In the realm of renewable energy, hydro and solar power are two important technologies to help wean society off of fossil fuels. Both hydro and solar technologies have found widespread use here and abroad, with large-scale generation facilities providing power for significant parts of the energy grid. Each method of energy generation has its own significant advantages and disadvantages, making them best suited for specific environments and applications.
Solar’s greatest advantage over hydropower is the simplicity of the technology. A hydroelectric project requires complex turbines and a source of running water of significant strength to drive the power generators. Solar, on the other hand, requires only a simple photovoltaic generation cell to provide electricity. PV panels have no moving parts and can be as lightweight or bulky as the application requires. Solar is also suitable for portable applications, unlike the more permanent and immovable hydroelectric installations. Solar is also better suited for home installations because many homeowners don't have access to a waterway suitable for power generation.
Hydroelectric power’s chief advantage over solar generation technology is reliability. A hydroelectric generator will continue to generate electricity as long as the water flows, and the waterways chosen for these projects provide a constant, steady stream of generating power. Solar, on the other hand, provides peak generation only when the sun is out and directly overhead, resulting in an uneven power generation profile. In addition, solar plants are dormant after the sun goes down, unless the solar plant uses a heat-capture technology such as molten salt to provide heat for nighttime generation.
Hydroelectric power generation has a much larger environmental footprint than solar generation. Hydro plants often change the natural flow of the waterways they take over, creating new lakes and reducing water flow downstream. Hydro installations can also affect wildlife in the area, blocking fish migration and altering habitats. Solar panels require some toxic chemicals to produce, but once installed, they have very little impact on the local environment outside of taking up large amounts of space in industrial-scale generation facilities.
While hydroelectric power can significantly alter the nature of a waterway, this alteration can have benefits to the community and to the downstream environment. Hydro plants and dams can create reservoirs, storing water against droughts and creating new habitats for fish and waterfowl as well as recreational areas for nearby populations. In addition, dams can help mediate the effects of excessive rainfall, preventing potentially catastrophic flooding by releasing water downstream in carefully controlled intervals.
- U.S. Department of Energy: Solar
- U.S. Deparment of Energy: Hydropower Technologies
- Solar Alaska: Solar vs. Wind vs. Hydro Power
- National Renewable Energy Laboratory: What is the Energy Payback for PV?
- U.S Energy Information Administration: Hydroelectric
- U.S Bureau of Reclamation: Hydroelectric Power
- L. Berga: Dams And Reservoirs, Societies And Environment in The 21st Century, Volume 1
- Tom Brakefield/Stockbyte/Getty Images