Natural Gas & The Low-Carbon Economy Figure 5: Annual Oil & Gas Production (Lower US 48 States)
Source: DOE, EIA
As the disparity in these numbers illustrates, reforming power generation will necessitate a systemic approach to the entire power sector. Besides being more efficient and cleaner than their coal counterparts, combined-cycle power plants are also cheaper and quicker to build. A survey of actual fossil, nuclear, and renewable power projects in 2008 determined that natural gas combined-cycle plants had the lowest construction costs of any available generating technology, under half the cost of a new pulverized coal plant and just one-fifth the estimated cost of a new nuclear plant. Under most assumptions for construction costs, government incentives, and carbon controls, combined- cycle plants are an extremely competitive source of electricity. However, the cost of gas-fired power is extremely sensitive to the price of gas, which has been highly volatile in recent years. At the average price of gas in 2009, the levelised cost was 5.5 cents per kilowatt-hour, compared with 8.6 cents per kilowatt-hour based on average 2008 gas prices. The recent decline in gas
growing amount of wind and solar power. Unlike coal plants, gas plants can be more easily turned on and off, enabling utilities to use them to balance variable generation from renewable energy sources. For this reason, nine solar thermal power plants built in California during the 1980s and early 1990s were designed as gas-solar hybrids, with auxiliary natural gas boilers or heat transfer fluid heaters to provide backup generation. Existing combined-cycle and peaking plants already provide de facto backup electricity for wind power in some parts
... natural gas generators are better
suited to play a complementary role in a generation mix that includes a growing amount of wind and solar power
prices has already led utilities to increase the utilization of their gas plants, raising the gas share of generation in 2009 to 23%, higher than at any time in the past three decades. The resulting drop in coal-fired power generation was responsible for almost half of the nearly 10% decline in US CO2 emissions from energy consumption between 2007 and 2009. And some utilities are deciding to make these changes permanent. Faced with the steep cost of installing pollution controls on its coal plants, North Carolina-based Progress Energy announced plans to permanently close 11 of its dirtiest coal plants over the next eight years, a total of almost 1,500 megawatts (MW), replacing them primarily with natural gas plants. In addition to the emissions savings they represent over
coal plants, natural gas generators are better suited to play a complementary role in a generation mix that includes a
worldPower 2010
of the country. In some cases, utilities may also be able to retrofit existing conventional power plants with renewable generators to reduce fossil fuel consumption and GHG emissions. The Florida Power and Light (FPL) Company is adding a 75-megawatt solar thermal field to a much larger natural gas plant in Indiantown, Florida. However, the potential of such large-scale retrofits will be limited by the land and resource requirements of renewable generating technologies. In the future, a new generation of gas-fired generators – from gas turbines to fuel cells – can be deployed as a complement to wind and solar power, both in dedicated gas-renewable hybrid systems and as independent components of a renewable-rich energy portfolio. Natural gas also lends itself to applications that increase overall energy efficiency. Like all thermal power plants, natural gas plants create heat as a by-product while generating electricity. While most plants discard this heat as waste, they can instead be designed to capture it for use in space heating, a process called
cogeneration or combined heat-and-power (CHP). Because it can be scaled more easily than coal, natural gas is the most common fuel used in combined heat-and-power applications, which are typically industrial scale or smaller. Cogeneration has enjoyed little policy support in the US, and as a result it provides just 8% of the country’s electricity. However, the figure is much higher in other countries where cogeneration has received more support: 39% in Finland and 52% in Denmark. A new generation of smaller, ‘distributed’ gas-fired generators
that harness waste heat for heating and cooling can provide better environmental performance than even the most efficient central-station plants while adding an economical and flexible element to the power grid. Technologies ranging from reciprocating engines (similar to those used in automobiles) to gas turbines and fuel cells can
117
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148