What is Net Zero?

What is "Net Zero Energy?"

In a nutshell, it is producing as much energy as one consumes, usually with renewable sources such as wind, biomass or photovoltaics.

Why is the Waverly Community Group looking at this issue?

A few community members are interested in achieving this balance. In the quest for this goal, those members committed to sharing information for others interested. We offer the following definitions as an introduction to the topic.

 What is "carbon free energy?"

"Carbon free energy" is energy that is produced or generated without producing any carbon dioxide emissions. 

What is a Power Purchase Agreement?

A Power Purchase Agreement is a legal agreement with a client agreeing to buy power from a provider producing carbon free energy.

What Is a Solar Power Purchase Agreement (SPPA)?

A Solar Power Purchase Agreement (SPPA) is a financial arrangement in which a third-party developer owns, operates, and maintains the photovoltaic (PV) system, and a host customer agrees to site the system on its roof or elsewhere on its property and purchases the system’s electric output from the solar services provider for a predetermined period. This financial arrangement allows the host customer to receive stable, and sometimes lower cost electricity, while the solar services provider or another party acquires valuable financial benefits such as tax credits and income generated from the sale of electricity to the host customer. Colorado State University has such a site on west LaPorte Avenue near the old Christman Air Field.

What is Net Energy Metering?

Net energy metering is used to measure a customer's total electric consumption against that customer's total on-site electric generation.  When a customer's onsite generation of power exceeds the amount that they use, the customer's solar energy system (or other renewable energy system) exports the extra electricity to the grid.  When the power requirements of the customer exceeds their onsite generation of power, the customer imports the electricity they need from electric grid. The customer pays the electric company for any extra power they use over the amount they generate - OR -  the customer receives a credit or refund from the electric company if they exported more power to the grid, than what they consumed. 

What is a PV or Photovoltaic Solar Electric Power System?
 

Solar electric power systems transform sunlight into electricity. Sunlight is an abundant resource. Every minute the sun bathes the Earth in as much energy as the world consumes in an entire year.

Solar cells employ special materials called semiconductors that create electricity when exposed to light. Solar electric systems are quiet and easy to use, and they require no fuel other than sunlight. Because they contain no moving parts, they are durable, reliable, and easy to maintain.

Solar cells, also known as photovoltaic (PV) cells, do the work of making electricity. Several types of solar electric technology are under development, but four crystalline silicon (a form of refined beach sand), thin films, concentrators, and thermophotovoltaics are illustrative of the range of technologies. Solar cells are connected to a variety of other components to make a solar electric power system.

A simple silicon solar cell can power a watch or calculator. However, it produces only a tiny amount of electricity. Connected together, solar cells form modules that can generate substantial amounts of power. Modules are the building blocks of solar electric systems, which can produce enough power for a house, a rural medical clinic, or an entire village. Large arrays of solar electric modules can power satellites or provide electricity for utilities.

 

Components of a typical standalone PV system using crystalline silicon technology. (Source: Solar Electric Power Association)

In addition to modules, several components are needed to complete a solar electric power system. Many systems include batteries, battery chargers, a backup generator, and a controller so that people in solar-powered homes and buildings can turn on the lights at night or run televisions or appliances on cloudy days. Grid-connected systems don't require batteries or backup generators because they use the grid for backup power. Some remote system applications, such as those used to pump water, do not require a backup power source.

 

            

CSU Foothills Campus Chrisman Field Solar Plant

A two megawatt solar power plant on the university's Foothills Campus will provide more than 10 percent of the electricity energy needs on the Foothills Campus. The 15 acre plant is one of the largest at a U.S. university. The project was made possible by a partnership with Xcel Energy and Fotowatio Renewable Ventures involving a long-term electricity contract known as a Power Purchase Agreement