Solar power’s shining moment
Case Presentation
Solar power is clean, abundant and renewable. The solar resources inthe Southwest deserts could produce sufficient electricity to fulfill all of the electrical needs of the U.S. Yet, solar power accounts for only 0.2% of all the electricity generated in the U.S.
Question: Is this the time for solar power? 
Answer: Maybe. Although solar panels remain relatively expensive to produce and install, with government subsidies or technological breakthroughs, solar may be able to compete with electricity from the grid.
Solar Power Basics - Photovoltaic and Concentrating Solar Power
The main methods for converting sunlight to electricity are the use of photovoltaic (PV) or concentrating solar power (CSP) technology. The oldest and most widely used PV technology is crystallized silicon. Silicon is very efficient at turning sunlight into electricity.
But, large silicon crystals are expensive and difficult to grow. Newer PV technology involves the use “thin film” photovoltaic technology (TFPV). TFPV uses smaller, cheaper crystals that are deposited onto flexible films. Its main disadvantage is low efficiency. Concentrating solar power (CSP) plants produce electric power by converting the sun’s energy into high temperature heat using various mirror configurations. The plants consist of 2 parts: one that collects solar energy and converts it to heat and another part that converts heat energy to electricity.
Solar One - U.S. Dept of Energy
Concentrating solar power systems can be combined with conventional natural gas turbine generators to allow production of electricity without interruptions through cloudy weather or nighttime.
Solar Power Disadvantages
The main disadvantages of solar power are cost, storage, and space.
Cost
Solar panels remain relatively expensive to make and solar power farms require a high initial investment. Until prices come down with technology innovations and production increases, solar only makes sense if generous government subsidies continue.
Storage
While cost is a major obstacle, storage is another disadvantage. The sun is an intermittent power source. There is no power generated at night. As such, power must be stored to be used when there is no sun or solar power must be supplemented by another source of power. Possible solutions: Remaining attached to the grid is one solution or creating a hybrid power plant (solar and natural gas) is another. Otherwise, battery storage is needed. Batteries are readily available, but must be properly disposed of so as not to negatively impact the environment.
Space
Solar power collection requires a great deal of space - either the side of a roof for a homeowner or acres of desert in the Southwest for a utility generator.
The good news for the homeowner is the use of TFPV technology to create “solar shingles” These solar shingles are far less unsightly than the old solar panels. But, they are still expensive even with incentives, require professional installation, and are difficult to troubleshoot should a problem arise with a faulty shingle. The challenge of space and land use has become a major issue for CSP. The federal government wants to encourage the development of CSP farms on public desert land. However there are two problems:
- Lack of water
- Concerns about how these will impact the pristine desert environment
CSP requires water as a cooling agent and although there are air-cooled systems, they are more expensive. CSP also requires clearing large swaths of desert land, which will impact the desert ecosystem. Given these issues water and desert conservationists are poised for a showdown on the one hand with developers of renewable energy and the Obama administration on the other. The National Park Service and Senator Dianne Feinstein (D. CA) have entered the fray sounding the alarm over the use of water, where water is so scarce, and the possible destruction of the pristine desert.
Conclusion: Solar power is currently still too expensive for general use without government subsidies or technological breakthroughs. Nonetheless, solar power is a key renewal energy source for the future. And, on the bright side, government subsidies and investments are increasing and technology advances are continuing. It is easy to see a future where solar’s current disadvantages will be overcome and prices will come down.
Copyright 2009 KJ Collins
Additional resource links follow:
