A. LNG is a natural gas that has been cooled for shipment and/or storage as a liquid. Natural gas in liquid form is more compact than in its traditional gaseous form so it is easier to transport from regions like Australia, Indonesia, South America, Africa, the Middle East and other areas where natural gas is plentiful.
Once the LNG reaches its destination, it is returned to its gaseous state before it is put into the utility system for use in homes and businesses.
A. LNG has been used extensively in Japan and Europe for many years. Large-scale LNG projects have been in operation in the United States for about 30 years and there are LNG facilities in Massachusetts, Maryland, Georgia and Louisiana. In other regions of the country, it is common to liquefy and store natural gas so it is available when needed such as for heating during cold weather.
A. In its liquid state, LNG cannot burn because it contains no oxygen. LNG only burns when gasified. When LNG is returned to its gaseous state it behaves the same as the natural gas currently used by our customers. Natural gas is non-toxic and lighter than air, so it dissipates harmlessly into the atmosphere. Safe use of natural gas requires maintenance and proper use and operation of appliances and equipment. It is always a good idea to have a licensed heating contractor or SDG&E check your gas appliances every year.
A. After LNG is converted back to natural gas, it is generally interchangeable with other natural gas flowing through the utility systems that originate from the Rocky Mountains, the Southwest, Canada and California. It does meet state specifications, but specific characteristics of this gas may differ slightly from current supplies. Industry testing indicates that there should not be a problem with home appliances/furnaces that are maintained and operated properly. Some commercial/industrial equipment may need to be adjusted to ensure it will continue to operate efficiently.
A. LNG is simply natural gas in a liquefied state. Natural gas is the cleanest-burning fossil fuel, which is why it has become the preferred fossil fuel for electric generation. Natural gas has been a key element in clean air strategies around the world, especially here in California.
SDG&E and Southern California Gas Company are implementing plans to reduce greenhouse gases emitted through their operations and help customers reduce their greenhouse emissions. Also, the utilities will continue to promote energy efficiency programs that save energy and thereby help to reduce greenhouse gas emissions.
A. Since the beginning of this decade, the cost of domestic natural gas has dramatically increased while domestic natural gas production has decreased--even as demand has continued to increase. Importing LNG is a proactive response to this challenge.
A. Yes, our average residential customer uses less natural gas than in the past. However, it is not enough to offset growth in the total number of households and businesses in southern California.
A. California investor-owned utilities like SDG&E currently are required to obtain 20 percent of their power from renewable resources by 2010. At the same time, computers and other electronics like high-definition televisions use more electricity. Also, the region is continuing to grow, so there are more households and businesses needing electricity.
A. Although the utilities do not control when natural gas from LNG will be delivered to our system, a LNG terminal currently being constructed in Mexico has indicated that it expects to begin delivering natural gas from LNG in 2008.
A. New gas supplies, such as LNG imports, will meet quality standards established by the California Public Utilities Commission but may differ from natural gas currently flowing in the SDG&E system. One measure of gas quality, used with vehicles, is the Methane Number (MN). It is similar to the octane ratings used with gasoline, but on a different scale. SDG&E expects new sources of natural gas entering the system to meet a minimum value of MN 80.
SDG&E has reviewed manufacturer fuel specifications, developed engine performance studies, and funded engine performance research to assess compressed natural gas CNG engine performance under a variety of conditions. This work shows that at a minimum value of MN 80, all CNG vehicles will operate safely and reliably.
The California Air Resources Board (CARB) has a separate statewide (CNG) fuel specification that sets prescriptive limits for each chemical constituent (i.e. ethane, propane, etc.). Although all CNG vehicles will operate safely and reliably at the new expected gas quality levels, this gas may not meet the CARB CNG fuel specification. In order to ensure compliance, SDG&E is seeking an exemption for our customers from the current CARB CNG fuel specification and is proposing an alternative MN 80 natural gas specification.
Changes in natural gas composition may increase emissions from CNG vehicles. SDG&E is working with state and local environmental agencies to understand, assess and address potential increases in emissions.
A. According to industry sources, most equipment fueled by natural gas should not be affected by LNG since gas quality standards set by California Public Utilities Commission (CPUC) are meant to ensure the interchangeability of different supplies. However, some commercial and industrial equipment may experience a small change in emissions or efficiency and may need to be adjusted. Also, potential supplies of natural gas from LNG may cause operational issues with older natural gas fueled vehicles in San Diego County.
Before this new gas supply is introduced into SDG&E's system, SDG&E will survey commercial and industrial customers in areas expected to receive the supply to identify equipment that may need to be tuned differently. We also will be monitoring the performance of equipment once this supply is delivered to determine if any problems arise.