crop yields showed 34 positive, 72 neutral, and 158 negative responses to shading, but patterns emerged: shade-tolerant leafy greens thrived, while sun-loving corn faltered. A critical insight is the 30-40% shading "sweet spot," where plant growth supports viable solar output (80-90% of full capacity).
Microclimate shifts were consistent: soil temperatures dropped 0.5-5.6°C, air humidity rose up to 14%, and soil moisture up to 21%. These mitigate drought stress, relevant for NZ's variable rainfall. A novel "tipping point" at 2 hectares reversed temperature effects, with larger arrays warming air slightly (+0.4°C per tenfold size increase).
| Crop Type | Yield Response to 30-40% Shading | NZ Suitability |
|---|---|---|
| Lettuce/Leafy Greens | Stable or +10-20% | High (cool climate tolerant) |
| Potatoes | Higher economic yield (uniform size) | Medium-High |
| Berries | Improved quality, reduced sunburn | High (premium crops) |
| Corn/Beans | -20-50% | Low |
Design matters: small-scale (<1000m²) uses taller mounts (3m+), suiting experiments; larger farms optimize energy with lower heights.
Microclimate Advantages for New Zealand Conditions
New Zealand's temperate oceanic climate (Köppen Cfb) aligns with positive yield zones identified. Panels stabilize temperatures, reducing frost risk—key for South Island horticulture. In drier Canterbury, moisture retention could cut irrigation by 15-25%, per modeling.
- Lower soil temps prevent heat stress on roots
- Higher humidity boosts pollination
- Windbreaks from arrays protect delicate crops
- Reduced evaporation conserves water amid droughts
Crop and Livestock Suitability in NZ Agrivoltaics
For horticulture, shade-lovers like brassicas and berries excel; potatoes surprisingly yield premium table sizes under partial shade. Pastoral: Massey University's Taranaki pilot showed pasture down 84% under panels but up 38% between, netting minor loss with sheep grazing benefits—less heat stress, more time resting.
Sheep thrive: Kohirā and Rangitaiki solar farms (32MW and 37MW) host flocks, panels providing shelter. Dairy trials pending, but shade could lift milk solids 5-10% in summer.
Read the full Lincoln studyExisting Pilots and Case Studies in Aotearoa
Waingawa Solar Farm (developer Lightyears Solar) integrates grazing; Te Aroha (280GWh) starts construction. Lincoln's upcoming 4ha Energy Farm, partnering Solar Bay, trials berries under varied panels—heights, types—for data on yields, biodiversity.
Early adopters report 20-40% income boosts from power purchase agreements (PPAs) at 10-15c/kWh.
Challenges and Mitigation Strategies
- Yield variability: Custom designs; trackers for seasonal adjustment
- High upfront costs: NZ$2-3M/MW; offset by subsidies, loans
- Grid integration: Rural bottlenecks; need upgrades
- Maintenance: Sheep trim grass, reducing mowing 50-70%
Policy gaps: No mandates like France, but Fast-Track Approvals aid projects.
Lincoln University's Energy Farm: Pioneering Research
This flagship will power campus (hot water, EVs), trial precision irrigation, and host student projects. Goals: carbon neutral by 2030, quantify dual productivity.
Policy, Economics, and Future Outlook
Government targets 8.7GW solar by 2050; agrivoltaics could supply 20%. MPI recommends incentives for dual-use. ROI: 8-12 years, enhanced by crop premiums.
Stakeholders: Farmers gain resilience; unis like Lincoln/Massey lead R&D; jobs in ag-tech surge.
Career Opportunities in Agrivoltaics Research
For those passionate about sustainable ag, NZ universities offer roles. Lincoln and Massey seek postdocs, lecturers in ag engineering.Browse research jobs; explore higher ed career advice or university jobs in NZ. NZ academic opportunities.
Conclusion: A Bright Future for NZ Agrivoltaics
The Lincoln study positions agrivoltaics as viable for NZ, blending food security with net-zero goals. With pilots scaling and research accelerating, farmers can diversify incomes sustainably. Check Rate My Professor for ag experts; pursue higher ed jobs in this field.
Photo by tyler richardson on Unsplash
