Frequently Asked Questions
Frequently Asked Questions
We all know solar power is a good choice for energy, but why? We’ll discuss solar facts and debunk some myths too.
SOLAR FACT: In a study by the National Renewable Energy Laboratory (NREL) conclusively demonstrates that energy payback for photovoltaic (PV) power is, in the worst case, less than 4 years. Given that PV module lifetimes are generally in excess of 30 years, a PV system will produce far more energy than it consumes over its lifetime.
Energy output and input ratios for concentrating solar power (CSP) solar thermal and devices are even more favorable, given their simple manufacture. This myth has its origins in the early history of PV power, when devices were essentially custom-fabricated for military, space and research markets.
SOLAR FACT: Solar PV technologies have declined in price every year since they were introduced onto the market, driven by improved research and development, and most of all by steady increases in sales volume. (In 1954, approximately one watt of PV generating devices was manufactured. In 2004, approximately one billion watts will be manufactured worldwide.) Every solar panel purchased makes the next one cheaper, in stark contrast to nonrenewable sources, which become scarcer and more expensive with every ton that is burned.
SOLAR FACT: Solar thermal is dependent on heat and PV Solar devices are dependent on light – and this light does not need to be direct. More important than place-to-place variations in solar intensity is the price of daytime electricity where you live and the existence of state incentives for clean energy. Learn more about solar power tax credits.
SOLAR FACT: PV systems produce no atmospheric emissions or greenhouse gases. Compared to fossil-generated electricity, each kilowatt of PV electricity annually offsets up to:
If the industry grows by the 25% per year as predicted PV in the United States will offset 10 million metric tons of CO2 per year by 2027 — equivalent to the annual increase emitted by U.S. fossil fuel electricity generation. This means that the emission rate will become negative thereafter as the PV contribution grows!
SOLAR FACT: This is a real business — one that has been growing by more than 35% per year over the past 2 years. In 2001, PV module shipments closed in on the 400-megawatt mark, representing a $2.5 to $3 billion market. The U.S.-based industry itself is now approaching $1 billion per year and providing 25,000 jobs. It’s expected to grow to the $10-$15 billion level in the next 20 years, providing 300,000 jobs by 2025. This sustained growth exceeds that of the semiconductor industry. A market shift has sparked the recent growth in the PV industry. It has shifted from almost completely remote, off-grid, and consumer products to nearly 60% grid-connected, distributed power. And these applications don’t represent small niche markets. They represent the significant growth path for PV — the true distributed power source.
SOLAR FACT: The energy payback period is dropping rapidly. For example, it takes today’s typical crystalline silicon module about 4 years to generate more energy than went into making the module in the first place. The next generation of silicon modules, which will employ a different grade of silicon and use thinner layers of semiconductor material, will have an energy payback of about 2 years. This means that these modules will produce “free” and clean energy for the remaining 28 years of their expected life.