Like a capped geothermal well building up steam, worldwide demand for the power generated from this underground resource is about to explode. Luckily, this explosion wouldn’t be of the destructive variety, as geothermal power represents one of the most promising and underutilized resources in the global campaign to find clean, sustainable, low carbon-emitting sources of energy.

According to the Boulder, Colo.-based, clean-technology market research firm, Pike Research, geothermal capacity is on the cusp of a major worldwide expansion. The company examines two scenarios, and in either case, the outcome looks good.

In the first scenario, which the company describes as “high-growth,” the industry is looking at 134 percent growth from current worldwide generating capacity of 10.7 gigawatts (GW) to 25.1 GW between 2010 and 2020. The second, more conservative estimate still projects growth of 34 percent to 14.3 GW in that time frame.

The high-growth scenario is an ideal convergence of all the best possible inputs for the industry, including a continued upswing in the price of oil, greater capital investment, data standardizations, the emergence of enhanced geothermal systems (EGS) to expand the range of geothermal power, technological breakthroughs in exploration and drilling, and continued public policy support.

Even if all of these events don’t take place, there will be no way to put a lid on growth. According to Pike, the 34 percent rate of expansion it projects in the more modest, business-as-usual scenario is consistent with the growth rates it has observed for the industry since 1990.

The race to find more clean and renewable sources of electricity is steering countries toward geothermal power, which is attractive for its low carbon output; its low costs; and its reliable, around-the-clock availability, unlike other forms of renewable power, such as solar and wind, which suffer from the variable nature of their resources.

According to Pike, the current worldwide installed geothermal capacity is spread across 26 countries with a combined output of approximately 67 terawatt-hours of electricity. Currently, the United States is the global geothermal leader with 3.1 GW of installed capacity.

Figures recently released from the Geothermal Energy Association (GEA) echo this assessment of the industry. According to the GEA, the geothermal industry in the United States is producing power in nine states: Alaska, California, Hawaii, Idaho, Nevada, New Mexico, Oregon, Utah and Wyoming. The industry is developing 146 projects across 15 states, with the total number of geothermal projects and prospects under development increasing 12 percent.