(Updated from The New Solar Electric Home - The Complete Guide to Photovoltaics for Your Home, 3rd Edition, 2008, by Joel Davidson and Fran Orner with our sincere thanks to Christina Bych)
PV has evolved from a scientific curiosity to a reliable power source for orbiting satellites and space stations to cost-effective power for remote homes and villages and to renewable energy distributed generation in cities and towns around the world. PV use will continue to rise rapidly as the need to replace fossil fuel and nuclear power plants becomes increasingly critical. The change to PV will accelerate as new materials and production methods come on-line. As more people understand how easy, practical and rewarding it is to use PV, electric utilities will find ways to integrate privately owned PV into the grid power mix. PV is already becoming an important addition to utility companies’ portfolios.
Building Integrated PV (BIPV) will become commonplace. Today, megawatts of PV roofs, curtain walls and power generating windows are being built. PV shade structures and carports are turning parking lots into solar power plants. Tomorrow, BIPV and PV shade structures, which are simply PV arrays with long legs, will be deployed on polluted urban wasteland as part of the “brownfields” cleanup process.
In the not-to-distant future - less than 10 years if we focus our resources on peace and plenty instead of war and waste - buildings will be rated either net energy consumers or producers. Older, high density, multi-story buildings like skyscrapers and inner-city hospitals with limited roof space or inadequate solar access will continue to be net energy consumers while new buildings will be designed to produce all the energy they consume. Low energy use buildings like warehouses will have PV roofs that produce excess electricity for sale for credit or directly to their neighbors.
Homes in the future will be super energy efficient and have PV roofs to provide all the home’s electricity plus power for the homeowner’s electric (EV) or hydrogen fuel cell automobile. PV modules are already available in many shapes, sizes and colors to fit any building application. Mounting hardware is already more user-friendly. Building-integrated mounting and wiring will be inconspicuous. Multi-purpose inverters that operate with or without batteries will allow you to choose battery backup now, later, or not at all and back-up power will be stored as hydrogen and utilized through fuel cells. PV on home, garages and carports will charge EVs and solar power stored in EV batteries will be fed back into the utility grid to reduce the need for polluting, inefficient fossil fuel peaker plants.
Electric service panels will be made solar-ready with built-in connections and circuit breakers for on-site power production. Electricians and tradespeople are learning how to install PV just as they learned to install heating and air condition units a few decades ago. Someday all electricians will be as familiar with PV as they are with lighting equipment.
PV will change the way people think about energy production. Most of us are already concerned about continuously increasing consumption, power plant pollution, diminishing energy resources and buying oil and gas from nations that harbor terrorists. On-site PV equipment costs are now included in homeowner’s mortgage payments in lieu of paying a separate monthly electric bill. Mortgage-financed PV is already cheaper in many places than utility power. In Asia, Europe and the United States every year hundreds of thousands of people buy PV for their homes, schools and businesses for economic and environmental reasons. This trend is expanding throughout the world.
In the future, politicians will be required to provide energy solutions that reduce the threat of war, improve the environment, and enhance individual freedom. Individuals and corporations will be held responsible for the energy resources they consume and the health and environmental impacts of their actions. PV will help everyone to meet these goals.
On-site PV use will grow by thousands of megawatts every year. Large-scale centralized PV power plants will still be required to power urban areas that house over 50% of world population, but plans are on the drawing board for a global network of PV arrays that will feed into a global electric grid. The Genesis Project is one such plan. Genesis, which stands for Global Energy Network Equipped with Solar cells and International Superconductor grids, is the brainchild of Dr. Yukinori Kuwano, one PV’s most innovative scientists and founder of Sanyo’s PV division. His 200-year plan is to make PV the planet’s prime energy source. (1)
The Genesis Project is not science fiction. A look at Earth from space shows that rainy and cloudy areas cover less than 30% of the total land mass and that it is always daylight on one side of the globe. A global PV power grid connected by super-conducting cables would enable daylight areas to provide clean solar energy around-the-clock. Super-conducting cables are practical today and plans are to increase their use. (2)
When Dr. Kuwano first proposed the Genesis Project, global energy demands were the equivalent of 14 billion barrels of crude oil per year. About 4% of the world's desert area (800 km square) covered with 10% efficient solar cells could meet this requirement.
Is a global PV grid possible? People who install PV power generation systems on their grid-connected homes and businesses are building the global PV network right now. As this trend grows, national networks will then be connected by superconductor cables now in development.
The United States, Canada and parts of Mexico are already interconnected as are the electric power grids of some European countries. The "Silk Road Genesis,” proposed by the Tokyu Construction Company, calls for the construction of PV power plants along that ancient trade route. The first stage of the project, which now includes the support of Sanyo and other companies, involves building over a hundred 100-megawatt PV plants along the Silk Road by 2030.
Desertec is another large scale project aimed at creating a global renewable energy plan based on the concept of harnessing sustainable power from sites where renewable sources of energy are more abundant and transferring it through high-voltage direct current transmission to consumption centers in north Africa and Europe. All kinds of renewable energy sources are envisioned, but the sun-rich deserts of the world play a special role. (3)
Even if it takes 50 years for a global electric grid to materialize, hundreds of megawatts of PV are already connected to local and regional grids while hundreds of thousands of households in developing countries are getting their first electricity from PV each year.
While you were reading this short chapter, more than 300 kilowatts or about 30,000 square feet of PV were installed. In 2013, over 4,220,000 watts (4.22 megawatts) of PV were installed every hour (4). We hope you will join the PV Revolution and go solar now.
(1) Genesis Project
(2) Super-conducting power cables