000

Environmental Benefits of Renewable Energy

 OR    

Renewable energy—wind, solar, geothermal, hydroelectric, and biomass—provides substantial benefits for our climate, our health, and our economy. Each source of renewable energy has unique benefits and costs; this page explores the many benefits associated with these energy technologies.

Solar, wind, and hydroelectric systems generate electricity with no associated air pollution emissions. In comparison, coal and natural gas plants have air and water pollution that is linked to breathing problems, neurological damage, heart attacks, and cancer.

Environmental damage affects everyone, but the costs and benefits of reducing environmental damage are not well matched or shared.  Air and water pollution can travel great distances and affect areas well removed from the sources of pollution.  There is a lot of evidence that the global environment is being degraded by the net effect of many activities that produce pollution either directly or indirectly.  The production of energy is a major contributor, especially the burning of fossil fuels.  Pollution of the environment can be reduced by adopting renewable energy, but there are costs involved. 

Some interesting links:

Solar Architecture in Ancient Greece

According to Socrates, the ideal home should be cool in summer and warm in winter. But Socrates' ideal was not easy to accomplish 2,500 years ago in ancient Greece. The Greeks had no artificial means of cooling their homes during the scorching summers; nor were their heating systems, mostly portable charcoal-burning braziers, adequate to keep them warm in winter.

Modern excavations of many Classical Greek cities show that solar architecture flourished throughout the area. Individual homes were oriented toward the southern horizon, and entire cities were planned to allow their citizens equal access to the winter sun. A solar-oriented home allowed its inhabitants to depend less on charcoal - conserving fuel and saving money.

Some Barriers to Implementation of PV Systems

Building Permits:

Scottsdale requires a structural engineer report on the specific structure for residential PV and DHW. This costs a minimum of $500, usually higher. However, this has identified some potentially dangerous residences.

The Cities of Gilbert and Mesa do not require any permit for residential systems that do not involve changes to the main service electrical panel. The City of Mesa extends this to commercial systems. In Mesa the exemption includes the parking canopy construction as “just another mounting structure for the solar". A zoning review may be required in Mesa unless there are existing canopies and the solar canopy fits in with the others. However, if a building permit is needed in Mesa, it generally takes ‘only’ 20 working days, but Mesa is on a 4-day/week schedule so this means 5 weeks.

Plan review and permits generally add about 2% to the cost of a PV system.

The Cities of Gilbert and Mesa have generally accepted roof layout requirements intended to improve fire fighter safety in the event a house fire requires roof ventilation or other fire fighter roof access. Since building permits are not required, there is no formal check on this unless complaints are filed. There are many residential PV systems that do not conform to this requirement. 

A recent project to install a covered parking canopy with a PV system on residential property in the City of Phoenix was a permit problem. In Phoenix simple PV systems can have a building permit issued ‘over the counter’ the same day with a set of properly designed plans. Not so simple with a large PV system on a separate parking canopy, located on a hillside lot. First of all, the Residential counter in the permit office takes a quick look at the plans and says “We are not staffed to review a parking structure, you need to go to the Commercial counter (another wait), then the Commercial counter looks up the property and states “This is residential, we cannot handle residential, go back to the Residential counter”. After insisting that the supervisors of these counters discuss this, they decide that two separate permits (structure and PV) are needed. The structure permit starts with a Site Plan that must include the square footages of the lot, hillside designated area, under roof area, disturbed areas, etc., all based on the original building permit for the lot many years ago. If the present owner of the lot does not have this information, one must wait for the City of Phoenix to search the archives. This took weeks and several meetings with zoning. Only after a building permit for the parking structure has been issued can a separate permit for the PV system be issued, and not over the counter. The whole procedure can take three months.

Concentrator photovoltaics (CPV)

Concentrator photovoltaics (CPV) is a photovoltaic technology that generates electricity from sunlight. CPV photovoltaic systems use lenses and curved mirrors to focus sunlight onto small, but highly efficient, multi-junction (MJ) solar cells. To keep the sun focused on the relatively small solar cells, CPV systems use solar trackers to keep the focus on the solar cells and sometimes use a cooling system to further increase efficiency.

 

Some good general references are:

 

Green Rhino Energy- Concentrating Photovoltaics (CPV)

An Arizona example: Agua Caliente PV Power Plant Among World’s Largest