Solar energy has declined in cost by an amazing 82 per cent over the last decade. Which has made it the lowest cost option in many places around the world. Recent electricity bids for new solar have continued to break records with bids as low as 1.3¢/kWh. This trend is heartening considering the huge challenge we all face in eliminating carbon emissions. We all need this to prevent the worst effects of global climate change.
However, there are serious concerns about the use of precious land for utility scale solar farms. In some cases, the solar array may displace farmland, or affect habitat for wildlife. Even solar arrays in the desert have an impact on the environment. Including access roads, construction of structures to support the panels and continuing maintenance.
Site selection for solar energy production
Fortunately, there is a slow revolution occurring in “solar siting” – where you put the panels. An obvious location is on top of large flat roofs. Which you might find in industrial parks, on warehouses and on big box retail locations. In these cases, it has long been an economic decision. There a commercial or industrial firm decides to add solar because it makes economic sense. Other organisations that might install solar are governments, schools and universities, and of course rooftop residential solar is very familiar and common these days.
With the growth of electric vehicles and the need for charging them, it seems like parking lots would be an obvious place to put solar panels and accompanying EV charging infrastructure. Cars staying cooler and the parking lot lasting longer are additional benefits.
Floatovaltaics
A more challenging location for solar panels is floating on a body of water. This could be a protected bay, lake or reservoir. Even a wastewater treatment pond could host solar generation. With floatovoltaics, not only do the panels generate electricity, the water helps keep the panels cool, increasing their efficiency and lifetime. Additionally, evaporation is reduced from the water and even algal blooms are suppressed.
In some cases, the panels can float on top of a pumped hydro reservoir, where the solar energy can be stored and released to support the grid. The other advantage is that the solar array can easily access the existing transmission infrastructure for the hydroelectric power generator.
Agri-voltaics
One of the most talked about innovations these days is agri-voltaics. In this case, solar is installed in such a way as to coexist with agriculture, providing benefits to both.
A basic example is to raise the panels above the ground high enough for sheep or other livestock to graze under them. The animals also help keep the area vegetation maintained.
Creating spacing in the solar array to allow light to reach the ground is one of the techniques of agri-voltaic installations. The spacing creates a range of habitats for a variety of plants. Agri-voltaics have been proposed as a way to create habitats for wildflowers and pollinators, or even as a place to keep beehives nearby.
Another benefit of growing plants beneath solar panels is that the plants require less watering and soil moisture remains higher. The plants also reduce the temperature of the air underneath, keeping the solar panels cooler, which increases the energy conversion efficiency.
The panels do block the sun, and therefore reduce the amount of light reaching the crops. For some crops, such as wheat, this would reduce the amount of produce harvested. However, for a variety of vegetables, such as tomatoes, spinach and peppers, the yield per acre has been shown to increase.
People are getting very creative about where solar generation might be installed. A recent study evaluated the effects of covering Californina’s 4,000 miles of canals with solar panels. Over 65 billion gallons of water per year would be saved just by keeping the sun from evaporating the water. Additionally, the panels would provide the energy for pumping the water and the water helps keep them cool. They also reduce the growth of plants and other organisms that clog and foul the canal.
Conclusion
All of these innovations make the case for solar power stronger and more compelling to all kinds of economic actors. onsemi enables this energy revolution with the key power semiconductors that are becoming the workhorses of the grid. From traditional IGBTs and gel-filled modules to next generation Silicon Carbide MOSFETs and our innovative Transfer Molded Power Integrated Modules (TM-PIM), we have solutions for a wide range of power levels and form factors. With gate drivers, protection, power supplies and more, onsemi has the complete solution with worldwide support and application expertise for solar, storage and EV charging.
Technological improvements and increases in production capacity have driven the reduction in the cost of solar power over the past few decades. The next stage is to optimise the installation and operation of the generation assets. Creative solar siting brings win-win benefits to the land, ecosystem, or infrastructure over which the panels are installed. Keep looking for these types of innovations as renewable energy and the inverterisation of the grid continue.
Discover more about onsemi and the possibility of energy revolution with the key power semiconductors: www.onsemi.com.