PV's Value to Customers and the Nation... Why Travel the Road?

"Sooner or later we shall have to go directly to the sun for our major supply of power. This problem of the direct conversion from sunlight into power will occupy more and more of our attention as time goes on, for eventually it must be solved."
— Edison Pettit, Wilson Observatory, 1932

Americans are clear about their preferred energy future — plentiful and reliable sources of clean energy at reasonable prices. At the same time, a number of drivers, trends, and issues make meeting these preferences difficult. Global economic and population growth, technological advances, power quality and reliability problems, environmental challenges, and utility restructuring underscore the need and opportunity for re-engineering the nation's energy generation and delivery systems in the coming years. So, although photovoltaics is not the entire solution to these challenges, this renewable-energy option can be an important contributor to the energy picture of the United States and the world.

Photovoltaics has a variety of attributes that will make it an important component of our nation's energy future. PV is a versatile electricity technology that can be used for many applications, from the very small to the very large. It is a modular technology that enables electric generating systems to be built incrementally to match growing demands. PV is easy to install, maintain, and use. It is a convenient technology that can be used anywhere there is sunshine and that can be mounted on almost any surface. PV can also be integrated into building structures to maximize aesthetics and multifunctional value. These positive attributes allow PV to address the following market drivers for energy in the United States.

Reliable power and power quality. The cost of power interruptions is very large, and some customers — for example, those with vital Web servers or critical hospital or industrial needs — cannot tolerate power interruptions or poor-quality power. Each year, U. S. businesses spend some $2 billion for industrial uninterruptible power supplies while consumers purchase another 200,000 small generators (about 3 kilowatts) because of concerns regarding power quality and reliability. Furthermore, losses incurred by businesses due to power quality and reliability problems account for more than $30 billion each year.¹

Dispersed-generation sources, such as PV, can improve grid reliability by reducing stresses on transmission and distribution systems. Photovoltaic technologies, in particular, provide ultimate power reliability with on-site generation. The reliability of photovoltaics is underscored, for example, by San Francisco's recently announced plan to install photovoltaic-powered traffic stoplights that have backup battery power at 100 key intersections. The City will rely on PV to prevent dangerous traffic snarls during potential rolling blackouts due to a strain on conventional power generation.² As noted, in this stand alone application of PV, a battery backup ensures that power is available even at night or when the sun isn't shining. For a grid-connected application, the grid uses the generated solar electricity "while the sun shines," saving the use of conventional fuel. In effect, this unspent fuel acts as the storage (backup) for electricity needed at other times (e.g., at night).

Plentiful power where you need it. Solar-electric power systems provide a domestic source of energy that is plentiful, sustainable, and available throughout the United States. As an example, one utility — Sacramento Municipal Utility District — estimates that sufficient commercial and residential roof space, parking lots, and transmission corridors exist with south-to-west orientation for solar-electric power to provide 15% of its peak power needs. To grasp the potential of solar-generated power, the total electricity demand for the United States today could be supplied by PV systems covering only 0.4% of the nation in a high-sunlight area such as the Desert Southwest — an area about 100 miles by 100 miles. In reality, though, this power generation will be distributed across the United States, bringing generation sources close to the consumer point of use.

Customer choice. Increasingly, electricity customers want to choose their energy supplier, for both greater control of their power and to illustrate other personal values, such as concern for the environment. Photovoltaic solar-electric power increases customers' choice over the type of energy resource desired. Customers can have PV panels mounted on their homes and businesses. Business and industry owners can generate power for industrial processes and to heat and air-condition multi-family residential and commercial buildings and facilities. Businesses can also use PV to meet their critical power needs during power outages and shortages. In a competitive marketplace, customer choice will rely on interconnection and net-metering standards that fairly compensate grid-connected PV users for the energy they generate and that provide safe, secure interconnections with the power grid.

High value and appropriate applications. Customers — whether residential, commercial, or industrial — recognize that many factors besides price affect the value of energy: for example, power reliability, power quality, freedom from price volatility, or preference for environmentally clean technologies. Utility companies that invest in PV for their customers will be more competitive in the future. As the utility market deregulates, customers will choose their electricity providers based, in part, on the offered price and on desired preferences. As customers learn more about the benefits of PV, solar-electric power will become the power of choice for a larger number of customers and in increasingly diverse applications.

As an example of this situation in another country, Japanese homeowners exhibit a willingness to buy PV — even at about twice the cost of conventional grid-supplied power. Having few domestic sources of conventional energy, Japanese consumers place high value on personal control over their energy future. In the United States, citizens typically have no perception of a power shortage; historically, power has been relatively inexpensive. But in the long term, energy will become more expensive on a national and global basis, and consumers need to prepare for the bump if local electricity rates begin to climb.

Environmental quality. Solar-electric photovoltaic systems, which produce no atmospheric emissions or greenhouse gases, make environmental sense for our nation. Compared to fossil-generated electricity, each kilowatt of solar photovoltaics could prevent substantial emissions that endanger our environment and personal health. Typically, on an annual "per kilowatt" basis, PV offsets or saves up to 16 kilograms of nitrous oxides (NOx), 9 kilograms of sulfurous oxides (SOx), and 0.6 kilogram of other particulates. In addition, one kilowatt of PV typically offsets between 600 and 2300 kilograms of carbon dioxide (CO2) per year.³ These savings, of course, vary with regional fossil fuel mix and solar insulation.

Building a PV infrastructure provides insurance against the threat of global warming and climate change. For example, a 2.5-kilowatt system covers less than 400 square feet of rooftop area and supplies the necessary electricity for a typical U. S. home. The annual amount of carbon dioxide saved by the system is about equal to that emitted by a typical family car during the same year.

Environmental and power-transmission limitations increasingly constrain our nation's population from increasing or even meeting their power needs. Little room exists to build intra-urban power plants, and public tolerance is low for new transmission lines. As a long-term strategy, distributed PV brings generation to the point of customer use to meet moderate peak loads — electricity when and where it is most needed.

PV's value to customers is straightforward — it is about choice. Choice of supply, generation, and use. We can see our preferred future, where solar electricity meets a significant portion of customer demand. PV is truly the power of choice.

1 Imre Gyuk, EESAT2000 Conference Paper, Electrical Energy Storage Systems, Applications and Technologies, Orlando, Florida, September 18-20, 2000; Venture Development Corporation. "The Global Markets for Uninterruptible Power Supplies, Volume 1: North America 5.0 KVA and Under," March 1999 (http://www.vdc-corp.com/news/news99/pr99-13-frames.html); Venture Development Corporation, "The Global Markets for Uninterruptible Power Supplies, Volume 2: North America Over 5.0 KVA," April 1999 (http://www.vdc-corp.com/news/news99/pr99-14-frames.html).
2 "February 2001, Miscellaneous," San Francisco Chronicle, 2/ 1/ 01, Article posted on NCPV Hotline, (http://www.nrel.gov/ncpv/hotline_ feb2001.html).

3 EPA, "Demonstrating Pollution Reduction Capability of Photovoltaics" (See http://www.pv.bnl.gov/biblio.htm#2000 for solar calculator); P. D. Moskowitz, "Photovoltaics: Environmental, Safety and Health Issues and Perspectives," Progress in Photovoltaics, Millennium Issue, 8, 27-38, 2000.

Next
Back
PV Roadmap

©2002 Sandia National Laboratories|Site Contact|Privacy and Security|PV Disclaimer | Contact Us