With so much regular buzz about solar power, I thought I’d provide a quick rundown on the available technologies. There are two main types of solar power technology: photovoltaics (PV) and solar thermal.
Photovoltaics are the most common form of solar energy today. This technology converts energy from the sun directly into electricity. PV projects are typically distributed solar rooftop projects. Pros of this type of solar power are that it can be up and running quickly, it doesn’t require long transmission lines to remote desert locations, and it’s not dependent on large amounts of water. Cons are that there’s a high cost of deployment because each system is a separate project, and the distributed nature of the projects are slow to scale.
Solar PV "Tree" in Styria, Austria
Solar thermal energy is a technology for harnessing solar energy for thermal energy, or heat. There are three types of solar thermal energy collectors: low-, medium- and high-temperature. Currently, distributed (or singular) solar thermal projects are considered low- and medium-temperature, only useful for hot water systems.
Concentrated solar power plant using parabolic trough design.
High-temperature solar thermal collectors, on the other hand, use concentrated solar power from a Solar Thermal Plant. These are large-scale desert projects that use concentrated solar radiation to achieve higher temperatures and create heat, which can then be stored, and later turned into electricity. The pros of solar thermal technology are lower prices because of the economy of scale, higher efficiency, and less intermittencies because the energy storage technology is better. The cons are that solar thermal plants in the desert depend on transmission lines to transmit power back to the grid, which are costly and difficult to build, they require a lot of water, which also adds cost and requires permits, and the large land needed also requires extensive permitting and long approval processes.
Earth2Tech also did a great summary of these pros and cons.
President Obama announced this morning that the U.S. would work to be a world leader in the fight against global warming, no longer “dragging its heels” over climate change — a long overdue move the Bush administration refused to make — saying, “It will be the policy of my administration to reverse our dependence on foreign oil while building a new energy economy that will create millions of jobs.”
Obama took action to make American cars more efficient and reduce greenhouse gas emissions by instructing the EPA to reconsider whether to allow California and 16 other states to limit automobile emissions beyond the restrictions of the federal government (such efforts were blocked by the Bush Administration in December 2007). In addition, Obama asked that the Transportation Department ensure America’s cars reach an average fuel efficiency of 35 miles per gallon by 2020 or sooner.
These comments come after an announcement over the weekend that Obama was setting up a temporary $100 billion program for new renewable energy projects, including the modernization of 3,000 miles of electrical transmission lines and his support for the installation of 40 million smart meters in American homes.
After eight years of appalling environmental policy and legislation, and zero leadership from Washington, Obama’s commitment to clean energy and reducing our dependence on foreign oil is very encouraging for the green tech industry and will surely spur investment and innovation, as well as create more accountability for automakers, energy companies and the federal government.
There’s been some interesting discussion around the Web in the last few weeks about the past, present and future of clean tech investments, including this piece on New York Times‘ Freakonomics blog. The debate includes insights from George Tolley, Professor Emeritus of Economics at the University of Chicago and president of RCF Inc.; John Whitehead, professor in the Department of Economics at Appalachian State University and contributor to the blog Environmental Economics; and Ethan Zindler, head of North American research at New Energy Finance. It’s a long read, but a well-rounded discussion on where the industry could be headed.
A few more stories of interest on green technology investments:
- San Jose Mercury News, “Clean-tech VC investments double to nearly $8 billion in 2008, but could drop in ‘09“
- Green Chip Stock, “Smart Grid: One of 2009’s Hottest Sectors“
- Wall Street Journal, “Investment in Clean Technology Suffers Steep Quarterly Decline“
- Financial Times, “Solar and biofuel projects score early 09 investments“
